Sunday, 31 May 2020

LOPHIIFORMES: ANGLERFISH

Humpback Anglerfish, Melanocetus johnsonii
The festive lassie you see here with her toothy grin and solo birthday-candle-style light is an Anglerfish.

They are bony fish of the teleost order Lophiiformes (Garman, 1899) and one of the most interesting, intriguing yet creepy, species on this planet.

There are over 200 species of anglerfish, most living in the pitch-black depths of the Atlantic and Antarctic oceans. They always look to be celebrating a birthday of some kind, albeit solo. This party is happening deep in our oceans right now and for those that join in, I hope they like it rough. The wee candle you see on her forehead is a photophore, a tiny bit of luminous dorsal spine. Many of our sea dwellers have photophores. We see them in glowing around the eyes of some cephalopods.

These light organs can be a simple grouping of photogenic cells or more complex with light reflectors, lenses, colour filters able to adjust the intensity or angular distribution of the light they produce. Some species have adapted their photophores to avoid being eaten, in others, it's an invitation to lunch but not in the traditional sense of that invite. In the anglerfish' world, it's dead sexy, an adaptation used to attract prey and mates alike, sometimes at the same time.

Deep in the murky depths of the Atlantic and Antarctic oceans, hopeful female anglerfish light up their sexy lures. When a male latches onto this tasty bit of flesh, he fuses himself totally.

He might be one of several potential mates. Each will take a turn getting close to her to see if she's the one. For her, it's not much of a choice. She's not picky, just hungry.

Mating is a tough business down in the depths. A friend asked if anglerfish mate for life. Well, yes... yes, indeed they do. Lure. Feed. Mate. Repeat. Once connected, the attachment is permanent. Her body absorbs his over time until all that's left are his testes. While unusual, it is only one of many weird and whacky ways our fishy friends communicate, entice, hunt and creatively survive and thrive. Ah, this planet has some evolutionary adaptations that are enough to break your brain. Anglerfish are definitely in with that lot.


Saturday, 30 May 2020

RED LIPPED BATFISH

Red Lipped Batfish, Ogcocephalus darwini
This sexy monkey with her luscious red pucker is a Red Lipped Batfish, Ogcocephalus darwini.

Our world's oceans have some of the most amazing, beautiful, ugly and interesting creatures on the planet. Red Lipped Batfish are no exception. They can be found along the sandy ocean floor and reefs around the Galapagos Islands and off the shores of Peru.

Their most distinguishing feature is revealed in their name and one look at this photo gives it away — they have very distinctive bright red lips. They also have a rather fetching illicium, the dangling projection you see here. It's a lure to attract prey to those luscious lips so she can enjoy a tasty snack. Above the illicium is an esca, an unusual feature that emits a bright light. Between the light and the lure, small fish and curious invertebrates — shrimp, molluscs, crab — deep in the Southeast Pacific investigate the light and get swallowed up by those lips.

Most of their flattened flounder-like bodies are light brown and a greyish in colour with white colouring on the underside. They are roughly the size of a dinner plate. On the top side of the batfish, there is usually a dark brown stripe starting at the head and going down the back to the tail.

Their face has a definite red sheen. Comically, with the red face and bored expressions, it looks like they're perpetually unimpressed and slightly embarrassed.

Once you get past those lips, the next thing that stands out with these interesting beauties is how they move. They're not terribly good swimmers but do walk rather well on their highly adapted fins. They march or waddle across the seafloor in search of more interesting sights to practise the art of deep-sea fishing.

Batfish are descendants of lophiiform fishes. In 2011, a new genus and species of batfish, Tarkus squirei, was described from Eocene (Ypresian) limestone deposits in the celebrated locality of Monte Bolca, Italy. Tarkus squirei was a tropical batfish that inhabited the inner-shelf palaeobiotopes of the central-western Tethys Sea.  Tarkus gen. nov. shows a certain degree of phenetic affinity with the extant shallow-water batfish genera Halieutaea and —more particularly — Halieutichthys. The specimens of this taxon are the first articulated skeletal remains of the Ogcocephalidae ever recorded as fossils, also representing the oldest members of the family known to date.

Reference: CARNEVALE, G., & PIETSCH, T. (2011). Batfishes from the Eocene of Monte Bolca. Geological Magazine, 148(3), 461-472. doi:10.1017/S0016756810000907

Friday, 29 May 2020

OF LAND AND SEA

Our dear penguins, seals, sea lions, walruses, whales, crocodiles and sea turtles were once entirely terrestrial. Many land animals have returned to the sea throughout evolutionary history. We have beautifully documented cases from amphibians, reptiles, birds and mammals from over 30 different lineages over the past 250 million years.

Some dipped a toe or two into freshwater ponds, but make no mistake, they were terrestrial. Each of these animals had ancestors that tried out the sea and decided to stay. They evolved and employed a variety of adaptations to meet their new saltwater challenges. Some adapted legs as fins, others became more streamlined, and still, others developed specialized organs to extract dissolved oxygen from the water through their skin or gills. The permutations are endless.

Returning to the sea comes with a whole host of benefits but some serious challenges as well. Life at sea is very different from life on land. Water is denser than air, impacting how an animal moves, sees and hears. More importantly, it impacts an air-breathing animal's movement on a pretty frequent basis. If you need air and haven't evolved gills, you need to surface frequently. Keeping your body temperature at a homeostatic level is also a challenge as water conducts heat much better than air. Even with all of these challenges, the lure of additional food sources and freedom of movement kept those who tried the sea in the sea and they evolved accordingly.

Most major animal groups appear for the first time in the fossil record half a billion years ago. We call this flourishing of species the Cambrian Explosion. While this was a hugely intense period of species radiation, the evolutionary origins of animals are likely to be significantly older. About 700 million years ago the Earth was covered in ice and snow. This was an ice age so intense we refer to this time in our ancient history as Snowball Earth. Once that ice receded, it exposed rocks that contained a variety of weird and wonderful fossils that speak to ancient animals that are only now being studied.

Dr Frankie Dunn, a palaeontologist and an Early Career Research Fellow at the Oxford University Museum of Natural History and Merton College is one of the folks who are examining this early history of some of our first animals. Her research focuses on the origin and early evolution of animals and particularly on the fossil record of the late Ediacaran Period (570 – 540 million years ago).  Dr Dunn's research is exploring ancient species like the long-extinct Rangeomorpha to help understand how animal body plans evolved in deep time well before the divergence of the extant (living) animal lineages.

Andy Temple (bless him) sent me a link for an online talk Dr Dunn is giving, The Chronicles of Charnia, Wed, June 17th at 7PM. She's based in Oxford so adjust your timezone accordingly. The talk is free but booking is required. Here's the link: https://event.webinarjam.com/register/59/xyy07flg 

This is an interesting article from Alicia Ault writing for the Smithsonian who interviewed Nick Pysenson and Neil Kelley about some of their research that touches on this area. They published a paper on it in the journal Science. Here's the link: https://science.sciencemag.org/content/348/6232/aaa3716

And Ault's work is definitely worth a read: https://www.smithsonianmag.com/smithsonian-institution/take-deep-dive-reasons-land-animals-moved-seas-180955007/

Thursday, 28 May 2020

SOOKE FOSSIL BIRDS: PENGUINS AND CORMORANTS

Stemec suntokum, a Fossil Plopterid from Sooke, British Columbia
The upper Oligocene Sooke Formation that outcrops on southwestern Vancouver Island, British Columbia is a wonderful place to collect and especially good for families.

As well as amazing west coast scenery, the beach site outcrop has a lovely soft matrix with well-preserved fossil molluscs, often with the shell material preserved (Clark and Arnold, 1923).

While the site has been known since the 1890s, my first trip here was in the early 1990s as part of a Vancouver Paleontological Society (VanPS) fossil field trip. The block of fossil mollusc specimens you see here is from the awesome John Fam, Vice-Chair of the VanPS on a family fossil field trip in July of 2019.

By the Oligocene ocean temperatures had cooled to near modern levels and the taxa preserved as fossils bear a strong resemblance to those found living beneath the Strait of Juan de Fuca today. Gastropods, bivalves, echinoids, coral, chitin and limpets are common-ish — and on rare occasions, fossil marine mammals, cetacean and bird bones are discovered.

Back in 2015, a family found the fossilized bones from a 25-million-year-old wing-propelled flightless diving bird while out strolling the shoreline near Sooke. Not knowing what they'd found but recognizing it as significant, the bones were brought to the Royal British Columbia Museum to identify.

The bones found their way into the hands of Gary Kaiser. Kaiser worked as a biologist for Environment Canada and the Nature Conservatory of Canada. After retirement, he turned his eye from our extant avian friends to their fossil lineage. The thing about passion is it never retires. Gary is now a research associate with the Royal British Columbia Museum, published author and continues his research on birds and their paleontological past.

Kaiser identified the well-preserved coracoid bones as the first example from Canada of a Plotopteridae, an extinct family that lived in the North Pacific from the late Eocene to the early Miocene. In honour of our First Nations communities who settled the Sooke area, Kaiser named the new genus and species Stemec suntokum.

Magellanic Penguin Chick, Spheniscus magellanicus
This is a very special find. Avian fossils from the Sooke Formation are rare. We are especially lucky that the bird bone was fossilized at all.  These are delicate bones and tasty. Scavengers often get to them well before they have a chance and the right conditions to fossilize.

Doubly lucky is that the find was of a coracoid, a bone from the shoulder that provides information on how this bird moved and dove through the water similar to a penguin. It's the wee bit that flexes as the bird moves his wing up and down.

Picture a penguin doing a little waddle and flapping their flipper-like wings getting ready to hop near and dive into the water. Now imagine them expertly porpoising —  gracefully jumping out of the sea and zigzagging through the ocean to avoid predators. It is likely that the Sooke find did some if not all of these activities.

When preservation conditions are kind and we are lucky enough to find the forelimbs of our plotopterid friends, their bones tell us that these water birds used wing-propelled propulsion to move through the water similar to penguins (Hasegawa et al., 1979; Olson and Hasegawa, 1979, 1996; Olson, 1980; Kimura et al., 1998; Mayr, 2005; Sakurai et al., 2008; Dyke et al., 2011).

Kaiser published on the find, along with Junya Watanabe, and Marji Johns. Their work: "A new member of the family Plotopteridae (Aves) from the late Oligocene of British Columbia, Canada," can be found in the November 2015 edition of Palaeontologia Electronica. If you fancy a read, I've included the link below.

The paper shares insights into what we've learned from the coracoid bone from the holotype Stemec suntokum specimen. It has an unusually narrow, conical shaft, much more gracile than the broad, flattened coracoids of other avian groups. This observation has led some to question if it is, in fact, a proto-cormorant of some kind. We'll need to find more of their fossilized lineage to make any additional comparisons.

Sooke, British Columbia Shoreline
Today, fossils from these flightless birds have been found outcrops in the United States and Japan (Olson and Hasegawa, 1996). They are bigger than the Sooke specimens, often growing up to two metres.

While we'll never know for sure, the wee fellow from the Sooke Formation was likely about a 50-65 cm long and weighed in around 1.72-2.2 kg — so roughly the length of a duck and weight of a small Magellanic Penguin, Spheniscus magellanicus, chick. To give you a visual, I've included a photo of one of these cuties here showing off his full range of motion and calling common in so many young.

The first fossil described as a Plotopteridae was from a wee piece of the omal end of a coracoid from Oligocene outcrops of the Pyramid Hill Sand Member, Jewett Sand Formation of California (LACM 8927). Hildegarde Howard (1969) an American avian palaeontologist described it as Plotopterum joaquinensis. Hildegarde also did some fine work in the La Brea Tar Pits, particularly her work on the Rancho La Brea eagles.

In 1894, a portion of a pelagornithid tarsometatarsus, a lower leg bone from Cyphornis magnus (Cope, 1894) was found in Carmanah Group on southwestern Vancouver Island (Wetmore, 1928) and is now in the collections of the National Museum of Canada as P-189401/6323. This is the wee bone we find in the lower leg of birds and some dinosaurs. We also see this same bony feature in our Heterodontosauridae, a family of early and adorably tiny ornithischian dinosaurs — a lovely example of parallel evolution.

Fossil coquina, Photo: John Fam
While rare, more bird bones have been found in the Sooke Formation over the past decade. In 2013, three avian bones were found in a single year. The first two were identified as possibly being from a cormorant and tentatively identified as Phalacrocoracidae tibiotarsi, the large bone between the femur and the tarsometatarsus in the leg of a bird.

They are now in the collections of the Royal BC Museum as (RBCM.EH2013.033.0001.001 and RBCM.EH2013.035.0001.001). These bones do have the look of our extant cormorant friends but the specimens themselves were not very well-preserved so a positive ID is tricky.

The third (and clearly not last) bone, is a well-preserved coracoid bone now in the collection at the RBCM as (RBCM.EH2014.032.0001.001).

Along with these rare bird bones, the Paleogene sedimentary deposits of the Carmanah Group on southwestern Vancouver Island have a wonderful diversity of delicate fossil molluscs (Clark and Arnold, 1923). Walking along the beach, look for boulders with white shelly material in them. You'll want to collect from the large fossiliferous blocks and avoid the cliffs. The lines of fossils you see in those cliffs tell the story of deposition along a strandline. Collecting from them is both unsafe and poor form as it disturbs nearby neighbours and is discouraged.

Sooke Formation Gastropods, Photo: John Fam
We find nearshore and intertidal genera such as Mytilus (mussels) and barnacles, as well as more typically subtidal predatory globular moon snails (my personal favourite), surf clams (Spisula, Macoma), and thin, flattened Tellin clams.

The preservation here formed masses of shell coquinas that cemented together but are easily worked with a hammer and chisel. Remember your eye protection and I'd choose wellies or rubber boots over runners or hikers.

You may be especially lucky on your day out. Look for the larger fossil bones of marine mammals and whales that lived along the North American Pacific Coast in the Early Oligocene (Chattian).

Concretions and coquinas on the beach have yielded desmostylid, an extinct herbivorous marine mammal, Cornwallius sookensis (Cornwall, 1922) and 40 cm. skull of a cetacean Chonecetus sookensis (Russell, 1968), and a funnel whale, a primitive ancestor of our Baleen whales.

A partial lower jaw and molar possibly from a large, bear-like beach-dwelling carnivore, Kolponomos, was also found here. A lovely skull from a specimen of Kolponomos clallamensis (Stirton, 1960) was found 60 km southwest across the Strait of Juan de Fuca in the early Miocene Clallam Formation and published by Lawrence Barnes and James Goedert. That specimen now calls the Natural History Museum of Los Angeles County home and is in collections as #131148.

References: L. S. Russell. 1968. A new cetacean from the Oligocene Sooke Formation of Vancouver Island, British Colombia. Canadian Journal of Earth Science 5:929-933
Barnes, Lawrence & Goedert, James. (1996). Marine vertebrate palaeontology on the Olympic Peninsula. Washington Geology, 24(3):17-25.

Fancy a read? Here's the link to Gary Kaiser's paper: https://palaeo-electronica.org/content/2015/1359-plotopterid-in-canada. If you'd like to head to the beach site, head to: 48.4°N 123.9°W, paleo-coordinates 48.0°N 115.0°W.

Wednesday, 27 May 2020

BOTTLENOSE DOLPHINS

These delightfully friendly and super smart fellows are Bottlenose dolphins. They are marine mammals who live in our world's oceans and breathe air at the surface, similar to humans.

They have lungs, inhaling and exhaling through a blowhole at the top of their heads instead of a through their nose.

Dolphins are social mammals and very playful. You may have seen them playing in the water, chasing boats or frolicking with one another. Humpback whales are fond of them and you'll sometimes see them hanging out together. They are also quite vocal, making a lot of interesting noises in the water. They squeak, squawk and use body language — leaping from the water while snapping their jaws and slapping their tails on the surface. They love to blow bubbles, will swim right up to you for a kiss and cuddle. Each individual dolphin has a signature sound, a whistle that is uniquely theirs. Dolphins use this whistle to tell one of their friends and family members from another.

Tuesday, 26 May 2020

GRAY WHALES: ESCHRICHTIUS ROBUSTUS

Young Gray Whale, Eschrichtius robustus
The lovely fellow you see here is a young Gray Whale, Eschrichtius robustus, with a wee dusting of barnacles and his mouth ajar just enough to show his baleen.

Two Pacific Ocean populations are known to exist: one of about 200 individuals whose migratory route is presumed to be between the Sea of Okhotsk off Russia's south coast and southern Korea, and a larger one with a population of about 27,000 individuals in the eastern Pacific.

This second group are the ones we see off the shores of British Columbia as they travel the waters from northernmost Alaska down to Baja California. Gray whale mothers make this journey accompanied by their calves, hugging the shore in shallow kelp beds and providing rare but welcome glimpses of this beauty.

The gray whale is traditionally placed as the only living species in its genus and family, Eschrichtius and Eschrichtiidae, but an extinct species was discovered and placed in the genus in 2017 — the Akishima whale, E. akishimaensis. Some recent DNA analyses suggest that certain rorquals of the family Balaenopteridae, such as the humpback whale, Megaptera novaeangliae, and fin whale, Balaenoptera physalus, are more closely related to the gray whale than they are to some other rorquals, such as minke. Still, others place gray whales as outside the rorqual clade, a kissing cousin if you will.

John Edward Gray placed it in its own genus in 1865, naming it in honour of physician and zoologist Daniel Frederik Eschricht. The common name of the whale comes from its colouration. The subfossil remains of now-extinct gray whales from the Atlantic coasts of England and Sweden were used by Gray to make the first scientific description of a species then surviving only in Pacific waters. The living Pacific species was described by American palaeontologist, Edward Drinker Cope as Rhachianectes glaucus in 1869.

Fin Whale, Balaenoptera physalus
Skeletal comparisons showed the Pacific species to be identical to the Atlantic remains in the 1930s, and Gray's naming has been generally accepted since. Although identity between the Atlantic and Pacific populations cannot be proven by anatomical data, its skeleton is distinctive and easy to distinguish from that of all other living whales.

In 1993, a twenty-seven million-year-old specimen was discovered in deposits in Washington state that represents a new species of early baleen whale. It is especially interesting as it is from a stage in the group’s evolutionary history when baleen whales transitioned from having teeth to filtering food with baleen bristles.

Visiting researcher Carlos Mauricio Peredo studied the fossil whale remains, publishing his research to solidify Sitsqwayk cornishorum (pronounced sits-quake) in the annals of history. The earliest baleen whales clearly had teeth, and clearly still used them. Modern baleen whales have no teeth and have instead evolved baleen plates for filter feeding. Look to the rather good close-up of this young Gray Whale here to see his baleen where once there was a toothy grin.

The baleen is the comb-like strainer that sits on the upper jaw of baleen whales and is used to filter food. We have to ponder when this evolutionary change —moving from teeth to baleen — occurred and what factors might have caused it. Traditionally, we have sought answers about the evolution of baleen whales by turning to two extinct groups: the aetiocetids and the eomysticetids.

The aetiocetids are small baleen whales that still have teeth, but they are very small, and it remains uncertain whether or not they used their teeth. In contrast, the eomysticetids are about the size of an adult Minke Whale and seem to have been much more akin to modern baleen whales; though it’s not certain if they had baleen. Baleen typically does not preserve in the fossil record being soft tissue; generally, only hard tissue, bones and teeth are fossilized.

Monday, 25 May 2020

MEGAPTERA NOVAENGLIAE

Humpback Whales, Megaptera novaeangliae, are a species of baleen whale.

There are 15 species of baleen whales. They inhabit all major oceans, in a wide band running from the Antarctic ice edge to 81°N latitude.

Humpback whales are rorquals, members of the Balaenopteridae family that includes the blue, fin, Bryde's, sei and minke whales. The rorquals are believed to have diverged from the other families of the suborder Mysticeti as long ago as the middle Miocene era. While cetaceans were historically thought to have descended from mesonychids— which would place them outside the order Artiodactyla— molecular evidence supports them as a clade of even-toed ungulates — our dear Artiodactyla. Baleen whales split from toothed whales, the Odontoceti, around 34 million years ago.

It is one of the larger rorqual species, with adults ranging in length from 12–16 m (39–52 ft) and weighing around 25–30 metric tons (28–33 short tons). The humpback has a distinctive body shape, with long pectoral fins and a knobbly head. It is known for breaching and other distinctive surface behaviors, making it popular with whale watchers.

Both male and female humpback whales vocalize, but only males produce the long, loud, complex "song" for which the species is famous. Males produce a complex song lasting 10 to 20 minutes, which they repeat for hours at a time. All the males in a group will produce the same song, which is different each season. Its purpose is not clear, though it may help induce estrus in females.

Found in oceans and seas around the world, humpback whales typically migrate up to 25,000 km (16,000 mi) each year. They feed in polar waters and migrate to tropical or subtropical waters to breed and give birth, fasting and living off their fat reserves. Their diet consists mostly of krill and small fish. Humpbacks have a diverse repertoire of feeding methods, including the bubble net technique.

Humpbacks are a friendly species that interact with other cetaceans such as bottlenose dolphins. They are also friendly and oddly protective of humans. You may recall hearing about an incident off the Cook Islands a few years back. In September of 2017, Nan Hauser was snorkeling and ran into a tiger shark. Two adult humpback whales rushed to her aid, blocking the shark from reaching her and pushing her back towards the shore. We could learn a thing or two from their kindness. We've not been as good to them as they've been to us.

Like other large whales, the humpback was a tasty and profitable target for the whaling industry. They were nearly hunted to extinction before the process was banned back in the 1960s. While stocks have partially recovered to some 80,000 animals worldwide, entanglement in fishing gear, collisions with ships, and noise pollution continue to affect the species. So be kind if you see them. Turn your engine off and see if you can hear their soulful cries echoing in the water.

Sunday, 24 May 2020

USING BARNACLES TO TRACK ANCIENT WHALES

We can trace the lineage of barnacles back to the Middle Cambrian. That's half a billion years of data to sift through. But if you divide that timeline in half yet again, we begin to understand barnacles and their relationship to other sea-dwelling creatures and their migration patterns.

It is through the study of fossil barnacles that are roughly 270,000 million years old that help track ancient whale migrations. University of California Berkeley doctoral student Larry Taylor, the lead author of the study, published March 25, 2019, in the peer-reviewed journal Proceedings of the National Academy of Sciences published on some clever findings. Taylor's research showed used fossil barnacles that hitched a ride on the backs of humpback and gray whales to reconstruct the migrations of whale populations millions of years ago.

The barnacles not only record details about the whales’ yearly travels but also retain this information after they become fossilized. By following this barnacle trail, Taylor et al. were able to reconstruct migration routes of whales from millions of years in the past.

Today, Humpback whales come from both the Southern Hemisphere (July to October with over 2,000 whales) and the Northern Hemisphere (December to March about 450 whales along Central America) to Panama (and Costa Rica). They undertake annual migrations from polar summer feeding grounds to winter calving and nursery grounds in subtropical and tropical coastal waters.

One surprise find is that the coast of Panama has been a meeting ground for humpback whales going back at least 270,000 years.

To see how the barnacles have traveled through the migration routes of ancient whales, the team used oxygen isotope ratios in barnacle shells and measured how they changed over time with ocean conditions. Did the whale migrate to warmer breeding grounds or colder feeding grounds? Barnacles retain this information even after they fall off the whale, sink to the ocean bottom, and become fossils. As a result, the travels of fossilized barnacles can serve as a proxy for the journeys of whales in the distant past.

Barnacles can play an important role in estimating paleo-water depths. The degree of disarticulation of fossils suggests the distance they have been transported, and since many species have narrow ranges of water depths, it can be assumed that the animals lived in shallow water and broke up as they were washed down-slope. The completeness of fossils, and nature of the damage, can thus be used to constrain the tectonic history of regions.

Saturday, 23 May 2020

BARNACLES: CUVIER TO DARWIN

Barnacles all closed up for protection.
One of the most interesting and enigmatic little critters we find at the seashore are barnacles. They cling to rocks at the waters' edge, closed to our curiosity, their domed mounds like little closed beaks shut to the water and the world.

They choose their permanent homes as larvae, sticking to hard substrates that will become their permanent homes for the rest of their lives. It has taken us a long time to find how they actually stick or what kind of "glue" they were using.

A clever fellow from Duke University's Marine Laboratory in Durhan, North Carolina finally cracked that puzzle. Instead of chopping up barnacles to see what makes them stick, he observed and collected the oozing glue from some Amphibalanus amphitrite as they secreted it.

Remarkably, the barnacle glue sticks to rocks in a similar way to how red cells bind together. Red blood cells bind and clot with a little help from some enzymes. These work to create long protein fibres that first blind, clot then form a scab. The mechanism barnacles use, right down to the enzyme, is very similar. That's especially interesting as about a billion years separate our evolutionary path from theirs.

So, with the help of their clever enzymes they can affix to most anything – ship hulls, rocks, and even the skin of whales. If you find them in tidepools, you begin to see their true nature as they open up, their delicate feathery finger-like projections flowing back and forth in the surf.

Barnacle Cirri seeking tasty plankton
Those wee feather-like bits you see are called cirri. Eight pairs of these thoracic limbs help barnacles to filter tasty bits of plankton from the surrounding water into their mouths.

Barnacles are cirripedes, a kind of crustacean that is covered with hard plates of calcium carbonate. Named for their cirri, they live stuck to hard surfaces in and around our world's oceans. While they do not look like crustaceans, they are definitely part of this taxonomic grouping that includes crab, lobster, crayfish, prawn, krill, and woodlice.

They have an old history. Their ancestors can be traced back to animals such as Priscansermarinus that lived during the Middle Cambrian – some 510 to 500 million years ago. I found my first barnacle fossil at a fossil site called Muir Creek on the south end of Vancouver Island. The fossil exposures at Muir are Oligocene, 20-25 million years old. This is about the time that barnacles can be found more readily as skeletal remains.

One of the reasons for the limited number of barnacle remains in the fossil record is their preferred habitat – high energy, shallow ocean environments. These tend to see a lot of tidal action that leads to erosion and barnacles being broken apart, slowly eroded down to bits too small to recognize for what they are.

One of the fossil remains we do find are not the barnacles themselves, but trace fossils of acrothoracican barnacle borings from Rogerella. These are commonly found in the fossil record beginning in the Devonian right up to today. Rogerella is a small pouch-shaped boring (a type of trace fossil) with a slit-like aperture currently produced by acrothoracican barnacles. These crustaceans extrude their legs upwards through the opening for filter-feeding (Seilacher, 1969; Lambers and Boekschoten, 1986). They are known in the fossil record as borings in carbonate substrates (shells and hardgrounds) from the Devonian to the Recent (Taylor and Wilson, 2003).

Barnacles' ancestry can be traced back to the Middle Cambrian
Barnacles were originally classified by Linnaeus and Cuvier as Mollusca, but in 1830 John Vaughan Thompson published observations showing the metamorphosis of the nauplius and cypris larvae into adult barnacles. He noted how these larvae were similar to those of crustaceans.

In 1834 Hermann Burmeister published further information, reinterpreting these findings. The effect was to move barnacles from the phylum of Mollusca to Articulata, showing naturalists that detailed study was needed to reevaluate their taxonomy.

Charles Darwin took up this challenge in 1846 and developed his initial interest in a major study published as a series of monographs in 1851 and 1854. Darwin undertook this study, at the suggestion of his friend Joseph Dalton Hooker, to thoroughly understand at least one species before making the generalizations needed for his theory of evolution by natural selection.

Barnacles are suspension feeders, sweeping small food into their mouth with their curved 'feet'. They are cemented to rock (usually), and covered with hard calcareous plates, which they shut firmly when the tide goes out. The barnacles reproduce sexually and produce little nauplius larvae that disperse in the plankton. Eventually, the larvae change into cypris form and attach on other hard surfaces to form new barnacles.

Friday, 22 May 2020

MANATEES AND DUGONGS

I'd always grouped the dugongs and manatees together. There are slight differences between these two groups. Both groups belong to the order Sirenia.

They shared a cousin in the Steller's sea cow, Hydrodamalis gigas, but that piece of their lineage was hunted to extinction by our species in the 18th century. Dugongs have tail flukes with pointed tips and manatees have paddle-shaped tails, similar to a Canadian Beaver.

Both of these lovelies from the order Sirenia went from terrestrial to marine, taking to the water in search of more prosperous pastures, as it were. They are the extant and extinct forms of the oddball manatees and dugongs.

We find dugongs today in waters near northern Australia and parts of the Indian and Pacific Oceans. They inhabit rivers and shallow coastal waters, making the best use of their fusiform bodies that lack dorsal fins and hind limbs. I've been thinking about them in the context of some of the primitive armoured fish we find in the Chengjiang biota of China, specifically those primitive species that were also fusiform.

They favour locations where seagrass, their food of choice, grows plentiful and they eat it roots and all. While seagrass low in fibre, high in nitrogen, and easily digestible is preferred, dugongs will also dine on lower grade seagrass, algae, and invertebrates should the opportunity arise. They've been known to eat jellyfish, sea squirts, and shellfish over the course of their long lives. Some of the oldest dugongs have been known to live 70+ years, which is another statistic I find surprising. They are large, passive, have poor eyesight, and look pretty tasty floating in the water; a defenseless floating buffet. Their population is in decline and yet they live on.

Thursday, 21 May 2020

DUGONG: SIRENIA

The dugong is a medium-sized marine mammal. It is one of four living species of the order Sirenia, which also includes three species of manatees. It is the only living representative of the once-diverse family Dugongidae; its closest modern relative, Steller's sea cow, was hunted to extinction in the 18th century.

While only one species of dugong is alive today – a second, the Steller's sea cow only left this Earth a few years ago. Sadly, it was hunted to extinction within 27 years of its discovery – about 30 species have been recovered in the fossil record

The first appearance of sirenians in the fossil record was during the early Eocene, and by the late Eocene, sirenians had significantly diversified. Inhabitants of rivers, estuaries, and nearshore marine waters, they were able to spread rapidly.

The most primitive sirenian known to date, Prorastomus, was found in Jamaica, not the Old World; however more recently the contemporary Sobrarbesiren has been recovered from Spain. The first known quadrupedal sirenian was Pezosiren from the early Eocene. The earliest known sea cows, of the families Prorastomidae and Protosirenidae, are both confined to the Eocene and were about the size of a pig, four-legged amphibious creatures. By the time the Eocene drew to a close, the Dugongidae had arrived; sirenians had acquired their familiar fully aquatic streamlined body with flipper-like front legs with no hind limbs, powerful tail with horizontal caudal fin, with up and down movements which move them through the water, like cetaceans.

The last of the sirenian families to appear, Trichechidae, apparently arose from early dugongids in the late Eocene or early Oligocene. The current fossil record documents all major stages in hindlimb and pelvic reduction to the extreme reduction in the modern manatee pelvis, providing an example of dramatic morphological change among fossil vertebrates.

Since sirenians first evolved, they have been herbivores, likely depending on seagrasses and aquatic angiosperms, tasty flowering plants of the sea, for food. To the present, almost all have remained tropical (with the notable exception of Steller's Sea Cow), marine, and angiosperm consumers. Sea cows are shallow divers with large lungs. They have heavy skeletons to help them stay submerged; the bones are pachyostotic (swollen) and osteosclerotic (dense), especially the ribs which are often found as fossils.

Eocene sirenians, like Mesozoic mammals but in contrast to other Cenozoic ones, have five instead of four premolars, giving them a 3.1.5.3 dental formula. Whether this condition is truly primitive retention in sirenians is still under debate.

Although cheek teeth are relied on for identifying species in other mammals, they do not vary to a significant degree among sirenians in their morphology but are almost always low-crowned —brachyodont — with two rows of large, rounded cusps — bunobilophodont. The most easily identifiable parts of sirenian skeletons are the skull and mandible, especially the frontal and other skull bones. With the exception of a pair of tusk-like first upper incisors present in most species, front teeth — incisors and canines — are lacking in all, except the earliest sirenians.

Wednesday, 20 May 2020

ANTHOZOA: CORALS

Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically live in compact colonies of many identical individual polyps.

Corals are important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.

A coral "group" is a colony of a myriad of genetically identical polyps. Each polyp is a sac-like animal typically only a few millimetres in diameter and a few centimetres in length. A set of tentacles surround a central mouth opening. Each polyp excretes an exoskeleton near the base. Over many generations, the colony thus creates a skeleton characteristic of the species which can measure up to several meters in size. Individual colonies grow by asexual reproduction of polyps. Corals also breed sexually by spawning: polyps of the same species release gametes simultaneously overnight, often around a full moon. Fertilized eggs form planulae, a mobile early form of the coral polyp which when mature settles to form a new colony.

Although some corals are able to catch plankton and small fish using stinging cells on their tentacles, most corals obtain the majority of their energy and nutrients from photosynthetic unicellular dinoflagellates of the genus Symbiodinium that live within their tissues. These are commonly known as zooxanthellae and gives the coral colour. Such corals require sunlight and grow in clear, shallow water, typically at depths less than 60 metres (200 ft). Corals are major contributors to the physical structure of the coral reefs that develop in tropical and subtropical waters, such as the Great Barrier Reef off the coast of Australia. These corals are increasingly at risk of bleaching events where polyps expel the zooxanthellae in response to stress such as high water temperature or toxins.

Other corals do not rely on zooxanthellae and can live globally in much deeper water, such as the cold-water genus Lophelia which can survive as deep as 3,300 metres (10,800 ft). Some have been found as far north as the Darwin Mounds, northwest of Cape Wrath, Scotland, and others off the coast of Washington State and the Aleutian Islands.

Tuesday, 19 May 2020

CANGREJO FÓSIL: COSTACOPLUMA

If you take a peek at this well-preserved fossilized crab, you can see the back section of his carapace composed of highly mineralized chitin.

Chitin is a polysaccharide — a large molecule made of many smaller monosaccharides or simple sugars, like glucose. It's handy stuff, forming crystalline nanofibrils or whiskers.

Chitin is actually the second most abundant polysaccharide after cellulose. It's interesting as we usually think of these molecules in the context of their sugary context but they build many other very useful things in nature — not the least of these are the hard outer shells or exoskeletons of our crustacean friends. There have been some wonderful studies published of late on the cuticular structure of crabs and in particular the Late Maastrichtian crab, Costacopluma mexicana, from deposits near the town of from near Paredón, Ramos Arizpe in what is now southern Coahuila (formerly Coahuila de Zaragoza), in north-eastern Mexico. We see this same species in the Upper Cretaceous Moyenne of Northeast Morocco and from the Pacific slope, Paleocene of California, USA. This beauty is in the collection of José F. Ventura‎.

While the crustacean cuticle has been the subject of study for over 250 years (Reaumur, 1712, in Drach, 1939), the focus of that early work has been the process of moulting. Because crabs and other crustaceans have a hard outer shell (the exoskeleton) that does not grow, they must shed their shells through a process called moulting. Just as we outgrow our shoes, crabs outgrow their shells.

In 1984, Roer and Dillaman took a whole new approach, instead looking at the exoskeleton as a mineralized tissue. The integument of decapod crustaceans consists of an outer epicuticle, an exocuticle, an endocuticle and an inner membranous layer underlain by the hypodermis. The outer three layers of the cuticle are calcified.

The mineral is in the form of calcite crystals and amorphous calcium carbonate. In the epicuticle, the mineral is in the form of spherulitic calcite islands surrounded by the lipid-protein matrix. In the exo- and endo-cuticles the calcite crystal aggregates are interspersed with chitin-protein fibres which are organized in lamellae. In some species, the organization of the mineral mirrors that of the organic fibres, but such is not the case in certain cuticular regions in the xanthid crabs.

Control of crystal organization is a complex phenomenon unrelated to the gross morphology of the matrix. Since the cuticle is periodically moulted to allow for growth, this necessitates a bidirectional movement of calcium into the cuticle during post-moult and out during premolt resorption of the cuticle.

These movements are accomplished by active transport affected by a Ca-ATPase and Na/Ca exchange mechanism. The epi- and exo-cuticular layers of the new cuticle are elaborated during pre-moult but do not calcify until the old cuticle is shed. This phenomenon also occurs in vitro in the cuticle devoid of living tissue and implies an alteration of the nucleating sites of the cuticle in the course of the moult.

We're still learning about the relationship between the mineral and the organic components of the cuticle, both regarding the determination of crystal morphology and about nucleation. While the Portunidae offers some knowledge of the mechanisms and pathways for calcium movement, we know nothing concerning the transport of carbonate. These latter areas of investigation will prove fertile ground for future work; work which will provide information not only on the physiology of Crustacea but also on the basic principles of mineralization. I'm interested to see what insights will be revealed in the years to come. Certainly, the bidirectional nature of mineral transport and the sharp temporal transitions in the nucleating ability of the cuticular matrix provide ideal systems in which to study these aspects of calcification.

Torrey Nyborg, Francisco J. Vega and Harry F. Filkorn, Boletín de la Sociedad Geológica Mexicana, Vol. 61, No. 2, Número especial XI Congreso Nacional de Paleontología, Juriquilla 2009 (2009), pp. 203-209. Coahuila paleo coordinates:25°32′26″N 100°57′2″W

Monday, 18 May 2020

CRABS AND CHITIN

Crabs are decapod crustaceans of the Phyllum Arthopoda. They inhabit all the world's oceans, many of our freshwater lakes and streams, and a call a few places on land home.

Crabs build their shells from highly mineralized chitin. Chitin gets around. It is the main structural component of the exoskeletons of many of our crustacean and insect friends. Shrimp, crab, and lobster all use it to build their exoskeletons.

Chitin is a polysaccharide — a large molecule made of many smaller monosaccharides or simple sugars, like glucose. It's handy stuff, forming crystalline nanofibrils or whiskers. Chitin is actually the second most abundant polysaccharide after cellulose. It's interesting as we usually think of these molecules in the context of their sugary context but they build many other very useful things in nature — not the least of these are the hard shells or exoskeletons of our crustacean friends.

Sunday, 17 May 2020

PROTOEASTER NODOSUS

If you happen to be swimming in the warm, shallow waters of the Indo-Pacific region, you may encounter one of the most charming of all the sea stars, Protoeaster nodosus.

These beauties are commonly known as Horned Sea Stars or, my personal favorite, Chocolate Chip Sea Stars.

They are part of the class Asteroidea (starfish or sea stars) one of the most diverse groups within the phylum Echinodermata and have a lengthy lineage in the fossil record stretching all the way back to the Triassic. These echinoderms make a living on near-shore sandy bottoms or lurk in the seagrass meadows of some of our most beautiful waters.

Chocolate Chip Sea Stars live in the waters off the Philippine Sea, off the coast of Australia and New Guinea. Their range extends to the Marshall Islands through central and southeastern Polynesia, past Easter Island and all the way up to Hawaii. Pretty much pick any of the top contenders for a warm, tropical vacation and they've beaten you to it!

This species of sea star has black rows of "horns" or "spines" meant to scare off predators. A noble deterrent for his fishy friends but I find this signature decoration rather fetching. These fellows like to graze on choice corals and sponges. They are also happy to make a meal of snails and bitter sea urchins when these ambrosial treats are presented. And they are social, both to mate, gathering in groups to aid in fertilization and acting as a softcover for shrimp, wee brittle stars and juvenile leatherjackets or filefish, who tuck in and enjoy the protective cover of those dark nodes.

Saturday, 16 May 2020

A TASTE FOR STUDIES

Green Sea Turtle, Chelonia mydas
While eating study specimens is not in vogue today, it was once common practice for researchers in the 1700-1880s. Charles Darwin belonged to a club dedicated to tasting exotic meats, and in his first book wrote almost three times as much about dishes like armadillo and tortoise urine than he did on the biogeography of his Galapagos finches.

One of the most famously strange scientific meals occurred on January 13, 1951, at the 47th Explorers Club Annual Dinner (ECAD) when members purportedly dined on a frozen woolly mammoth. The prehistoric meat was supposedly found on Akutan Island in Alaska, USA, by the eminent polar explorers' Father Bernard Rosecrans Hubbard, “the Glacier Priest,” and Captain George Francis Kosco of the US Navy.

This much-publicized meal captured the public’s imagination and became an enduring legend and source of pride for the Club, popularizing an annual menu of “exotics” that continues today, making the Club as well-known for its notorious hors d’oeuvres like fried tarantulas and goat eyeballs as it is for its notable members such as Teddy Roosevelt and Neil Armstrong.

The Yale Peabody Museum holds a sample of meat preserved from the 1951 meal, interestingly labeled as a South American Giant Ground Sloth, Megatherium, not Mammoth. The specimen of meat from that famous meal was originally designated BRCM 16925 before a transfer in 2001 from the Bruce Museum to the Yale Peabody Museum of Natural History (New Haven, CT, USA) where it gained the number YPM MAM 14399.

The specimen is now permanently deposited in the Yale Peabody Museum with the designation YPM HERR 19475 and is accessible to outside researchers. The meat was never fixed in formalin and was initially stored in isopropyl alcohol before being transferred to ethanol when it arrived at the Peabody Museum. DNA extraction occurred at Yale University in a clean room with equipment reserved exclusively for aDNA analyses.

In 2016, Jessica Glass and her colleagues sequenced a fragment of the mitochondrial cytochrome-b gene and studied archival material to verify its identity, which if genuine, would extend the range of Megatherium over 600% and alter views on ground sloth evolution. Their results showed that the meat was not Mammoth or Megatherium, but a bit of Green Sea Turtle, Chelonia mydas. So much for elaborate legends. The prehistoric dinner was likely meant as a publicity stunt. Glass's study emphasizes the value of museums collecting and curating voucher specimens, particularly those used for evidence of extraordinary claims. Not so long before Glass et al. did their experiment, a friend's mother (and my kayaking partners) served up a steak from her freezer to dinner guests in Castlegar that hailed from 1978. Tough? Inedible? I have it on good report that the meat was surprisingly divine.

Reference: Glass, J. R., Davis, M., Walsh, T. J., Sargis, E. J., & Caccone, A. (2016). Was Frozen Mammoth or Giant Ground Sloth Served for Dinner at The Explorers Club?. PloS one, 11(2), e0146825. https://doi.org/10.1371/journal.pone.0146825
at 17:48 

Friday, 15 May 2020

SOUTH AMERICAN TAPIR

South American Tapir, Tapirus terrestris
This little sweetie with his brown fur stripped and dotted with bits of white is a South American tapir, Tapirus terrestris.

He's a water baby and a relative of the rhinoceros. Tapir love the water. They play, swim, dive, and use it to protect themselves from predators.

Their feet are specially designed for swimming and walking on muddy shores. Each of their front feet has four splayed toes, a bit like having a fin or snowshoe on your feet. Their back feet have a similar design but with three toes. They nap and hide in the forest during the day and then head out at night to munch on leaves, shoots, fruit, and other green goodies in the Amazon Rainforest and the River Basin in South America, east of the Andes.

They can be found in Venezuela, Colombia, and the Guianas in the north to Brazil, Argentina, and Paraguay in the south, to Bolivia, Peru, and Ecuador in the west. Three species of Tapir call Columbia home and much of the scientific research is focussed on this area. They're also hiring if you'd like to get more involved. While many find them adorable, sadly, they are also appreciated for their beautiful coats. Their dwindling numbers are largely due to poaching for their meat and hide, as well as habitat destruction. If I had the means, I'd buy up a big chunk of land where they could roam free. Some folks are helping and you can, too. There is a Tapir Preservation Fund set-up to aid these cuties with additional habitat. I'll pop the link here so you can check them out. They have a Facebook page and on it, there is the sweetest video of a Tapir sitting in the waves watching the sunset. Do check it out. It's very sweet.

Tapir Specialist Group: https://tapirs.org/conservation/tsgcf/
TSG Brazil: Rua Lindóia, 79046-150 Campo Grande, Brazil / +55 67 3344-0240

Thursday, 14 May 2020

DRIFTWOOD CANYON: FOSSIL TAPIRS, HEDGEHOGS, BIRDS & FLOWERS

Early Eocene Tapir from Driftwood Canyon
Driftwood Canyon in British Columbia is known for its beautiful early Eocene plants. It's not surprising to find wonderful wee mammals making a living in this warm, wet, steamy rainforest setting 51 million years ago.

Today, Driftwood Provincial Park is about halfway between Prince George and Prince Rupert near the town of Smithers. The rocks that make up the strata here started out further to the south, riding geologic plates to their current location.

Along with the Tapir and a rather sweet hedgehog, we also find birds, insects, and a huge variety of fossil plants in these outcrops. Fossils of plant remains are rare but include up to 29 genera. The most common plant fossils found are leafy shoots of the dawn redwood, Metasequoia, and the floating fern Azolla primaeva as mats of plants or as isolated fossils.

Fossil fish from Driftwood Canyon in the Canadian Museum of Nature includes specimens collected in the 1930s; however, Driftwood Canyon fossils have only been studied since the 1950s.

The Driftwood Canyon fossil beds are best known for the abundant and well-preserved insect and fish fossils (Amia, Amyzon, and Eosalmo). The insects are particularly diverse and well preserved and include water striders (Gerridae), aphids (Aphididae), leafhoppers (Cicadellidae), green lacewings (Neuroptera), spittlebugs (Cercopidae), march flies (Bibionidae), scorpionflies (Mecoptera), fungus gnats (Mycetophilidae), snout beetles (Curculionidae), and ichneumon wasps.

A fossil species of green lacewing (Neuroptera, Chrysopidae) was recently named Pseudochrysopa harveyi to honour the founder of the park, Gordon Harvey. Fossil feathers are sometimes found and rare rodent bones are sometimes found in fish coprolites. Most recently, fossil palm beetles (Bruchidae) were described from the beds, confirming the presence of palms (Arecaceae) in the local environment in the early Eocene.

Alder, Alnus sp., still common today are also found, as well as the leaves or needles and seeds of pines, Pinus sp., the golden larch, Pseudolarix sp., cedars, Chamaecyparis and/or Thuja spp., redwood Sequoia sp., and rare Ginkgo and sassafras, Sassafras hesperia, leaves. A lovely permineralized pine cone Pinus driftwoodensis and associated 2-needle foliage were described from the site in the 1980s.

Rare flowers and the seeds of flowering plants have been collected, including Ulmus, Florissantia, and Dipteronia, a genus of trees related to maples, Acer. spp., that today grows in eastern Asia.

If you fancy a trip to Driftwood Canyon Provincial Park, follow Driftwood Road from Provincial Highway 16. A car park just off the road access leads to an interpretive sign and a bridge across Driftwood Creek. A short interpretive trail leads visitors to a cliff-face exposure of Eocene shales. Signate speaks to how these beds were deposited in an inter-montane lake. Interbedded within the shales are volcanic ash beds, the result of area volcanoes that were erupting throughout the life of the Eocene lake that produced the shales.

Wednesday, 13 May 2020

WOLVERINE RIVER DINOSAUR TRACKS

Jen Becker, British Columbia Paleontological Alliance Field Trip
In the summer of 2005, I joined Jen Becker, and fellow delegates from the British Columbia Paleontological Symposium for an impromptu late-night tour of Wolverine River, one of many prolific research sites of Lisa Buckley, a vertebrate paleontologist working in the Tumbler Ridge area of British Columbia.

There are two types of footprints at the Wolverine River Trackside –theropods (at least four different sizes) and ankylosaurs. The prints featured in this photo were laid down by some lumbering ankylosaurs out for a stroll in soft mud. Many of the prints are so shallow that they can only be recognized by the skin impressions pressed into the mud. We'd been up to the fossil sites in the day but wanted to come back in the evening to see them by lamplight. After a lovely dinner, we hiked up to Wolverine in the dark. We filled the tracks with water and lit them with warm yellow lamplight. Some clever soul brought a sound system and played spooky animal calls to add prehistoric ambiance. A truly amazing evening.

Tuesday, 12 May 2020

DARWIN AND THE GREAT DEBATE

Oxford University Museum of Natural History was established in 1860 to draw together scientific studies from across the University of Oxford.

On 30 June 1860, the Museum hosted a clash of ideologies that has become known as the Great Debate.

Even before the collections were fully installed, or the architectural decorations completed, the British Association for the Advancement of Science held its 30th annual meeting to mark the opening of the building, then known as the University Museum. It was at this event that Samuel Wilberforce, Bishop of Oxford, and Thomas Huxley, a biologist from London, went head-to-head in a debate about one of the most controversial ideas of the 19th century – Charles Darwin's theory of evolution by natural selection.

Notable collections include the world's first described dinosaur,  Megalosaurus bucklandii, and the world-famous Oxford Dodo, the only soft tissue remains of the extinct dodo. Although fossils from other areas have been assigned to the genus, the only certain remains of Megalosaurus come from Oxfordshire and date to the late Middle Jurassic. In 1824, Megalosaurus was the first genus of non-avian dinosaur to be validly named. The type species is Megalosaurus bucklandii, named in 1827.

In 1842, Megalosaurus was one of three genera on which Richard Owen based his Dinosauria. On Owen's direction, a model was made as one of the Crystal Palace Dinosaurs, which greatly increased the public interest for prehistoric reptiles. Subsequently, over fifty other species would be classified under the genus, originally because dinosaurs were not well known, but even during the 20th century after many dinosaurs had been discovered. Today it is understood these additional species were not directly related to M. bucklandii, which is the only true Megalosaurus species. Because a complete skeleton of it has never been found, much is still unclear about its build.

The Museum is as spectacular today as when it opened in 1860. As a striking example of Victorian neo-Gothic architecture, the building's style was strongly influenced by the ideas of 19th-century art critic John Ruskin. Ruskin believed that architecture should be shaped by the energies of the natural world, and thanks to his connections with a number of eminent Pre-Raphaelite artists, the Museum's design and decoration now stand as a prime example of the Pre-Raphaelite vision of science and art.

Monday, 11 May 2020

NORTHERN BC FOSSIL SITES

Heidi Henderson with Daniel & Charles Helm, Tumbler Ridge
In 2000, Mark Turner and Daniel Helm were tubing down the rapids of Flatbed Creek just below Tumbler Ridge.

As they walked up the shoreline excitement began to build as they quickly recognized a series of regular depressions as dinosaur footprints.

Their discovery spurred an infusion of tourism and research in the area and the birth of the Peace Region Palaeontology Society and Dinosaur Centre.

The Hudson's Hope Museum has an extensive collection of terrestrial and marine fossils from the area. They feature ichthyosaurs, a few marine reptiles, and some hadrosaur tracks. The tracks the boys found were identified the following year by Rich McCrae as those of a large quadrupedal dinosaur, Tetrapodosaurus borealis, an ichnotaxon liked to ankylosaurs.

Closer study and excavation of the area yielded a 25 cm dinosaur bone thus doubling the number of dinosaur bones known from British Columbia at the time. The dinosaur finds near Tumbler Ridge are significant. Several thousand bone fragments have been collected, recorded, and now reside within the PRPRC collections, making for one of the most complete assemblages for dinosaur material from British Columbia. Some of these precious fossil sites were buried underwater by the Site C Dam, depending on your view. The Dam destroyed one of the world's precious wildlife corridors and submerge valuable carbon sinks and agricultural land therein threatening fossil sites and food security in the North.

We have many marine reptiles and can even brag the largest specimen of Shonisaurus. Dr. Betsy (Liz) Nicholls, Rolex Laureate Vertebrate Palaeontologist from the Royal Tyrrell Museum, excavated and published on an ichthyosaur from the Upper Triassic Pardonet Formation, Shonisaurus sikanniensis. This big fellow is estimated to have grown to 21 metres (69 FT) in length, making him the largest marine reptile on record. Liz excavated the type specimen of Shonisaurus sikanniensis over three field sessions in one of the most ambitious fossil excavations ever ventured. Her efforts from 1999 through 2001, both in the field and lobbying back at home, paid off. Betsy published on this new species in 2004, the culmination of her life’s work and her last paper as we lost her to cancer in autumn of that year.

The true reveal for the paleontological significance is still to come. There are Triassic marine outcrops in northern British Columbia that extend from Wapiti Lake to the Yukon border. I'm excited about the future of paleontology in the region as more of these fruitful outcrops are discovered, collected and studied.

Sunday, 10 May 2020

CRETACEOUS HADROSAUR FROM ALBERTA

A rare and very beautifully preserved Cretaceous Hadrosaur Tooth. This lovely specimen is from one of our beloved herbivorous "Duck-Billed" dinosaurs from 68 million-year-old outcrops near Drumheller, Alberta, Canada, and is likely from an Edmontosaurus.

When you scour the badlands of southern Alberta, most of the dinosaur material you'll find are from hadrosaurs. These lovely tree-less valleys make for excellent-searching grounds and have led us to know more about hadrosaur anatomy, evolution, and paleobiology than for most other dinosaurs.

We have oodles of very tasty specimens and data to work with. We've got great skin impressions and scale patterns from at least ten species and interesting pathological specimens that provide valuable insights into hadrosaur behaviour. Locally, we have an excellent specimen you can visit in the Courtenay and District Museum on Vancouver Island, Canada. The first hadrosaur bones were found on Vancouver Island a few years back by Mike Trask, VIPS, on the Trent River near Courtenay.

The Courtenay hadrosaur is a first in British Columbia, but our sister province of Alberta has them en masse. Given the ideal collecting grounds, many of the papers on hadrosaurs focus on our Canadian finds. These herbivorous beauties are also found in Europe, South America, Mexico, Mongolia, China, and Russia. Hadrosaurs had teeth arranged in stacks designed for grinding and crushing, similar to how you might picture a cow munching away on the grass in a field. These complex rows of "dental batteries" contained up to 300 individual teeth in each jaw ramus. But even with this great number, we rarely see them as individual specimens.

They didn't appear to shed them all that often. Older teeth that are normally shed in our general understanding of vertebrate dentition, were resorped, meaning that their wee osteoclasts broke down the tooth tissue and reabsorbed the yummy minerals and calcium.

As the deeply awesome Mike Boyd notes, "this is an especially lucky find as hadrosaurs did not normally shed so much as a tooth, except as the result of an accident when feeding or after death. Typically, these fascinating dinosaurs ground away their teeth... almost to nothing."

In hadrosaurs, the root of the tooth formed part of the grinding surface as opposed to a crown covering over the core of the tooth. And curiously, they developed this dental arrangement from their embryonic state, through to hatchling then full adult.

There's some great research being done by Aaron LeBlanc, Robert R. Reisz, David C. Evans and Alida M. Bailleul. They published in BMC Evolutionary Biology on work that looks at the histology of hadrosaurid teeth analyzing them through cross-sections. Jon Tennant did a nice summary of their research. I've included both a link to the original journal article and Jon Tennant's blog below.

LeBlanc et al. are one of the first teams to look at the development of the tissues making up hadrosaur teeth, analyzing the tissue and growth series (like rings of a tree) to see just how these complex tooth batteries formed.

They undertook the first comprehensive, tissue-level study of dental ontogeny in hadrosaurids using several intact maxillary and dentary batteries and compared them to sections of other archosaurs and mammals. They used these comparisons to pinpoint shifts in the ancestral reptilian pattern of tooth ontogeny that allowed hadrosaurids to form complex dental batteries.

References:

LeBlanc et al. (2016) Ontogeny reveals function and evolution of the hadrosaurid dinosaur dental battery, BMC Evolutionary Biology. 16:152, DOI 10.1186/s12862-016-0721-1 (OA link)

To read more from Jon Tennant, visit: https://blogs.plos.org/paleocomm/2016/09/14/all-the-better-to-chew-you-with-my-dear/

Photo credit: Derrick Kersey. For more awesome fossil photos like this from Derrick, visit his page: https://www.facebook.com/prehistoricexpedition/

Saturday, 9 May 2020

PROSAUROLOPHUS MAXIMUS

Reconstruction of Prosaurolophus maximus
Prosaurolophus was a large-headed duckbill dinosaur. The most complete described specimen has a skull around 0.9 metres (3.0 ft) long on a skeleton about 8.5 metres (28 ft) long. It had a small, stout, triangular crest in front of the eyes; the sides of this crest were concave, forming depressions.

This crest grew isometrically (without changing in proportion) throughout the lifetime of the individual, leading to speculation that the species may have had a soft tissue display structure, such inflatable nasal sacs.

When originally described by Brown, Prosaurolophus maximus was known from a skull and jaw. Half of the skull was badly weathered at the time of examination, and the level of the parietal was distorted and crushed upwards to the side.

The different bones of the skull are easily defined with the exception of the parietal and nasal bones. Brown found that the skull of the already described genus Saurolophus is very similar overall but also smaller than the skull of P. maximus. The unique feature of a shortened frontal in lambeosaurines is also found in Prosaurolophus, and the other horned hadrosaurines Brachylophosaurus, Maiasaura, and Saurolophus. Although they lack a shorter frontal, the genera Edmontosaurus and Shantungosaurus share an elongated dentary structure.

Prosaurolophus maximus, Ottawa Museum of Nature
Patches of preserved skin are known from two juvenile specimens, TMP 1998.50.1 and TMP 2016.37.1; these pertain to the ventral extremity of the ninth through fourteenth dorsal ribs, the caudal margin of the scapular blade, and the pelvic region. Small basement scales (scales which make up the majority of the skin surface), 3–7 millimetres (0.12–0.28 in) in diameter, are preserved on these patches - this is similar to the condition seen in other saurolophine hadrosaurs.

More uniquely, feature scales (larger, less numerous scales which are interspersed within the basement scales) around 5 millimetres (0.20 in) wide and 29 millimetres (1.1 in) long are found interspersed in the smaller scales in the patches from the ribs and scapula (they are absent from the pelvic patches). Similar scales are known from the tail of the related Saurolophus angustirostris (on which they have been speculated to indicate pattern), and it is considered likely adult Prosaurolophus would've retained the feature scales on their flanks like the juveniles.

Image: Three-dimensional reconstruction of Prosaurolophus maximus. Created using the skull reconstructions in the original description as reference. (Fig. 1 and 3 in Brown 1916). According to Lull and Wright (1942), the muzzle was restored too long in its original description. This has been corrected for. The colours and/or patterns, as with nearly all reconstructions of prehistoric creatures, are speculative. Created & uploaded to Wikipedia by Steveoc 86.

Friday, 8 May 2020

DELGADOCRINUS OPORTOVINUM

This exceptionally well-preserved crinoid, Delgadocrinus oportovinum, was found on October 11, 1905, by Nery Delgado during his work mapping the geology and paleontology of Portugal.

His find resulted in the creation of a new family, Delgadocrinoinidae, a new genus and a new species.

Ausich et al. published on New and Revised Occurrences of Ordovician Crinoids from Southwestern Europe in the Journal of Paleontology, November 2007. In their work, they honour Delgado. His find was the first record of an Ordovician crinoid from Portugal, Delgadocrinus oportovinum, marking it as the oldest known crinoid from the Iberian Peninsula, Arenigian/Oretanian boundary, early Darriwilian.

The team took a comprehensive look at the Ordovician crinoids of southwestern Europe, including taxa based on articulated crowns and stems. This summary incorporates new material, new localities, and a revision of some southwestern Europe occurrences and is well worth a read. The Type Specimen you see here is now housed in the Natural History Museum of Lisbon. Luis Lima shared a photo of his recent visit to their beautiful collections and kindly granted permission to share the photo.

Reference: Ausich, William & Sá, Artur & Gutiérrez-Marco, Juan. (2007). New and revised occurrences of Ordovician crinoids from southwestern Europe. Journal of Paleontology - J PALEONTOL. 81. 1374-1383. 10.1666/05-038.1.

Thursday, 7 May 2020

ANCIENT SWAMPS AND SOLAR FLARES

If fossil fuels are made from fossils, are oil, gas and coal made from dead dinosaurs? Well, no, but they are made from fossils. We do not heat our homes or run our cars on dead hadrosaurs. No mighty T-Rex burns up your chimney, instead, for the most part, we burn very humble dead algae. Yep, plants. Really old ones.

I know, right? It sounds much less exciting, but the process by which algae and other plant life soak up the Sun's energy, store it for millions of years, then give it all up for us to burn as fuel is a pretty fantastic tale!

Fossil fuel is a fuel formed by a natural process, the anaerobic decomposition of buried dead organisms who soaked up and stored energy from ancient photosynthesis. Picture ancient trees, algae and peat soaking up the sun, then storing that energy for us to use millions of years later. These organisms and their resulting fossil fuels are millions of years old, sometimes more than 650 million years. That's way back in the day when Earth's inhabitants were mostly viruses, bacteria and some early multi-cellular jelly-like critters.

Fossil fuels consist mainly of dead plants – coal from trees, and natural gas and oil from algae, a diverse group of aquatic photosynthetic eukaryotic organisms I like to think of as pond scum. These deposits are called fossil fuels because, like fossils, they are the remains of plants and animals that lived long ago.

If we could go back far enough, we'd find that our oil, gas, and coal deposits are really remnants of algal pools, peat bogs and ancient muddy swamps. Dead plants and algae accumulate and over time, then pressure turns the mud and dead plants into rock. Geologists call the once-living matter in the rock kerogen. If they haven't been cooked too badly, we call them fossils.

Kerogen is the solid, insoluble organic matter in sedimentary rocks and it is made from a mixture of ancient organic matter. A bit of this tree and that algae all mixed together to form a black, sticky, oily rock. The Earth’s internal heat cooks the kerogen. The hotter it gets, the faster it becomes oil, gas, or coal. If the heat continues after the oil is formed, all the oil turns to gas. The oil and gas then seep through cracks in the rocks. Much of it is lost. We find oil and gas today because some happened to become trapped in porous, sponge-like rock layers capped by non-porous rocks. We tap into these the way you might crack into a bottle of olive oil sealed with wax.

Fossil fuel experts call this arrangement a reservoir and places like Alberta, Iran and Qatar are full of them. A petroleum reservoir or oil and gas reservoir is a subsurface pool of hydrocarbons contained in porous or fractured rock formations. Petroleum reservoirs are broadly classified as conventional and unconventional reservoirs. In the case of conventional reservoirs, the naturally occurring hydrocarbons, such as crude oil or natural gas, are trapped by overlying rock formations with lower permeability. In unconventional reservoirs, the rocks have high porosity and low permeability which keeps the hydrocarbons trapped in place, so these unconventional reservoirs don't need a rock cap.

Coal is an important form of fossil fuel. Much of the early geologic mapping of Canada (and other countries) was done for the sole purpose of mapping the coal seams. You can use it to heat your home, run a coal engine or sell it for cold hard cash. It's a dirty fuel, but for a very long time, most of our industries used it as the sole means of energy. But what is so bad about burning coal and other fossil fuels? Well, many things...

Burning fossil fuels, like oil and coal, releases large amounts of carbon dioxide and other gases into the atmosphere. They get trapped as heat, which we call the greenhouse effect. This plays havoc with global weather patterns and our world does not do so well when that happens. The massive end-Permian extinction event, the worst natural disaster in Earth's history — when 90% of all life on Earth died —  was caused by massive volcanic eruptions that spewed gas and lava, covering the Earth in volcanic dust, then acid rain. Picture Mordor times ten. This wasn't a culling of the herd, this was full-on decimation. I'll spare you the details, but the whole thing ended poorly.

Dirty or no, coal is still pretty cool. It is wild to think that a lump of coal has the same number of atoms in it as the algae or rain forest that formed it. Yep, all the same atoms, just heated and pressurized over time. When you burn a lump of coal, the same number of atoms are released when those atoms dissipate as particles of soot. You may wonder what makes a rock burn. It's not intuitive that it would be possible, and yet there it is. Coal is combustible, meaning it is able to catch fire and burn. Coal is made up mostly from carbon with some hydrogen, sulphur (smells like rotting eggs, stinky pew), oxygen and nitrogen thrown in.

It is just that the long-ago rain forest was far less dense than the coal you hold in your hand today, and so is the soot into which it dissipates once burned. The energy was captured by the algal pool or rain forest by way of photosynthesis, then that same energy is released when the coal is burnt. So the energy captured in gravity and released billions of years later when the intrinsic gravity of the coal is dissipated by burning. It's enough to bend your brain.

The Sun loses mass all the time because of its process of fusion of atomic content and radiating that energy as light. Our ancient rain forests and algal pools on Earth captured some of it. So maybe our energy transformations between the Earth and the Sun could be seen more like ping-pong matches, with energy, as the ball, passing back and forth.

As mass sucks light in (hello, photosynthesis), it becomes denser, and as mass radiates light out (hello, heat from coal), it becomes less dense. Ying, yang and the beat goes on.