MAMMOTH HOT SPRINGS

Mammoth Hot Springs Yellowstone National Park

SILURIAN SEA SCORPION

The impressive homeotype specimen of a Eurypterus lacustris duo hails from Late Silurian deposits of New York. These lovelies are now housed in UCMP Berkeley's paleontological collections.

About two dozen families of eurypterids “sea scorpions” are known from the fossil record. Although these ancient predators have a superficial similarity, including a defensive needle-like spike or telson at their tail end, they are not true scorpions.

They are an extinct group of arthropods related to spiders, ticks, mites and other extant creepy crawlies.

Eurypterids hunted fish in the muddy bottoms of warm shallow seas before moving on to hunting grounds in fresh and brackish water during the latter part of their reign.They declined in numbers and diversity until becoming extinct during the Permian–Triassic extinction event (or sometime shortly before) 251.9 million years ago. As to the oldest and youngest of the order, we can look to the Stylonurina. Members of the suborder are collectively and informally known as "stylonurine eurypterids" or "stylonurines". They are known from deposits primarily in Europe and North America, but also in Siberia.

Compared to the suborder, Eurypterina, the stylonurines were comparatively rare and retained their posterior prosomal appendages for walking. Despite their rarity, the stylonurines have the longest temporal range of the two suborders. The suborder contains some of the oldest known eurypterids, such as Brachyopterus, from the Middle Ordovician as well as the youngest known eurypterids, from the Late Permian. They remained rare throughout the Ordovician and Silurian, though the radiation of the mycteropoids (a group of large sweep-feeding forms) in the Late Devonian and Carboniferous is the last major radiation of the eurypterids before their extinction in the Permian.

PERFECTLY ROLLED TRILOBITE

GASTROPODS

Gastropods, or univalves, are the largest and most successful class of molluscs. They started as exclusively marine but have adapted well and now their rank spends more time in freshwater than in salty marine environments.

Many are marine, but two-thirds of all living species live in freshwater or on land. Their entry into the fossil record goes all the way back to the Cambrian.

Slugs and snails, abalones, limpets, cowries, conches, top shells, whelks, and sea slugs are all gastropods. They are the second-largest class of animals with over 60,000–75,000 known living species.

The gastropods are originally sea-floor predators, though they have evolved to live happily in many other habitats. Many lines living today evolved in the Mesozoic. The first gastropods were exclusively marine and appeared in the Upper Cambrian (Chippewaella, Strepsodiscus).

By the Ordovician, gastropods were a varied group present in a variety of aquatic habitats. Commonly, fossil gastropods from the rocks of the early Palaeozoic era are too poorly preserved for accurate identification. Still, the Silurian genus Poleumita contains fifteen identified species.

Most of the gastropods of the Palaeozoic era belong to primitive groups, a few of which still survive today. By the Carboniferous, many of the shapes we see in living gastropods can be matched in the fossil record, but despite these similarities in appearance the majority of these older forms are not directly related to living forms. It was during the Mesozoic era that the ancestors of many of the living gastropods evolved.

In Mesozoic rocks, gastropods are more common as fossils and their shells often very well preserved. While not all gastropods have shells, the ones that do fossilize more easily and consequently, we know a lot more about them. We find them in fossil beds from both freshwater and marine environments, in ancient building materials and as modern guests of our gardens.

FOSSIL TURTLE

Fossil Turtle. Photo credit: Luis Lima. Lisbon Museum Collection

URSAVUS: BLACK BEAR CUB

Hiking in BC, both grizzly and black bear sightings are common. Nearly half the world's population, some 25,000 grizzlies, roam the Canadian wilderness.

Both bear families descend from a common ancestor, Ursavus, a bear-dog the size of a raccoon who lived more than 20 million years ago. Seems an implausible lineage given the size of their very large descendents. An average Grizzly weighs in around 800 lbs (363 kg), but a recent find in Alaska tops the charts at 1600 lbs (726 kg). This mighty beast stood 12' 6' high at the shoulder, 14' to the top of his head. It is one of the largest grizzly bears ever recorded.

PERFECT SYMMETRY: BRACHIOPODS

Brachiopods are bottom-feeding marine animals that appeared at the beginning of the Cambrian. They are abundant little fellows with more than 35,000 known species. Some have lived their time on Earth and are now extinct. Others have done well and we see them in our oceans today.

FOSSIL CRINOID: UINTACRINUS OF UTAH

Crinoids are one of my favourite echinoderms. It is magical when all the elements come together to preserve a particularly lovely specimen in such glorious detail. 

If you look closely at the detail here you can see a stunning example of Upper Cretaceous, Santonian age, Uintacrinus socialis — named by O.C. Marsh for the Uinta Mountains of Utah nearly 150 years ago.  

These lovelies are best known from the Smoky Hills Niobrara Formation of central Kansas. 

Crinoids are unusually beautiful and graceful members of the phylum Echinodermata. They resemble an underwater flower swaying in an ocean current. 

But make no mistake they are marine animals. Picture a flower with a mouth on the top surface that is surrounded by feeding arms. Awkwardly, add an anus right beside that mouth. 

Crinoids with root-like anchors are called sea lilies. They have graceful stalks that grip the ocean floor. Those in deeper water have longish stalks up to 3.3 ft or a meter in length. Then there are other varieties that are free-swimming with only vestigial stalks. They make up the majority of this group and are commonly known as feather stars or comatulids. 

Unlike the sea lilies, the feather stars can move about on tiny hook-like structures called cirri. It is these same cirri that allow crinoids to latch to surfaces on the seafloor. Like other echinoderms, crinoids have pentaradial symmetry. The aboral surface of the body is studded with plates of calcium carbonate, forming an endoskeleton similar to that in starfish and sea urchins.

These make the calyx somewhat cup-shaped, and there are few, if any, ossicles in the oral (upper) surface, an area we call the tegmen. It is divided into five ambulacral areas, including a deep groove from which the tube feet project, and five interambulacral areas between them. 

Crinoids are alive and well today. They are also some of the oldest fossils on the planet. We have lovely fossil specimens dating back to the Ordovician — if one ignores the enigmatic Echmatocrinus of the Burgess Shale. And they can be quite plentiful. Crinoid fossils, and in particular disarticulated crinoid columnals, can be so abundant that they at times serve as the primary supporting clasts in sedimentary rocks.

NATURAL HISTORY MUSEUM LISBON

Natural History Museum, Lisbon / Photo credit: Luis Lima

This beautiful "old school" gallery you see here is in the National Museum of Natural History and Science in Lisbon, Portugal. To the locals, it is the Museu Nacional de História Natural e da Ciência and is the country's main museum focusing on nature.

Its rich collections, gathered over more than 250 years, span zoology, anthropology, geology and botany.

The museum has activities for the promotion of natural history and science awareness, with space for artistic exhibitions, conferences, debates, workshops and courses.

The Museum Director is Professor Miguel Magalhaes Ramalho, geologist, researcher coordinator and former professor of the University of Lisbon.

ICELANDIC PONIES

FOSSIL PREPARATION

GLORIOUS SHARK OF CHUBUT

Carcharocles chubutensis, meaning "glorious shark of Chubut," from the ancient Greek is an extinct species of prehistoric mega-toothed sharks in the genus Carcharocles.

These big beasties lived during Oligocene, Miocene, and Pliocene, 28-5 million years ago. This fellow is considered to be a close relative of the famous prehistoric mega-toothed shark, C. megalodon, although the classification of this species is still disputed.

Swiss naturalist Louis Agassiz first identified this shark as a species of Carcharodon in 1843. In 1906, Ameghino renamed this shark as C. chubutensis. In 1964, shark researcher, L. S. Glikman recognized the transition of Otodus obliquus to C. auriculatus. In 1987, shark researcher, H. Cappetta reorganized the C. auriculatus - C. megalodon lineage and placed all related mega-toothed sharks along with this species in the genus Carcharocles. At long last, the complete Otodus obliquus to C. megalodon progression became clear and has since gained the acceptance of his peers. The specimen you see here is in the Geological Museum in Lisbon. Photo credit: Luis Lima.

HIKING BIG WHITE

BRITISH COLUMBIAN ICE AGE

It has long been accepted that the most recent series of ice ages began approximately 1.6 million years ago, beginning as ice accumulations at higher altitudes with the gradual cooling of the climate. Four times the ice advanced and receded, most recently melting away somewhere around 10,000 years ago. Ice retreated from southwestern British Columbia and the Puget Sound area around 15,000 years ago.

In the southern Interior, ice built up first in the northern Selkirk Mountains, then slowly flowed down into the valleys. Once the valleys were filled, the depth of the ice increased until it began to climb to the highlands and finally covered most of the Interior of British Columbia.

Between ice advances, there were times when the Kamloops area was ice free and the climate warm and hospitable. Glacial ice was believed to have initiated its most recent retreat from the South Thompson area around 11,000 to 12,000 years ago, but salmon remains from 18,000 years ago suggest that it may have actually began its northwest decline much earlier and indicating a much warmer climate in the Interior than archaeologists or geologists had originally estimated.

CAMPANIAN NAUTILUS

A picture perfect Campanian nautilus, Eutrophoceras irritilansis, from deposits near Coahuila, northern Mexico. Collection of Jose Ventura.

SUMAS FOSSIL SLIDE SITE

George Mustoe, Sumas Fossil Slide Site

The Sumas Fossil Slide Site revealed wonderfully preserved Eocene plant fossils. Here a fossil Palm Trunk impression is getting prepped by George Mustoe.

In 2009, there was a large downpour that hit Washington State causing massive slides. The blocks you see here all came crashing down on the hillside. Once the skies cleared, hikers found plant impressions in the rock and alerted the local paleo community. I was invited to tag along on a trip to photograph the site while George Mustoe took moulds of the palm trunks and trackways. The slide site at Sumas Mountain revealed many large exposures of fossil plants. Some exposures were 10 feet across. There was great excitement at seeing shorebird tracks and trackways of the large flightless bird Diatryma.

WASHINGTON FOSSIL FIELD TRIP

Sumas Slide Site, Sumas, Washington State

Two hundred million years ago, Washington was two large islands, bits of continent on the move westward, eventually bumping up against the North American continent and calling it home.

The shifting continues, subtling changing the landscape like a breath. We only notice when pockets of resistance manifest as earthquakes, some newsworthy, some all but unnoticed. For now, the more extreme movement has subsided laterally and continues vertically, pushing California towards the North Pole. Hello Baja-BC.

The upthrusting of plates moves our mountain ranges skyward – the path of least resistance. And it is this dynamic movement that's created the landscape we see today.

The 3,000 meters of stratigraphic section on Chuckanut Drive spans an age range of just a few million years. The lower part is late Paleocene with a radiometric age of around 56 million years. The upper part of the section is early Eocene. The fossils found here lived and died very close to where they are now but in a much warmer, wetter, swampy setting.

The exposures of the Chuckanut Formation were once part of a vast river delta; imagine, if you will, the bayou country of the Lower Mississippi. The siltstones, sandstones, mudstones and conglomerates of this formation were laid down during a time of luxuriant plant growth in the subtropical flood plain that covered much of the Pacific Northwest.

This ancient wetland provided ideal conditions to preserve the many trees, shrubs and plants that thrived here giving us a lot of information about climate, temperature, the water cycle and humidity of the region.

The Chuckanut flora is made up predominantly of plants whose modern relatives live in tropical areas such as Mexico and Central America. While less abundant, evidence of the animals that called this ancient swamp home are also found here. Rare bird, reptile, and mammal tracks have been immortalized in the outcrops of the Chuckanut Formation.

Tracks of a type of archaic mammal of the Orders Pantodonta or Dinocerata (blunt foot herbivores), footprints from a small shorebird, and tracks from an early equid or webbed bird track give evidence to the vertebrates that inhabited the swamps, lakes and river ways of the Pacific Northwest 50 million years ago.

Fossil mammals and bird trackways from Washington cause great excitement. The movement of these celebrity vertebrates was captured in the soft mud on the banks of a river, one of the only depositional environments favorable for track preservation.

Hence the terrestrial paleontological record of Washington State at sites like Chuckanut and Racehorse Creek (U-Pb 53 Ma.) is primarily made up of plant material with some wonderfully enticing mammal, shorebird and large Diatryma bird tracks to shake things up.

YORKSHIRE COAST AMMONITE

A stunning example of the ammonite Androgynoceras from the Yorkshire Coast, England. This beauty is in the collection of the deeply awesome Harry Tabiner ❤️

EOCENE FOSSIL PALM FROND

Eocene Fossil Palm Frond

MASSIVE BOULDERS: SUMAS SLIDE SITE

Sumas Fossil Slide Site

There was a large downpour that hit Washington State causing massive slides. The blocks you see here all came crashing down on the hillside.

Once the skies cleared, hikers found plant impressions in the rock and alerted the local paleo community. I was invited to tag along on a trip to photograph the site while George Mustoe took molds of the palm trunks and trackways.

The slide site at Sumas Mountain revealed many large exposures of fossil plants. Some exposures were 10 feet across. There was great excitement at seeing shorebird tracks and trackways of the large flightless bird Diatryma.

FORTUNE FAVORS THE BOLD

Audaces fortuna iuvat

Ursus curious! A young Black Bear (Ursus americanus) cub checks out a frisky, startled Striped Skunk (Mephitis mephitis) both native species in southern British Columbia. Generally, the aroma from a skunk is enough of a deterrent to keep curiosity at bay. Not in this case.

Bear cubs are known for being playful and all together too curious. They usually stick pretty close to Mamma but sometimes an intriguing opportunity for discovery will cross their path and entice them to slip away just for a few minutes to check it out.

The karma gods were good to this wee one. Nobody was skunked in this quest for exploration, though not for lack of trying.

LASALLE LIMESTONE CRINOIDS

Two beautiful fossil crinoid specimens, Stellarocrinus virgilensis and Braneocrinus, from Pennsylvanian deposits, Bond Formation, LaSalle limestone, Ocoya, Illinois. Collection of Michael O'Shea.

BOBBING IN THE BRINE

APODEROCERAS, YOUR GRACE

This stunning specimen with her regal ridges (and small anomaly) is an Apoderoceras ammonite. Apoderoceras are an extinct genus of cephalopod, an active predatory mollusk belonging to the subclass Ammonoidea.

Apoderoceras is, in fact, a wonderful example of sexual dimorphism within ammonites as the macroconch (putative female) shell grew to diameters in excess of 40 cm – many times larger than the diameters of the microconch (putative male) shell. Apoderoceras has been found in the Lower Jurassic of Argentina, Hungary, Italy, Portugal, and most of North-West and central Europe, including as this one is, the United Kingdom. She was found on the beaches of Charmouth in West Dorset, then prepped expertly by the lovely and talented Lizzie Hingley. 

Neither Apoderoceras nor Bifericeras donovani are strictly index fossils for the Taylori subzone, the index being Phricodoceras taylori. Note that Bifericeras is typical of the earlier Oxynotum Zone, and ‘Bifericeras’ donovani is doubtfully attributable to the genus.

The International Commission on Stratigraphy (ICS) has assigned the First Appearance Datum of genus Apoderocerasas and of Bifericeras donovani the defining biological marker for the start of the Pliensbachian Stage of the Jurassic, 190.8 ± 1.0 million years ago.  As the brilliant Murray Edmunds points out, this lovely large specimen (macroconch) of Apoderoceras is likely a female. Her larger body perfected for egg production.

Cat's Paw Suture Walls of Apoderoceras

Apoderoceras (Family Coeloceratidae) appears ‘out of nowhere’ in the basal Pliensbachian and dominates the ammonite faunas of NW Europe. It is superficially similar to the earlier Eteoderoceras (Family Eoderoceratidae, of the Raricostatum Zone), but on close inspection can be seen to be quite different.  It is, therefore, an ‘invader’ and its ancestry is cryptic.

The Pacific ammonite Andicoeloceras, known from Chile, appears quite closely related and may be ancestral, but the time correlation of Pacific and NW European ammonite faunas is challenging. Even if Andicoeloceras is ancestral to Apoderoceras, no other preceding ammonites attributable to Coeloceratidae are known. (Maybe there are clues in the Lias of Canada?) Apoderoceras remains present in NW Europe throughout the Taylori Subzone, showing endemic evolution.

It becomes progressively more inflated during this interval of time, the adult ribs more distant, and there is evidence that the diameter of the macroconch evolved to become larger. At the end of the Taylori Subzone, Apoderoceras disappeared as suddenly as it appeared in the region, and ammonite faunas of the remaining Jamesoni Zone are dominated by the Platypleuroceras–Uptonia lineage, generally assigned (but erroneously, IMO!) to the Family Polymorphitidae.

In the NW European Taylori Subzone, Apoderoceras is accompanied (as well as by the Eoderoceratid, B. donovani, which is only documented from the Yorkshire coast, although I know of examples from Northern Ireland) by the oxycones Radstockiceras (quite common) and Oxynoticeras (very rare), the late Schlotheimid, Phricoderoceras (uncommon: note P. taylori is a microconch, and P. lamellosum the macroconch), and the Eoderoceratid, Tetraspidoceras (very rare).

Thank you to Murray Edmunds for his advice, guidance and corrections as we explore Apoderoceras and the ammonite faunas of the Pacific and NW Europe. You are deeply awesome, my friend!
Check out Murray’s Research Gate site for more interesting tidbits!

https://www.researchgate.net/profile/Murray_Edmunds; the photo above of the Cat's Paw Sutures of an Apoderoceras from Dorset are from the lovely Simon Guscott. Appreciate you!

DINOGORGON: TERROR OF THE LATE PERMIAN

Dinogorgon Rubidgei / Photo: Jonathan Blair / Corbis

A quarter of a billion years ago, long before dinosaurs or mammals evolved, this three-metre (10-foot) gorgonopsid, Dinogorgon, terrorized the floodplains of what is now South Africa and Tanzania during the Late Permian.

For many years, we've believed that these mighty hunters reigned and died out in less than a million years. Dinogorgon is meant to have vanished during one of the greatest mass extinction events on the planet, the Permian Extinction. We've recorded five mass extinction events in our humble 4.6 billion year history. The event from the Permian wiped our about nine of every ten plant and animal species on the planet. New fossil evidence suggests that there were actually two mass extinctions during this time, with a sixth event happening around 260 million years ago.

UPPER CRETACEOUS NANAIMO GROUP

Upper Cretaceous Nanaimo Group / Denman Island

The Upper Cretaceous Nanaimo Group of southwest British Columbia is a four-kilometre thick succession of mostly deep marine siliciclastics sitting directly above the Insular Superterrane.

This succession has been the focus of many paleomagnetic, isotope geochemistry, paleontology, and sedimentology studies with the aim of untangling the tectonic history and paleolatitude of the Insular Superterrane during the Nanaimo Group deposition some 90 to 65 million years ago.

One would think that these research papers would support each other in terms of that deposition. Much to our chagrin, we're still working through the strata to define both the formal stratigraphy, untangle if it was deposited in single or multiple basins and match it up with local and regional correlations.

The upper two-thirds of the succession is continuously and well exposed on Denman and Hornby islands and represents the best example of this part of the succession in the northern half of what we consider the single Nanaimo Basin. This area includes the previously only informally defined type areas for the Geoffrey and Spray formations, defined here formally for the first time with type sections and detailed descriptions. New interpretations of the geology of these islands demonstrate that previously interpreted major faults do not exist, resulting in stratigraphic and age controls that are both different and simpler than previously interpreted. The redefined stratigraphy of the northern part of the basin is remarkably similar to that of southern areas in both type and age, affirming both a single basin evolution and a single stratigraphic nomenclature.

FOSSIL TRACKWAYS

Ichnofossil Trackways. Photo credit: Luis Lima. Lisbon Museum Collection

SHONISAURUS POPULARIS

ICHTHYOSAUR VERTEBRAE AND RIBS

A very well preserved ichthyosaur block with three distinct vertebrae and some ribs just peeking out. You can see the edges of the ribs nicely outlined against the matrix.

Ichthyosaurs are an extinct order of marine reptiles from the Mesozoic era. They evolved from land-dwelling, lung-breathing reptiles who returned to our ancient seas and evolved into the fish-shaped creatures we find in the fossil record today.

They were visibly dolphin-like in appearance but seem to share some other qualities as well. These lovelies were warm-blooded and used their coloration as camouflage. The smaller of their lineage to avoid being eaten and the larger to avoid being seen by prey. Ichthyosaurs also had insulating blubber, a lovely adaptation to keep them warm in cold seas.

Over time, their limbs fully transformed into flippers, sometimes containing a very large number of digits and phalanges. Their flippers tell us they were entirely aquatic as they were not well-designed for use on land. It was their flippers that first gave us the clue that they gave birth to live young; a hypothesis later confirmed by fossil embryo and wee baby ichy specimens.

We find their fossil remains in outcrops spanning from the mid-Cretaceous to the earliest Triassic. As we look through the fossils, we see a slow evolution in body design moving towards that enjoyed by dolphins and tuna by the Upper Triassic, albeit with a narrower, more pointed snout.

During the early Triassic period, ichthyosaurs evolved from a group of unidentified land reptiles. They were particularly abundant in the later Triassic and early Jurassic periods before being replaced as a premier aquatic predator by another marine reptilian group, the Plesiosauria, in the later Jurassic and Cretaceous periods. The block you see here is from Middle Triassic (Anisian/Ladinian) outcrops in the West Humboldt Mountains, Nevada.

ROLLED TRILOBITE

FOSSIL CROCODILE

Fossil Crocodile, Lisbon Natural History Museum. Photo: Luis Lima

This well-preserved fossil crocodile is around 12 million years old and hails from Chelas, a locality near the airport in Lisbon. This fellow was quite the beast. The complete crocodile would have been 8-9 meters in length.

This specimen is housed in the Geological Museum of Lisbon. The museum was built in 1857 and is home to beautiful paleontology, archaeology and mineral specimens.

DEVONIAN FISH

CHAMPAGNE-ARDENNE HOPLITES

An excellent example of the ammonite, Hoplites bennettiana (Sowby, 1826) with a pathology. This beauty is from Albian deposits near Carrière de Courcelles, Villemoyenne, laid down in the Cretaceous near la région de Troyes (Aube) Champagne in northeastern France.

L'Albien or Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It was named after Alba, the Latin name for the River Aube, a tributary of the Seine that flows through the Champagne-Ardenne region of northwestern France.

The Albian is the youngest or uppermost subdivision of the Lower Cretaceous, approximately 113.0 ± 1.0 Ma to 100.5 ± 0.9 Ma (million years ago).

At the time that this fellow was swimming in our oceans, ankylosaurs were strolling about Mongolia and stomping through the foliage in Utah, Kansas and Texas. Bony fish were swimming over what would become the strata making up Canada, the Czech Republic and Australia. Cartilaginous fish were prowling the western interior seaway of North America and a strange extinct herbivorous mammal, Eobaatar, was snuffling through Mongolia, Spain and England. Interesting times.

Hoplites maritimus / Hoplites rudis

Hoplites are amongst my favourite ammonites. I still have a difficult time telling them apart. To the right, you can see a slightly greyish, Hoplites maritimus, from Sussex England. Below him is a brownish Hoplites rudis from outcrops between Courcelles and Troyes, France. There are many Hoplites species. Each has a nicely raised tire-track ribbing. My preference is for Hoplities bennetianus (or bennettiana). I'm still sorting out the naming of that species. The difference between Hoplites bennettiana and Hoplites dentatus is seen on the venter.

Hoplites shells have compressed, rectangular and trapezoidal whorl sections. They have pronounced umbilical bullae from which their prominent ribs branch out. The ends of the ribs can be both alternate or opposite. Some species have zigzagging ribs and these usually end thickened or raised into ventrolateral tubercules.

Ammonites were predatory, squid-like creatures that lived inside coil-shaped shells. Like other cephalopods, ammonites had sharp, beaklike jaws inside a ring of tentacles that extended from their shells to snare prey such as small fish and crustaceans. Some ammonites grew more than three feet (one meter) across — possible snack food for the giant mosasaur Tylosaurus.

Ammonites constantly built new shell as they grew, but only lived in the outer chamber. They scooted through the warm, shallow seas by squirting jets of water from their bodies. A thin, tubelike structure called a siphuncle reached into the interior chambers to pump and siphon air and helped them move through the water.

Ammonites first appeared about 240 million years ago, though they descended from straight-shelled cephalopods called bacrites that date back to the Devonian, about 415 million years ago. They were prolific breeders, lived in schools, and are among the most abundant fossils found today. They went extinct with the dinosaurs 65 million years ago. Scientists use the various shapes and sizes of ammonite shells that appeared and disappeared through the ages to date other fossils.

Hoplites sp. from the Early Cretaceous of Dorset, UK

During their evolution, three catastrophic events occurred. The first during the Permian period (250million years ago), only 10% survived.  They went on to flourish throughout the Triassic period, but at the end of this period (206 million years ago), all but one species died. Then they began to thrive from the Jurassic period until the end of the Cretaceous period when all species of ammonites became extinct.

Ammonites began life very tiny, less than 1mm in diameter, and were vulnerable to attack from predators. They fed on plankton and quickly assumed a strong protective outer shell. They also grew quickly with the females growing up to 400% larger than the males; because they needed the larger shell for egg production. Most ammonites only lived for two years.  Some lived longer becoming very large. The largest ever found was in Germany (6.5 feet in diameter).

Ammonites lived in shallow waters of 100 meters or less. They moved through the water by jet propulsion expelling water through a funnel-like opening to propel themselves in the opposite direction. They were predators (cephalopods) feeding on most living marine life including mollusks, fish even other cephalopods. Ammonites would silently stalk their prey then quickly extend their tentacles to grab it.  When caught the prey would be devoured by the Ammonites' jaws located at the base of the tentacles between the eyes.

Hoplites dentalus, from Albian deposits near Troyes, France

Most ammonites have coiled shells. The chambered part of the shell is called a phragmocone.  It contains a series of progressively layered chambers called camerae, which were divided by thin walls called septae. The last chamber is the body chamber.

As the ammonite grew, it added new and larger chambers to the opened end of the shell. A thin living tube called a siphuncle passed through the septa, extending from the body to the empty shell chambers.

This allowed the ammonite to empty water out of the shell chambers by hyperosmotic active transport process. This process controlled the buoyancy of the ammonite's shell.

First Photo: Hoplites Bennettiana from near Troyes, France. Collection de Christophe Marot

Second Photo: Top: Hoplites maritimus from Sussex, UK. Bottom: Hoplites rudis from near Troyes, France. Collection of Mark O'Dell

Third Photo: Hoplites sp. from the Early Cretaceous of Dorset, UK. Natural Selection Fossils

Fourth Photo: Hoplites dentalus from Albian deposits near Troyes, France. Collection of Stéphane Rolland.

Wright, C. W. (1996). Treatise on Invertebrate Paleontology, Part L, Mollusca 4: Cretaceous Ammonoidea (with contributions by JH Calloman (sic) and MK Howarth). Geological Survey of America and University of Kansas, Boulder, Colorado, and Lawrence, Kansas, 362.

Amédro, F., Matrion, B., Magniez-Jannin, F., & Touch, R. (2014). La limite Albien inférieur-Albien moyen dans l’Albien type de l’Aube (France): ammonites, foraminifères, séquences. Revue de Paléobiologie, 33(1), 159-279.

OSTEOLOGIE DU MEGATHERIUM

This lovely illustration of Megatherium, a fossil sloth discovered in South America was published in 1825 by Georges Cuvier as part of his work comparing specimens from South America to those from the Paris Basin.

Jean Louis Denis was the engraver who created this lovely plate. We have Leonard C. Bruno to thank for access to this image. He took black and white photos of the plate and published them in 1987 to the Library of Congress with full open access. Illus. in: Recherches sur les ossemens fossiles / Georges Cuvier. Third ed. Paris: G. Dufour et E. d'Ocagne, 1825, pl. 16. Published in: The tradition of science / Leonard C. Bruno. Washington, D.C. : Library of Congress, 1987, p. 215.

SLOTHS AND AVOCADOS

In 1788, this magnificent specimen of a Megatherium sloth was sent to the Royal Cabinet of Natural History from the Viceroyalty of Rio de la Plata.

The megaterios were large terrestrial sloths belonging to the group, Xenarthra. These herbivores inhabited large areas of land on the American continent. Their powerful skeleton enabled them to stand on their hind legs to reach leaves high in the trees, a huge advantage given the calories needed to be consumed each day to maintain their large size.

Avocados were one of the food preferences of our dear Giant ground sloths. They ate then pooped them out, spreading the pits far and wide. The next time you enjoy avocado toast, thank this large beastie. One of his ancestors may have had a hand (or butt) in your meal.

In 1788, Bru assembled the skeleton as you see it here. It is exhibited at the Museo Nacional De Ciencias Naturales in Madrid, Spain, in its original configuration for historic value. If you look closely, you'll see it is not anatomically correct. But all good paleontology is teamwork. Based upon the drawings of Juan Bautista Bru, George Cuvier used this specimen to describe the species for the very first time.

GASTROPODA

ZENAPIS PODOLICA

A Devonian fish mortality plate showing all lower shields of Zenaspis podolica (Lankester, 1869) and Stensiopelta pustulata (and possibly Victoraspis longicornualis) from Lower Devonian deposits of Podolia, Ukraine.

Zenaspis is an extinct genus of jawless fish which existed during the early Devonian period. Due to it being jawless, Zenaspis was probably a bottom feeder.

The lovely 420 million-year-old plate you see here is from Podolia or Podilia, a historic region in Eastern Europe, located in the west-central and south-western parts of Ukraine, in northeastern Moldova. Podolia is the only region in Ukraine where Lower Devonian remains of ichthyofauna can be found near the surface.

For the past 150 years, vertebrate fossils have been found in more than 90 localities situated in outcrops along banks of the Dniester River and its northern tributaries, and in sandstone quarries. At present faunal list of Early Devonian agnathans and fishes from Podolia number 72 species, including 8 Thelodonti, 39 Heterostraci, 19 Osteostraci, 4 Placodermi, 1 Acanthodii, and 1 Holocephali (Voichyshyn 2001a, modified).

In Podolia, Lower Devonian redbeds strata (the Old Red Formation or Dniester Series) can be found up to 1800 m thick and range from Lochkovian to Eifelian in age (Narbutas 1984; Drygant 2000, 2003). In the lower part (Ustechko and Khmeleva members of the Dniester Series) they consist of multicoloured, mainly red, fine-grained cross-bedded massive quartz sandstones and siltstones with seams of argillites (Drygant 2000).

We see fossils beds of Zenaspis in the early Devonian of Western Europe. Both Zenaspis pagei and Zenaspis poweri can be found up to 25 centimetres long in Devonian outcrops of Scotland.

Reference: Voichyshyn, V. 2006. New osteostracans from the Lower Devonian terrigenous deposits of Podolia, Ukraine. Acta Palaeontologica Polonica 51 (1): 131–142. Photo care of Fossilero Fisherman.

THE LAST ICE AGE

The massive ice sheets of the Pleistocene covered much of the planet. They contained so much of the Earth's water that sea levels dropped to 100 metres lower than they are today.

FIRST ITALIAN FOSSILS OF AGRIOTHERIUM

Agriotherium / Short-Faced Bear

Fossil remains of Agriotherium, the short-faced giant bear, have been found in Collepardo, Italy. A fragment of a mandible was unearthed back in 2015 in the province of Frosinone. Thanks to several years of research and a recent CT scan, the team from Sapienza University of Rome were finally ready to publish.

Agriotherium is one of the largest of the mighty carnivores that lived in Europe back in the Pleistocene. They weighed as much as 900 kilos (almost 2,000 lbs) and grew up to 2.5 meters tall. These ancient bears roamed prehistoric Italy amid a humid and temperate climate, competing for food resources with some of our ancestors as they only becoming extinct 2.6 million years ago.

CAMBRIAN SEA ANEMONE

A stunning Cambrian soft-bodied Sea Anemone from outcrops near Malong, China. Collection of Marc R. Hänsel

PREHISTORIC BUGS: WANNERIA DUNNAE

Wanneria dunnae, an impressive trilobite from British Columbia's Eager Formation near Cranbrook. Trilobites were among the earliest fossils with hard skeletons. They were the dominant form of life at the beginning of the Cambrian Period. This specimen of Wanneria dunnae from the East Kootenay of British Columbia is typical of the group. Trilobite eyes were compound like those of modern crustaceans and insects. The eyes of these earliest trilobites are not well-known as the visual surface dropped away and was lost during molting long before they ever became fossils.

ZITRONENFALTER: GONEPTERYX RHAMNI

IRIDESCENT EUHOPLITES

A beautiful Euhoplites ammonite from Folkstone, UK. Euhoplites is an extinct ammonoid cephalopod from the Lower Cretaceous, characterized by strongly ribbed, more or less evolute, compressed to inflated shells with flat or concave ribs, typically with a deep narrow groove running down the middle. In some, ribs seem to zigzag between umbilical tubercles and parallel ventrolateral clavi. In others, the ribs are flexious and curve forward from the umbilical shoulder and lap onto either side of the venter.

Its shell is covered in the lovely lumps and bumps we associate with the genus. The function of these adornments are unknown. They look to have been a source of hydrodynamic drag, preventing Euhoplites from swimming at high speeds. Studying them may give some insight into the lifestyle of this ancient marine predator. Euhoplites had shells ranging in size up to a few inches.

We find them in Lower Cretaceous, middle to upper Albian age strata. Euhoplites has been found in Middle and Upper Albian beds in France where it is associated respectively with Hoplites and Anahoplites, and Pleurohoplites, Puzosia, and Desmoceras; in the Middle Albian of Brazil with Anahoplites and Turrilites; and in the Cenomanian of Texas. It is the most common ammonite fossil of the Folkstone fossil beds in southeastern England where a variety of species are found, including this 37mm beauty from the collections of José Juárez Ruiz.

FIRE-KISSED ARTHROPOD

This fellow is Chengjiangocaris kunmingensis, a rather glorious fuxinhuiid arthropod. While he looks like he could be from the inside of the Lascaux Caves and their fire-kissed Palaeolithic paintings, albeit by a very ancient Picasso, he was found at a Cambian fossil site in southern China.

As his name indicates, he is from a fossil site in the Yunnan region near Kunming. He is unusual in many ways, both because of the remarkable level of preservation and the position in which he was found. This fellow was a bit of a tippy arthropod. His carapace had flipped over before fossilisation, allowing researchers to to examine this fuxianhuiid's head and legs in great detail without a carapace in the way.

The roughly 518-million-year-old site contains a dizzying abundance of beautifully preserved weird and wonderful life-forms, from jellyfish and comb jellies to arthropods and algae and is about 10 million years older than the Burgess Shale. Photo credit: Yie Jang (Yunnan University)

ANCIENT ONES

WASH ON, WASH OFF

If you were a fish living in the warm turquoise waters off the coast of Bonaire, you may not hear those words, but you'd see the shrimp sign language equivalent. It seems Periclimenes yucatanicus or Spotted Cleaner Shrimp is doing a booming business in the local reefs by setting up a fish washing service.

That's right, a Fish Wash. You'd be hard pressed to find a terrestrial Molly Maid with two opposable thumbs as studious and hardworking as this wee marine beauty.

This quiet marine mogul is turning out to be one of the ocean's top entrepreneurs. Keeping its host and diet clean and green, the spotted shrimp hooks up with the locals, in this case, local sea anemones and sets up a fish wash. Picture a car wash but without the noise and teenage boys. The signage posted is the shrimps' natural coloring which attracts fish from around the reefs.

Wash on, wash off.

Once within reach, the shrimp cleans the surface of the fish, giving the fish a buff and the shrimp its daily feed.