EARLY PREDATORY DINOSAURS

Predatory dinosaurs were an important ecological component of terrestrial Mesozoic ecosystems.

Though theropod dinosaurs carried this role during the Jurassic and Cretaceous Periods (and probably the post-Carnian portion of the Triassic), it is difficult to depict the Carnian scenario, due to the scarcity of fossils.

Until now, knowledge on the earliest predatory dinosaurs mostly relies on herrerasaurids recorded in the Carnian strata of South America. Phylogenetic investigations recovered the clade in different positions within Dinosauria, whereas fewer studies challenged its monophyly.

Although herrerasaurid fossils are much better recorded in present-day Argentina than in Brazil, Argentinean strata so far yielded no fairly complete skeleton representing a single individual.

Here, the authors describe Gnathovorax cabreirai, a new herrerasaurid based on an exquisite specimen found as part of a multi-taxic association form southern Brazil. The type specimen comprises a complete and well-preserved articulated skeleton, preserved in close association (side by side) with rhynchosaur and cynodont remains.

Given its superb state of preservation and completeness, the new specimen sheds light on poorly understood aspects of the herrerasaurid anatomy, including endocranial soft tissues.

The specimen also reinforces the monophyletic status of the group and provides clues on the ecomorphology of the early carnivorous dinosaurs. Indeed, an ecomorphological analysis employing dental traits indicates that herrerasaurids occupy a particular area in the morphospace of faunivorous dinosaurs, which partially overlaps the area occupied by post-Carnian theropods. This indicates that herrerasaurid dinosaurs preceded the ecological role that later would be occupied by large to medium-sized theropods. Link to the paper: https://peerj.com/articles/7963/

OXFORD UNIVERSITY MUSEUM OF NATURAL HISTORY

Oxford University Museum of Natural History was established in 1860 to draw together scientific studies from across the University of Oxford. Today, the award-winning Museum continues to be a place of scientific research, collecting and fieldwork and plays host to a number of programmes and exhibitions.

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

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

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

On 30 June 1860, the Museum hosted a clash of ideologies that has become known as the Great Debate. Even before the collections were fully installed, or the architectural decorations completed, the British Association for the Advancement of Science held its 30th annual meeting to mark the opening of the building, then known as the University Museum. It was at this event that Samuel Wilberforce, Bishop of Oxford, and Thomas Huxley, a biologist from London, went head-to-head in a debate about one of the most controversial ideas of the 19th century – Charles Darwin's theory of evolution by natural selection.

TURTLES: LIVING FOSSILS

Turtle ribs fuse together with some of their vertebrae so they have to pump air in and out of the lungs with their leg muscles instead?

Another unusual feature in turtles is their limb girdles (pectoral and pelvic) have come to lie 'within' their rib cage, a feature that allows some turtles to pull its limbs inside the shell for protection. Sea turtles didn't develop this behaviour (or ability) and do not retract into their shells like other turtles.

Turtle shells are different from the armoured “shells” we see on dinosaurs like the ankylosaurs. Turtles are covered by a special bony or cartilaginous shell developed from their ribs that acts as a shield. It is fundamentally different from the armour seen on our other vertebrate pals. Turtle armour is made of dermal bone and endochondral bones of the vertebrae and rib cage.

Armadillos have armour formed by plates of dermal bone covered in relatively small, overlapping epidermal scales called "scutes," composed of bone with a covering of horn. In crocodiles, their exoskeletons form their armour. It is made of protective dermal and epidermal components that begin as rete Malpighii: a single layer of short, cylindrical cells that lose their nuclei over time as they transform into a horny layer.

Depending on the species and age of the turtle, turtles eat all kinds of food including seagrass, seaweed, crabs, jellyfish, and shrimp,. That tasty diet shows up in the composition of their armour as they have oodles of great nutrients to work with. The lovely example you see here is from the Oxford Museum collections.

CRETACEOUS HADROSAUR TOOTH

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

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

We have oodles of very tasty specimens and data to work with. We've got great skin impressions and scale patterns from at least ten species and interesting pathological specimens that provide valuable insights into hadrosaur behaviour. These herbivorous beauties are also found in Europe, South America, Mexico, Mongolia, China and Russian. Together, this abundance of specimens has provided great insight into their evolution, dining habits and social preferences. We know they liked to live in herds. They were terrestrial but also water babies — paddling around in freshwater pools to snack on the tasty greenery that lined its sides. They had adapted webbing in their feet to be as nimble on land as they were in the water. 

There are papers on all aspects of hadrosaurian life and not surprisingly — given the ideal collecting grounds — many of those papers focus on our Canadian finds. Hadrosaurs had teeth arranged in stacks designed for grinding and crushing, similar to how you might picture a cow munching away on the grass in a field. These complex rows of "dental batteries" contained up to 300 individual teeth in each jaw ramus. But even with this great number, we rarely see them as individual specimens.

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

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

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

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

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

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

References:

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

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

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

ZENAPSIS MORTALITY PLATE

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

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

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

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

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

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

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

HADROSAURUS OF THE UPPER CRETACEOUS NANAIMO GROUP

Hadrosaurus, also known as the "duck-billed" dinosaurs, were a very successful group of plant-eaters that thrived throughout western Canada during the late Cretaceous, some 70 to 84 million years ago. Hadrosaurs may have lived as part of a herd, dining on pine needles, twigs and flowering plants.

There are two main groups of Hadrosaurs, crested and non-crested. The bony crest on the top of the head of the hadrosaurs was hollow and attached to the nasal passages. It is thought that the hollow crest was used to make different sounds. These sounds may have signalled distress or been the mating calls used to attract mates. Given their size it would have made for quite the trumpeting sound.

This beautiful specimen graces the back galleries of the Courtenay and District Museum on Vancouver Island, British Columbia, Canada. I was very fortunate to have a tour this past summer with the deeply awesome Mike Trask joined by the lovely Lori Vesper. The museum houses an extensive collection of palaeontological and archaeological material found on Vancouver Island, many of which have been donated by the Vancouver Island Palaeontological Society.

Dan Bowen, Chair of the Vancouver Island Palaeontological Society, shared a photo of the first partly articulated dinosaur from Vancouver Island ever found. The research efforts of the VIPS run deep in British Columbia and this new very significant find is no exception. A Hadrosauroid dinosaur is a rare occurrence and further evidence of the terrestrial influence in the Upper Cretaceous, Nanaimo Group, Vancouver Island.

This fossil bone material was found years ago by Mike Trask of the Vancouver Island Palaeontological Society. You may recall that he was the same fellow who found the Courtenay elasmosaur. The bone was initially thought to be a plesiosaur but turned out to be a hadrosauroid. The find was confirmed by hadrosaur authority Dr. David Evans, senior curator of the Royal Ontario Museum.
You can see the articulated Hadrodauriod fossil bone Mike found now prepped fully prepped.

This fellow has kissing cousins over in the state of New Jersey where this species is the official state fossil. The first of his kind was found by John Estaugh Hopkins in New Jersey back in 1838.

EDIBLE MYTILUS EDULIS

Blue mussels live in intertidal areas and inlets attached to rocks and other hard substrates by strong, stretchy thread-like structures called byssal threads.

They are tasty, edible marine bivalves, molluscs, in the family Mytilidae and they've done well for themselves. Mussels have a range of over 4000 km in waters around the world.

Temperature, salinity and food supply are key factors in how mussels grow and have a huge impact on their shape. Environmental stressors cause curvatures to show up in mussel populations and can help us understand environmental changes happening in our local waters.

BEAKS AND FRILLY SADDLES

A lovely example of the ammonite, Cératites Nodosus, an extinct genus of nektonic marine carnivore from shell limestone superior deposits near Alsace on the Rhine River plain of northeastern France.

You can see the nice ceratitic suture pattern on this specimen with his smooth lobes and frilly saddles. The sutures would have increased the strength of the shell and allowed Ceratites (de Haan, 1825) to dive deeper, bearing the additional pressure of the sea in search of food.

Ammonite shells are made up predominantly of calcium carbonate in the form of aragonite and proteinaceous organic matrix or conchiolin arranged in layers: a thin outer prismatic layer, a nacreous layer and an inner lining of prismatic habitat. While their outer shells are generally aragonite, aptychus are distinct as they are composed of calcite.

The aptychus we see here, hard anatomical structures or curved shelly plates now understood to be part of the body of an ammonite, are often referred to as beaks. If you look closely at this specimen, you can see the beak of the ammonite, that wee pointed piece, near the centre.

These ammonites lived in open shallow, to subtidal and basinal environments some 247 to 221 million years ago. We've found them, thus far, in just over forty collections from nearly ninety fossil deposits around the globe. Fossils of species have been found in the Triassic of Austria, Canada, China, France, Germany, Hungary, India, Israel, Italy, Pakistan, Poland, Russia, Thailand, Turkey and the United States.

The parent taxon is Ceratitinae according to E. T. Tozer 1981. That's our own Tim Tozer, one of the great knights-errant of the Triassic timescale. It was Tim Tozer and Norm Silberling who published the classic milestones of the Triassic timescale, "Biostratigraphic Classification of the Marine Triassic in North America, Geological Society of America, Special Paper 110." The Global Triassic: Bulletin 41 from the New Mexico Museum of Natural History and Science by Lucas and Spielmann honours them in their work. Collection of Ange Mirabet, Strasbourg, France.

SKOMER ISLAND PUFFIN

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 are interested in.

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! They are hindered by short wings, which makes flight challenging but still possible with effort. Once they get some speed on board, they can fly up to 88 km an hour.

Their sexy orange beaks (dead sexy, right?) 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 (awe) 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 fledgling 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.

YORKSHIRE ANDROGYNOCERAS

A stunning example of the ammonite Androgynoceras from the Yorkshire Coast, England.

The Geology of Yorkshire in northern England shows a very close relationship between the major topographical areas and the geological period in which their rocks were formed. The rocks of the Pennine chain of hills in the west are of Carboniferous origin whilst those of the central vale are Permo-Triassic.

The North York Moors in the north-east of the county are Jurassic in age while the Yorkshire Wolds to the southeast are Cretaceous chalk uplands. The plain of Holderness and the Humberhead levels both owe their present form to the Quaternary ice ages. The strata become gradually younger from west to east. Much of Yorkshire presents heavily glaciated scenery as few places escaped the direct or indirect impact of the great ice sheets as they first advanced and then retreated during the last ice age. This beauty is in the collection of the deeply awesome Harry Tabiner.

OH MIGHTY CHORDATE

You and I are vertebrates, we have backbones. Having a backbone or spinal column is what sets apart you, me and almost 70,000 species on this big blue planet.

So which lucky ducks evolved one? Well, ducks for one. Warm-blooded birds and mammals cheerfully claim those bragging rights. They're joined by our cold-blooded, ectothermic friends, the fish, amphibians and reptiles. All these diverse lovelies share this characteristic.

And whether they now live at sea or on land, all of these lineages evolved from a marine organism somewhere down the line, then went on to develop a notochord and spinal column. Notochords are flexible rods that run down the length of chordates and vertebrates. They are handy adaptations for muscle attachment, helping with signalling and coordinating the development of the embryonic stage. The cells from the notochord play a key role in the development of the central nervous system and the formation of motor neurons and sensory cells. Alas, we often take our evolution for granted.

Let's take a moment to appreciate just how marvellous this evolutionary gift is and what it allows us to do. Your backbone gives your body structure, holds up that heavy skull of yours and connects your tasty brain to your body and organs. Eating, walking, fishing, hunting, your morning yoga class, are all made possible because of this adaptation. Pick pretty near anything you love to do and it is only possible because of your blessed spine.

And it sets us apart from our invertebrate friends.

While seventy thousand may seem like a large number, it represents less than three to five percent of all described animal species. The rest is made up of the whopping 97%'ers, our dear invertebrates who include the arthropods (insects, arachnids, crustaceans, and myriapods), mollusks (our dear chitons, snails, bivalves, squid, and octopus), annelids (the often misunderstood earthworms and leeches), and cnidarians (our beautiful hydras, jellyfish, sea anemones, and corals).

You'll notice that many of our invertebrate friends occur as tasty snacks. Having a backbone provides a supreme advantage to your placement in the food chain. Not always, as you may include fish and game on your menu. But generally, having a backbone means you're more likely to be holding the menu versus being listed as an appetizer. So, enjoy your morning 'downward dog' and thank your backbone for the magical gift it is.

VIPS RESEARCH FROM THE FIELD

Meet Fergusonites hendersonae, a Late Hettangian (Early Jurassic) ammonite from the Taseko Lakes area of British Columbia, Canadian Rockies.

I had the very great honour of having this fellow, a new species of nektonic carnivorous ammonite, named after me by paleontologist Louse Longridge from the University of British Columbia. I'd met Louise as an undergrad and was pleased as punch to hear that she would be continuing the research by Dr. Howard Tipper.

We did several expeditions over three field seasons to the Taseko Lake area of the Rockies. We were joined by many wonderful researchers from Vancouver Island Palaeontological Society and Vancouver Paleontological Society, as well as the University of British Columbia.

The fossils found here are from the Lower Jurassic, Lower Sinemurian, Little Paradise Member of the Last Creek formation. Several ammonites species can be found here including Arnioceras semicostatum and Arnioceras miserable.

Both Dan Bowen, VIPS and John Fam, VanPS, were instrumental in planning those fossil field trips. The VIPS has been especially active in planning and executing excellent research expeditions that have brought many new fossil species to light. These trips were no exception. They were to yield many new species and help mint out a new Ph.D. We endured elevation sickness, rain, snow, grizzly bears and very chilly nights (we were sleeping next to a glacier at one point) but were rewarded by the enthusiastic crew, helicopter rides (which really cuts down the hiking time) excellent specimens and stunningly beautiful country. We were also blessed with excellent access as the area is closed to collecting except via permit.

Building on the work of Dr. Howard Tipper and Dr. Louise Longridge, along with Taylor et al from 2001, Pengfei Hou did a Master's thesis through UBC in 2014 on Sinemurian (Early Jurassic) stratigraphy at Last Creek, British Columbia and Five Card Draw, Nevada, looking at the paleontological and environmental implications of the assemblages.

As part of that work, he collected over 400 ammonite specimens from the Last Creek Formation in Last Creek, British Columbia and the Sunrise Formation in Five Card Draw, Nevada. The research led to three new species: Tipperoceras n. sp. A, Tmaegoceras obesus n. sp., Arnioceras n. sp.

Reference: PaleoDB 157367 M. Clapham GSC C-208992, Section A 09, Castle Pass Angulata - Jurassic 1 - Canada, Longridge et al. (2008)

Full reference: L. M. Longridge, P. L. Smith, and H. W. Tipper. 2008. Late Hettangian (Early Jurassic) ammonites from Taseko Lakes, British Columbia, Canada. Palaeontology 51:367-404
PaleoDB taxon number: 297415; Cephalopoda - Ammonoidea - Juraphyllitidae; Fergusonites hendersonae Longridge et al. 2008 (ammonite); Average measurements (in mm): shell width 9.88, shell diameter 28.2; Age range: 201.6 to 196.5 Ma. Locality info: British Columbia, Canada (51.1° N, 123.0° W: paleo coordinates 22.1° N, 66.1° W)

WEE SNOUT LION: CURCULIONIDAE

Wee Eocene Snout Weevil / Photo: Jim Barkley

A lovely fossil Snout Weevil, family Curculionidae, from the Green River Formation of Western Colorado, USA.

This fellow is from the collection of the deeply awesome Jim Barkley. He gets credit for the lovely photography, too, which shows the exquisite detail on this specimen.

Fossil weevil specimens can be found in the Eocene Green River Formation that outcrops in Wyoming, Colorado and Utah. The Formation is famous for its diverse faunal and floral assemblage of fossils and its fish in particular.

The site boasts beautifully preserved fossil stromatolites, plants, invertebrates and vertebrates. Specimens include reptiles, a broad selection of mammals and, surprise, even primates!

Weevils are herbivorous beetles. They're what your Mamma would call, "good little eaters." And there are plenty of them. The Curculionidae is the family of the "true" weevils and is one of the largest animal families. We likely still haven't met them all. A family reunion would include 6,800 genera and 83,000 species at last count. But don't place your final catering order just yet. If we include all the closely related weevil-type beetles in the superfamily Curculionoidea, we'd have to include an additional ten families. Quadruple that catering menu.

Weevils look like little tiny anteaters with a long 'snout' or rostrum, at the front of their head. Some of the members of this family have rather poor reputations as they make a living by damaging plants of interest to us humans.

Topping the hugely unpopular list is the boll weevil, Anthonomus grandis, a native of Mexico (until it's US invasion in 1892) and famous destroyer of cotton crops.

The Ips genus, feeding on Ponderosa pine, introduces a fungus to the tree. The fungus blocks resin canals, which leaves the weevil free to eat. Resin would normally wash the insects out; it is a defence mechanism. The fungus often kills the tree, and groups of dead trees are a focus for forest fires. In this way the insect is indirectly responsible for serious fires. The maize weevil, Sitophilus zeamais, is a major pest. It attacks both standing crops and stored cereal products, including wheat, rice, sorghum, oats, barley, rye, buckwheat, peas, and cottonseed.

ERINACEUS EUROPAUS

This little cutie is a Western European hedgehog, Erinaceus europaus, in the subfamily Erinaceinae (Fischer, 1814). They are native to western Europe, Asia, Africa and have been introduced (oops!) to New Zealand.

There are seventeen species of hedgehog in five genera. They share distant ancestry with the family Soricidae (shrews) and the gymnures.

Hedgehogs are considered "Living Fossils" as they have changed very little over the past 15 million years. These small mammals are loners with their own kind but live in close proximity to our human population. They dwell in inhabited areas, farmland, deciduous forests and desert. You'll know them by their distinctive spiny look (which may remind you of very tasty chocolates from Purdy's in Canada) and their adorable piglike snorts and grunts as they make their way through the underbrush looking for tasty snacks.

Look for them in the evening in hedgerows and undergrowth as they hunt for frogs, toads, snails, bird eggs, grassroots, berries, insects, worms and snakes. They fatten themselves up in preparation for hibernation. They'll find a nice burrow or built a nest in leaves or compost heaps. In Europe, they generally hibernate by October or November and become active again in March to mid-April once temperatures reach over 15 degrees.

MAASTRICHTIAN CLUPEIFORMES

A stunning example of the Late Cretaceous fish, Gasteroclupea branisai, from Bolivia. This beauty is housed in the Natural History Museum Alcide d'Orbignay of Cochabamba.

Gasteroclupea is a genus of prehistoric clupeiform fish related to modern anchovies and herrings.

Clupeiformes are physostomes, which means that the gas bladder has a pneumatic duct connecting it to the gut. This handy little evolutionary feature lets them fill or empty the gas bladder via their mouth. They typically lack lateral lines but have nicely defined eyes, fins and scales. They are generally silvery fish with streamlined, spindle-shaped, bodies, and often found in schools. Most species eat plankton which they filter from the water with their gills.

Gasteroclupea date back to the Maastrichtian of the Late Cretaceous. We find fossils of the genus in the Yacoraite Formation of Argentina and in the El Molino Formation of Bolivia, as you see here. Photo credit: Gilberto Juárez Huarachi‎.

PHEASANT PHASIANUS

These playful lovelies are beautiful examples of the Common Pheasant, Phasianus Cholchicus.

We associate them with tweet shorn English aristocrats jauntily going about the hunt on horseback. 

Pheasants build their nests on the ground and can fly for short distances. They spend their days searching the scrub in fields and around streams looking for tasty insects, seeds and grain.

ARMOURED AGNATHA

This lovely specimen, showing both the positive and negative of the fossil, is an armoured agnatha jawless bony fish, Victoraspis longicornualis, from Lower Devonian deposits of Podolia, Ukraine.

Victoraspis longicornualis was named by Anders Carlsson and Henning Bloom back in 2008. The new osteostracan genus and species were described based on material from Rakovets' present-day Ukraine. This new taxon shares characteristics with the two genera Stensiopelta (Denison, 1951) and Zychaspis (Javier, 1985).

Agnatha is a superclass of vertebrates. This fellow looks quite different from our modern Agnatha, which includes lamprey and hagfish. Ironically, hagfish are vertebrates that do not have vertebrae. Sometime in their evolution, they lost them as they adapted to their environment. Photo: Fossilero Fisherman

TRIASSIC AMMONOIDS

CANGREJO FÓSIL: COSTACOPLUMA

Cuticular structure in a Late Maastrichtian crab, Costacopluma mexicana, from deposits near the town of from near Paredón, Ramos Arizpe in what is now southern Coahuila (formerly Coahuila de Zaragoza), north-eastern Mexico. We see this same species in the Upper Cretaceous Moyenne of Northeast Morocco and from the Pacific slope, Paleocene of California, USA. This beauty is in the collection of José F. Ventura‎.

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

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

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

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

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

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

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

BIBONIDAE: LATE BLOOMING POLLINATORS

A recent post of the fossils found at McAbee in the Interior of British Columbia has me thinking of March Flies. March Flies are hardy, medium-sized flies in the Order Diptera, with a body length ranging from 4.0 to 10.0 mm. They tend to make for excellent specimens as they fossilize rather well. This species is one of the most satisfying fossils to collect in the Eocene deposits of McAbee and in the outskirts of Princeton, British Columbia.

The body is black, brown, or rusty, and thickset, with thick legs. The antennae are moniliform. The front tibiae bear large strong spurs or a circlet of spines. The tarsi are five-segmented and bear tarsal claws, pulvilli, and a well-developed empodium. As it is with many species, these guys included, the teens of this species are troublesome but the adults turn out alright. As larvae, Bibionidae is an agricultural pest, devouring all those tasty young seedlings you've just planted.

Then, as they mature their tastes turn to the nectar of flowers from fruit trees and la voila, they become your best friends again. With their physical and behavioural transformation complete, Bibionidae becomes a welcome garden visitor, pulling their weight in the ecosystems they live in by being important pollinators.

AMMONITE CLUSTER

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. 

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

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. 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. Ammonites were skilled and successful hunters. They caught their prey while swimming and floating in the water column. This cluster of ammonites cemented together in death would have hunted our ancient seas as keen predators.

MARINE REPTILES OF THE HUMBOLDTS

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

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

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

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

We find their fossil remains in outcrops spanning from the mid-Cretaceous to the earliest Triassic. As we look through the fossils, we see a slow evolution in body design moving towards that enjoyed by dolphins and tuna by the Upper Triassic, albeit with a narrower, more pointed snout. During the early Triassic period, ichthyosaurs evolved from a group of unidentified land reptiles that returned to the sea. They were particularly abundant in the later Triassic and early Jurassic periods before being replaced as a premier aquatic predator by another marine reptilian group, the Plesiosauria, in the later Jurassic and Cretaceous periods.

The block you see here is from Middle Triassic (Anisian/Ladinian) outcrops in the West Humboldt Mountains, Nevada.

SUNRISE FORMATION, NEVADA

At the entrance to the Pliensbachian-Toarcian localities at Joker Peak and Mina Peak Members of the Sunrise Formation, Nevada, USA.

The ammonites of this section were first studied by Dr. Paul Smith, past Chair of Earth and Ocean Sciences, University of British Columbia and more recently by Andrew Caruthers et al.

Caruthers and his team also took a goodly look at the Early Jurassic coral fauna. Caruthers is an interesting cat. He uses a combination of invertebrate paleontology and isotope geochemistry to ponder the effects of paleoclimate change and mass extinction. He's turned his eye in recent years to the Paleozoic of the Michigan Basin AND he's based in Kalamazoo, MI. Yep, Kalamazoo.

Others have taken up the mantle of discovery from these sites. Pengfei Hou did his 2014 Masters thesis comparing the Sinemurian (Early Jurassic) stratigraphic sections of Last Creek, British Columbia and Five Card Draw, Nevada including a detailed taxonomic study from the Involutum Zone to the lower part of the Harbledownense Zone of the Sinemurian.

DUBIOUS DAONELLA DUBIA

Triassic ammonoids, West Humboldt Mountains, Nevada, USA. This was the site of the 1905 Expedition of the University of California’s Department of Geology in Berkeley funded by the beautiful and bold, Annie Alexander, the women to whom the UCMP owes both its collection and existence.

Paleontologist J.P. Smith joined that expedition and published on the marine fauna in the early 1900s.

They formed the basis for his monograph on North American Middle Triassic marine invertebrate fauna published in 1914. N. J. Siberling from the US Geological Survey published on these outcrops in 1962. His work included nearly a dozen successive ammonite faunas, many of which were variants on previously described species.

Evidently, his collections consisted mainly of weathered material and were made without stratigraphic control because he believed that most, if not all, of these species, were coexistent. The fossiliferous beds found here, as well as localities in north-western Nevada, were designated the 'Daonella dubia' zone. Dubious would be closer to the truth. We've since mapped them out from stratigraphic sections to place them in the correct order of their occurrence.

SMILODON FATALIS

During the last ice age, huge cats bigger than an African lion prowled Alberta, including the fearsome beast commonly known as the sabre-toothed tiger.

The proper name for the extinct predator with foot-long, serrated knife-like canines is Smilodon fatalis.

Up until the discovery of the fossil from Medicine Hat, Alberta, the species had never been found further north than Idaho. Or so it was thought...

A few years ago, a few small fossils caught the eye of researcher Ashley Reynolds as she was rummaging through the drawers at the Royal Ontario Museum in Toronto. The drawer was part of a treasure trove of 1,200 specimens collected in the 1960s by University of Toronto palaeontologist C.S. Churcher and his team. The specimens were collected over many field seasons along the bluffs of the South Saskatchewan River near Medicine Hat.

Churcher was a palaeontologist with a keen eye and a delightful man. I had the very great pleasure of listening to many of his talks out at UBC and at a few VanPS meetings in the mid-2000s. "Rufus" was a thoroughly charming storyteller and shared many of his adventures from the field. He moved out to the West Coast for his retirement but his keen love of the science kept him giving talks to enthralled listeners keen to hear about his survey of the Dakhleh Oasis in the Western Desert of Egypt, geomorphology, stratigraphy, recent biology, Pleistocene and Holocene lithic cultures, insights learned from Neolithic Islamic pottery to Roman settlements.

The specimens he had collected had been roughly sorted but never examined in detail. Reynolds, who was researching the growth patterns and life histories of extinct cats by looking at their bones, decided to look more carefully at the fossils Churcher had found, keen to add them to her research. And what a find she made!

One of the fossils labelled Smilodon was too small a piece to be identified. But another, a bone from the ancient cat's right front paw, was identical to other Smilodon bones and was positively identified as Canada's first Smilodon. CBC did a nice write up on her discoveries. 

References:
https://www.cbc.ca/n…/technology/sabre-toothed-cat-1.5305505

LATE HETTANGIAN TO EARLY SINEMURIAN FAUNA

Hiking the hills of Nevada looking for David Taylor's faunal succession based on ammonoids established for the Late Hettangian to Early Sinemurian interval in the Western Cordillera.

It was a tremendous experience to walk through time and compare the fossil assemblages here with our own in the Canadian Rockies.

Here the faunal sequence consists of one zone and four informal biochronologic units or assemblages and was outlined by Taylor as follows: Paracaloceras morganense assemblage, Badouxia oregonensis assemblage, Canadensis Zone, Metophioceras trigonatum assemblage and Coroniceras involutum. They matched up to specimens we collected over three field seasons to similar faunal outcrops of Late Hettangian to Early Sinemurian of the Last Creek and Tyaughton area of the Canadian Rockies.

The succession also correlates with the interval delineated by the Northwest European Angulata Zone through the Lyra Subzone. Two new genera (Guexiceras and Tipperoceras) are described along with 23 new species. The phylogenetic relationships of the earliest Jurassic ammonite superfamilies indicate that it is useful to include under the Psiloceratida, the Psilocerataceae and their derivatives including the Lytocerataceae. The Arietitaceae were derived from Hettangian lytocerataceans.

CAMBRIAN ARTHROPODS OF THE BALANG

A large extinct bivalved arthropod, Tuzoia sinesis (Pan, 1957) from Cambrian deposits of the Balang Formation. The Balang outcrops in beautiful Paiwu, northwestern Hunan Province in southern China. The site is intermediate in age between the Lower Cambrian Chengjiang fauna of Yunnan and the Lower to Middle Cambrian, Kaili Lagerstätten of Guizhou in southwestern China.

This specimen was collected earlier this week. It is one of many new and exciting arthropods to come from the site.

Balang has a low diversity of trilobites and many soft-bodied fossils similar in preservation to Canada's Burgess Shale. Some of the most interesting finds include the first discovery of anomalocaridid appendages (Appendage-F-type) from China along with the early arthropod Leanchoiliids with his atypical frontal appendages (and questionable phylogenetic placement) and the soft-shelled trilobite-like arthropod, Naraoiidae.

While the site is not as well-studied as the Chengjiang and Kaili Lagerstätten, it looks very promising. The exceptionally well-preserved fauna includes algae, sponges, chancelloriids, cnidarians, worms, molluscs, brachiopods, trilobites and a few non-mineralized arthropods. It is an exciting time for Cambrian paleontology. The Balang provides an intriguing new window into our ancient seas and the profound diversification of life that flourished there.

LATE SILURIAN EURYPTERID

The impressive homeotype specimen of Eurypterus lacustris from Late Silurian deposits in New York. UCMP Berkeley's paleontological collections.

About two dozen families of eurypterids “sea scorpions” are known from the fossil record. Although these ancient predators have a superficial similarity, including a defensive needle-like spike or telson at their tail end, they are not true scorpions. They are an extinct group of arthropods related to spiders, ticks, mites and other extant creepy crawlies.

Eurypterids hunted fish in the muddy bottoms of warm shallow seas some 460 to 248 million years ago before moving on to hunting grounds in fresh and brackish water during the latter part of their reign. Their numbers diminished greatly during the Permian-Triassic extinction, becoming extinct by 248 million years ago.

ESMERALDINA ROWEII

An Esmeraldina roweii multi-block of lovely trilobites from the Lower Lower Cambrian Poleta Formation of Esmeralda County, near Goldfield Nevada, plus a very interesting creature off to the lower left who looks to be an unidentified arthropod.

A very developed trilobite with long genal and axial spines, plus the ability to enroll. And all of this before the Olenellids existed. Collection of the deeply awesome George Walter Ast. Goldfield is located 247 miles southeast of Carson City, along U.S. Route 95.

MAMMUT AMERICANUM

The American Mastodon, Mammut americanum. Mastodons resemble elephants, but are more like elephant cousins.

A second species, Mammut pacificus, has recently been described from fossils found in Idaho and California. This specimen can be seen at the Smithsonian National Museum of Natural History. Photo credit: Guy Leahy.