WHY DID THE COYOTE SURVIVE? AN ICE AGE STORY FROM THE LA BREA TAR PITS

Coyote, Canis latrans

Dire wolves vanished. Sabre-toothed cats vanished. American lions, western camels, native horses and giant ground sloths disappeared from the region.

Coyotes survived.

They survived the climatic upheaval at the end of the Pleistocene, the collapse of large-animal communities and the loss of many of the predators and prey species that had shared their world. 

Later, they survived persecution, poisoning, trapping, expanding cities, fragmented habitats and the arrival of freeways.

Today, coyotes still move through Los Angeles. They trot along drainage corridors, cross residential streets, shelter in patches of urban vegetation and appear on security cameras looking remarkably composed for animals trespassing beneath a porch at three in the morning.

The city changed beyond recognition. The coyote remained.

Its great advantage was not enormous size, exceptional speed or a mouth filled with theatrical weaponry. It was flexibility. When the menu changed, the coyote changed with it. When habitats shifted, it moved. When competitors disappeared, it expanded. When humans remade the continent, the coyote examined our roads, farms, golf courses and suburbs and appears to have said, “We can work with this.”

THE COYOTES OF LA BREA

Coyotes are among the most common mammals preserved at the La Brea Tar Pits, although they are outnumbered by dire wolves and sabre-toothed cats.

During the Late Pleistocene, natural asphalt seeped to the surface in what is now central Los Angeles. Water, dust and leaves sometimes concealed the sticky deposits. Large herbivores became trapped, and their distress attracted predators and scavengers. Some of those animals stepped onto the same asphalt and joined the deposit themselves.

This predator-trap effect helps explain why carnivore fossils are so abundant at La Brea. A single trapped bison could attract several dire wolves, a sabre-toothed cat and any number of smaller opportunists prepared to investigate the commotion.

Coyotes were excellent candidates. They were hunters, scavengers and attentive observers of everyone else’s business.

The coyote fossils from La Brea are generally associated with the robust Late Pleistocene form traditionally called Canis latrans orcutti. 

These Ice Age coyotes were not identical to the slender animals slipping through modern Los Angeles. They were larger, more powerfully built and equipped with deeper jaws and more strongly developed meat-shearing teeth.

They were, in short, rather more wolfish.

This was an animal living among formidable competitors. Dire wolves hunted large prey, sabre-toothed cats ambushed herbivores and American lions occupied the landscape. The Pleistocene coyote needed to find its place within this heavily armed carnivore guild while avoiding becoming lunch, competition or an accidental asphalt ornament.

A LARGER, TOUGHER ICE AGE COYOTE

Studies comparing Pleistocene coyotes with modern animals have found significant differences in skull and jaw anatomy.

The ancient coyotes had deeper, more robust lower jaws. Their carnassial teeth—the specialized slicing teeth used by carnivorous mammals—provided a relatively long shearing surface, while the grinding portion of the tooth row was less emphasized. This anatomy suggests a diet containing more meat and possibly larger prey than that of many modern coyotes.

The teeth also show evidence of heavy wear and breakage. That may indicate more frequent processing of bone, carcasses and large prey. Ice Age coyotes were not simply modern coyotes wearing heavier winter coats. They occupied a somewhat different ecological role.

Research led by palaeontologist Julie Meachen found that Pleistocene coyotes were larger and more robust than their Holocene descendants. Their reduction in body size occurred around the time of the end-Pleistocene megafaunal extinctions, when many of North America’s largest mammals disappeared.

A later study of coyote jaws found a corresponding shift in feeding anatomy. Pleistocene coyotes possessed features associated with greater carnivory and the processing of large prey, while modern animals have more gracile jaws and a greater capacity for grinding a varied diet. 

The earliest Holocene coyotes were intermediate in form, providing a fascinating anatomical bridge between the Ice Age bruiser and the modern omnivorous survivor. The study was published in PLOS ONE.

When the large prey disappeared, the large coyote did not stubbornly insist that mammoth was still on the menu. It became smaller.

WHAT HAPPENED AT THE END OF THE ICE AGE?

The end of the Pleistocene brought sweeping ecological change to North America.

The climate warmed. Rainfall patterns shifted. Vegetation changed. Fire activity increased in some regions. Human populations spread across the continent. Meanwhile, many large mammals—including mammoths, mastodons, ground sloths, native horses, camels and ancient bison species—declined and vanished.

Large predators followed them into extinction. Dire wolves, sabre-toothed cats and American lions disappeared.

Coyotes did not.

The loss of megafauna would have removed carcasses and large prey from the landscape. A predator strongly dependent on those resources faced a crisis. For coyotes, however, the ecological transformation became an invitation to change.

Smaller prey remained abundant. Rabbits, hares, rodents, reptiles, birds and insects were still available. Carrion remained useful. Fruits and other plant foods could supplement the diet. A smaller body required fewer calories and made hunting smaller prey more efficient.

Natural selection does not require a species to plan for the future. Individual animals vary. Those whose bodies and behaviours work best under new conditions are more likely to survive and reproduce. Over generations, the population changes.

The modern coyote emerged from this altered world leaner, more lightly built and less dependent on large prey.

It traded specialization for options. The decision has served it exceedingly well.

WHAT DID LA BREA COYOTES EAT?

Pleistocene coyotes were more carnivorous than most modern populations, but they were probably never as specialized as the largest Ice Age predators.

Their robust jaws and enlarged meat-shearing surfaces suggest that they could process substantial quantities of flesh and bone. They may have hunted medium-sized animals, scavenged megafaunal carcasses and fed opportunistically around kills made by larger predators.

Stable-isotope analyses support a distinction between coyotes and the large carnivores at La Brea. Dire wolves, sabre-toothed cats and American lions appear to have relied heavily on large herbivores such as bison and camels. Coyotes show evidence of a broader, more omnivorous diet. They are not picky eaters.

This wider feeding niche may have buffered them when large prey populations collapsed.

A sabre-toothed cat was magnificently equipped to subdue large animals. A coyote was equipped to see what else might be available.

There is great evolutionary value in being willing to eat something no one else considers worth chasing.

WHAT DO COYOTES EAT TODAY?

Almost anything nutritious enough to justify the effort. Just like us, with less Doritos.

Coyotes are classified within the mammalian order Carnivora, but that does not mean they eat meat exclusively. They are opportunistic omnivores whose diets change with location, season and availability.

Their prey can include:

• Mice, voles and rats
• Rabbits and hares
• Ground squirrels
• Gophers
• Birds and eggs
• Snakes and lizards
• Frogs
• Fish
• Insects
• Carrion
• Young or vulnerable deer
• Fruit, berries and other plant material

They may also consume agricultural crops, pet food, compost and discarded human food when those resources are available. This does not mean garbage is their preferred natural diet. It means coyotes are observant and generally unwilling to let edible calories go to waste.

In the Santa Monica Mountains, studies found that coyotes fed primarily on native fruits and small mammals such as rabbits, mice and woodrats. Domestic pets represented less than one per cent of the measured diet. Natural prey and fruits form the majority of their food in this region.

Research in heavily fragmented parts of Los Angeles produced a similar result. Although urban coyotes consumed more human-associated material, their diet still consisted largely of natural prey and fruit. Domestic cats, including feral cats, made up about one per cent of the diet recorded in the most fragmented areas studied. The Natural History Museums of Los Angeles County uses these findings to separate the animal’s actual urban ecology from some of its more dramatic reputation.

Coyotes can prey on unattended small pets, and sensible precautions are important. But the average urban coyote is not spending every evening developing an elaborate scheme involving someone’s Pomeranian.

It is more likely looking for rodents, fallen fruit and an easy route back into cover.

WHERE DID COYOTES COME FROM?

The coyote, Canis latrans, belongs to the dog family, Canidae. Its deeper evolutionary story began long before the Ice Age.

Canids originated in North America more than 30 million years ago and evolved into a remarkable variety of forms. Some were small and fox-like. Others developed heavy jaws capable of crushing bone. Over time, members of the dog lineage spread into Eurasia, Africa and South America.

Coyote ancestry is associated with a group of increasingly wolf-like canids that appeared in North America during the later Neogene.

An extinct canid called Eucyon davisi lived in North America during the Miocene and Pliocene. It was a medium-sized, coyote-like animal and belonged near the ancestry of the genus Canis, although evolutionary relationships among fossil canids are continually reassessed as new material and genetic evidence become available.

By the Pliocene, a canid called Canis lepophagus—its name means “hare-eating dog”—was widespread across North America. It is frequently discussed as a possible close relative or ancestral form near the line leading toward coyotes and wolves.

Fossils recognizably attributed to Canis latrans appear by the Early Pleistocene, roughly one million years ago, although the precise boundaries between early coyotes and closely related fossil canids are debated. Later Pleistocene coyotes are known from sites across western and southern North America, including California, Idaho, Texas, Mexico and Central America.

Coyotes are therefore not recent arrivals on this continent. They are thoroughly North American animals with roots extending deep into the fossil record.

They did not come to the modern city. We built the modern city in their homeland.

WHO ARE THE COYOTE’S LIVING RELATIVES?

Coyotes are close relatives of wolves and domestic dogs. They share the family Canidae and are traditionally placed with grey wolves, dogs, jackals and several other canids in or near the genus Canis.

Their relationships are complicated because members of the wolf-like canid group diverged relatively recently in evolutionary terms and can sometimes interbreed. Coyotes have produced fertile hybrids with grey wolves and domestic dogs. Genetic exchange has occurred naturally where expanding coyote populations encountered wolves, particularly in eastern North America.

This does not mean every large eastern coyote is simply “half wolf,” nor does it make coyotes a vague mixture rather than a species. Populations have complex histories, and the proportion of wolf or dog ancestry varies geographically.

The relationships among coyotes, grey wolves, red wolves and eastern wolves remain subjects of scientific debate. Fossils, modern anatomy and genomic data do not always arrange themselves into a perfectly tidy family tree. Canid evolution is less a series of cleanly separated branches than a thicket in which some branches have occasionally leaned over and exchanged genes.

Dire wolves, despite their familiar name, were much more distantly related. Genetic research indicates that dire wolves belonged to an ancient American canid lineage that had been separate from the ancestors of living wolves and coyotes for millions of years. They are now commonly placed in the genus Aenocyon as Aenocyon dirus.

The dire wolf was a large grey wolf, and it was not the coyote’s oversized sibling.

It represented another evolutionary experiment—one that ended while the coyote lineage continued.

WHERE DO COYOTES LIVE?

Coyotes were once associated primarily with the grasslands, prairies and deserts of central and western North America. During the nineteenth and twentieth centuries, however, they dramatically expanded their range.

They moved north into boreal regions, east through forests and agricultural landscapes, west into coastal habitats and south through Mexico into Central America. Today, coyotes occupy nearly every part of continental North America and extend well into Central America.

A 2018 study mapping their expansion found that the process accelerated around 1900. Forest clearing, agricultural development and the removal of larger predators such as wolves helped open new habitat. Roads, railways and fragmented landscapes also created corridors through which coyotes could travel. 

Coyotes now live in:

• Deserts
• Prairies
• Grasslands
• Mountain valleys
• Shrublands
• Forests
• Coastal environments
• Agricultural regions
• Suburbs
• Major cities

The Smithsonian’s Movement of Life project describes coyotes as having pronounced behavioural, dietary and physical plasticity. Their ability to adjust to changing landscapes has allowed them to spread from the Great Plains into most of Canada and Central America.

The coyote’s preferred habitat appears to be wherever it can find food, cover and a reasonable chance of not being bothered.

That leaves rather a lot of the continent.

HOW DO COYOTES LIVE?

Coyotes are socially flexible as well as dietary generalists.

They may live alone, as mated pairs or in family groups. Their social structure changes according to food supply, habitat and population density. A pair may defend a territory together and raise pups, while older offspring sometimes remain temporarily with their parents.

Coyotes generally breed once each year. Pups are born in dens that may be dug by the coyotes themselves or adapted from burrows made by other animals. Both parents can contribute to feeding and protecting the young.

Their famous vocalizations help maintain social bonds and communicate territorial ownership. A few coyotes can sound like a much larger group because their howls, yips and barks overlap and change in pitch.

The result is known as the beau geste effect: a small number of animals produces the auditory impression of an entire coyote convention taking place just beyond the trees.

Coyotes also adjust their daily schedules. In regions with little human activity, they may be active during daylight. In cities and suburbs, they often become more nocturnal, moving when streets and public spaces are quieter.

They do not need to understand urban planning.

They need only learn when we go inside.

THE COYOTE IN MODERN LOS ANGELES

Los Angeles has changed profoundly since Ice Age coyotes became trapped at La Brea.

Woodlands and open country have been replaced or divided by homes, roads, businesses and freeways. Large native herbivores no longer move through central Los Angeles, and asphalt now covers the ground intentionally.

Coyotes adapted.

They travel along river channels, railway corridors, utility routes, park edges and strips of vegetation. They use culverts and underpasses. They rest in surprisingly small patches of cover and cross developed areas during quieter hours.

Research shows that many urban coyotes continue to prefer natural or semi-natural habitat whenever it is available. They do not necessarily choose dense development. Instead, they learn to navigate through it.

This distinction matters. A coyote seen in a neighbourhood is not automatically dependent on human food or unusually aggressive. It may simply be moving between hunting areas.

The city presents opportunities but also serious risks. Coyotes are struck by vehicles, exposed to rodenticides, injured by fencing and vulnerable to conflict when people intentionally or unintentionally feed them.

Their survival in urban landscapes should not be mistaken for an effortless life. Adaptable does not mean invulnerable.

WHY DIDN’T PEOPLE ELIMINATE THEM?

Coyotes have endured centuries of deliberate control efforts, including trapping, shooting and poisoning.

Yet broad campaigns to eliminate them have repeatedly failed.

Their mobility allows individuals to recolonize vacant territories. Their flexible social structure helps populations reorganize. Food availability and population density can influence reproduction and survival. Remove coyotes from suitable habitat and, if the resources remain, others may eventually move in.

Human changes to the landscape have also favoured them in unexpected ways. The removal of wolves reduced an important competitor and predator. Forest clearing created open habitat supporting rodents and rabbits. Agricultural lands and suburbs supplied new food resources and travel corridors.

The National Park Service notes that the combination of wolf removal, habitat change, a flexible diet and high reproductive capacity allowed coyotes to thrive despite extensive control efforts.

We attempted to remove the coyote while repeatedly redesigning the continent in its favour.

The coyote noticed.

SPECIALISTS, GENERALISTS AND THE ART OF SURVIVAL

The survival of coyotes does not mean specialists are poorly evolved.

A specialist can be superbly adapted to a stable environment. Sabre-toothed cats were powerfully constructed to capture large prey. Dire wolves were highly effective carnivores within Pleistocene ecosystems. Their success lasted for hundreds of thousands of years.

The problem arrives when the environment changes faster than the specialist can respond.

Generalists are not necessarily the strongest, fastest or most efficient animals in any one category. Their advantage lies in having alternatives. If one prey species declines, they can hunt another. If one habitat disappears, they can use a different one. If a familiar food becomes scarce, they can investigate something new.

Coyotes retained that flexibility while also changing physically. As the megafaunal world ended, their descendants became smaller and developed jaws better suited to a broader diet.

Survival was not a matter of simply remaining unchanged.

The coyote survived because it could become a different kind of coyote.

THE COYOTE REMAINED

The coyotes whose bones lie within the La Brea asphalt lived in a world of mammoths, camels, giant ground sloths, dire wolves and sabre-toothed cats.

They were larger than today’s coyotes, with stronger jaws and teeth adapted for a more carnivorous diet. They scavenged from large carcasses and competed in a landscape ruled by formidable predators.

Then that world came apart.

The large herbivores disappeared. The great predators vanished after them. Vegetation changed, climates shifted and humans transformed the continent.

The coyote grew smaller, broadened its diet and carried on.

Today, its descendants eat rodents beneath fruit trees, travel along concrete drainage channels and cross streets laid over the bones of their Ice Age relatives.

The asphalt seeps at La Brea preserved coyotes from a lost ecosystem. Beyond the park, living coyotes continue to move through the same landscape, altered almost beyond recognition.

Dire wolves vanished. Sabre-toothed cats vanished. American lions, western camels, native horses and giant ground sloths vanished from the region.

The coyote remained—not because it resisted change, but because it was exceptionally good at changing with it.

REFERENCES

Hody, J. W., & Kays, R. (2018). Mapping the expansion of coyotes (Canis latrans) across North and Central America. ZooKeys, 759, 81–97. https://doi.org/10.3897/zookeys.759.15149

Meachen, J. A., Janowicz, A. C., Avery, J. E., & Sadleir, R. W. (2014). Ecological changes in coyotes (Canis latrans) in response to the Ice Age megafaunal extinctions. PLOS ONE, 9(12), e116041. https://doi.org/10.1371/journal.pone.0116041

Meachen, J. A., & Samuels, J. X. (2012). Evolution in coyotes (Canis latrans) in response to the megafaunal extinctions. Proceedings of the National Academy of Sciences, 109(11), 4191–4196. https://doi.org/10.1073/pnas.1113788109

Sacks, B. N., Mitchell, K. J., Quinn, C. B., Hennelly, L. M., Sinding, M.-H. S., Statham, M. J., Preckler-Quisquater, S., Fain, S. R., Kistler, L., Vanderzwan, S. L., Meachen, J. A., Ostrander, E. A., & Frantz, L. A. F. (2021). Pleistocene origins, western ghost lineages, and the emerging phylogeographic history of the red wolf and coyote. Molecular Ecology, 30(17), 4292–4304. https://doi.org/10.1111/mec.16048

Stock, C., & Harris, J. M. (2001). Rancho La Brea: A Record of Pleistocene Life in California (7th ed.). Natural History Museum of Los Angeles County, Science Series No. 37.

Wang, X., & Tedford, R. H. (2008). Dogs: Their Fossil Relatives and Evolutionary History. Columbia University Press.

Wilson, P. J., Rutledge, L. Y., Wheeldon, T. J., Patterson, B. R., & White, B. N. (2021). Considering Pleistocene North American wolves and coyotes in the eastern Canis origin story. Ecology and Evolution, 11, 9137–9147. Open-access article

La Brea Tar Pits. “Mammal Collections.” Natural History Museums of Los Angeles County. https://tarpits.org/research-collections/tar-pits-collections/mammal-collections

National Park Service. “Coyotes.” Santa Monica Mountains National Recreation Area. Updated May 24, 2022. https://www.nps.gov/samo/learn/nature/coyotes.htm

National Park Service. “Carnivores: Coyote.” Mount Rainier National Park. Updated March 11, 2025. https://www.nps.gov/mora/learn/nature/carnivores.htm

Ordeñana, M. “Coyotes of L.A.’s Urban Core: Using Science to Separate Fact from Fiction.” Natural History Museum of Los Angeles County. https://nhm.org/stories/coyotes-las-urban-core-using-science-separate-fact-fiction

Smithsonian Institution. “Coyote: Canis latrans.” Movement of Life. https://movementoflife.si.edu/species/coyote/

WHAT IS A FOSSIL? A MESSAGE FROM DEEP TIME

Pick up a fossil and you are holding evidence of a life.

Not merely an old rock. Not an attractive geological paperweight. Not something the Earth made solely to tempt us into climbing unstable slopes in inappropriate footwear.

A fossil is a message from the past.

It may be a bone, tooth, shell or leaf. It may be the delicate impression of a feather, the tunnel left by a burrowing animal or the footprints of a creature that crossed a muddy shoreline hundreds of millions of years ago.

It may even be fossilized dung.

The fossil record has never been overly concerned with dignity.

Together, fossils preserve the history of life on Earth: its astonishing experiments, spectacular successes, evolutionary detours and occasional catastrophes. They introduce us to organisms no human ever saw alive and to ecosystems that vanished long before our own species appeared.

But what exactly qualifies as a fossil—and how can something as fleeting as a footprint survive for millions of years?

Let us begin at the beginning.

SO, WHAT IS A FOSSIL?

Dinosaur Footprints near Tumbler Ridge, BC

A fossil is naturally preserved evidence of past life. That definition is deliberately broad because life leaves evidence in many different ways.

A fossil can be part of an organism’s body, such as a bone, tooth, shell, leaf or piece of wood. It can also be a mark made by an organism while it was alive: a footprint, burrow, feeding trail, nest or bite mark.

The organism itself does not necessarily need to be present.

This is one of the most important things to understand about fossils. We often picture a magnificent dinosaur skeleton standing in a museum, every rib neatly arranged and every tooth poised for drama. Yet complete skeletons are extraordinarily rare. Most fossils are fragments: a single tooth, part of a shell, a scrap of leaf, one vertebra or a dark smudge of carbon in the rock.

Some fossils are so small that thousands could sit comfortably on the head of a pin. Others belong to animals that stretched longer than a city bus.

All of them are evidence.

We divide fossils into two major categories: body fossils and trace fossils. The distinction is simple, but it opens the door to an astonishing variety of preservation.

BODY FOSSILS: WHEN PART OF THE ORGANISM REMAINS

A body fossil preserves part of the organism itself—or a direct impression, mould or cast of its remains.

The most familiar body fossils include:

• Bones
• Teeth
• Shells
• Exoskeletons
• Scales
• Wood
• Leaves
• Seeds
• Pollen
• Spores

Cenoceras Fossilized Shell Material

Hard parts are much more likely to enter the fossil record because they resist decay longer than soft tissues. Teeth are especially durable. A vertebrate animal may lose and replace thousands of teeth during its lifetime, greatly improving the odds that at least a few will survive long enough to become fossils.

This is one reason isolated fossil teeth are much more common than complete fossil animals. Nature produces teeth generously and skeletons only once per customer.

Shells also have an excellent chance of preservation. Ancient seafloors could accumulate the remains of countless brachiopods, molluscs, corals and other marine organisms. Over time, those shells became part of the sediment and, eventually, part of the rock itself.

The most durable portions of an organism dominate the fossil record. According to the National Park Service overview of body fossils, bones, teeth, shells, mineralized plates and wood are preserved far more frequently than skin, organs, flowers or fruit.

This creates an immediate problem.

The fossil record is not a complete census of everything that ever lived. It has a built-in preference for organisms with hard parts, those living in places where burial could occur and those fortunate enough to die under favourable conditions.

A clam living on a muddy seafloor has a better chance of becoming a fossil than a soft-bodied creature living on a windswept mountain. This does not mean the mountain creature was less important. It was simply less likely to leave us its forwarding address. We find many more of the durable creatures than we do the squishy. 

TRACE FOSSILS: WHEN BEHAVIOUR BECOMES STONE

Theropod Track, Thailand

Trace fossils preserve evidence of what an organism did rather than the organism’s actual body.

They are also called ichnofossils, from the Greek word ichnos, meaning track or trace. Scientists who specialize in studying them are called ichnologists.

Trace fossils include:

• Footprints and trackways
• Burrows and tunnels
• Trails
• Resting impressions
• Nests
• Root traces
• Feeding marks
• Bite marks
• Borings in shells or wood
• Coprolites, or fossilized dung
• Regurgitated material
• Gastroliths associated with an animal

A body fossil can tell us that an organism existed. A trace fossil may reveal what it was doing.

A line of footprints can show whether an animal walked on two legs or four. The distance between prints can help researchers estimate speed. Several parallel trackways may suggest that animals moved together, although such interpretations must be made carefully.

A burrow can reveal how an animal moved through sediment, searched for food or protected itself. Bite marks can document interactions between predator and prey. A resting impression can preserve the outline of an animal settling momentarily onto a soft surface.

Trace fossils often remain in the substrate where the behaviour originally occurred. Unlike bones, which may be carried away by water, scavengers or gravity, a burrow generally records activity at that exact location.

This gives trace fossils an extraordinary quality. They preserve moments. An animal stepped here. A worm burrowed here. Something bit this shell.

A dinosaur crossed this stretch of wet sediment, placing one foot after another beneath a sky no human would ever see. The animal continued on. The moment passed. But the ground remembered.

YES, FOSSILIZED POO IS A REAL FOSSIL

Coprolites are fossilized faeces, and they are among some of our most personal treasures.

They vary enormously in size and appearance. Some resemble pellets, spirals or lumpy stones. Others are difficult to distinguish from ordinary rock without examining their shape, contents or chemical composition.

Coprolites can preserve:

• Bone fragments
• Fish scales
• Plant fibres
• Seeds
• Pollen
• Insect remains
• Parasite eggs
• Chemical evidence of diet

They can help researchers determine whether an animal ate meat, plants, insects, fish—or almost anything unfortunate enough to fit inside it.

The difficulty lies in identifying the producer. Unless a coprolite is found directly associated with a particular animal, assigning it to a species can be challenging. Size, shape, contents and geological context may narrow the possibilities, but we must resist the temptation to point dramatically at every ancient dropping and declare, “Tyrannosaurus!”

Not every large coprolite came from the most famous carnivore available.

Still, fossilized dung offers something bones alone cannot: evidence of a meal passing through an animal’s digestive system. Coprolites are trace fossils that can provide direct clues about ancient diets.

One creature’s private moment has become everyone’s scientific business. Deep time can be terribly indiscreet.

DOES A FOSSIL HAVE TO BE TURNED TO STONE?

No. “Fossil” describes evidence of past life, not one particular style of preservation.

Some fossils are petrified or mineralized. Others preserve original material. Fossils can occur as impressions, carbon films, moulds, casts or remains trapped in substances such as amber, tar or ice.

Let us look at a few possibilities.

Permineralized Fossils

Bones and wood contain microscopic spaces. After burial, mineral-rich water may move through the sediment and deposit minerals inside those spaces.

This process is called permineralization.

The original structure may remain while its pores become filled with minerals such as silica, calcite or iron compounds. The result is denser and heavier than the original material but can preserve remarkable internal detail.

Petrified wood is a beautiful example. Its tissues may become mineralized so precisely that growth rings and cellular structures remain visible.

Replacement Fossils

In some fossils, the original biological material dissolves and is gradually replaced by minerals. The new mineral preserves the form—and sometimes even the microscopic structure—of the original organism.

It is rather like replacing a building one brick at a time while somehow retaining its shape.

Moulds and Casts

Imagine a shell buried in sediment.

The sediment hardens around it, but the shell later dissolves, leaving an empty impression. This cavity is a mould. If minerals or sediment later fill that mould and harden, they create a cast: a three-dimensional replica of the original shell.

An internal mould can form when sediment fills the inside of a shell and hardens before the shell disappears. Such fossils are sometimes called steinkerns, a German term meaning “stone kernel.”

Nothing of the original shell may remain, yet its shape survives. The body is gone. The absence has become the fossil. 

Compression and Carbon Films

McAbee Fossil Plants

Plants and soft-bodied organisms may be buried and flattened beneath accumulating sediment. Pressure drives away liquids and gases, sometimes leaving a thin film rich in carbon.

These fossils can appear as dark, delicate outlines on the rock. Leaves may preserve their veins. 

Fish may retain the shapes of scales and fins. Soft-bodied animals can sometimes be recorded in astonishing detail.

They are the geological equivalent of silhouettes—life pressed into stone. Some of the lovely specimens we find at the Eocene McAbee Fossil Beds near Cache Creek, British Columbia, are a great example.

Amber Preservation

Amber begins as sticky resin produced by ancient trees. Small organisms such as insects, spiders, mites and fragments of plants can become trapped in the resin. As the resin is buried and chemically altered over time, it becomes amber.

Amber can preserve extraordinary detail: hairs, wings, compound eyes and delicate structures that would normally decay rapidly.

It can even preserve tiny moments of behaviour. Organisms have been found trapped while feeding, mating, carrying pollen or interacting with parasites.

Amber is not a perfect time capsule, however, and it has not provided usable dinosaur DNA. The mosquitoes of Jurassic Park remain unemployed. If you are looking for some superb examples of amber preservation, check out the collection of Harry Tabiner in the UK. He has a remarkable eye and enviable collection, which he shares online.

Ice, Dryness and Natural Tar 

Cold, arid or oxygen-poor conditions can dramatically slow decay. Mammoths preserved in frozen ground may retain hair, skin, muscle and stomach contents. Natural tar deposits can preserve vast collections of bones, although the remains themselves may be stained, altered or compressed.

These forms of preservation remind us that a fossil does not need to resemble a traditional stone skeleton. Fossilization is not a single recipe. It is a vast collection of unlikely outcomes.

WHAT ABOUT FOOTPRINTS? HOW CAN A HOLE BECOME A FOSSIL?

A footprint fossil begins with a perfectly ordinary step.

An animal walks across a surface soft enough to receive an impression but firm enough to retain its shape. Mud and damp sand are excellent candidates.

The track must then be buried before wind, waves, rain, other animals or enthusiastic members of the herd destroy it. A new layer of sediment settles over the surface, filling and protecting the impression.

With continued burial, both layers may harden into rock. Millions of years later, erosion separates them again. One surface may preserve the original footprint as a depression. The layer that filled the print may preserve a raised natural cast.

Tracks are not simply stamps of the foot. The animal’s weight can deform layers beneath the surface, producing structures known as undertracks. These may be less anatomically precise than the original print but can still record the passage of the animal.

Interpreting tracks requires caution. Wetness, sediment texture, erosion and the animal’s movement can all alter a footprint’s appearance. The same animal could leave surprisingly different tracks after walking only a short distance.

We must study the track, the sediment and the entire trackway—not merely find three vaguely pointed marks and immediately summon the media.

HOW OLD DOES SOMETHING HAVE TO BE BEFORE IT BECOMES A FOSSIL?

You may have heard that a fossil must be at least 10,000 years old.

That figure is commonly used as a practical dividing line in educational materials and some regulatory contexts, but nature has not installed an official fossil clock that rings at midnight on an organism’s ten-thousandth birthday.

We may use terms such as subfossil for relatively recent remains that are not fully fossilized or that retain considerable original material. The terminology can vary depending on the field, material and legal jurisdiction.

Age alone is not the only consideration. Geological context, preservation and scientific usage all matter.

An ammonite shell 100 million years old is unquestionably a fossil. A mammoth tusk 30,000 years old is also a fossil, even if some of its original material remains. Very recent bones from an archaeological site may be described as remains rather than fossils.

The boundary is useful, but it is not a magical transformation.

ARE ALL FOSSILS VISIBLE?

Not remotely. Some of the most important fossils on Earth are microscopic.

Microfossils include fossilized pollen, spores, algae, bacteria, protists and the tiny shells or skeletal elements of marine organisms.

They may be smaller than a grain of sand, yet they occur in enormous numbers and can be tremendously useful. Because some microscopic organisms evolved rapidly and lived across wide geographic areas, their fossils can help scientists date and correlate rock layers.

Microfossils also reveal ancient environments. Different species lived under different conditions, so their presence can provide clues about water depth, temperature, salinity, oxygen levels and climate.

Oil and gas exploration has long relied on micropalaeontology to interpret underground rock layers. A microscopic fossil no larger than a speck of dust may help identify the age and environment of rocks buried kilometres beneath the surface.

Dinosaurs receive the posters. Microfossils quietly organize geological time. Alas, always the bridesmaid, never the bride... Dinos get all the love.

CAN MOLECULES BE FOSSILS?

Ancient life can sometimes leave chemical evidence even when no recognizable body or trace remains.

These signals are often called chemical fossils or biomarkers.

Certain molecules are associated with particular groups of organisms or biological processes. Modified versions of those compounds may survive in ancient rocks, providing evidence that particular kinds of life were present.

Stable isotope patterns can also carry biological information. Living organisms use elements in ways that can leave characteristic chemical signatures in their tissues or surrounding sediments.

Chemical fossils require careful interpretation because geological heat, pressure and contamination can alter molecular evidence. But when combined with other data, they can help scientists investigate some of the earliest chapters in the history of life.

Sometimes life leaves a bone. Sometimes it leaves a footprint. Sometimes it leaves little more than chemistry.

IS A DINOSAUR SKELETON IN A MUSEUM MADE OF REAL FOSSILS?

Sometimes entirely. Sometimes partly. Sometimes hardly at all.

Complete dinosaur skeletons are rare. Museum mounts are often composites, combining fossil bones from more than one individual of the same species. Missing elements may be reconstructed as casts.

In some displays, the original fossils are too heavy, fragile or scientifically valuable to suspend in a dramatic pose. Museums may mount lightweight replicas while keeping the genuine fossils safely stored for research.

This does not make the display fake. A high-quality cast reproduces the shape and surface detail of the original fossil while protecting irreplaceable material. Casts can also be shared with museums, schools and researchers around the world.

Labels generally explain which elements are original fossils and which are reconstructed. It is always worth looking.

The glamorous skeleton towering over the gallery may be a carefully assembled ambassador for a far more fragmentary animal.

IS EVERY OLD BONE A FOSSIL?

No. Sometimes an old bone is just that, an old bone. Not a fossil. Age and appearance alone do not prove that something is fossilized. Modern bones can become stained by soil and minerals, making them look ancient. Conversely, genuine fossils do not always appear dramatically different from ordinary bone.

Identification may involve examining:

• Geological context
• Colour and density
• Surface texture
• Internal structure
• Mineral composition
• Associated fossils
• Degree of mineralization
• Evidence of recent organic material

And no, licking it is not the preferred scientific method but, I confess, it is helpful in the field. Not fully diagnostic, but helpful. I have a good friend Skippy who swears by it.

There is an old field trick based on the idea that porous fossil bone may stick slightly to the tongue, but modern bone can do the same, as can many ordinary rocks. The technique is unhygienic, unreliable and particularly regrettable when the mystery specimen is not bone at all.

Use a hand lens. Use comparative anatomy. Use laboratory analysis. Leave your tongue out of the peer-reviewed methodology.

WHY ARE FOSSILS SO RARE?

To become a fossil, an organism must pass through a series of improbable filters. Fossils are not rare per se, as I can think of localities with hundreds spread across the surface and more beneath, but they are rare in the sense that only a small percentage of the organisms that have lived have been preserved this way. To become a fossil is a bit of a process, as you might expect. 

First, the organism, dino, plant, or what have you, must die in a place where preservation is possible.

Then its remains must escape scavengers, decay, trampling, weather and destruction. They must be buried. The sediment must remain intact as it becomes rock. The fossil must survive heat, pressure, chemical alteration, faulting, erosion and the slow recycling of Earth’s crust.

Finally, it must become exposed—or be reached by excavation—at precisely the right time for someone to recognize it. Too early, and it remains buried. Too late, and erosion destroys it.

The fossil record is therefore both magnificent and profoundly incomplete.

Most organisms that ever lived left no known fossil. Entire species may have appeared, flourished and vanished without preserving a trace that we have yet discovered.

Soft-bodied organisms are especially underrepresented. Environments such as mountains, forests and tropical soils generally offer fewer opportunities for long-term preservation than lakes, river floodplains and marine sediments.

When we reconstruct ancient ecosystems, we are working with survivors of a second kind—not organisms that survived extinction, but evidence that survived geology.

IS A FOSSIL THE SAME THING AS A ROCK?

A fossil is preserved within a geological material, and many fossils have been heavily mineralized, but “fossil” and “rock” are not interchangeable terms.

A rock forms through geological processes and may contain fossils. A fossil is evidence of past life preserved within rock, sediment, amber, ice or another natural context.

The distinction can become wonderfully complicated.

A fossil shell may retain original shell material. A petrified log may be almost entirely mineral. A mould contains none of the organism but preserves its shape. A trace fossil may consist entirely of disturbed sediment.

So, is a fossil a rock? Sometimes it has effectively become one. But what makes it a fossil is not simply its material. It is the biological information it carries.

WHAT CAN ONE FOSSIL TELL US?

Far more than its name. A fossil’s anatomy may reveal how an organism moved, fed or defended itself. Growth rings can record seasons or age. Microscopic wear on teeth may reveal diet. Bone injuries can preserve evidence of accidents, disease, combat and healing.

The surrounding sediment can tell us whether the organism lived in a river, desert, forest, lake or sea. Associated fossils help reconstruct the plants, animals and microorganisms sharing that environment.

Chemical analysis may reveal temperature, water conditions, migration or food-web relationships. Footprints may preserve speed and direction. Burrows can reveal oxygen levels in ancient sediments. Coprolites can contain the remains of a final meal.

Even the way a body was buried matters. Were the bones scattered by a river? Gnawed by scavengers? Transported by waves? Buried in a sudden flood?

The study of what happens to an organism between death, burial and discovery is called taphonomy. It helps palaeontologists separate evidence of how an animal lived from evidence of what happened after it died. A fossil is not simply an object. It is a scene containing clues.

WHAT IS NOT A FOSSIL?

Not every interesting pattern in rock was created by life.

Mineral crystals, concretions, sedimentary structures and weathered rocks can resemble eggs, shells, bones, skin, feathers or entire mysterious creatures. These geological look-alikes are sometimes called pseudofossils. Or, leaverits, as in leave it right there. 

Manganese minerals can grow in branching patterns resembling ferns. Concretions can look remarkably like eggs. Layered rocks may split into shapes suggesting shells or leaves. Some rocks possess suspiciously skull-like features and an unreasonable amount of charisma.

The human brain excels at recognizing familiar forms. This tendency, called pareidolia, helps us see faces in clouds, animals in tree bark and dinosaurs in the landscaping gravel.

None of this makes an unusual rock uninteresting. A pseudofossil can still be geologically beautiful.

It simply tells a different story.

THE FOSSIL RECORD IS BIASED

The fossil record is sometimes imagined as a great stone library containing the complete history of life.

It is more like a library after fire, flood, renovation, several lost catalogues and four billion years of questionable management.

Some chapters are richly detailed. Others contain a few scattered sentences. Entire volumes are missing.

Organisms with shells, bones or teeth are more likely to be preserved than soft-bodied organisms. Aquatic environments are generally better represented than upland habitats. Abundant and widespread species have a greater chance of discovery than rare, geographically restricted ones.

Even human activity introduces bias. Fossils are more likely to be discovered where rocks are exposed, where researchers can travel and where scientific work has been funded.

Palaeontologists must account for these biases when interpreting patterns of diversity, evolution and extinction. An absence of fossils does not necessarily prove that an organism was absent. It may mean that the right rocks were not deposited, did not survive or have not yet been explored.

The fossil record is incomplete. But incomplete does not mean useless. It means we must read it carefully.

A FOSSIL IS A RELATIONSHIP

There is another way to think about fossils. A fossil is not merely a thing that was once alive. It is the relationship between life and the Earth that preserved it. The organism contributed its body or behaviour. The environment supplied mud, sand, ash, resin, ice or minerals. Time transformed the evidence. Erosion returned it to the light. Then someone noticed.

That final part matters. A fossil can lie exposed among a thousand ordinary stones and remain silent until a curious person stops, looks closely and asks a question.

What made this shape? Why is this shell inside a mountain? Who walked here? What kind of world once existed beneath my feet? Every fossil discovery begins with attention. And many great specimens have been found by folk of all ages (many of them too young to vote) who take notice of the world around them.

A MESSAGE THAT SURVIVED

To hold a fossil is to hold a contradiction. It is evidence of death that teaches us about life. It is a motionless object that may record movement. It is a fragment capable of revealing an ecosystem.

It is ancient, yet newly discovered.

The animal, plant or microorganism did not set out to leave us a message. The footprint was not made for our benefit. The shell did not settle onto the seafloor hoping to appear one day in a museum drawer.

And yet the evidence survived.

Across burial, mineralization, shifting continents, rising mountains and relentless erosion, something remained.

A tooth.

A leaf.

A burrow.

A trail across the mud.

A tiny, stubborn piece of deep time waiting for someone to recognize it.

That is a fossil.

MOVE OVER, T. REX: THERE IS A NEW KING IN TOWN

Eighty million years ago, long before Texas acquired highways, cattle ranches or the unshakeable belief that everything should be larger there, much of the region lay beneath a warm inland sea.

And cruising through those waters was an animal that appears to have taken the entire “bigger in Texas” philosophy rather seriously.

Meet Tylosaurus rex, a newly recognized species of giant mosasaur described in 2026.

It measured as much as 13.2 metres long, carried a mouthful of finely serrated teeth and possessed adaptations for unusually powerful jaw and neck muscles.

In short, it was an enormous marine lizard with steak knives for teeth and the disposition of something that had never once been asked to use its indoor voice.

The name Tylosaurus rex means “king of the tylosaurs.”

Yes, that makes it another T. rex. No, it was not a dinosaur.

Mosasaurs were enormous marine reptiles belonging to the squamate lineage that includes modern snakes and lizards. Their ancestors began as land-dwelling animals, but by the Late Cretaceous their descendants had become thoroughly committed to ocean life.

They developed streamlined bodies, paddle-like limbs and long, powerful tails. Some grew to extraordinary sizes and occupied the upper reaches of Cretaceous marine food webs.

While Tyrannosaurus rex would not appear until millions of years later, Tylosaurus rex was already patrolling the Western Interior Seaway—the vast body of water that once divided North America into eastern and western landmasses.

The resemblance between the two kings is largely one of reputation. Both were enormous apex predators, both possessed formidable skulls, and both appear to have occasionally settled disagreements by biting one another in the face.

Ah, royalty.

A FOSSIL HIDING IN PLAIN SIGHT

The story of Tylosaurus rex is a lovely little tale. It is one that sparks a gleeful, "oh, what do we have here?" The story begins inside a museum drawer.

Lead author Amelia Zietlow was studying a mosasaur fossil in the collection of the American Museum of Natural History when she noticed that it did not fit comfortably with Tylosaurus proriger, the species to which it had been assigned.

It was larger. Its anatomy was different. Its teeth carried fine serrations—an unusual feature among mosasaurs.

That suspicious specimen led researchers back through fossils held in several museum collections. More than a dozen specimens, most collected from northern Texas decades earlier, began to reveal a consistent pattern.

These were not simply especially large or slightly peculiar examples of T. proriger. They represented another species.

In May 2026, Zietlow, Michael Polcyn and Ronald Tykoski formally described Tylosaurus rex in the Bulletin of the American Museum of Natural History. The fossils came from rocks of Campanian age, approximately 80 million years old. Read the original scientific paper through the American Museum of Natural History.

This is one of my favourite kinds of palaeontological revelation: not a fossil newly pulled from the earth, but an animal newly seen.

The bones had been found. They had been collected, prepared, catalogued and cared for. What changed was the question being asked of them.

Museum collections are not mausoleums for finished ideas. They are scientific libraries, and occasionally one of the books turns out to have been shelved under the wrong name.

THE SIZE OF A SCHOOL BUS

The specimens assigned to Tylosaurus rex produced estimated body lengths ranging from about 7.7 to 13.2 metres. The largest was approximately the length of a school bus.

Imagine, if you will, a school bus with flippers, a long muscular tail and a skull designed to make the other residents of the seaway reconsider their afternoon plans.

The species was consistently larger than Tylosaurus proriger in the researchers’ comparisons, although the authors appropriately caution that preservation and sampling can influence apparent size differences in the fossil record.

The skull is where matters become especially interesting.

Tylosaurus rex possessed structural features associated with enlarged jaw and neck muscles. Its teeth were also finely serrated, providing cutting edges that would have helped it process large prey.

This was a long animal powerfully built at the business end.

The precise menu is not preserved as a tidy Cretaceous restaurant bill, but the Western Interior Seaway contained abundant fish, sharks, turtles, seabirds and other marine reptiles. A predator of this size and construction may have been capable of attacking a considerable variety of animals.

It was, in scientific terms, a very large problem with flippers.

THE BLACK KNIGHT (NO, NOT BATMAN... HE'S THE DARK KNIGHT...NON-AQUATIC)

One of the most memorable specimens is held by the Perot Museum of Nature and Science in Dallas.

Nicknamed the “Black Knight,” it is missing the tip of its snout and has a fractured lower jaw. Researchers believe the injuries were inflicted by another similarly sized tylosaur.

That means at least some members of this species survived spectacularly violent encounters with their own kind.

Whether these battles involved territory, mates, food or the Cretaceous equivalent of someone cutting ahead in the ammonite queue is impossible to know. Yet the injuries provide a rare glimpse into behaviour.

Bones do more than reveal anatomy. They can preserve the consequences of a life actually lived: disease, healing, predation, combat and survival.

The Black Knight was not simply a representative diagram of a species. It was an individual animal that experienced an exceptionally bad day and lived long enough for its damaged bones to record the event.

A FAMILY TREE IN NEED OF PRUNING

The 2026 study named a spectacular predator, and also revised the anatomical character list used to reconstruct relationships among mosasaurs. 

Some earlier analyses relied upon datasets assembled from limited specimens and repeated through successive studies. Returning to the fossils allowed the team to reassess which features were genuinely useful for distinguishing species and tracing evolutionary relationships.

Mosasaur evolution was remarkably rapid.

Their terrestrial ancestors entered aquatic environments during the Cretaceous, and within a relatively short geological interval, mosasaurs diversified into an impressive variety of marine predators. Some developed crushing teeth suited to hard-shelled prey. Others possessed slender jaws for catching fish. 

The tylosaurs became long-snouted, powerful hunters and were among the first mosasaur lineages to achieve truly gigantic body sizes.

Tylosaurus rex appears to represent an especially robust expression of that experiment: larger, heavily muscled and equipped with unusually sharp-edged teeth.

Evolution did not simply produce a big mosasaur. It produced a big mosasaur and then apparently gave it upgrades.

THE IMPORTANCE OF LOOKING AGAIN

There is something deeply satisfying about a fossil that refuses to remain what its label says it is.

For decades, these Texas specimens were known, preserved and studied under another name. Their discovery as a distinct species required someone to pause, notice the inconsistencies and ask whether the established identification was actually correct.

That is science at its finest.

Science is not weakened when an old interpretation changes. It is doing precisely what it is meant to do: responding to evidence, refining its explanations and occasionally admitting that the giant, serrated-toothed marine lizard in the cupboard has been misidentified.

The description of Tylosaurus rex also honours Texas palaeontologist John Thurmond, who had suspected decades earlier that the region’s unusual tylosaur fossils might represent a separate species. 

John had solid instincts. He was bang on.

LONG LIVE THE KING

Around 80 million years ago, Tylosaurus rex moved through a sea that no longer exists.

Above it flew pterosaurs and ancient birds. Beneath it swam fish, sharks, turtles and other marine reptiles. Ammonites drifted through the water carrying their beautifully coiled shells, presumably hoping not to draw attention to themselves.

Then the seaway vanished. Sediments became stone. Bones were buried, uncovered and placed in museums beneath names that seemed reasonable at the time.

It took a fresh pair of eyes to recognize the king.

Museum collections are a wonderful place to poke about and time and time again that looking with fresh eyes pays gold. It is true for Canada's first Sabre-toothed cat fossil and Vancouver Island's first dinosaur, too. They were both sitting pretty, woefully mislabeled then serendipity along with fresh eyes revealed the truth.

New species may already be resting in cabinets and storerooms, patiently waiting for someone to notice that their teeth are a little too serrated, their jaws a little too muscular and their identity altogether more magnificent than the label suggests.

And somewhere in Texas, the other T. rex is finally enjoying its coronation.

Lead Image: Amelia Zietlow, lead author of the new study, examines the Tylosaurus rex holotype skeleton (PMNS 8029) in February 2023 at the Perot Museum of Nature and Science.

Courtesy of Perot Museum of Nature and Science

Charming end note:

As well as these lovelies, there is also an ancient marsupial lion (Thylacoleo rex), a blind, cave-dwelling salamander (Typhlomolge rex), and a parasitic leech (Tyrannobdella rex), who are proudly in the T. rex club.

SEX, MOVEMENT AND A 567-MILLION-YEAR-OLD SEAFLOOR

Dickinsonia, Kimberella, and Funisia

Long before teeth began biting, shells began clattering, or trilobites developed the audacity to scuttle fashionably across the seafloor, something was stirring in the ancient waters of northern Canada.

It was soft. It was strange. In some cases, it looked rather like a quilted bathmat.

And according to a remarkable collection of fossils announced in 2026, it was already moving, feeding and finding increasingly creative ways to make more of itself some 567 million years ago.

Welcome to the Ediacaran, an interval of Earth history spanning approximately 635 to 539 million years ago. It was a world before dinosaurs, before forests, before fish and even before the evolutionary enthusiasm of the Cambrian Explosion.

There were no ammonites spiralling through the seas, no crabs shuffling sideways and no vertebrates of any kind looking down their noses at the spineless masses.

Indeed, there were no noses.

For most of Earth’s history, life had been microscopic. Bacteria and other single-celled organisms had occupied the planet for billions of years, quietly transforming its oceans and atmosphere. Then, during the Ediacaran, large, multicellular organisms began appearing in the fossil record.

Some resembled fronds, discs, tubes, cushions or segmented mattresses. Others looked so unlike living organisms that we are still debating where—or whether—they belong on the modern tree of life.

These soft-bodied communities are collectively known as the Ediacara Biota, and the fossils discovered in the Mackenzie Mountains of the Northwest Territories are giving us an extraordinary new look at this evolutionary experiment.

A LOST SEAFLOOR IN THE CANADIAN NORTH

The fossils come from the lower Blueflower Formation near Sekwi Brook, a remote area of the Mackenzie Mountains. We've recovered more than 100 specimens from rocks that once formed part of a deep marine slope on the ancient continent of Laurentia—the continental core upon which much of present-day North America would eventually assemble.

The collection includes several organisms normally associated with what palaeontologists call the White Sea assemblage, a particularly diverse phase of Ediacaran life traditionally dated to between about 559 and 550 million years ago.

The Canadian fossils appear to be older.

Radiometric dates from nearby rock units, combined with their position in the geological sequence, indicate that the fossil-bearing beds may be close to 567 million years old. If that interpretation is correct, these organisms were living five to ten million years earlier than comparable communities were previously thought to have appeared.

Ten million years may seem an almost comically imprecise appointment by human standards. If someone tells you they will meet you for coffee sometime within the next ten million years, I would advise ordering without them.

In evolutionary history, however, pushing the appearance of complex behaviours back by several million years is significant. It changes how we understand the timing, geography and environmental setting of early animal evolution.

The fossils also include six groups not previously documented in North America, connecting this Canadian site with Ediacaran communities found in places such as Russia, South Australia and Namibia.

Apparently, even 567 million years ago, life was already more widely travelled than many of us.

MEET THE QUILTED BATHMAT

Dickensonia Fossils

Among the most intriguing fossils is Dickinsonia, one of the great celebrities of the Ediacaran—although celebrity looked considerably flatter in those days.

Dickinsonia had an oval, segmented body that could range from a few millimetres to well over a metre in length, depending upon the species and specimen. Its repeated rib-like units gave it the appearance of a quilted cushion, a bathmat or perhaps a very ambitious pancake.

For many years, scientists debated whether Dickinsonia was an animal, a fungus, a giant single-celled organism, a lichen or a member of an entirely extinct branch of life.

Chemical evidence preserved in some specimens, including cholesterol-related molecules associated with animals, has strengthened the argument that Dickinsonia belonged somewhere within the animal kingdom.

It did not possess an obvious mouth, gut, head or limbs. Instead, it may have absorbed nutrients through the underside of its body as it moved across microbial mats covering the seafloor.

Fossilized impressions sometimes occur alongside patches where the microbial mat appears to have been disturbed or consumed. These “feeding traces” suggest that Dickinsonia did not simply sit in one place looking decorative. It moved from one patch of food to another.

This was not movement in the style of a cheetah, a salmon or even an especially motivated snail. There was no dramatic pursuit, no snapping of jaws and certainly no soundtrack.

But movement directed toward food represents behaviour. It means an organism could interact with its surroundings, respond to opportunity and relocate its remarkably bathmat-like self when dinner required it.

The Mackenzie Mountain specimens may extend the known record of such mobile animals by millions of years.

ENTER THE SEAFLOOR SCRAPER

Then there is Kimberella.

This low, oval organism possessed a more clearly defined front and back than many of its Ediacaran neighbours. It may have had a muscular foot and moved across the seafloor in a manner somewhat comparable to a mollusc.

Scientists have found distinctive scratch-like feeding traces called Kimberichnus associated with Kimberella. These marks were probably produced as the animal scraped or raked microbial material from the seafloor.

At Sekwi Brook, both the body fossil and its characteristic traces occur within the ancient community. Together, they provide compelling evidence that Kimberella lived and fed in this deep-water environment rather than being washed in from somewhere shallower.

Whether Kimberella was a true mollusc, a close relative of molluscs or something branching near the base of the bilaterian family tree remains debated. Bilaterians are animals with broadly symmetrical left and right sides—a sprawling evolutionary club that eventually came to include worms, insects, molluscs, dinosaurs and ourselves.

If Kimberella was an early bilaterian, then it represents an important step toward the more mobile, muscular and behaviourally complex animals that would flourish during the Cambrian.

It also suggests that the ancient seafloor had acquired its own small cleaning crew.

No eyes. No teeth. No tiny branded apron. Just a soft-bodied scraper working methodically across the microbial buffet. 

I think of it as the Ediacaran’s plecostomus—Hypostomus plecostomus, the suckermouth catfish, or common pleco—merrily scraping away. No relation, of course, but I cannot shake the association from my mind.

AND THEN THERE WAS SEX—PROBABLY

The wonderfully provocative part of our story belongs to Funisia.

Funisia was a tube-shaped organism that lived attached to the seafloor, often in dense clusters. Individuals grew close together, forming communities that might have resembled stands of narrow marine tubes rising from the sediment.

Previous research on similarly sized clusters of Funisia from South Australia suggested that the organisms may have reproduced sexually through synchronized spawning. Modern corals and other marine animals use a comparable strategy, releasing eggs and sperm into the surrounding water at roughly the same time.

We cannot, of course, observe an Ediacaran spawning event directly. No fossil preserves a discreet little sign reading, “Reproduction underway—please give the tubes some privacy.”

The interpretation comes from the organisms’ distribution, size patterns and colonial growth. The evidence suggests that Funisia may have reproduced through waterborne stages, perhaps dispersing offspring or larvae over considerable distances.

The Canadian fossils show that Funisia was not confined to South Australia, as once thought. Its presence on Laurentia supports the idea that some Ediacaran organisms could disperse across ancient oceans.

One specimen from the Blueflower Formation may also record an early stage of branching growth.

So, while the site does not preserve sex itself, it contains a member of a lineage associated with some of the earliest evidence for sexual reproduction among complex organisms.

Sex, it appears, may be nearly as old as awkwardness—though awkwardness, being soft-bodied, has left a frustratingly poor fossil record.

LIFE BELOW THE LIGHT

The depth of the Canadian site may be just as important as the age of its fossils.

White Sea communities were previously best known from comparatively shallow marine environments. 

The Blueflower fossils, however, lived on a deeper continental slope, probably below the photic zone—the depth to which sufficient sunlight penetrates for photosynthesis.

This was not a bright tropical reef. It was a dark offshore world beyond the regular disturbance of waves and storms.

At first glance, deep water might seem an inhospitable nursery for early animals. Yet it may have offered one considerable advantage: stability.

Shallow environments can experience rapid changes in temperature, oxygen, currents and storm activity. Deeper settings may remain more consistent over time. That stability could have provided early animals with an environment in which new body plans and ecological strategies could develop.

The discovery supports a fascinating possibility: some early animal groups may have become established offshore and later expanded into shallower environments.

That is the reverse of a pattern commonly observed later in the fossil record, when evolutionary innovations often appear first in shallow, nearshore habitats before spreading into deeper water.

Early animal evolution may not have followed the rules we derived from its descendants.

This is one of the delights of palaeontology. The rocks are under no obligation whatsoever to respect our favourite theories.

PRESERVING THE IMPROBABLE

Finding these fossils is remarkable because the organisms had few hard parts—or none at all.

Bones, teeth and shells fossilize relatively readily because their mineralized tissues resist decay and destruction. Soft bodies normally collapse, decompose or become someone else’s lunch long before burial can preserve them.

Ediacaran fossils required exceptional circumstances. Organisms had to be covered quickly by sediment, and microbial mats may have helped stabilize their impressions. Even then, what remains is often a faint outline, ridge or textured surface rather than a conventional body fossil.

Researchers examined the Blueflower specimens using carefully controlled lighting and Reflectance Transformation Imaging. This technique combines photographs taken with light coming from different directions, allowing subtle surface details to be examined digitally.

In palaeontology, lighting is everything. A fossil that looks like an unremarkable slab beneath flat light can suddenly reveal the ghost of an organism when illuminated from the side.

The specimens collected during the study are housed at the Prince of Wales Northern Heritage Centre in Yellowknife, where these ancient residents of the North remain in the North.

BEFORE THE CAMBRIAN EXPLOSION

The Mackenzie Mountain fossils also help soften the old idea that complex animal life appeared suddenly during the Cambrian Explosion, beginning around 539 million years ago.

The Cambrian remains one of the most spectacular evolutionary intervals in Earth history. Animals developed mineralized skeletons, increasingly complex sensory systems, new feeding strategies and an impressive assortment of grasping, burrowing, swimming and biting equipment.

But it was not a beginning from nothing.

The Ediacaran world was already experimenting with movement, symmetry, feeding, reproduction, ecological communities and relationships between organisms and their environments.

The Cambrian Explosion had a prelude.

It was quiet, soft-bodied and frequently shaped like household furnishings, but it mattered.

The Blueflower fossils suggest that the transition from the older Avalon communities to the more diverse White Sea organisms was not necessarily a sharp replacement. The two groups may have overlapped in time and environment, pointing toward a more gradual evolutionary progression.

Evolution rarely arrives on cue, neatly replaces the previous cast and pauses for scientists to label the scene. It branches, overlaps, experiments and leaves us to reconstruct the performance hundreds of millions of years later.

THE SEAFLOOR THAT CHANGED THE STORY

Some 567 million years ago, the ancient seafloor of northern Laurentia hosted a community unlike anything alive today.

Dickinsonia moved across microbial mats, absorbing food beneath its quilted body.

Kimberella crept and scraped, leaving evidence of purposeful feeding behind it.

Funisia gathered in tubular communities and may have relied upon a reproductive strategy capable of carrying new generations across ancient seas.

None had bones. None had teeth. None could have imagined trilobites, dinosaurs, mammoths or palaeontologists hiking through the Mackenzie Mountains in search of their faint impressions.

Yet within these soft bodies were some of the behaviours that would come to define animal life: movement, feeding, environmental awareness, community and reproduction.

The ancient Canadian seafloor was not empty and it was not waiting for the Cambrian to make life interesting.

It was already alive with evolutionary possibility.

Soft, strange and quietly getting on with the complicated business of becoming an animal.

The 2026 research was published by Scott D. Evans, Erik A. Sperling, Kimberly V. Lau and Justin V. Strauss in Science Advances as “Discovery of White Sea assemblage fossils from Laurentia.” 

Additional information sourced from the American Museum of Natural History, and an institutional research article published by Dartmouth’s Faculty of Arts and Sciences on June 9, 2026. 

If you're searching for it, it is not a separate scientific study; it explains the same peer-reviewed Science Advances paper in accessible language.

Dartmouth is directly connected to the research through Dr. Justin Strauss, an associate professor of Earth and Planetary Sciences at Dartmouth. Strauss was a co-corresponding author of the scientific paper and led the expedition that recovered the fossils from the Mackenzie Mountains.

Dickensonia Image: Asset id: 1960060888.

FOSSILS, FAIRY TALES AND A QUIET REVOLUTION: CLEMENTINE HELM BEYRICH

Clementine Helm Beyrich

On a grey Berlin morning in the winter of 1863, a young girl named Anna quietly entered her foster mother’s study.

She expected to find Clementine Helm bent over the draft of a gentle domestic tale—something proper, improving and entirely suitable for the young ladies of nineteenth-century Europe.

Instead, she found her deep in conversation with a visiting scientist.

He spoke of fossil beds in Prussia and the strange creatures entombed within them—remnants of vanished worlds written into layers of stone. 

Anna watched, transfixed, as Clementine’s eyes lit up. This was no performance of polite interest. It was the unmistakable spark of genuine curiosity.

After the scientist departed, Clementine returned to her manuscript with renewed purpose.

In that moment, Anna glimpsed what readers across Central Europe would soon discover: her aunt was not simply writing stories. She was quietly—and rather brilliantly—rewriting the boundaries of what women and girls were permitted to know about the natural world.

And she was smuggling fossils into the nursery.

A Childhood Surrounded by Science

Clementine Helm Beyrich was born in 1825 and grew up at the edges of two very different worlds.

One was governed by the strict expectations placed upon girls in the German states: be dutiful, be modest, learn the domestic arts and try not to ask too many inconvenient questions.

The other was alive with scientific discovery.

Orphaned at an early age, Clementine was raised first by one maternal uncle and then another—the renowned mineralogist Christian Samuel Weiss. His Berlin household was steeped in geology, crystallography and energetic intellectual debate. Rocks were not merely rocks; they were evidence. Crystals held mathematical order. The Earth had a history, and that history could be read.

It was an extraordinary environment for a girl of her time, and Clementine absorbed it eagerly.

She later travelled to Berlin to earn a teaching diploma at the Königliche Luisenstiftung, one of the few institutions where a determined young woman could pursue advanced education. She taught for several years, developing the discipline, empathy and instinct for explanation that would later shape her writing.

A good teacher understands that knowledge need not be made dull to be respectable. Clementine seems to have understood this particularly well.

A Household of Geologists, Writers and Ideas

In 1848, Clementine married Heinrich Ernst Beyrich, one of her uncle’s former students. He would become a celebrated geologist and palaeontologist—and the sort of husband whose professional conversations were likely to include ancient seas, extinct organisms and the careful naming of rock layers.

Their Berlin home became a gathering place for scientists, artists and writers. Among their circle were Theodor Fontane, Otto Roquette and Friedrich Eggers, members of the Rütli literary group.

Clementine reportedly held her own in these conversations with warmth, intelligence and a quiet but formidable wit.

One can imagine the scene: earnest gentlemen debating geology over coffee while Clementine listened, questioned, remembered—and later transformed their grand scientific discussions into stories that children could actually understand.

The couple had no children of their own. After Clementine’s sister died in 1851, however, they adopted and raised her nieces, Anna and Elly. Surviving letters and diaries reveal the closeness of their relationship. The girls helped shape Clementine’s understanding of young readers, while she encouraged their intellectual curiosity in return.

This was a household where girls were cared for. It was also one in which they were expected to think.

Science Between the Covers

Clementine published her first work, a collection of children’s songs, in 1861. Over the following three decades, she produced more than 40 books, along with numerous stories, fairy tales and anthologies. She also established an annual almanac for girls with fellow writer Frida Schanz.

Her work travelled well beyond Germany and was translated into English, French, Dutch and Scandinavian languages.

Her best-known novel, Backfischchens Leiden und Freuden, published in 1863, became a beloved example of the Backfischroman—a genre written for adolescent girls. The term Backfisch referred to a girl somewhere between childhood and adulthood: not quite ready for society’s formal table, as it were, but no longer a minnow either.

Yet Clementine’s books offered far more than pleasant entertainment and lessons in good behaviour.

She gave her young readers access to science.

Geology, palaeontology, biology and the emerging debates of the scientific world appeared throughout her stories. Fossils and natural history were woven into narratives about girls learning who they were and what they might become.

In Dornröschen und Schneewittchen, Clementine even referred openly to Charles Darwin’s On the Origin of Species. This was a bold choice. Darwin’s ideas remained deeply controversial, and scientific debate was hardly considered appropriate reading material for girls.

Clementine disagreed—quietly, but quite decisively.

Her heroines were curious, educated and eager to understand the world around them. They were not decorative creatures waiting patiently for life to happen. They observed, questioned and participated in the unfolding story of scientific discovery.

In other words, they behaved like scientists.

Breaking Barriers—Quietly and Brilliantly

During the nineteenth century, women were largely barred from formal study in geology and the other natural sciences. Academic societies, universities and professional appointments were overwhelmingly closed to them.

Clementine found another route.

Imagination became her passport, and literature became her lecture hall.

Through her family and social circles, she encountered many of the people and ideas transforming nineteenth-century science. Her world connected her to figures such as Alexander von Humboldt, Ernst Haeckel, Christian Samuel Weiss, and Heinrich Ernst Beyrich. She absorbed the great debates surrounding geology, deep time, fossils and evolution, then translated them into engaging stories for younger readers.

She may not have held a university position or published geological monographs under her own name, but she became something equally influential: a gifted popularizer of geoscience at a time when most women were denied even the social permission to be curious.

That matters.

Scientific knowledge does not advance only through laboratories, museums and scholarly papers. It also grows through the people who carry ideas beyond those walls—those who make discovery feel possible to someone encountering it for the first time.

Through fairy tales enlivened by fossils and novels threaded with natural history, Clementine carried science into households across Central Europe. Her books reached girls who might never enter a university, attend a geological lecture or be invited into a learned society.

Within those pages, however, they could wander through deep time.

They could encounter vanished worlds, consider evolution and recognize that curiosity was not a masculine trait. Intellect belonged to them, too.

Clementine Helm Beyrich died in 1896, only a month after her husband. Yet the quiet revolution she helped nurture continued long after her final chapter.

Her legacy lives not only in the books she wrote, but in the minds she opened—especially those of the girls who saw themselves reflected in her intelligent, inquisitive heroines and understood that the story of science included them.

ROCK TO MUSEUM: JOURNEY OF A FOSSIL

Finding a fossil is like time-traveling with your hands. 

One moment you’re walking along a riverbank or quarry, scanning the ground, and the next—a fragment of bone, a whorl of an ammonite, or the outline of a fern leaf catches your eye. 

That thrill? It never gets old.

But the real magic happens after discovery. Fossils are often locked away in hard rock, fragile as porcelain and millions of years old. 

Paleontologists and citizen scientists use delicate tools—dental picks, air scribes, and fine brushes—to slowly free them, grain by grain. In some cases, a fossil is encased in plaster field jackets to keep it safe during transport, like a mummy wrapped for a journey through time.

Fossil Prep Lab

Once back in the lab, preparation becomes part science, part art. 

Stabilizing cracks, cleaning away stone, and sometimes even using microscopes to reveal the smallest details—all of this ensures the fossil tells its story clearly. 

For research, every surface and feature matters: teeth reveal diets, bone growth shows age, and even microscopic scratches whisper about ancient ecosystems.

When the work is done, fossils can either stay in collections for study or move into museum galleries. There, preparators mount them with custom armatures or create casts so the originals remain protected. Under lights and glass, these specimens connect us to their history—turning silent stone into storytellers. 

Prepping with an Air Scribe

Sometimes we see the specimen in isolation and other times we see who that creature was living amongst, how it made a living and what the environmental conditions were like. 

We might look at the pollen in the rock next to the fossil or bits of debris that help share these clues. 

Every fossil in a museum has taken this long journey: discovered in the field, carefully freed in the lab, then shared with the world. 

As you walk through the paleo exhibits at museums, you will begin to see the amount of time and patience that goes into preparing those specimens, both for study and display. 

A MOST PERSONAL FOSSIL: WHAT ANCIENT POO TELLS US ABOUT PREHISTORIC LIFE

Coprolites: Fossil Poop

Not every fossil enters the scientific record wrapped in dignity.

Some emerge from the rock with elegant ribs, formidable teeth or shells spiralled like mathematical poetry. Others are, quite unmistakably, ancient poo.

These geological indiscretions are known as coprolites—fossilized droppings left behind by animals that lived thousands or even millions of years ago. They may lack the grandeur of a dinosaur skull, but they are among the most intimate messages ever delivered from the prehistoric world.

A bone tells us that an animal lived. A coprolite tells us what it had for lunch. Sometimes, it also tells us whether lunch fought back.

The word coprolite comes from the Greek words kopros, meaning dung, and lithos, meaning stone. The term was introduced in the nineteenth century by the English geologist and fossil hunter William Buckland, a man who was famously fascinated by the less glamorous evidence left behind by ancient animals.

Despite the name, coprolites are not simply old droppings that have dried out and somehow survived. Like other fossils, their original material has usually been altered or replaced by minerals over time. Under the right conditions, an animal’s waste may be buried rapidly in sediment, protected from scavengers and decay, and gradually transformed into stone.

The result is a remarkably personal time capsule.

Inside a coprolite, we may discover fragments of bone, fish scales, shells, plant fibres, pollen, seeds and other traces of an ancient meal. Some even preserve the remains of parasites—proof that intestinal freeloaders have been making themselves unwelcome for a very long time.

Nature, it seems, invented digestive inconvenience well before humanity invented antacids.

WHO LEFT IT?

Determining that something is fossilized dung is only the beginning. Identifying the creature responsible can be considerably more difficult.

Unlike a tooth or skull, a coprolite rarely comes with the name of its producer conveniently attached. Its size, shape and contents can offer clues, but several animals living in the same environment may have produced similar droppings.

Researchers therefore study where the specimen was found, which animals are known from the surrounding rocks and what the coprolite contains. Spiralled coprolites, for example, may have been produced by animals with spiral-shaped intestinal valves, including certain ancient fishes and sharks. Large coprolites packed with shattered bone could point toward a sizeable carnivore with powerful jaws and an enthusiastic approach to dinner.

Even then, assigning a coprolite to a particular species may remain uncertain. Fossil poo is informative, but it is not always cooperative.

THE ORIGINAL DINNER RECEIPT

Coprolites provide evidence that skeletons alone cannot.

A collection of sharp teeth may suggest that an animal was a predator, but a coprolite containing chewed bone offers direct evidence of what at least one animal actually consumed. Plant-filled specimens can reveal the vegetation available in an ancient ecosystem. Fish scales, shell fragments and tiny bones may expose relationships between predator and prey.

Occasionally, tooth marks or partially digested remains reveal how food was processed. The condition of the material may even provide clues about digestive chemistry and how efficiently an animal broke down its meals.

Coprolites can also help reconstruct entire food webs. By combining their contents with fossil plants, pollen, footprints, bones and environmental evidence preserved in the surrounding rock, scientists can begin to understand who lived in an ecosystem, who ate whom and what happened after everyone had finished eating.

It is prehistoric ecology reconstructed from the least glamorous evidence imaginable.

THE PROBLEM WITH PREHISTORIC POO

Of course, not every suspiciously shaped lump is a coprolite.

Rocks are perfectly capable of impersonating biological objects. Mineral concretions, mud structures and strangely weathered stones may all resemble fossilized droppings—sometimes with alarming conviction.

Shape alone is rarely enough to confirm an identification. Researchers may examine a suspected coprolite under a microscope, study thin sections, analyze its chemical composition or use imaging technology to look inside without destroying it.

Phosphates associated with digested material can support an identification, as can recognizable food remains embedded within the specimen. Context matters enormously. A poo-shaped stone found in sediment containing abundant animal fossils is more promising than an identical lump discovered somewhere with no evidence of ancient life.

Sometimes a strangely shaped rock is a trace of prehistoric behaviour.

Sometimes it is simply a rock with an unfortunate silhouette.

Coprolites inevitably inspire laughter—and rightly so. Palaeontology does not become less serious when we admit that some fossils are funny.

But beneath the humour lies an extraordinary scientific resource. Coprolites preserve moments that bones often cannot: an animal feeding, digesting and moving through its environment. They capture behaviour rather than merely anatomy.

They remind us that prehistoric animals were not static museum displays. They hunted, grazed, scavenged, swallowed, digested, hosted parasites and occasionally consumed things they may later have regretted.

Millions of years later, we examine the mineralized remains of those meals and try to reconstruct the vanished worlds around them.

It is humbling, really.

We spend our lives hoping to leave behind something meaningful—a great work, a lasting legacy, perhaps a beautifully preserved skeleton in a respectable museum.

Have you found fossilized poop? Good on you! It is a mark of pride in any civilized collection!

Yet for some ancient creatures, the most revealing thing they ever left us was what they left behind.

Image: Asset id: 2461279721; Fossilized dinosaur feces (coprolites) on display at Rainbow Forest Museum and Visitor Center in Petrified Forest National Park, Arizona. Dinosaur droppings or poop fossil.