PUNTLEDGE ELASMOSAUR

Puntledge Elasmosaur found by Mike Trask

This lengthy beauty is an elasmosaur, a large marine reptile now housed in the Courtenay and District Museum on Vancouver Island.

This specimen was found by Mike Trask and his daughter in the winter of 1988 while fossil collecting along the Puntledge River. While he couldn't have known it at the time, it was this discovery and those that followed that would spark a renewed interest in palaeontology on Vancouver Island and the province of British Columbia.

Mike had foraged ahead, adding chalk outlines to interesting fossil and nodules in the 83 million-year-old shales along the riverbank. His daughter, Heather, was looking at the interesting features he had just outlined when they both noticed some tasty blocks and concretions in situ just a few meters away. Taking a closer look, they were thrilled to discover that they held the bones of a large marine reptile.

Unsure of what exactly they'd discovered but recognizing them as significant, Mike reached out to Dr. Betsy Nicholls at the Royal Tyrell Museum.

It was Betsy who'd written up the incomplete specimen of fossil turtle, Desmatochelys cf. D. lowi — Reptilia: Chelonioidea — found by Richard Bolt, VIPS, in the shales of the Trent River Formation along the Puntledge River in the early 1990s. Dr. Nicholls wrote up the paper and published in the Canadian Journal of Earth Sciences in 1992.

At that time, it was the first documented account of a Cretaceous marine vertebrate from the Pacific coast of Canada, which shows you how much we've learned about our Pacific coast in just the last few years.

The Desmatchelys find inspired the 1999 BCPA Symposium conference logo. Every second year, the BCPA hosts a symposium. The 1999 conference at UBC was the first time the Vancouver Paleontological Society had hosted a BCPA conference. The conference abstract was graced with a trilobite embedded within a turtle, celebrating recent significant contributions to Canadian palaeontology.

Elasmosaur skull and teeth found by Mike Trask

When Mike showed her the bones he'd found, Betsy confirmed them to be that of an elasmosaur, a large marine reptile with a small head, razor-sharp teeth and a long neck  — and the first discovery of an elasmosaur west of the Canadian Rockies — another first. It was one of those moments that lights up and inspires a whole community.

When the bones were fully excavated, this 15-meter marine beauty underwent a year of preparation to reveal the skeleton you see here. You can visit the fully prepped specimen and see the articulated bones beneath a glass case in the Courtenay Museum on Vancouver Island.

The Puntledge Elasmosaur has graced the cover of Canada's stamps and was voted as British Columbia's Provincial Fossil in 2019. This honour has the Puntledge Elasmosaur cozied up to other provincial symbols and emblems that include the Pacific Dogwood, Jade, the Steller's Jay, Western Red Cedar, Spirit Bear and Pacific Salmon. The runner-up for BC's Provincial Fossil was Shonisaurus sikanniensis, a massive 21-metre ichthyosaur found in Triassic outcrops in northern British Columbia. That beauty is a worthy reminder of what hunted in our ancient oceans some 220 million years ago.

BCPA Symposium / Heidi Henderson, Mike Trask, Adam Melzak

Since that first moment of discovery, many wonderful events transpired. In the Fall of 1991, Mike Trask was teaching a course on paleontology at the North Island College.

Two of his students were Ann and Joe Zanbilowitz. With the classroom portion of the course finished up, the group set out for a fossil expedition on the Puntledge River. Within five minutes of their search, Joe found a few small articulated vertebrae that we now know to be the type specimen of the mosasaur, Kourisodon puntledgensis. That find, along with some of the other paleontological goodies from the area, prompted the formation of the Vancouver Island Palaeontological Society from an idea to a registered society in 1992. By 1993 membership had grown from a dozen to 250.

In 1992, the Vancouver Island Palaeontological Society passed a motion to encourage the formation of a provincial umbrella group to act as an advocate to promote interaction amongst various paleontological organizations. Through the efforts of Mike Trask, Dan Bowen, Rolf Ludvigsen and others, the first meeting of the Board of Directors of the B.C. Paleontological Alliance was held in 1993.

Mike Trask hiking up at Landslide Lake, British Columbia

In 1994 the membership of the VIPS split into three regional societies, the original VIPS, the new VanPS in Vancouver, and the new VIPMS, the Vancouver island Paleontological Museum Society based in Qualicum.

In 1995, the Victoria Palaeontological Society, the VicPS, was formed. This was followed by the Tumbler Ridge Foundation (TRMF) and opening of the Dinosaur Discovery Gallery in Tumbler Ridge.

The British Columbia Paleontological Alliance and various regional societies, particularly the Vancouver Island Palaeontological Society (VIPS), continue to make significant contributions to paleontology. We've now found the fossil remains of an elasmosaur and two mosasaurs along the banks of the Puntledge River, says Dan Bowen, Chair of the Vancouver Island Palaeontological Society.

The first set of about 10 mosasaurs vertebrae (Platecarpus) was found by Tim O’Bear and unearthed by a team of VIPS and Museum enthusiasts led by Dr. Rolf Ludvigsen. Dan Bowen and Joe Morin of the VIPS later prepped these specimens for the Museum.

In 1993, just a few years later, a new species of mosasaur, Kourisodon puntledgensis, a razor-toothed mosasaur, was found upstream of the elasmosaur site by Joe Zembiliwich on a field trip led by Mike Trask. A replica of this specimen now calls The Canadian Fossil Discovery Centre in Morden home.
What is significant about this specimen is that it is a new genus and species. At 4.5 meters, it is a bit smaller than most mosasaurs and similar to Clidastes, but just as mighty.

Comox Valley Elasmosaur / Dino Stamps of Canada

Interestingly, this species has been found in this one locality in Canada and across the Pacific in the basal part of the Upper Cretaceous — middle Campanian to Maastrichtian — of the Izumi Group, Izumi Mountains and Awaji Island of southwestern Japan. We see an interesting correlation with the ammonite fauna from these two regions as well.

The Courtenay and District Museum, the community surrounding it and allied organizations like the Vancouver Island Palaeontological Society (VIPS), have a lot to be proud of. Their outreach and educational programs continue to inspire young and old alike. These discoveries led to the expansion of the local museum, the elasmosaur excavation area becoming a provincial heritage site and the impetus for many, many teaching programs since.

Oh, and Mike Trask — he continues to be deeply awesome, intuitive and exceptionally observant. The good Master Trask went on to find the first hadrosauroid in the province. While Alberta is littered with them, a Hadrosauroid dinosaur is a rare occurrence in this part of Canada and further evidence of the terrestrial influence in the Upper Cretaceous, Nanaimo Group of Vancouver Island. Perhaps one day we'll be seeing a duck-billed dinosaur from British Columbia gracing Canada's stamps. Fancy that.

References: Nicholls, E. L. and Meckert, D. (2002). Marine reptiles from the Nanaimo Group (Upper Cretaceous) of Vancouver Island. Canadian Journal of Earth Science 39(11):1591-1603.
Tanimoto, M. (2005). "Mosasaur remains from the Upper Cretaceous Izumi Group of Southwest Japan" (PDF). Netherlands Journal of Geosciences. 84: 373–378. doi:10.1017/s0016774600021156.
Ferocious new mosasaur skeleton coming to Morden | CBC News". CBC. Retrieved 2018-07-16.

BCPA Regional Paleontology Societies: https://bcfossils.ca/regional-societies

FROM RUSSIA WITH LOVE: INDOSPHINCTES

Stunning preservation on this lovely microconch of the ammonite, Indosphinctes (Elatmites) aff. submutatus (Nikitin, 1881), from Jurassic, Middle Callovian outcrops of the Kosmoceras jason zone near the Oka River. The exposures are near the city of Elatma in the Ryazan Region of central Russia. 

This specimen is 70 mm at the widest part of the ammonite and is the smaller male form of this species. 

Ryazan Oblast borders Vladimir Oblast (N), Nizhny Novgorod Oblast (NE), the Republic of Mordovia (E), Penza Oblast (SE), Tambov Oblast (S), Lipetsk Oblast (SW), Tula Oblast (W), and Moscow Oblast (NW).

Ryazan Oblast lies in the central part of the Russian Plain between the Central Russian and Volga uplands. The terrain is flat — with the highest point being no more than 300 m above sea level. The soils here are podzolic and boggy on the banks of the Oka. further to the south, they become more fertile with podzolic and leached black-earths. This specimen is in the collection of the deeply awesome Emil Black. 

DEVONIAN MORTALITY PLATE: ZENASPIS

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

Zenaspis is an extinct genus of jawless fish which thrived during the early Devonian. Being jawless, Zenaspis was probably a bottom feeder, snicking on debris from the seafloor.

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, the 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) are up to 1800 m thick and range from Lochkovian to Eifelian in age (Narbutas 1984; Drygant 2000, 2003). In their lower part (Ustechko and Khmeleva members of the Dniester Series) they consist of multicoloured, mainly red, fine-grained cross-bedding massive quartz sandstones and siltstones with seams of argillites (Drygant 2000).

We also see fossils 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 the awesome Fossilero Fisherman.

FOSSIL HUNTRESS PODCAST

After much thinking and dreaming — the Fossil Huntress Podcast is now live. This is pure geeky goodness from the Fossil Huntress in personal bite-sized bits. 

If you love palaeontology, you'll love this podcast. Learn about fossils, head out on some virtual fossil field trips and palaeontological excavations, meet some truly awesome palaeo folk and share in the passion of fossils. 

We'll talk about what fossils are, who collects them and how to tell if you've found a fossil. You'll also learn the palaeontological history of the province of British Columbia, our regional societies and how the Huntress found her passion.

You can listen on Google Podcasts, Apple iTunes, Anchor, Spotify, Breaker, RadioPublic, Overcast and Pocket Casts right now. If you have ideas for an episode, feel free to send me a message on the Fossil Huntress page on Facebook or drop me a DM on Twitter or Instagram. I'm super excited to share all kinds of geeky goodness with you. I hope it lifts you up and gets you curious about the world so you'll join me on many exciting adventures.

Podcast Link: Fossil Huntress — Paleo Sommelier: https://anchor.fm/fossil-huntress

TRILACINOCERAS NORVEGICUM

A lovely example of Trilacinoceras norvegicum (Sweet, 1958), a nektonic carnivorous cephalopod from Ordovician outcrops on Helgö Island, Hovindsholm, Helgøya, Lake Mjosa, Norway.

This has been a site of human habitation for more than 5,000 years. Vikings, kings, traders, farmers —  and geologists have walked these fields.

To give that timeframe a bit of context, that's about the age of Skara Brae, the Neolithic settlement in Orkney, Scotland — and older than Stonehenge which clocks in at 3000 BC to 2000 BC and the Great Pyramids — built around 2560 BC.

For my friend, Gale Bishop, that's about 469 km west or a good 7-hour drive from your ancestral home in Ask, just north of Bergen and just south of Knarvik where many of my relatives live — Hei du!

The fossils found here are part of the Engervik Member, Elnes Formation, Aseri, and date back to the Middle Ordovician, 463.5 - 460.9 million years ago. W. C. Sweet did fossil fieldwork here in the 1950s and published a paper on the Middle Ordovician of the Oslo Region, Norway 10. Nautiloid Cephalopods. Norsk Geologisk Tidsskrift 38:1-178.

Deservedly, Sweetoceras boreale is named for him and is one of the most delightful species names of all time. In the 1960s, Yochelson picked up where Sweet left off, continuing the survey of the Middle Ordovician of the Oslo region. I chose this Trilacinoceras for a holiday post because their curly tops remind me of a wee Norwegian gnome, or Nisse from the Norse niðsi, a dear little relative. My Swedish relatives call them Tomte, a throwback to Saint Birgitta of Sweden in the 1300s.

Helgøya is an island in Mjøsa located in the Ringsaker municipality of Hedmark county, Norway. It was formerly a part of the Nes municipality. And long before that, it was the ruling centre for the Kings in Hedmark, where bold men and women held great blót celebrations to Odin and planned raids and expansion into Europe and Russia — roughly A.D. 793 — the beginning of the Viking Age.

Today, it is lush and green and easy to explore — or fish. Mjøsa is Norway's largest lake, as well as one of the deepest lakes in Norway and in Europe. Battles have been fought on its waters and its depths hold interesting archaeological and paleontological secrets. They also hold a goodly amount of large and tasty trout, pike, perch, burbot and graylings.

Helgøya is the largest freshwater island in Norway at 18.3 km². The island is delightful to explore and home to 32 farms. One of the most beautiful of these is the Hovinsholm manor. You can visit the farm in both summer and winter (both equally beautiful) and enjoy a café, workshop or their Christmas market. They have lush gardens and some very friendly horses you can pet — or spoil with apples, as you do. The property is massive at 2012 acres, divided into grain, potatoes and forest. It has been home to kings and court. It was a monastery in the Middle Ages from the 5th to the 15th century. Today, Tolle Hoel Slotnæs, and his wife, Charlotte Holberg Sveinsen own and run the manor with their three daughters.

Hovinsholm, Helgøya, Lake Mjosa, Norway

Helgøya means, "Holy Island," in Norwegian. There is a lovely double meaning here and such layered history. The manor, in its various iterations, has been on this site since the 1500s. They had their own Christian manor church until 1612.

On the southern tip of the island, there is an old pagan temple to the Norse Gods, Thor, Frigg, Loki, Hod, Heimdall, Tyr, and Baldur.

Here, farmers of the area would gather at four blót sacrifices a year that followed the seasons, one for each of the winter solstice, spring equinox, summer solstice and autumn equinox. Animals would be sacrificed, their blood splattered on altars, walls and folk around them. Toasts were made. The first was in honour of Thor or Odin, “to the king and victory.” Odin, although nominally chief of the gods, was more the god of aristocrats. If a king were toasting, particularly a Danish King, it would be for Odin. If you look at place names in Scandinavia, you'll see him conspicuously absent in favour of Thor, the god of the common man.

When the farmers at Helgøya were shouting "Skål," it was likely for Thor. The toasting and drinking continued with cups emptied for Njörd and Freyr and Freyja in the hope of securing a prosperous future. Finally, personal pledges (and beer-soaked boasts) would be made to undertake great exploits, Valknut — to die well in battle — and finally to kinsmen laid to rest now drinking with the gods in Valhalla. Weapons, jewellery and tools were thrown into the lake as offerings.

If they were gathering for Jol (Old Norse), Jul (Norwegian) or the Yule blót, they'd also make a large sun wheel (picture a circle with a cross in the middle), carve it up with runes, set it on fire and roll it down a hill. It was quite a celebration with the festivities going on for three days and nights. With the formalities over, people did as people do  — drink, sing, boast, play games and find someone to bed down with — Gods be good.

Thor and Odin are still going strong nearly 1,000 years after the end of the Viking Age. You'd think that the old Nordic religion — the belief in the Norse gods — disappeared with the introduction of Christianity. That is not the case. There are still folk in Denmark (Odin-lovers) and Norway (Thor's their guy) who follow the old Norse religion and worship its ancient gods — right down to the splatter.

If you visit Norway at Christmas, Jul (Yule), you'll find much more of the pagan than the Christian in the festivities. King Haakon, old Haakon the Good, Hákon Góði or Håkon den Gode,  moved the Winter Solstice or Yule, Jul, Jol blót over to match up with the Christian holiday (December 25th) in his attempts to introduce Christianity in the 10th century but both traditions are still celebrated but without an overtly religious tone.

Old traditions run deep, animals are still sacrificed (but without all the splatter), bread is baked, houses cleaned, beer is abundant and fires warmth the hearth.

After all the drinking, toasting and feasting at the Jul blót, leftover food was not cleaned up but left overnight for the little relatives. Though shy, Nisse like a good feast and failing to offer them their tithe brings ill-fortune.

But we started this journey together admiring a lovely (and oddly festive) Ordovician cephalopod. Go on, picture him in red and white with a little beard. If you fancy a visit to the Ordovician outcrops, you can find them at Nes-Hamar, Norway. 60.0° N, 11.2° E: paleo-coordinates 33.7° S, 10.3° W. Look for gastropods (five known species) and cephalopods (at least 15 species).

If you'd like to visit the burial mound of Haakon the Good, you'll want to head to Seim, Hordaland, about 10 km north of Knarvik. Good 'ol Haakon may have tried to bring Christianity to Norway but he died full Viking — taking an arrow at the Battle of Fitjar. Many of my rellies live in Knarvik. We've spent many a sunny afternoon feasting at the Håkonarspelet summer festivals and exploring Haakon's burial mound at Håkonhaugen in Seim.

If you're more of the manor type, you can stop by Hovinsholm gård, Helgøyvegen 850, 2350 Nes på Hedmarken, Norway. If you're curious and want to see the farmstead, head on over to: https://www.skafferiet.no/about. If you need to square things up with Odin, you're on your own.

E. L. Yochelson. 1963. The Middle Ordovician of the Oslo Region, Norway. 15. Monoplacophora and Gastropoda. Norsk Geologisk Tidsskrift 43 (2):133-213.

BARNACLES: CUVIER TO DARWIN

Barnacles All Closed Up

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.

BARNACLES IN KWAK'WALA

In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, barnacles are known as k̕wit̕a̱'a and broken barnacle shells are known as t̕sut̕su'ma.

BARNACLES IN THE FOSSIL RECORD

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).

Barnacle Ancestry Goes Back to the Middle Cambrian

FROM MOLLUSCA TO ARTICULATA

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 IN A NUT SHELL

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.

PERCHED IN THE MIST: PUFFINS

This lovely fellow perched in the mist is a Puffin. They hunt and munch on small fish, eels, herring, hake and capelin. 

Their diet varies to their geographic location — and like any good foodie — depends on what's in season. 

Puffins are any of three small species of alcids or auks in the bird genus Fratercula with a brightly coloured orange beak during the breeding season. 

Their sexy orange beaks shift from a dull grey to bright orange when it is time to attract a mate. While not strictly monogamous, most Puffins choose the same mate year upon year producing adorable chicks or pufflings from their mating efforts. 

Female Puffins produce one single white egg which the parents take turns to incubate over a course of about six weeks. Their dutiful parents share the honour of feeding the wee pufflings five to eight times a day until the chick is ready to fly. Towards the end of July, the fledgeling Puffins begin to venture from the safety of their parents and dry land. Once they take to the seas, mom and dad are released from duty and the newest members of the colony are left to hunt and survive on their own.

These are pelagic seabirds that feed primarily by diving in the water. They breed in large colonies on coastal cliffs or offshore islands, nesting in crevices among rocks or in burrows in the soil. Two species, the tufted puffin and horned puffin are found in the North Pacific Ocean, while the Atlantic puffin is found in the North Atlantic Ocean. This lovely fellow, with his distinctive colouring, is an Atlantic Puffin or "Sea Parrot" from Skomer Island near Pembrokeshire in the southwest of Wales. Wales is bordered by Camarthenshire to the east and Ceredigion to the northeast with the sea bordering everything else. It is a fine place to do some birding if it's seabirds you're after.

These Atlantic Puffins are one of the most famous of all the seabirds and form the largest colony in Southern Britain. They live about 25 years making a living in our cold seas dining on herring, hake and sand eels. 

Some have been known to live to almost 40 years of age. They are good little swimmers as you might expect, but surprisingly they are great flyers, too! The evolutionary gods were not kind in their flight design. They are hindered by short wings, making flight a bit of a challenge but still possible. Once they get some speed on board, they can fly up to 88 km an hour.

The oldest alcid fossil is Hydrotherikornis from Oregon dating to the Late Eocene while fossils of Aethia and Uria go back to the Late Miocene. Molecular clocks have been used to suggest an origin in the Pacific in the Paleocene. Fossils from North Carolina were originally thought to have been of two Fratercula species but were later reassigned to one Fratercula, the tufted puffin, and a Cerorhinca species. Another extinct species, Dow's puffin, Fratercula dowi, was found on the Channel Islands of California until the Late Pleistocene or early Holocene.

The Fraterculini are thought to have originated in the Pacific primarily because of their greater diversity there; there is only one extant species in the Atlantic, compared to two in the Pacific. The Fraterculini fossil record in the Pacific extends at least as far back as the middle Miocene, with three fossil species of Cerorhinca, and material tentatively referred to that genus, in the middle Miocene to late Pliocene of southern California and northern Mexico.

Although there no records from the Miocene in the Atlantic, a re-examination of the North Carolina material indicated that the diversity of puffins in the early Pliocene was as great in the Atlantic as it is in the Pacific today. This diversity was achieved through influxes of puffins from the Pacific; the later loss of species was due to major oceanographic changes in the late Pliocene due to closure of the Panamanian Seaway and the onset of severe glacial cycles in the North Atlantic.

MANATEE AND CALF

Manatee and calf

Female manatees usually have one calf every two to five years. The calf swims alongside his Mamma for two years or more, munching on greenery. 

Once full-grown at a whopping 5,44 kilograms or 1,200 pounds, this little fellow will eat ten percent of his body weight in plant mass every day. 

Calves nurse from their mother’s teats, which are found right where the forward limbs meet the body. The calves also can start nibbling on plants at only a few weeks old.

STELLAR SEA COW

This adorable aquatic vacuum is a dugong. I had always grouped the dugongs and manatees together. There are slight differences between these two but both 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 — similar to whales — 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 have 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 have 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 defenceless floating buffet. Their population is in decline and yet they live on.

DUGONG: SIRENIA

One of the most delightful creatures to ever grace this planet is the dugong — a species of sea cow found throughout the warm latitudes of the Indian and western Pacific Oceans. 

It is one of four living species of the order Sirenia, which also includes three species of manatees — their large, fully aquatic, mostly herbivorous marine mammal cousins.

The closest living relatives of sirenians are elephants. Manatees evolved from the same land animals as elephants over 50 million years ago. If not for natural selection, we might have a much more diverse showing of the Sirenia as their fossil lineage shows a much more diverse group of sirenians back in the Eocene than we have today. 

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 the 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.

SERENGETI OF TEXAS

Eighty years ago, during the Great Depression, unemployed Texans were put to work as fossil hunters. 

The fossils collecting program was part of the State-Wide Paleontologic-Mineralogic Survey that was funded by the Works Progress Administration (WPA), a federal agency that provided work to millions of Americans during the Great Depression. 

From 1939 to 1941, the agency partnered with the UT Bureau of Economic Geology, which supervised the work and organized field units for collecting fossils and minerals across the state. Despite lasting only three years, the program was responsible for the excavation of thousands of fossils from across Texas including four dig sites in Bee and Live Oak counties, with the majority of their finds housed in what is now the Texas Vertebrate Paleontology Collections at the Jackson School Museum of Earth History. 

If you are like me, this sounds like a wonderful idea and work akin to paradise. You will be shocked to know that there were grumblings of malcontent by some of the workers. And yet, happy or sad, those lovely folk unearthed tens of thousands of specimens 80 years ago that only now are being studied in their complete context. 

The collection is housed in the state collections of The University of Texas at Austin and for the past few years, Steven May, a UT researcher, has been poking through those drawers with a special interest in specimens from dig sites near Beeville, Texas. 

Over the years, a number of scientific papers have been published on select groups of WPA specimens. But May's paper is the first to study the entire fauna. This extensive collection of fossils is helping to fill in gaps in the state's ancient environment.

The fauna from this area paints a picture of our modern-day Serengeti — with specimens including elephant-like animals, rhinos, alligators, antelopes, camels, 12 types of horses and several species of carnivores. In total, the fossil trove contains nearly 4,000 specimens representing 50 animal species, all of which roamed the Texas Gulf Coast 11 million to 12 million years ago.

In addition to shedding light on the inhabitants of an ancient Texas ecosystem, the collection is also valuable because of its fossil firsts. They include a new genus of gomphothere, an extinct relative of elephants with a shovel-like lower jaw, and the oldest fossils of the American alligator and an extinct relative of modern dogs.

The emphasis on big mammals is due in large part to the collection practices of the fossil hunters, most of whom were not formally trained in palaeontology. Large tusks, teeth and skulls were easier to spot — and more exciting to find — than bones left by small species.

"They collected the big, obvious stuff," May said. "But that doesn't fully represent the incredible diversity of the Miocene environment along the Texas Coastal Plain."

In order to account for gaps in the collection, May tracked down the original dig sites so he could screen for tiny fossils such as rodent teeth. One of the sites was on a ranch near Beeville owned by John Blackburn. Using aerial photography and notes from the WPA program stored in the university's archives, May and the research team were able to track down the exact spot of an original dig site.

"We're thrilled to be a part of something that was started in 1939," Blackburn said. "It's been a privilege to work with UT and the team involved, and we hope that the project can help bring additional research opportunities."

Reference: Steven R. May. The Lapara Creek Fauna: Early Clarendonian of south Texas, USA. Palaeontologia Electronica, 2019 DOI: 10.26879/929

MESOZOIC BIRDS OF THE JEHOL BIOTA

The Fossil Birds of the Jehol Biota have caused an international stir amongst palaeontologists. The Jehol outcrops of northeastern China has unearthed some of the most important Mesozoic bird specimens worldwide over the past two decades.

This is a tale of how that all began. Back in November 1993, Chinese palaeontologists Hou Lianhai and Hu Yoaming, of the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing received a call from an excited local fossil collector.

He claimed to have quite a remarkable specimen on his hands. The team visited Zhang He at his home in Jinzhou, or Chinchow, a coastal prefecture-level city in central-west Liaoning province

Zhang showed them a spectacular fossil bird specimen he'd recently purchased at a local flea market. Very little was known about the specimen but it was clearly important and the team was hopeful more of this paleo goodness might turn up.

They didn't have that long to wait. A month after his visit to Zhang, Hou learned about a second specimen discovered by a local farmer, Yang Yushan. Things were looking up. Best of all, he learned that both specimens were likely from the same locality in Shangyuan, Beipiao. This was not a one-off discovery or an amazing but anonymous find. With two specimens to compare, the locality determined, the possibility of an interesting publication and career advancement would be a reality.

In 1995, the two specimens, as well as a third, were formally described as a new genus and species, Confuciusornis sanctus, by Hou and colleagues. The generic name combines the philosopher Confucius with a Greek ὄρνις, (ornis), "bird". The specific name means "holy one" in Latin and is a translation of Chinese 圣贤, shèngxián, "sage", again in reference to Confucius.

The first discovered specimen was designated the holotype and catalogued under the specimen number IVPP V10918; it comprises a partial skeleton with skull and parts of the forelimb.

Of the other two skeletons, one (paratype, IVPP V10895) comprises a complete pelvis and hind limb, and the other (paratype, IVPP V10919–10925) a fragmentary hind limb together with six feather impressions attached to both sides of the tibia or shin bone.

All was well until those reading the journal articles realized that the two paratype specimens only comprise bones that were unknown from the holotype. An oversight, likely by design, but this lack of overlap between the specimens made their referral to the species speculative. The lack of overlap also gave a wide margin for error in the naming of additional, albeit hopeful, new species names — names that would later need to be amended. Luckily, the discovery of a veritable treasure trove of well-preserved specimens shortly after confirmed that the specimens indeed represented a single species.

Together with the early mammal Zhangheotherium, which was discovered about the same time, Confuciusornis was considered the most remarkable fossil discovery of the Jehol biota.

It has also given us another fossil-rich Lagerstätte that includes a wonderful mix of advanced and ancient species. My speculation is that northeast Asia was isolated for part of the Jurassic by the Turgai Sea that separated Europe from Asia at that time. The fossils at Jehol are numerous and exceptionally well preserved. Think of the Cambrian goodies at Burgess or the Altmühltal Formation, Jurassic Konservat-Lagerstätte at Solnhofen. Quite remarkably, fully articulated skeletons, soft tissues, colour patterns, stomach contents, and twigs with leaves and flowers still attached, can be found within the Jehol biota.

A beautifully preserved Archaeopteryx

In the late 1990s, Confuciusornis was considered both the oldest beaked bird as well as the most primitive bird after Archaeopteryx. It was also considered to be only slightly younger than Archaeopteryx. 

Yixian Formation, the rock unit where most Confuciusornis specimens have been found, was thought to be of Late Jurassic (Tithonian) age at the time.

Although two bird genera, Sinornis and Cathayornis, had already described from the Jehol biota back in 1992, these were based on fragmentary remains and stem from the younger Jiufotang Formation. At the time, the Jiufotang was thought to be Early Cretaceous. Both formations have since been dated to the Lower Cretaceous — Barremian to Aptian — 131–120 million years ago.

In 1995, local farmers began digging for fossils near the village of Sihetun, Beipiao, in what would become one of the most productive localities of the Jehol biota. The then largely unknown site is truly world-class. Large-scale professional excavations at this single locality have been carried out by the IVPP from 1997 onwards. Not one, not two, but several hundred specimens of Confuciusornis have now been unearthed from here. Many additional sites producing fossils of the Jehol biota have been recognized since, distributed over a large region including Liaoning, Hebei, and Inner Mongolia.

Due to the great abundance, preservation, and commercial value of the fossils, excavations by local farmers produced an unusually high number of fossils. Although some of these fossils have been added to the collections of Chinese research institutions, more have been smuggled out of the country.

In 1999, it was estimated that the National Geological Museum of China in Beijing housed nearly a hundred (100) specimens of Confuciusornis, and in 2010, the Shandong Tianyu Museum of Nature was reported to possess five hundred and thirty-six (536) specimens. While it is illegal to export them, the majority of specimens are still held privately and thus are not available for research. I see them on social media and occasionally they come up for sale on eBay.

At one time forty individuals were discovered on a surface of about 100 m2. This unusual bone bed was likely the result of an entire flock of birds being simultaneously killed by ash, heat or poisonous gas following the volcanic eruptions that caused the tuff stone in which the fossils were found to be deposited as lake sediments. An avian death bed is highly unusual. Very sad for our feathered friends but grateful for what has been revealed by this rare event.

Notes: Confuciusornis chuonzhous was named by Hou in 1997 based on specimen IVPP V10919, originally a paratype of Confuciusornis sanctus. The specific name refers to Chuanzhou, an ancient name for Beipiao. Confuciusornis chuonzhous is now generally considered synonymous with Confuciusornis sanctus.

Confuciusornis suniae, named by Hou in the same 1997 publication, was based on specimen IVPP V11308. The specific name honours Madam Sun, the wife of Shikuan Liang who donated the fossil to the IVPP. Confuciusornis suniae is now usually considered synonymous with Confuciusornis sanctus.

Reference: Zhou, Z; Hou, L. (1998). "Confuciusornis and the early evolution of birds". Vertebrata PalAsiatica. 36 (2): 136–146.

Zhou, Z. (2006). "Evolutionary radiation of the Jehol Biota: chronological and ecological perspectives". Geological Journal. 41 (3–4): 377–393. doi:10.1002/gj.1045.

SNAILS, SLUGS AND LIMPETS

Gastropods 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 and 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 FUELS AND THE EARTH'S MASS

A bright, beautiful young mind asked the question, "does Earth's mass decrease when we burn fossil fuels? And if it does, is it measurable? Do we know how much of the Earth’s mass has been lost so far?"

Well, Melaina, the Earth’s mass does decrease when fossil fuels are burnt. But not in the sense you were probably imagining, and only to a very, very small degree.

There is no decrease in chemical mass. Burning fossil fuels rearranges atoms into different molecules, in the process releasing energy from chemical bonds, but in the end, the same particles — protons, neutrons, and electrons — remain, so there is no decrease in mass there.

But energy is released, and some of that energy is radiated out into space, escaping from the Earth entirely. Einstein's Theory of Relativity tells us that energy does have mass: E=mc^2, or m=E/c^2. When a chemical bond that stores energy is formed, the resulting molecule has a very tiny bit more mass than the sum of the masses of the atoms from which it was formed, so a net gain. Wait, what?

Again, this is an exceedingly tiny bit. In very rough numbers, worldwide energy consumption is about 160,000 terawatt-hours per year, and about 80% of that comes from fossil fuels. That is about 450,000,000 TJ/year (tera-joules/year). The speed of light is 300,000,000 meter/s; dividing 450,000,000 TJ by (300,000,000 m/s)^2 gives a decrease in mass of 5000 kilograms per year.

That is an exceedingly small fraction — 50 billionths of one percent — of the approximately 10,000,000,000,000 kilograms of fossil fuels consumed per year. And as far as making the Earth lighter, it’s a tenth of a billionth of a billionth of a percent of the Earth’s mass.

Of course, the energy in fossil fuels originally came from the Sun, and in absorbing that sunlight the Earth’s mass increases slightly. I picture the Earth expanding and contracting, taking a deep breath, then exhaling. We don't see this when we look, but it is a great visual for imaging this never-ending give and take process. I'm not sure how we'd measure the small changes to the Earth's net mass on any given day. The mass of the Earth may be determined using Newton's law of gravitation. It is given as the force (F), which is equal to the Gravitational constant multiplied by the mass of the planet and the mass of the object, divided by the square of the radius of the planet.

Newton's insight on the inverse-square property of gravitational force was from an intuition about the motion of the earth and the moon. The mathematical formula for gravitational force is F=GMmr2 F = G Mm r 2 where G is the gravitational constant. I know, Newton’s law could use some curb appeal but it is super useful when understanding what keeps the Earth and other planets in our solar system in orbit around the Sun and why the Moon orbits the Earth. We have Newton to thank for his formulas on the gravitational potential of water when we build hydroelectricity dams. Newton’s ideas work in most but not all scenarios. When things get very, very small, or cosmic, gravity gets weird... and we head on back to Einstein to make sense of it all.

There was a very cool paper published yesterday by King Yan Fong et al. in the journal Nature that looked at heat transferring in a previously unknown way — heat transferred across a vacuum by phonons — tiny, atomic vibrations. The effect joins conduction, convection and radiation as ways for heating to occur — but only across tiny distances. The heat is transferred by phonons — the energy-carrying particles of acoustic waves, taking advantage of the Casimir effect, in which the quantum fluctuations in the space between two objects that are really, really close together result in physical effects not predicted by classical physics. This is another excellent example of the universe not playing by conventional rules when things get small. Weird, but very cool!

But the question was specifically about the mass of the Earth and the burning of fossil fuels, and that process does decrease the mass.

So it is mostly true that the Earth’s mass does not decrease due to fossil fuel burning because the numbers are so low, but not entirely true. The fuel combines with oxygen from the atmosphere to produce carbon dioxide, water vapour, and soot or ash. The carbon dioxide and water vapour go back into the atmosphere along with some of the soot or ash, the rest of which is left as a solid residue. The weight of the carbon dioxide plus the water vapour and soot is exactly the same as the weight of the original fuel plus the weight of the oxygen consumed. In general, the products of any chemical reaction whatsoever weigh the same as the reactants.

There is only one known mechanism by which Earth’s mass decreases to any significant degree: molecules of gas in the upper atmosphere (primarily hydrogen and helium, because they are the lightest) escape from Earth’s gravity at a steady rate due to thermal energy. This is counterbalanced by a steady rain of meteors hitting Earth from outer space (if you ever want to hunt them, fly a helicopter over the frozen arctic, they really stand out), containing mostly rock, water, and nickel-iron. These two processes are happening all the time and will continue at a steady rate unchanged by anything we humans do. So, the net/net is about the same.

So, the answer is that the Earth's mass is variable, subject to both gain and loss due to the accretion of in-falling material (micrometeorites and cosmic dust), and the loss of hydrogen and helium gas, respectively. But, drumroll please, the end result is a net loss of material, roughly 5.5×107 kg (5.4×104 long tons) per year.

The burning of fossil fuels has an impact on that equation, albeit a very small one, but an excellent question to ponder. A thank you and respectful nod to Les Niles and Michael McClennen for their insights and help with the energy consumption figures.

DOUVILLEICERAS MAMMILLATUM

Some lovely examples of Douvilleiceras mammillatum (Schlotheim, 1813), ammonites from the Lower Cretaceous (Middle-Lower Albian) Douvilliceras inequinodum zone of Ambarimaninga, Mahajanga Province, Madagascar.

The genus Douvilleiceras range from Middle to Late Cretaceous and can be found in Asia, Africa, Europe and North and South America. 

We have beautiful examples in the early to mid-Albian from the archipelago of Haida Gwaii in British Columbia. Joseph F. Whiteaves was the first to recognize the genus from Haida Gwaii when he was looking over the early collections of James Richardson and George Dawson. The beauties you see here measure 6cm to 10cm.

HOPLITES: TIRE-TRACK RIBBING

Hoplites Bennettiana, Troyes, France

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.

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).

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.

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. 

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 the typical 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 centre but I still find the distinctions subtle.

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 tubercles.

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

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

ABUNDANCE TO EXTINCTION: THE AMMONITES

Early Cretaceous Hoplites sp. Dorset, UK

Ammonites were predatory, squid-like creatures that lived inside coil-shaped shells. 

Like other cephalopods, ammonites had sharp, beak-like 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.

These sea creatures were constantly building new shell as they grew. 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. Most of the shell was unused as they preferred to inhabit only the outer 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 the water out of the shell chambers by hyperosmotic active transport process. This process controlled the buoyancy of the ammonite's shell. 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.

They first appeared about 240 million years ago, though they descended from straight-shelled cephalopods called bacrites that date all the way back to the Devonian — some 415 million years. 

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.

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 molluscs, 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.

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

Photo Two: 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.

AVIAN RELATIONS

Although most of the skeletal features differentiating birds from other extant vertebrates can be traced back to the Mesozoic dinosaurs (Makovicky; Zanno, 2011; Xu et al., 2014a), the integration of the fossil record of stem-avians — all taxa closer to birds than crocodiles — with the developmental biology of living birds is more controversial.

The evolution of the three-fingered hand of birds from the ancestral pentadactyl condition of tetrapods is still debated, the former having been considered alternatively as homologous to the medial most three (I–II–III) or the central (II–III–IV) fingers of reptiles (Wagner & Gauthier, 1999; Bever, Gauthier & Wagner, 2011; Xu et al., 2014a).

This controversy has often been depicted as a dichotomy between a paleontological approach supporting the I–II–III pattern in three-fingered theropods, Tetanurans, and a developmental approach supporting the II–III–IV pattern based on the topology of the embryonic mesenchymal condensations from which the avian digits develop (Wagner & Gauthier, 1999).

Yet, both fossil and embryological data are involved in the two alternative interpretations (Bever, Gauthier & Wagner, 2011; Vargas et al., 2008; Xu et al., 2009; Tamura et al., 2011), and may eventually support additional, more complex, homology frameworks (Xu et al., 2014a). Pivotal among the fossil evidence, the unusual hand of the Late Jurassic ceratosaurian Limusaurus has been argued to support a II–III–IV digital identity in birds and a complex pattern of homeotic transformations in three-fingered, Tetanuran, theropods (Xu et al., 2009; Bever, Gauthier & Wagner, 2011), although criticism to this interpretation has been raised from both paleontological and developmental perspectives (Wang et al., 2011; Carrano & Choiniere, 2016).

Following the reinterpretation of the digital identity along the avian stem of Xu et al. (2009), a series of paleontological studies in the last decade used the II–III–IV homology pattern as a morphological framework for three-fingered theropods, challenging the I–II–III pattern traditionally followed in the interpretation of the theropod hand (Xu, Han & Zhao, 2014b). It must be remarked that the evolutionary scenario supporting the II–III–IV homology pattern of Xu et al. (2009) makes predictions that can be falsified in the fossil record (Bever, Gauthier & Wagner, 2011): the phalangeal formula at the root of Ceratosauria should be markedly simplified, compared to the ancestral theropod formula (i.e., 0-3-3/2-1-X vs 2-3-4-1-0).

The new ceratosaurian theropod, Saltriovenator zanellai, from the Saltrio Formation, Lower Jurassic, Lower Sinemurian, ∼198 million-year-old outcrops of Northern Italy (Dal Sasso, 2003), show a mosaic of features seen in four-fingered theropods and in basal tetanurans. Although fragmentary, the new theropod allows the reconstruction of the ancestral ceratosaurian hand, shedding light on the evolutionary digit pattern in tetanuran fingers and thus along the lineage leading to bird origin. The occurrence of large averostran theropods in the fossil record also helps us to understand the body size of this new Italian specimen and its stratigraphic and geochronological context.

The new find, in the context of Early Jurassic neotheropods Skeletal remains of theropod dinosaurs are extremely rare in the Lower Jurassic and most reports are of only fragmentary remains (Benton, Martill; Taylor, 1995; Owen, 1863; Woodward, 1908; Andrews, 1921; Cuny & Galton, 1993; Delsate & Ezcurra, 2014).

Ceratosaurian-grade taxa are absent until Middle Jurassic times (Maganuco et al., 2007; Pol & Rauhut, 2012), with one exception from the Pliensbachian–Toarcian of Northern Africa (Allain et al., 2007). This paucity of skeletal remains is a considerable gap in our knowledge of these animals at a time when theropods were diversifying rapidly. Just after the Triassic–Jurassic mass extinction event we begin to see a rich, worldwide distribution revealed through ichnofossils (Delsate & Ezcurra, 2014).

In Europe, we find theropod remains from the Hettangian, mostly non-diagnostic at the generic level: Scotland (Benton, Martill & Taylor, 1995), England (Owen, 1863; Woodward, 1908; Andrews, 1921), France (Cuny & Galton, 1993), and Luxembourg (Delsate & Ezcurra, 2014).

Two species of the genus Sarcosaurus have been reported from the Hettangian of England, S. woodi from Barrow upon Soar, Leicestershire, based on an isolated pelvis, vertebra, and proximal femur (BMNH 4840/1), and S. andrewsi (Huene, 1932), based on a partial tibia (NHMUK R3542) (Woodward, 1908).

There's also the neotheropod Dracoraptor hanigani, from the Hettangian of Wales, described by Martill et al. in 2016 on the basis of a 40% complete skeleton including cranial and postcranial material. In the rest of the world, the most famous Early Jurassic theropod is certainly Dilophosaurus wetherilli from the Hettangian of Arizona (Welles, 1954, 1984), which is known from several specimens.

Other relevant taxa are Sinosaurus (=“Dilophosaurus” sinensis) from the Hettangian–Sinemurian of China (Hu, 1993), Coelophysis rhodesiensis from the Hettangian–Pliensbachian of South Africa and Zimbabwe (Raath, 1990), a personal favourite Dracovenator from the Hettangian of South Africa (Yates, 2005), Cryolophosaurus from the Early Jurassic (?Sinemurian–Pliensbachian) of Antarctica (Hammer & Hickerson, 1994), Podokesaurus from the Pliensbachian to Toarcian of Massachusetts (Talbot, 1911), Segisaurus from the Pliensbachian to Toarcian of Arizona (Carrano, Hutchinson & Sampson, 2005), “Syntarsus” kayentakatae from the Hettangian of Arizona (Rowe, 1989), and Berberosaurus from the Toarcian of Morocco (Allain et al., 2007).

Ignored is the enigmatic genus Eshanosaurus from the Lower Jurassic of China, tentatively dated as Hettangian (Xu, Zhao & Clark, 2001), pending correct identification and reliably dating, as this purported therizinosaurian coelurosaur might just well be a sauropodomorph.

In this context, the discovery of the new specimen from the Sinemurian of Italy is extremely relevant as it is among the oldest Jurassic theropods, it is larger than all other pre-Aalenian theropods and it helps us to understand some of the macroevolutionary patterns that would have characterized the evolution of Theropoda during the Jurassic.

It also represents the first dinosaur skeleton from the Italian Alps, the first of Jurassic age, and the second theropod skeleton found in Italy after Scipionyx samniticus (Dal Sasso & Signore, 1998; Dal Sasso & Maganuco, 2011). The discovery of the specimen was described accidentally. For a more detailed account, see Dal Sasso, 2004 or the post here from March 9, 2020.

EVOLUTION OF FISH

The evolution of fish began about 530 million years ago with the first fish lineages belonged to the Agnatha, a superclass of jawless fish.

We still see them in our waters as cyclostomes but have lost the conodonts and ostracoderms to the annals of time. 

Like all vertebrates, fish have bilateral symmetry; when divided down the middle or central axis, each half is the same. Organisms with bilateral symmetry are generally more agile, making finding a mate, hunting or avoiding being hunted a whole lot easier. While we still find them on our menus, the ability to move quickly means they avoid being the snack of choice, an honour that falls more to the invertebrates with whom they share the sea.

When we envision fish, we generally picture large eyes, gills, a well-developed mouth. The earliest animals that we classify as fish appeared as soft-bodied chordates who lacked a true spine. While they were spineless, they did have notochords, a cartilaginous skeletal rod that gave them more dexterity than the cold-blooded invertebrates who shared those ancient seas and evolved without a backbone.

Fish would continue to evolve throughout the Paleozoic, diversifying into a wide range of forms. Several forms of Paleozoic fish developed external armour that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many species, including sharks, became formidable marine predators rather than just the prey of arthropods.

Fishes in general respire using gills, are most often covered with bony scales and propel themselves using fins. There are two main types of fins, median fins and paired fins. The median fins include the caudal fin or tail fin, the dorsal fin, and the anal fin. Now there may be more than one dorsal, and one anal fin in some fishes.

The paired fins include the pectoral fins and the pelvic fins. And these paired fins are connected to, and supported by, pectoral and pelvic girdles, at the shoulder and hip; in the same way, our arms and legs are connected to and supported by, pectoral and pelvic girdles. This arrangement is something we inherited from the ancestors we share with fishes. They are homologous structures.

When we speak of early vertebrates, we're often talking about fishes. Fish is a term we use a lot in our everyday lives but taxonomically it is not all that useful. When we say, 'fish' we generally mean an ectothermic, aquatic vertebrate with gills and fins.

Rhacolepis Buccalis, an extinct genus of ray-finned fossil fish

Fortunately, many of our fishy friends have ended up in the fossil record. We may see some of the soft bits from time to time, as in the lovely Rhacolepis Buccalis, an extinct genus of ray-finned fossil fish in carbonate concretion from the Lower Cretaceous, Santana Formation, Brazil.

Not surprisingly, vertebrates with hard skeletons have a much better chance of being preserved than those with just soft parts and no teeth or bone to speak of.

In British Columbia, we have lovely two-dimensional Eohiodon rosei, a common freshwater fossil fish well-represented in Eocene deposits from the Allenby of Princeton and McAbee Fossil Beds near Cache Creek. We also have the Tiktaalik roseae, a large freshwater fish, from 375 million-year-old Devonian deposits on Ellesmere Island in Canada's Arctic. Tiktaalik is a wonderfully bizarre creature with a flat, almost reptilian head but also fins, scales and gills. We have other wonders from this time. There are also spectacular antiarch placoderms, Bothriolepsis, found in the Upper Devonian shales of Miguasha in Quebec.

There are fragments of bone-like tissues from as early as the Late Cambrian with the oldest fossils that are truly recognizable as fishes come from the Middle Ordovician from North America, South America and Australia. At the time, South America and Australia were part of a supercontinent called Gondwana. North America was part of another supercontinent called Laurentia and the two were separated by deep oceans.

Eohiodon rosei, McAbee Fossil Beds

These two supercontinents and others that were also present were partially covered by shallow equatorial seas and the continents themselves were barren and rocky. Land plants didn't evolve until later in the Silurian Period.

In these shallow equatorial seas, a large diverse and widespread group of armoured, jawless fishes evolved: the Pteraspidomorphi. The first of our three groups of ostracoderms. The Pteraspidomorphi are divided into three major groups: the Astraspida, Arandaspida and the Heterostraci.

The oldest and most primitive pteraspidomorphs were the Astraspida and the Arandaspida. You'll notice that all three of these taxon names contain 'aspid', which means shield. This is because these early fishes and many of the Pteraspidomorphi possessed large plates of dermal bone at the anterior end of their bodies. This dermal armour was very common in early vertebrates, but it was lost in their descendants.

Arandaspida is represented by two well-known genera: Sacabampaspis, from South America and Arandaspis from Australia. Arandaspis have large, simple, dorsal and ventral head shields. Their bodies were fusiform, which means they were shaped sort of like a spindle, fat in the middle and tapering at both ends. Picture a sausage that is a bit wider near the centre with a crisp outer shell.