Showing posts with label fossilhuntress. Show all posts
Showing posts with label fossilhuntress. Show all posts

Friday, 24 December 2021

ICE, SNOW, REINDEER AND ICHTHYOSAURS: SVALBARD

Reindeer, Rangifer tarandus 
Ice, Snow, Reindeer & Ichthyosaurs — Svalbard is just what I imagine my version of Valhalla to be like, without all the mead, murder and mayhem. 

This Norwegian archipelago sits between mainland Norway and the North Pole. 

One of the world’s northernmost inhabited areas, it is known for its rugged, remote terrain of glaciers and frozen tundra sheltering polar bears, reindeer and Arctic fox. 

It is also known for reindeer. The lovelies you see here are all females as the males lose their antlers in the winter. So Rudolf and the rest of Santa's crew who pull his sleigh for him would have all been females as they are pictured with antlers. They are also shown flying across the sky, so the science gets a bit creative.

The Northern Lights or Nordlys are visible during winter, and summer brings the Midnight Sun — sunlight 24 hours a day. Norway or Norge is one of the very few locations where sunset merges into the sunrise, with no darkness in between, creating a soft, captivating twilight in which to view the world. 

The Botneheia Formation is made up of dark grey, laminated shales coarsening upwards to laminated siltstones and sandstones. South of the type area, the formation shows four coarsening-upward units. 

The formation is named for Botneheia Mountain, a mountain in Nordenskiöld Land at Spitsbergen, Svalbard. It has a height of 522 m.a.s.l., and is located south of Sassenfjorden, east of the valley of De Geerdalen. 

Svalbard, Norway
I was asked recently if folk head out in the torrential rain or ice and snow to fossil collect. I would generally say yes for those where the potential prize always outweighs the weather. For Svalbard, it is a resounding yes. 

You have to remove the snow cover — or ice if you are impatient or unlucky — to get to the outcrops here. It is well worth the effort. Beneath the icy cover, you find lovely ammonoids and bivalves. 

Tastier still, ichthyosaur remains are found here. The first Triassic ichthyosaurs from Svalbard were found in the early 20th century. Now there are quite a few Triassic and Jurassic ichthyosaur species from this archipelago.

Two ichthyosaur specimens have been recovered that are of particular interest. They comprise part of the trunk and the caudal vertebral column respectively. 

Some features, such as the very high and narrow caudal and posterior thoracic neural spines, the relatively elongate posterior thoracic vertebrae and the long and slender haemapophyses indicate that they probably represent a member of the family Toretocnemidae. 

Ichthyosaur Bones
Numerous ichthyosaur finds are known from the underlying Lower Triassic Vikinghøgda Formation and the overlying Middle to Upper Triassic Tschermakfjellet Formation, the new specimens help to close a huge gap in the fossil record of the Triassic ichthyosaurs from Svalbard. 

There is a resident research group working on the Triassic ichthyosaur fauna, the Spitsbergen Mesozoic Research Group. 

Lucky for them, they often find the fossil remains fully articulated — the bones having retained their spatial relationship to one another. 

Most of their finds are of the tail sections of primitive Triassic ichthyosaurs. In later ichthyosaurs, the tail vertebrae bend steeply downwards and have more of a fish-like look. 

In these primitive ancestors, the tail looks more eel-like — bending slightly so that the spines on the vertebrae form more of the tail. 

Maisch, Michael W. and Blomeier, Dierk published on these finds back in 2009: Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen Band 254 Heft 3 (2009), p. 379 - 384. Nov 1, 2009.

Svalbard, Norway (Norge)
Svalbard was so remote that there were no Inuit or First Nation settlements. It is certainly possible an earlier people came through these islands, but they did not leave any trace of their travels. 

The first documented travellers to explore Spitsbergen arrived in 1795 as part of a hunting expedition. They included people from the arctic town of Hammerfest in Norway's far north. They were an excellent choice as they were used to barren, inhospitable lands and sailed to discover more. 

We know them as the Coast Sámi — a hearty, rugged people probably best known in history for their chieftain, Ottar. He left Hammerfest in the 9th century to visit then join King Alfred the Great's court in a newly forming England. 

Expeditions to the remote islands of Svalbard continued into the early 1800s and finally, a settlement was eked out of the cold landscape and slowly expanded to the rest of the islands. While today the islands are called Svalbard, I would have named them for the Norwegian word for remote — fjernkontroll.

Aristoptychites euglyphus and Daonella sp.
This marvellous block is filled with Aristoptychites (syn = Arctoptychites) euglyphus (Mojsisovics, 1886) and Daonella sp., oyster-like clams or bivalves from the Middle Triassic, Ladinian, rugged windswept outcrops at the top of the Daonella Shales, Botneheia Formation, Spitzbergen, Edgeøya and Barentsøya, eastern Svalbard, Norway. 

Daonella and Monotis are important species for our understanding of biostratigraphy in the Triassic and are useful as Index fossils. 

Index fossils are fossils used to define and identify geologic periods or faunal stages. To be truly useful, they need to have a short vertical range, wide geographic distribution and rapid evolutionary development.

Daonellids preferred soft, soupy substrates and we tend to find them in massive shell beds. Generally, if you find one, you find a whole bunch cemented together in coquina. The lovely block you see here is in the collections of the deeply awesome John Fam. 

Learning Languages

The Sámi languages (/ˈsɑːmi/ SAH-mee), Sami or Saami, are a group of Uralic languages spoken by the Sámi people in Northern Europe in parts of northern Finland, Norway, Sweden, and extreme northwestern Russia. Of the world's languages, I find them the most difficult for my mind and tongue to wrap around. The Uralic languages will be familiar to you as Hungarian (Magyar nyelv), Finnish and Estonian. 

Since my Sámi is terrible, I will share a few words of Norwegian that may come in handy if you visit Svalbard and have a hankering for their tasty fossils or fossiler. To say, ice, snow, reindeer and ichthyosaurs in Norwegian, you would say: is, snø, reinsdyr og ikthyosaurer

To say, "hello, where can I find fossils?" Use, "Hei, hvor kan jeg finne fossiler?" An expression you may not need but circumstances being what they are, "That is a big polar bear," is "Det er en stor isbjørn." A solid follow-up would be, "nice bear, run..." as "Fin bjørn, løp..." Good luck with that.

Wishing you and yours the very best of the holidays however you celebrate. 

Thursday, 23 December 2021

DINOFLAGELLATES: TEENSY OCEAN STARS

This showy Christmas Cracker is a Dinoflagellate

The showy royal blue Christmas cracker looking fellow you see here is a dinoflagellate. 

Bioluminescent dinoflagellates are a type of plankton — teensy marine organisms that make the seaways shimmer as you swim through them or the tide crashes them against the shore. 

The first modern dinoflagellate was described by Baker in 1753, the first species was formally named by Muller in 1773. 

The first fossil forms were described by Ehrenberg in the 1830s from Cretaceous outcrops. More dinoflagellates have lived, died and gone extinct than there are living today. We know them mainly from fossil dinocysts dating back to the Triassic. They are one of the most primitive of the eukaryotic group with a fossil record that may extend into the Precambrian. They combine primitive characteristics of prokaryotes and advanced eukaryotic features.

The luciferase found in dinoflagellates is related to the green chemical chlorophyll found in plants. Their twinkling lights are brief, each containing about 100 million photons that shine for only a tenth of a second. While each individual flicker is here and gone in the wink of an eye, en masse they are breathtaking. I have spent several wondrous evenings scuba diving amongst these glittering denizens off our shores. What you know about light above the surface does not hold true for the light you see as bioluminescence. Its energy and luminosity come from a chemical reaction. 

In a luminescent reaction, two types of chemicals — luciferin and luciferase — combine together. Together, they produce cold light — light that generates less than 20% thermal radiation or heat. 

The light you see is produced by a compound called Luciferin. It is the shiny, showy bit in this chemical show. Luciferase acts as an enzyme, the substance that acts as a catalyst controlling the rate of chemical reactions, allowing the luciferin to release energy as it is oxidized. 

The colour of the light depends on the chemical structures of the chemicals. There are more than a dozen known chemical luminescent systems, indicating that bioluminescence evolved independently in different groups of organisms.

Coelenterazine is the type of luciferin we find in shrimp, fish and jellyfish. Dinoflagellates and krill share another class of unique luciferins, while ostracods or firefleas and some fish have a completely different luciferin — but all produce lights of various colours to great effect.  

Tuesday, 14 December 2021

AMMOLITE: LOVE, GREED AND GLORY

Ammolite from the Bearpaw Formation
Ammolite is an opal-like organic gemstone found primarily along the eastern slopes of the Rocky Mountains of North America. 

The mining of ammolite is a serious business. I happened upon a locality while in search of fossilized oysters along the St. Mary's River in Alberta. It was one of the few times that I have ever been shot at. 

They sunk the wee boat I was using as a raft to haul my finds but I will give them credit for firing warning shots and not actually trying to hit me. With that, I can safely say that ammolite inspires strong emotions amongst fossil collectors — love, greed and glory. 

It is made of the fossilized shells of ammonites, which in turn are composed primarily of aragonite, the same mineral contained in shell nacre, with a microstructure inherited from the shell. It is one of few biogenic gemstones along with amber and pearl.

The chemical composition of ammolite is variable. Aside from aragonite, it may include a mix of calcite, silica, pyrite or wee bits and pieces of other minerals. The shell itself may contain a number of trace elements based on the chemical composition of the original sediments where it was fossilized and chemical goodies carried in from groundwater. Most anything can be found in the mix, but primarily we see aluminium, barium, chromium, copper, iron, magnesium, manganese, strontium, titanium, and vanadium. 

Its crystallography is orthorhombic, a seven-sided crystal system. Its hardness is 3.5–4.5, and its specific gravity is 2.60–2.85. The refractive index of Canadian material (as measured via sodium light, 589.3 nm) is as follows: α 1.522; β 1.672–1.673; γ 1.676–1.679; biaxial negative. Under ultraviolet light, ammolite may fluoresce a mustard yellow.

Ammolite comes from the fossil shells of the Upper Cretaceous disk-shaped ammonites Placenticeras meeki and Placenticeras intercalare, and to a lesser degree, the cylindrical baculite, Baculites compressus. The ammonites that form our Alberta ammolite inhabited a prehistoric, inland subtropical sea that bordered the Rocky Mountains — the Cretaceous Western Interior Seaway. 

As the cephalopods died, they sank to the bottom and were buried by layers of bentonitic mud that eventually became shale. Many gem-quality ammonites are found within siderite concretions. These sediments preserved the aragonite of the shells, preventing them from converting to calcite.

Ammolite: Colourful Microstructure of Aragonite
An iridescent opal-like play of colour is shown in fine specimens in shades of yellow, orange, red, green and gold. 

The iridescence is due to the microstructure of the aragonite: unlike most other gems, whose colours come from light absorption, the iridescent colour of ammolite comes from interference with the light that rebounds from stacked layers of thin platelets that make up the aragonite. 

The thicker the layers, the more reds and greens are produced; the thinner the layers, the more blues and violets predominate. Reds and greens are the most commonly seen colours, owing to the greater fragility of the finer layers responsible for the blues. 

When freshly quarried, these colours are not especially dramatic; the material requires polishing and other treatments to reveal the specimen's full-colour potential.

Ammolite itself is quite thin, generally 0.5–0.8 millimetres (0.02–0.03 inches) thick. This thin coating covers a matrix typically made up of grey to brown shale, chalky clay, or limestone. Truly, when you find these ammonites in the field, they do not look like much. They are perhaps a nice shape but often matte grey and unappealing until prepared.  

Frost shattering of these specimens is common. If left exposed to the elements the thin ammolite tends to crack and flake. Prolonged exposure to sunlight can also lead to bleaching of the generally intense colouration. The cracking results in a tessellated appearance, sometimes described as a "dragon skin" or referred to as a stained glass window pattern. 

Ammolite mined from deeper deposits may be entirely smooth or with a rippled surface. Occasionally a complete ammonite shell is recovered with its structure well-preserved: fine, convoluted lines delineate the shell chambers, and the overall shape is suggestive of a nautilus. While these shells may be as large as 90 centimetres (35.5 inches) in diameter, the iridescent ammonites — as opposed to the pyritized variety — are typically much smaller. Most fossilized shells have had their aragonite pseudomorphously replaced by calcite or pyrite, making the presence of ammolite particularly uncommon.

In 1981, ammolite was given official gemstone status by the World Jewellery Confederation (CIBJO), the same year commercial mining of ammolite began. It was designated the official gemstone of the City of Lethbridge, Alberta in 2007.

Ammolite is also known as aapoak — Kainah for "small, crawling stone" — gem ammonite, calcentine, and Korite. The latter is a Trade name given to the gemstone by the Alberta-based mining company Korite. Roughly half of all ammolite deposits are contained within the Kainah (Kainaiwa) reserve, and its inhabitants play a major role in ammolite mining. Marcel Charbonneau and his business partner Mike Berisoff were the first to create commercial doublets of the gem in 1967. They went on to form Ammolite Minerals Ltd.

Monday, 13 December 2021

BELEMNITES: SQUID-LIKE CEPHALOPODS

Lower Jurassic Belemnites, Photo: Georg Laki
Belemnitida is an extinct order of squid-like cephalopods that swam our ancient seas from the Late Triassic to Late Cretaceous. 

Unlike squid, belemnites had an internal skeleton that made up the cone and it is this hard part that we often find fossilized. 

The parts are, from arms to tip: the tongue-shaped pro-ostracum, the conical phragmocone, and the pointy guard.  

When you find these as fossils, it is not intuitive as to what kind of animal they came from. This is the internal hard part of a rather soft, squishy squid-like fellow. 

Because the softer bits are often scavenged and decay, we rarely see them fossilized. Instead, we get what looks like a pointy selection of cigar-shaped goodies that are all that is left of these marine cephalopods. 

We find this fossil in many places around the world. Some friends shared where they have personally found them which I thought might be of interest to you. Arno Martini has found them in northern California, Anne Glenn finds them in Wyoming, Marco Valentin has an enviable collection from Hannover, Misburg, Germany, Juanjo Ugalde Robledo finds them in La Rioja, Spain, Barbara Hnb finds them in Normandy, Patrick Buster finds them in the Navesink Formation of New Jersey, Kim Pervis shared a monograph on Mississippian Belemnites by Rousseau. 

Georg Laki has collected many of their number in the Early Jurassic (Sinemurian/Pliensbachian) of South Luxembourg at Gasperich. I included a photo of Georg's belemnites (with permission) here for you to enjoy. He has a lovely collection that shows the variety of these fossils. 

Anatomy of a Belemnite Fossil

Other notable finds are from Scott Carpenter and his daughter who collect them on the Jurassic Coast, Gabriel Santos who collects them in Peniche, Portugal and Rossi Franco shared a belemnite he found in the building materials used to construct the Bank of Italy in Genoa. 

There are also some wonderfully preserved plates of multiple Jurassic belemnites from Mistelgau, Germany you may want to take a boo at. Imagine slate grey to honey brown Youngibelus and Paxillosus clusters on a beige matrix. Quite stunning. 

I have found them around British Columbia, as has Lloyd Rempel, including at Harrison Lake, British Columbia, Canada. 

Wednesday, 8 December 2021

ORTHOCONE: STRAIGHT-SHELLED NAUTILOIDS

Orthocone Nautiloid Fossil
An orthocone is an unusually long, straight shell of a nautiloid cephalopod. You have likely seen them from Ontario or Morocco. These straight-shelled nautiloids rules our seas during the Ordovician, nothing else was even close in size to them. 

To put that into context, they would have been more than two times longer than the tallest person you know. 

During the 18th and 19th centuries, all shells of this type were named Orthoceras, creating a wastebasket taxon, but it is now known that many groups of nautiloids developed or retained this type of shell.

An orthocone can be thought of as a nautilus but with a pencil-straight, uncoiled shell. You have likely seen living nautilus in the sea if you are very lucky or on social media, if your curiosity has you streaming cephalopod posts. Living nautilus are chunky and coiled with a wee squid-like body living within their shells that they use for protection and the air within for buoyancy to move through the water. Their ancestors were not dissimilar. For a long while, we thought that these marine lovelies represented the most primitive form of nautiloid, but we now know that the earliest nautiloids had shells that were slightly curved. 

An orthoconic form evolved several times amongst cephalopods. Amongst nautiloid cephalopods, we 
see this in the primitive ellesmerocerids, the endocerids — apex predators of the Ordovician who dined on trilobites, molluscs and brachiopods, in the generally straight-shelled actinocerids, the orthoceratoids (perhaps the last unexplored wilderness in the Cephalopoda).

Orthocone Fossil
We see this form again in the rather smallish order bactritids (relatively speaking within the vast array of the Class Cephalopoda).

These lovely straight-shelled fossils are found in Late Cambrian to Late Triassic outcrops but they were most common in the early Paleozoic. Revivals of the orthocone design later occurred in other cephalopod groups, notably baculitid ammonites in the Cretaceous Period. 

Orthocone nautiloids range in size from wee little fellas less than 25 mm (1 in) to a massive 5.2 metres or 17 feet long in the case of the giant endocerids of the Ordovician. Never underestimate just how large a cephalopod can get. If our oceans remain fertile, I expect we'd see one larger than a city block one day.


Saturday, 4 December 2021

DRIFTWOOD CANYON FOSSIL BEDS / KUNGAX

White Eared Puffbird, Nystalus chacuru
Driftwood Canyon Provincial Park 

Driftwood Canyon Provincial Park covers 23 hectares of the Bulkley River Valley, on the east side of Driftwood Creek, a tributary of the Bulkley River, 10 km northeast of the town of Smithers in northern British Columbia. 

Wet'suwet'en First Nation

The parklands are part of the asserted traditional territory of the Wet'suwet'en First Nation which includes lands around the Bulkley River, Burns Lake, Broman Lake, and François Lake in the northwestern Central Interior of British Columbia. 

The Wetʼsuwetʼen are part of the Dakelh or Carrier First Nation, and in combination with the Babine First Nation are referred to as the Western Carrier. They speak Witsuwitʼen, a dialect of the Babine-Witsuwitʼen language which, like its sister language Carrier, is a member of the Athabaskan family.

Their oral history or kungax recounts a time when their ancestral village, Dizkle or Dzilke, once stood upstream from the Bulkley Canyon. This cluster of cedar houses on both sides of the river was said to be abandoned because of an omen of impending disaster. The exact location of the village has been lost. The neighbouring Gitxsan people of the Hazelton area have a similar tale, though the village in their version is referred to as Dimlahamid or Temlahan. Their house groups include the Gilseyhu or Big Frog Clan, the Laksilyu or Small Frog Clan, the Tsayu or Beaver Clan, the Gitdumden or Wolf and Bear Clan and the Laksamshu or Fireweed and Owl Clan.

The park was created in 1967 by the donation of the land by the late Gordon Harvey (1913–1976) to protect fossil beds on the east side of Driftwood Creek. The beds were discovered around the beginning of the 20th century. 

Driftwood Canyon Fossil Beds

Driftwood Canyon is recognized as one of the world’s most significant fossil beds. It provides park users with a fascinating opportunity to understand the area’s evolutionary processes of both geology and biology. We have found plant, fish and insect fossil here that include Dawn Redwood, alder, fossil salmon, wasps, water striders and vertebrate material. Bird feathers are infrequently collected from the shales; however, two bird body fossils have been found here.

In 1968, a bird body fossil was collected in the Eocene shales of the Ootsa Lake Group in Driftwood Canyon Provincial Park by Pat Petley of Kamloops. Pat Petley donated the specimen in 2000 to the Thompson Rivers University (TRU) palaeontology collections. This fossil bird specimen is tentatively identified as the puffbird, Piciformes Bucconidae, of the genus Primobucco.

Primobucco is an extinct genus of bird placed in its own family, Primobucconidae. The type species, Primobucco mcgrewi, lived during the Lower Eocene of North America. It was initially described by American paleo-ornithologist Pierce Brodkorb in 1970, from a fossil right-wing, and thought to be an early puffbird. However, the discovery of a further 12 fossils in 2010 indicate that it is instead an early type of roller.

Related fossils from the European Messel deposits have been assigned to the two species P. perneri and P. frugilegus. Two specimens of P. frugilegus have been found with seeds in the area of their digestive tract, which suggests that these birds were more omnivorous than the exclusively predaceous modern rollers. The Driftwood specimen has never been thoroughly studied. If there is a grad student out there looking for a worthy thesis, head on down to the Thompson Rivers University where you'll find the specimen on display.

Another fossil bird, complete with feathers, was collected at Driftwood Canyon in 1970, This one was found by Margret and Albrecht Klöckner who were travelling from Germany. Theirs is a well-travelled specimen, having visited many sites in BC as they toured around, then to Germany and finally back to British Columbia when it was repatriated and donated to the Royal British Columbia Museum in Victoria. I'm not sure if it is still on display or back in collections, but it was lovingly displayed back in 2008. There is a new grad student, Alexis, looking at Eocene bird feathers down at the RBCM, so perhaps it is once again doing the rounds. 

This second bird fossil is of a long-legged water bird and has been tentatively identified by Dr. Gareth Dyke of the University of Southampton as possibly from the order Charadriiformes, a diverse order of small to medium-ish water birds that include 350 species of gulls, plovers, sandpipers, terns, snipes, and waders. Hopefully, we'll hear more on this find in the future.

What To Know Before You Go

If you fancy a visit to Driftwood Canyon Park, the park is accessible from Driftwood Road from Provincial Highway 16. You are welcome to view and photograph the fossils found here but collecting is strictly forbidden. 

Driftwood Canyon is recognized as one of the world’s most significant fossil beds. It provides park users with a fascinating opportunity to understand the area’s evolutionary processes of both geology and biology. The day-use area is open from May 15 to September 2. There is a short, wheelchair-accessible interpretative trail that leads from the parking are to the fossil beds. Pets are welcome on leash. Signs along the trail provide information on fossils and local history. 

Below a cliff face at the end of the trail is a viewing area that has interpretive information and viewing area overlooking Driftwood Creek.

This park proudly operated by Mark and Anais Drydyk
Email: kermodeparks@gmail.com / Tel: 1 250 877-1482 or 1 250 877-1782

Driftwood Canyon Provincial Park Brochure: 
https://bcparks.ca/explore/parkpgs/driftwood_cyn/driftwood-canyon-brochure.pdf?v=1638723136455


Wednesday, 17 November 2021

UPPER CRETACEOUS TOOTHED BIRDS IN SOUTH AMERICA

70-Million-Year-Old Toothed Enantiornithes Bird Beak
Teeth and jaws, beaks and claws — all species adapt and change over time based on survival. One of the key features of being alive is needing to eat. Depending on what is on the menu, we adapt accordingly. 

I had been thinking about this from a very mammal-centric perspective, but it is true for all animals — birds included.

When we think of our feathered friends, we think of beaks and feathers. True, birds descend from the mighty lineage of dinosaurs, but our experience of them is of their modern forms. 

This modern viewpoint of their characteristics makes beaks with teeth seemingly more fantasy than reality — except this has not always been the case. 70 million years ago, birds flying our Cretaceous skies in what would become South America, Europe and Asia had teeth embedded in their beaks.

The discovery of polyphyodonty and dental replacement in toothed stem birds dates back to the nineteenth century. Marsh reported replacement teeth inside resorption pits in the Late Cretaceous Hesperornis and Ichthyornis.

Enantiornithine Birds & Cladogram
The birds that inhabit the current biomes do not have teeth, but the primitive birds found as fossils in the Upper Cretaceous of Brazil certainly did. 

These ancient relatives to our modern fauna had teeth embedded in their jaw-beaks, clawed fingers and a long tail. 

Both these ancient birds and their modern cousins are descended from the dinosaurs, more specifically the Maniraptora, that clade of coelurosaurian dinosaurs characterized by long arms and three-fingered hands — reduced or fused in some lineages — and semi-lunate or half-moon shaped bone in their wrists you will know as the carpus. 

As with all the dinosaurs in this clad, they had teeth and lots of them.

William Nava, head of the Marília Museum of Paleontology, São Paulo, Brazil, uncovered an outcrop in the city of Presidente Prudente with abundant fossilized bird bones. 

Bird bones are a rare thing as they are delicate, often scavenged before burial and hollow, making them poor candidates for preservation. While bird bones preserved as fossils are generally rare, this was not the case at William's Quarry. The site was a smorgasbord of bones from a number of primitive bird species that lived at the end of the Cretaceous. 

The birds belong to the group of Enantiornithes who looked very much like our modern birds on the outside, but internally they had clawed fingers on each wing and teeth which they replaced in a similar fashion to most reptiles. 

Two other sites have exceptionally preserved Enantiornithes bones. Since most Enantiornithes bones are fragmentary, some species are only known from a piece of a single bone. We are luckier at some sites than others. Almost all complete, fully articulated fossil specimens with soft tissue preserved were known from Las Hoyas in Cuenca, Spain and the Jehol group in Liaoning, China. But the fossil outcrops in the Adamantina Formation, Bauru Group of Brazil can now be added to that very short list.  

If you fancy a read, check out their publication, Dental replacement in Mesozoic birds: evidence from newly discovered Brazilian enantiornithines.” The team included Yun-Hsin Wu and Luis M. Chiappe of the Natural History Museum of Los Angeles County, David J. Bottjer of the University of Southern California, William Nava from the Marília Museum of Paleontology, and Agustín G. Martinelli from the Vertebrate Paleontology Section of the Bernardino Rivadavia Argentine Museum of Natural Sciences.

Publication link: https://www.nature.com/articles/s41598-021-98335-8

Images: Photographs of the enantiornithine specimens MPM-90, MPM-373, and MPM-351, and a simplified cladogram highlighting the stem avian taxa discussed in this study. MPM-373: (a) dorsal view; (b) right lateral view; (c) left lateral view. MPM-90: (d) dorsal view; (e) right lateral view. MPM-351: (f) left lateral view. En external nares, Fp frontal process. With an embedded illustration of a reconstruction of Sinornis santensis by McBlackneck. There is some mice type used so feel free to click the image to see if full size.

The studied specimens consist of two sets of premaxillae (MPM-90 and MPM-373) and an incomplete left dentary (MPM-351) exquisitely preserved in three dimensions. These specimens are housed at the Museu de Paleontologia de Marília (MPM), São Paulo State, Brazil.

Monday, 15 November 2021

BLADDER-BEARERS: HOODED SEALS

If you frequent the eastern coast of North America north of Maine to the western tip of Europe, along the coast of Norway near Svalbard you may have glimpsed one of their chubby, dark silver-grey and white residents. 

Hooded seals, Cystophora cristata, are large phocid seals in the family Phocidae, who live in some of the chilliest places on Earth, from 47° to 80° N in latitude. 

These skilled divers are mainly concentrated around Bear Island, Norway, Iceland, and northeast Greenland. 

In rare cases, we find them in the icy waters in Siberia. They usually dive depths of 600 m (1,968 ft) in search of fishy treats but can go as deep as 1000 m (3,280 ft) when needed. That is deep into the cold, dark depths of our oceans. Sunlight entering the sea may travel as deep as 1,000 m (3,280 ft) under the right conditions, but there is rarely any significant light beyond 200 meters (656 ft). This is the dark zone and the place we find our bioluminescent friends. 

Hooded seals have a sparse fossil record. One of the first fossils found was a Pliocene specimen from Anvers, Belgium discovered in 1876. In 1983 a paper was published claiming there were some fossils found in North America thought to be from Cystophora cristata. Of the three accounts, the most creditable discovery was from a sewer excavation in Maine, the northeasternmost U.S. state, known for its rocky coastline, maritime history and nature areas like the granite and spruce islands of Acadia National Park. A scapula and humeri were found among other bones and thought to date to the post-Pleistocene. 

Of two other accounts, one was later reassigned to another species and the other left unsolved. (Folkow, et al., 2008; Kovacs and Lavigne, 1986; Ray, 1983)

The seals are typically silver-grey or white in colour, with black spots that vary in size covering most of the body. 

Hooded seal pups are known as, Blue-backs as their coats are blue-grey on the back with whitish bellies, though this coat is shed after 14 months of age when the pups moult.

FIRST NATION, INUIT, METIS, MI'KMAQ L'NU

In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, seal are known as migwat — and fur seals are known as x̱a'wa.

Hooded seals live primarily on drifting pack ice and in deep water in the Arctic Ocean and North Atlantic. Although some drift away to warmer regions during the year their best survival rate is in colder climates. They can be found on four distinct areas with pack ice: near Jan Mayen Island, northeast of Iceland; off Labrador and northeastern Newfoundland; the Gulf of St. Lawrence; and the Davis Strait, off midwestern Greenland. 

The province of Newfoundland and Labrador is home to the Inuit, the Innu, the Mi'kmaq L'nu and the Southern Inuit of NunatuKavut, formerly the Labrador Inuit-Metis. The Hooded Seals that visit their traditional territory were a welcome source of food and clothing. In Mi'kmaw, the language spoken in Mi'kma'ki, the territory of the Mi'kmaq L'nu, the word for seal is waspu.

HOODED SEAL HABITAT

Males are localized around areas of complex seabeds, such as Baffin Bay, Davis Strait, and the Flemish Cap. Females concentrate their habitat efforts primarily on shelf areas, such as the Labrador Shelf. 

Females reach the age of sexual maturity between two and nine years old and it is estimated that most females give birth to their first young at around five years of age. Males reach sexual maturity a little later around four to six years old but often do not mate until much later. Females give birth to one young at a time through March and April. The gestation period is 240 to 250 days. 

Blue-back, Hooded Seal Pup
During this time the fetus, unlike those of other seals, sheds its lanugo — a covering of fine soft hair that is replaced by thicker pelage — in the uterus. 

These young are precocious and at birth are able to move about and swim with ease. They are independent and left to fend for themselves immediately after they have been weaned.

Hooded seals are known to be a highly migratory species that often wander long distances, as far west as Alaska and as far south as the Canary Islands and Guadeloupe. 

Prior to the mid-1990s, hooded seal sightings in Maine and the east Atlantic were rare but began increasing in the mid-1990s. From January 1997 to December 1999, a total of 84 recorded sightings of hooded seals occurred in the Gulf of Maine, one in France and one in Portugal. 

From 1996 to 2006, five strandings and sightings were noted near the Spanish coasts in the Mediterranean Sea. There is no scientific explanation for the increase in sightings and range of the hooded seal.

Cystophora means "bladder-bearer" in Greek and pays homage to this species' inflatable bladder septum on the heads of adult males. The bladder hangs between the eyes and down over the upper lip in a deflated state. 

The hooded seal can inflate a large balloon-like sac from one of its nostrils. This is done by shutting one nostril valve and inflating a membrane, which then protrudes from the other nostril. 

I was thinking of Hooded seals when contemplating the nasal bladders of Prosaurolophus maximum, large-headed duckbill dinosaurs, or hadrosaurid, in the ornithischian family Hadrosauridae. Perhaps both species used these bladders in a similar manner — to warn predators and attract mates.

Hooded seals are known for their uniquely elastic nasal cavity located at the top of their head, also known as the hood. Only males possess this display-worthy nasal sac, which they begin to develop around the age of four. The hood begins to inflate as the seal makes its initial breath prior to going underwater. It then begins to repetitively deflate and inflate as the seal is swimming. 

The purpose of this is acoustic signalling. It occurs when the seal feels threatened and attempt to ward off hostile species when competing for resources such as food and shelter. It also serves to communicate their health and superior status to both other males and females they are attempting to attract. 

In sexually mature males, a pinkish balloon-like nasal membrane comes out of the left nostril to further aid it in attracting a mate. This membrane, when shaken, is able to produce various sounds and calls depending on whether the seal is underwater or on land. Most of these acoustic signals are used in an acoustic situation (about 79%), while about 12% of the signals are used for sexual purposes.

References: Ray, C. 1983. Hooded Seal, Cystophora cristata: Supposed Fossil Records in North America. American Society of Mammalogists, Vol. 64 No. 3: 509-512; Cystophora cristata, Hooded Seal", 2007; "Seal Conservation Society", 2001; Kovacs and Lavigne, 1986.

Mi'kmaq Online Dictionary: https://www.mikmaqonline.org/servlet/dictionaryFrameSet.html?method=showCategory&arg0=animal

Tuesday, 24 August 2021

GULLS: TSIK'WI

A gull cries in protest at not getting his share of a meal

Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. 

The Laridae are known from not-yet-published fossil evidence from the Early Oligocene — 30–33 million years ago. 

Three gull-like species were described by Alphonse Milne-Edwards from the early Miocene of Saint-Gérand-le-Puy, France. 

Another fossil gull from the Middle to Late Miocene of Cherry County, Nebraska, USA, has been placed in the prehistoric genus Gaviota

These fossil gulls, along with undescribed Early Oligocene fossils are all tentatively assigned to the modern genus Larus. Among those of them that have been confirmed as gulls, Milne-Edwards' "Larus" elegans and "L." totanoides from the Late Oligocene/Early Miocene of southeast France have since been separated in Laricola.

Gulls are most closely related to the terns in the family Sternidae and only distantly related to auks, skimmers and distantly to waders. 

A historical name for gulls is mews, which is cognate with the German möwe, Danish måge, Swedish mås, Dutch meeuw, Norwegian måke/måse and French mouette. We still see mews blended into the lexicon of some regional dialects.

In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, gulls are known as t̕sik̕wi. Most folk refer to gulls from any number of species as seagulls. This name is a local custom and does not exist in the scientific literature for their official naming. Even so, it is highly probable that it was the name you learned for them growing up.

If you have been to a coastal area nearly everywhere on the planet, you have likely encountered gulls. They are the elegantly plumed but rather noisy bunch on any beach. You will recognize them both by their size and colouring. 

Gulls are typically medium to large birds, usually grey or white, often with black markings on the head or wings. They typically have harsh shrill cries and long, yellow, curved bills. Their webbed feet are perfect for navigating the uneven landscape of the foreshore when they take most of their meals. 

Most gulls are ground-nesting carnivores that take live food or scavenge opportunistically, particularly the Larus species. Live food often includes crab, clams (which they pick up, fly high and drop to crack open), fish and small birds. Gulls have unhinging jaws which allow them to consume large prey which they do with gusto. 

Their preference is to generally live along the bountiful coastal regions where they can find food with relative ease. Some prefer to live more inland and all rarely venture far out to sea, except for the kittiwakes. 

The larger species take up to four years to attain full adult plumage, but two years is typical for small gulls. Large white-headed gulls are typically long-lived birds, with a maximum age of 49 years recorded for the herring gull.

Gulls nest in large, densely packed, noisy colonies. They lay two or three speckled eggs in nests composed of vegetation. The young are precocial, born with dark mottled down and mobile upon hatching. Gulls are resourceful, inquisitive, and intelligent, the larger species in particular, demonstrating complex methods of communication and a highly developed social structure. Many gull colonies display mobbing behaviour, attacking and harassing predators and other intruders. 

Certain species have exhibited tool-use behaviour, such as the herring gull, using pieces of bread as bait with which to catch goldfish. Many species of gulls have learned to coexist successfully with humans and have thrived in human habitats. Others rely on kleptoparasitism to get their food. Gulls have been observed preying on live whales, landing on the whale as it surfaces to peck out pieces of flesh. They are keen, clever and always hungry.

Sunday, 22 August 2021

CAVE BEAR: URSUS URALENSIS

This glorious and slightly terrifying skull is from a fossil cave bear, Ursus uralensis, from Pleistocene deposits in Russia.

Both the cave bear and the brown bear are thought to be descended from the Plio-Pleistocene Etruscan bear, Ursus etruscus, that lived about 5.3 Mya to 100,000 years ago. 

The last common ancestor of cave bears and brown bears lived between 1.2–1.4 Mya. The immediate precursor of the cave bear was probably Ursus deningeri, the Deninger's bear — a species restricted to Pleistocene Europe about 1.8 Mya to 100,000 years ago. 

The transition between Deninger's bear and the cave bear is given as the last interglacial, although the boundary between these forms is arbitrary, and intermediate or transitional taxa have been proposed, Ursus spelaeus deningeroides, while other authorities consider both taxa to be chronological variants of the same species.

Cave bears found in different regions vary in age, thus facilitating investigations into evolutionary trends. The three anterior premolars were gradually reduced, then disappeared, possibly in response to a largely vegetarian diet. 

In a fourth of the skulls found in the Conturines, the third premolar is still present, while more derived specimens elsewhere lack it. The last remaining premolar became conjugated with the true molars, enlarging the crown and granting it more cusps and cutting borders. This phenomenon, called molarization, improved the mastication capacities of the molars, facilitating the processing of tough vegetation. This allowed the cave bear to gain more energy for hibernation while eating less than its ancestors.

A lone Grizzly Bear / Na̱ndzi
In 2005, scientists recovered and sequenced the nuclear DNA of a cave bear that lived between 42,000 and 44,000 years ago. 

The procedure used genomic DNA extracted from one of the animal's teeth. Sequencing the DNA directly (rather than first replicating it with the polymerase chain reaction), the scientists recovered 21 cave bear genes from remains that did not yield significant amounts of DNA with traditional techniques.

This study confirmed and built on results from a previous study using mitochondrial DNA extracted from cave bear remains ranging from 20,000 to 130,000 years old. 

Both show that the cave bear was more closely related to the brown bear and polar bear than it was to the American black bear, but had split from the brown bear lineage before the distinct eastern and western brown bear lineages diversified and before the split of brown bears and polar bears. The divergence date estimate of cave bears and brown bears is about 1.2–1.4 Mya. However, a recent study showed that both species had some hybridization between them.

We are blessed to have them living amongst us today on the rugged west coast of British Columbia. In the Kwak'wala language of the Kwakiutl First Nations of the Pacific Northwest, this big fellow is na̱ndzi — a lovely, large peaceful bear.

Friday, 20 August 2021

ORIGINS OF THE WOOLLY MAMMOTHS

Woolly Mammoths, Mammuthus primigenius,  have always held wonder for me. These massive, hairy — and likely very smelly beasts — lived alongside us for a time. 

If you stood beside him and reached way up, you might be able to touch his tusks but likely not reach up to his mouth or even his eyes. 

He had a shaggy coat of light or dark coloured hair with long outer hair strands covering a dense thick undercoat. His oil glands would have worked overtime to secrete oils, giving him natural waterproofing. Some of the hair strands we have recovered are more than a meter in length. These behemoth proboscideans boasted long, curved tusks, little ears, short tails and grazed on leaves, shrubs and grasses that would have been hard work to get at as much of his world was covered in ice and snow during his reign.

We first see Woolly Mammoths in northeastern Siberia dating back 700,000 years. We find them in East Asia as far back as 800,000 years ago. They arose from the massive steppe mammoths, Mammuthus trogontherii, slowly evolving traits we see in this older species to the mammoths we think of today. 

Over time, their body size shrank and their teeth and tusks evolved to take advantage of the tough vegetation available to those few animals who could chew their way through ice and snow and work these tundra grasses into a digestible form. 

The enamel plates of their cheek teeth multiplied while the enamel itself became thinner. Tusks slowly took on more of a curved to act as ploughs for the snow. 

Those smaller than their predecessors, they were still formidable. Their size offered protection against predators once full grown. Sadly for the juveniles, they offered tasty prey to big cats like Homotherium who roamed these ancient grasslands alongside them.

The Mammoths of the Steppe spread to the northern areas of Eurasia, down through Europe, into the British Isles to Spain and crossed over to populate North America via the Bering Isthmus. It was the lowered sea levels during the last Ice Age that exposed dry land between Asia and the Americas. Here in this flat, grassy treeless plain known as the Bering Land Bridge or Isthmus, animals, including humans, could migrate from Europe west into North America.

The woolly mammoth coexisted with our ancestors who made good use of their bones and tusks for tools, housing, art and food. The last of their lineage died out relatively recently on Wrangel Island until 4,000 years ago — a time when we were making our first harps and flutes in Egypt, dams, canals and stone sculptures in Sumer, using numbers for the first time and using tin to make tools.

Thursday, 19 August 2021

DUGONG: SEA COW

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, 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, 18 August 2021

TITANITES: THE FERNIE AMMONITE

Titanites occidentalis, Fernie Ammonite
The Fernie ammonite, Titanites occidentalis, from outcrops on Coal Mountain near Fernie, British Columbia, Canada. 

This beauty is the remains of a carnivorous cephalopod within the family Dorsoplanitidae that lived and died in a shallow sea some 150 million years ago.

If you would like to get off the beaten track and hike up to see this ancient beauty, you will want to head to the town of Fernie in British Columbia close to the Alberta border. 

There was some active logging along the hillside in 2021, so if you are looking at older directions on how to get to the site be mindful that many of the trailheads have been altered and a fair bit of bushwhacking will be necessary to get to the fossil site proper. That being said, the loggers did give the ammonite a wide berth and have left it intact.

Driving to the trail base is along an easy access road just east of town along Fernie Coal Road. There are some nice exposures of Cretaceous plant material on the north side (left-hand side) of the road as you head from Fernie towards Coal Creek. I recently drove up to Fernie to look at Cretaceous plant material and locate the access point to the now infamous Late Jurassic (Tithonian) Titanites (S.S. Buckman, 1921) site. While the drive out of town is on an easy, well-maintained road, the slog up to the ammonite site is a steep 3-hour push.

Fernie, British Columbia, Canada
The first Titanites occidentalis was about one-third the size and was incorrectly identified as Lytoceras, a fast-moving nektonic carnivore. The specimen you see here is significantly larger at 1.4 metres (about four and a half feet) and rare in North America. 

Titanites occidentalis, the Western Giant, is the second known specimen of this extinct fossil species. The first was discovered in 1947 in nearby Coal Creek by a British Columbia Geophysical Society mapping team. When they first discovered this marine fossil high up on the hillside, they could not believe their eyes — both because it is clearly marine at the top of a mountain and the sheer size of this ancient beauty.

In the summer of 1947, a field crew was mapping coal outcrops for the BC Geological Survey east of Fernie. One of the students reported finding “a fossil truck tire.” Fair enough. The similarity of size and optics are pretty close to your average Goodridge. 

A few years later, GSC Paleontologist Hans Frebold described and named the fossil Titanites occidentalis after the large Jurassic ammonites from Dorset, England. The name comes from Greek mythology. Tithonus, as you may recall, was the Prince of Troy. He fell in love with Eos, the Greek Goddess of the Dawn. Eos begged Zeus to make her mortal lover immortal. Zeus granted her wish but did not grant Tithonus eternal youth. He did indeed live forever — ageing hideously. Ah, Zeus, you old trickster. It is a clever play on time placement. Dawn is the beginning of the day and the Tithonian being the latest age of the Late Jurassic. Clever Hans!

HIKING TO THE FERNIE AMMONITE

From the town of Fernie, British Columbia, head east along Coal Creek Road towards Coal Creek. The site is 3.81 km from the base of Coal Creek Road to the trailhead as the crow flies. I have mapped it here for you in yellow and added the wee purple GPS marker for the ammonite site proper. There is a nice, dark grey to black roadcut exposure of Cretaceous plants on the north side of the dirt road that is your cue to pull over and park.  

You access what is left of the trailhead on the south side of the road. You will need to cross the creek to begin your ascent. There is no easy way across the creek and you'll want to tackle this one with a friend when the water level is low. 

The beginning of the trail is not clear but a bit of searching will reveal the trailhead with its telltale signs of previous hikers. This is a 1-2 hour moderate 6.3-kilometre hike up & back bushwhacking through scrub and fallen trees. Heading up, you will make about a 246-metre elevation gain. You will likely not have a cellular signal up here but if you download the Google Map to your mobile, you will have GPS to guide you. The area has been recently logged so much of the original trail has been destroyed. There may now be easier vehicle access up the logging roads but I have not driven them since the logging and new road construction.

If you are coming in from out of town, the closest airport is Cranbrook. Then it is about an hour and change to Fernie and another 15-minutes or so to park near the site.

You will want to leave your hammers with your vehicle (no need to carry the weight) as this site is best enjoyed with a camera. 

This is a site you will want to wear hiking boots to access. Know that these will get wet as you cross the creek. 

If you would like to see the ammonite but are not keen on the hike, a cast has been made by fossil preparator Rod Bartlett is on display at the Courtenay Museum in Courtenay, Vancouver Island, Canada. 

As your feet move up the hillside, you can imagine this land 10,000 years ago, rising above great glaciers. Where footfalls trace the steps of those that came before you. This land has been home to the Ktunaxa or Kukin ʔamakis First Nations whose oral history have them living here since time immemorial. Like them, take only what you need and no more than the land offers — packing out anything that you packed in. 

Fernie Ammonite Palaeo Coordinates: 49°29'04"N 115°00'49"W

Tuesday, 17 August 2021

AMMONITE: INDEX FOSSILS AS TIME KEEPERS

Argonauticeras besairei, José Juárez Ruiz
An exceptional example of the fractal building of an ammonite septum, in this clytoceratid Argonauticeras besairei from the awesome José Juárez Ruiz.

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

Like other cephalopods, ammonites had sharp, beak-like jaws inside a ring of squid-like tentacles that extended from their shells. 

They used these tentacles to snare prey, — plankton, vegetation, fish and crustaceans — similar to the way a squid or octopus hunt today.

Catching a fish with your hands is no easy feat, as I am sure you know. But the Ammonites were skilled and successful hunters. They caught their prey while swimming and floating in the water column. 

Within their shells, they had a number of chambers, called septa, filled with gas or fluid that were interconnected by a wee air tube. By pushing air in or out, they were able to control their buoyancy in the water column.

They lived in the last chamber of their shells, continuously building new shell material as they grew. As each new chamber was added, the squid-like body of the ammonite would move down to occupy the final outside chamber.

They were a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. 

These molluscs, commonly referred to as ammonites, are more closely related to living coleoids — octopuses, squid, and cuttlefish) than they are to shelled nautiloids such as the living Nautilus species.

The Ammonoidea can be divided into six orders:

  • Agoniatitida, Lower Devonian - Middle Devonian
  • Clymeniida, Upper Devonian
  • Goniatitida, Middle Devonian - Upper Permian
  • Prolecanitida, Upper Devonian - Upper Triassic
  • Ceratitida, Upper Permian - Upper Triassic
  • Ammonitida, Lower Jurassic - Upper Cretaceous

Ammonites have intricate and complex patterns on their shells called sutures. The suture patterns differ across species and tell us what time period the ammonite is from. If they are geometric with numerous undivided lobes and saddles and eight lobes around the conch, we refer to their pattern as goniatitic, a characteristic of Paleozoic ammonites.

If they are ceratitic with lobes that have subdivided tips; giving them a saw-toothed appearance and rounded undivided saddles, they are likely Triassic. For some lovely Triassic ammonites, take a look at the specimens that come out of Hallstatt, Austria and from the outcrops in the Humboldt Mountains of Nevada.

Hoplites bennettiana (Sowby, 1826) Christophe Marot
If they have lobes and saddles that are fluted, with rounded subdivisions instead of saw-toothed, they are likely Jurassic or Cretaceous. If you'd like to see a particularly beautiful Lower Jurassic ammonite, take a peek at Apodoceras. Wonderful ridging in that species.

One of my favourite Cretaceous ammonites is the ammonite, Hoplites bennettiana (Sowby, 1826). This beauty is from Albian deposits near Carrière de Courcelles, Villemoyenne, near la région de Troyes (Aube) Champagne in northeastern 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.

In some classifications, these are left as suborders, included in only three orders: Goniatitida, Ceratitida, and Ammonitida. Once you get to know them, ammonites in their various shapes and suturing patterns make it much easier to date an ammonite and the rock formation where it is found.

Ammonites first appeared about 240 million years ago, though they descended from straight-shelled cephalopods called bacrites that date back to the Devonian, about 415 million years ago, and the last species vanished in the Cretaceous–Paleogene extinction event.

They were prolific breeders that evolved rapidly. If you could cast a fishing line into our ancient seas, it is likely that you would hook an ammonite, not a fish. They were prolific back in the day, living (and sometimes dying) in schools in oceans around the globe. We find ammonite fossils (and plenty of them) in sedimentary rock from all over the world.

In some cases, we find rock beds where we can see evidence of a new species that evolved, lived and died out in such a short time span that we can walk through time, following the course of evolution using ammonites as a window into the past.

For this reason, they make excellent index fossils. An index fossil is a species that allows us to link a particular rock formation, layered in time with a particular species or genus found there. 

Generally, deeper is older, so we use the sedimentary layers of rock to match up to specific geologic time periods, rather like the way we use tree rings to date trees. A handy way to compare fossils and date strata across the globe.

References: Inoue, S., Kondo, S. Suture pattern formation in ammonites and the unknown rear mantle structure. Sci Rep 6, 33689 (2016). https://doi.org/10.1038/srep33689

https://www.nature.com/articles/srep33689?fbclid=IwAR1BhBrDqhv8LDjqF60EXdfLR7wPE4zDivwGORTUEgCd2GghD5W7KOfg6Co#citeas

Photos: Argonauticeras besairei from the awesome José Juárez Ruiz.

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

Monday, 16 August 2021

PSEUDOTHURMANNIA PICTETI

Pseudothurmannia is a genus of extinct cephalopods belonging to the subclass Ammonoidea and included in the family Crioceratitidae of the ammonitid superfamily Ancylocerataceae.

Ammonites have intricate and complex patterns on their shells called sutures. The suture patterns differ across species and tell us what time period the ammonite is from.

We can see from the suture patterns shown here and by comparing it to others that are similar that this fast-moving nektonic carnivore lived in the Cretaceous, from the Hauterivian to the Barremian.

Like other cephalopods, ammonites had sharp, beak-like jaws inside a ring of squid-like tentacles that extended from their shells. They used these tentacles to snare prey — plankton, vegetation, fish and crustaceans — similar to the way a squid or octopus hunt today.

Catching a fish with your hands is no easy feat, as I'm sure you know. Ammonites were skilled and successful hunters. They caught their prey while swimming and floating in the water column. 

Within their shells, they had a number of chambers, called septa, filled with gas or fluid that were interconnected by a wee air tube. By pushing air in or out, they were able to control their buoyancy in the water column. They lived in the last chamber of their shells, continuously building new shell material as they grew. As each new chamber was added, the squid-like body of the ammonite would move down to occupy the final outside chamber.

Shells of Pseudothurmannia can reach a diameter of about 4–12 centimetres (1.6–4.7 in). They show flat or slightly convex sides, with dense ribs and a subquadrate whorl section.

We find fossils of Pseudothurmannia in Cretaceous outcrops in Antarctica, Czechoslovakia, France, Hungary, Italy, Japan, Morocco, Spain, Russia and the United States. The specimen you see here is in the collection of the deeply awesome Manuel Peña Nieto from Córdoba, Spain and is from the Lower Cretaceous of Mallorca.

Friday, 30 July 2021

OPABINIA REGALIS

Opabinia regalis is an extinct stem-group arthropod found in the Greater Phyllopod Bed, Middle Cambrian Burgess Shale Lagerstätte of British Columbia, Canada. 

These marine arthropods flourished from 505 million years ago to 487 million years ago.

Charles Doolittle Walcott found nine partially complete fossils of Opabinia regalis and a few of what he classified as Opabinia media, that he published in 1912. 

The bizarre arthropod's name is derived from the Opabin pass between Mount Hungabee and Mount Biddle, southeast of Lake O'Hara, British Columbia, Canada. 

In 1966–1967, Harry B. Whittington found a rather good specimen which he published in 1975. He provided a detailed description based on a very thorough dissection of some specimens and photographs of these specimens lit from a variety of angles. Harry was a very thorough fellow.

But he was still ridiculed. Opabinia looked so strange that the audience at the first presentation of Whittington's analysis laughed.

Earth's ancient seas teemed with new life 541 - 485 Million Years Ago. The Cambrian Explosion had arrived. Weird and wonderful life forms like Hallucigenia and Anomalocaris are found in the fossil record giving us a peek at ancient life half a billion years ago.