DIGITS AND PHALANGES

While they resembled fish and dolphins, Ichthyosaurs were large marine reptiles belonging to the order known as Ichthyosauria or Ichthyopterygia.

In 2018, Benjamin Kear and his team delved into a new are of study through technology that allows us to look at ichthyosaur remains at the molecular level. Their findings suggest ichthyosaurs had skin and blubber quite similar to our modern dolphins.

While ichthyosaurs 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. 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 find later confirmed by fossil embryo and wee baby ichy finds. They thrived during much of the Mesozoic era; based on fossil evidence, they first appeared around 250 million years ago (Ma) and at least one species survived until about 90 million years ago into the Late Cretaceous.

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.

In the Late Cretaceous, ichthyosaurs were hard hit by the Cenomanian-Turonian anoxic event. As the deepest benthos layers of the seas became anoxic, poisoned by hydrogen sulphide, deep water marine life died off. This caused a cascade that wreaked havoc all the way up the food chain. At the end of that chain were our mighty predaceous marine reptiles.

Bounty turned to scarcity and a race for survival began. The ichthyosaurs lost that race as the last lineage became extinct. It may have been their conservative evolution as a genus when faced with a need for adaptation to the world in which they found themselves and/or being outcompeted by early mosasaurs.

There are promising discoveries coming out of strata from the Cretaceous epeiric seas of Texas, USA from Nathan E. Van Vranken. His published paper from 2017, "An overview of ichthyosaurian remains from the Cretaceous of Texas, USA," looks at ichthyosaurian taxa from the mid-Cretaceous (Albian–Cenomanian) time interval in North America with an eye to ichthyosaurian distribution and demise.

Photo: This beautifully preserved Ichthyosaur paddle with its incredible detail is from Early Jurassic (183 Million Years) deposits in the Ohmden, Posidonia Shale Formation, Baden-Württemberg, east of the Rhine, southwestern Germany.

SALTRIO THEROPOD

In the summer of 1996, Angelo Zanella, an avocational fossil collector and active collaborator at the Museo di Storia Naturale di Milano (MSNM) spotted some intriguing fossil bone sticking out of a large block of rock while hunting for ammonites in the Salnova marble quarry.

The quarry is in the Alpine foothills, at the Swiss–Italian border near Saltrio. Saltrio is about 80 km north of Milan in the province of Varese, Lombardy, Italy.

Zanella reported the bones to the MSNM, which arranged a paleontological expedition to the site. The research was difficult because the explosives used for industrial quarrying had blown up the fossil-bearing layer and had broken it into hundreds of pieces.

The Saltrio quarry has been active since the 15th century as one of the finest sites of marble production, and the “Saltrio Stone” provides high-quality building materials for many famous Italian monuments  — the Scala Opera House in Milan and the Mole Antonelliana in Turin. They actively use dynamite to extract the marble. Great for the workers who are not required to manually break-up the massive pieces. Less so for the fossils. The bones from the Saltrio theropod were blown to bits just prior to Zanella's discovery then had to be pieced back together.

Three years later, after 1,800 h of chemical preparation in the Laboratory of the MSNM, 132 remains were extracted from three main blocks. Although fragmentary, jaw fragments, one tooth, rib remains, pectoral and limb bones were analyzed and found to be that of a large theropod dinosaur.

The Saltrio theropod (MSNM V3664) became popular by the name, Saltriosauro, and so it was reported (Dal Sasso, 2001a) and preliminarily described (Dal Sasso, 2001b, 2004).

Pictured above: selected elements used in the diagnosis of Saltriovenator zanellai n. gen. n. sp. Right humerus in medial (A), frontal (B) and distal (C) views; (D) left scapula, medial view; (E) right scapular glenoid and coracoid, lateral view; (F) furcula, ventral view; tooth, labial (G) and apical (H) views; (I) left humerus, medial view; right second metacarpal in dorsal (J), lateral (L) and distal (N) views; first phalanx of the right second digit in dorsal (K), lateral (M) and proximal (O) views; (P–T) right third digit in proximal, dorsal and lateral views; (U) right distal tarsal IV, proximal view; third right metatarsal in proximal (V) and frontal (X) views; second right metatarsal, proximal (W) and frontal (Y) views; (Z) reconstructed skeleton showing identified elements (red). Abbreviations as in text, asterisks mark autapomorphic traits. Scale bars: 10 cm in (A)–(E), (I), and (U)–(Y); two cm in (F), and (J)–(T); one cm in (G).

Photos by G. Bindellini, C. Dal Sasso and M. Zilioli; drawing by M. Auditore. - https://peerj.com/articles/5976/

T. REX: THE ULTIMATE PREDATOR

The first skeleton of Tyrannosaurus rex was discovered in 1902 in Hell Creek, Montana, by the Museum's famous fossil hunter Barnum Brown. Six years later, Brown discovered a nearly complete T. rex skeleton at Big Dry Creek, Montana.

The rock around it was blasted away with dynamite to reveal a “magnificent specimen” with a “perfect” skull. This skeleton, AMNH 5027, is on view in the American Museum of Natural History's Hall of Saurischian Dinosaurs. It's also reproduced in their new exhibition T. rex: The Ultimate Predator Exhibition should you find yourself lucky enough to be in New York.

PROSAUROLOPHUS MAXIMUS

Prosaurolophus maximus, Ottawa Museum of Nature

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

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

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

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

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

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

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.

KASKAPAU FORMATION: DINOSAUR BONE

Dinosaur bone / Kaskapau Formation

Bones from a variety of dinosaurs have been found in the Tumbler Ridge area of British Columbia.

Here plaster is used to protect a valuable dinosaur bone collected from Flatbed Creek near Tumbler Ridge. The bone is from the Kaskapau Formation (Turonian) and was found a few metres away from a Tetrapodosaurus, "four-footed lizard," trackway.

Both Rich McCrea and Lisa Buckley have published extensively on the fossil material from this area. Additional Papers: Arbour et al. (2008ish) wrote up a paper in the Canadian Journal of Earth Science on dinosaur material collected in the 60s from BC; Rylaarsdam et al. contributed to the same journal two years earlier on the association of dinosaur footprints and skeletal material in the Kaskapau Formation.

DINOSAUR GEORGE PODCAST

Recently, I had the very great pleasure of chatting with the deeply awesome "Dinosaur George" Blasting for his Dinosaur George Podcast. We talked about fossil sites of the Pacific Northwest, what's cool in paleontology, new fossil discoveries, finds that have made me cry and hunting ammonites (while getting shot at) in Alberta, Canada.

George is the host of the Dinosaur George Podcast. And, as one might expect, it is devoted entirely to paleontology and the natural sciences. In each episode, he and a guest explore what paleontologists do, what area of research or discovery lights them up, how they know what kind of fossil they have found and share personal stories from the field. If you're interested in learning more about paleontology, I highly recommend it.

Dinosaur George interviews some of the most interesting cats in paleo. Evolutionary Biologist, Dr. Devin O'Brien was on recently talking about canine teeth of our beloved saber-tooth-cat, Smilodon. Paleo-artist, Eric Warren shared about his craft which is a mix of science with pure-hearted creativity, and Dr. Dave Hone waxed poetic about pterosaurs. The podcast promises a veritable who's who in paleontology eager to share their love of fossils, along with stories of their very best and very worst days in the field.

Give it a listen. I'm hugely biased (we love George) but I'm not alone. The Dinosaur George Podcast just made the Top 5 Podcasts of all time. I'll pop a live link here: http://www.dinosaurgeorgepodcast.com/

FOOTSTEPS THROUGH TIME

Dinosaur Trackway / Trace Fossils

Walking along the beach at sunset, the last rays of the day catch the edges of ancient trackways of meat-eating dinosaurs who hunted in packs 100 million years ago. These were living, breathing, fear and awe-inspiring beasts that we may never meet in person but can imagine in vivid detail.

It is through their footsteps, these trace fossils, that we get our first peek at behavior we might not otherwise have known. Trace fossils or ichnofossils are burrows, footprints, tracks or even feces left behind by plants and animals that lived long ago. They may have scurried across a muddy exposure or eaten a tasty meal then pooped it out -- leaving behind clues to how they lived, what they ate and what the environment was like at the time.

Dinosaur footprints are an excellent example as they tend to make the news and are met with great excitement. Worm burrows on the other hand often go unnoticed and do not receive the hoopla and applause they deserve.

Ichnofossils can tell us a great deal about ancient environments, the behavior of ancient life and fill in gaps for us through the information they contain. As you might expect, trace fossils are often formed in soft substrates, particularly nice soft mud and sand. Those footprints you left at the beach or along a soft riverbank are candidates for fossilized trackways given the right condition and ichnological studies of the future.

CRETACEOUS SPINE LIZARD: SPINOSAURUS

Spinosaurus was a huge carnivorous theropod dinosaur who lived in the swamps of North Africa during the upper Albian to upper Turonian stages of the Cretaceous, some 112 to 93.5 million years ago.

Larger even than some Tyrannosaurus and Giganotosaurus, this fellow weighed up to 21,000 kg and with all that mass was still an accomplished swimmer.

The genus was known first from Egyptian remains discovered in 1912 and described by German palaeontologist Ernst Stromer in 1915. 

The original remains were destroyed in World War II, but additional material came to light in the early 21st century.  It is unclear whether one or two species are represented in the fossils reported in the scientific literature. The best known species is S. aegyptiacus from Egypt, although a potential second species, S. maroccanus, has been recovered from Morocco. 

The contemporary spinosaurid genus Sigilmassasaurus has also been synonymized by some authors with S. aegyptiacus, though other researchers propose it to be a distinct taxon. 

CRETACEOUS BONE BEDS

Einiosaurus procurvicornis was a horned dinosaur that roamed North America 74 million years ago. We find their bones in mass bone beds in Cretaceous outcrops of Montana and the Blackfeet Nation. The fossils have been recovered from rich bonebeds, largely consisting of only Einiosaurus fossils. Bonebeds with only one species are called monospecific bonebeds. But why do they occur? ⁣

⁣The most commonly suggested reason is that a herd of animals was suddenly killed by a natural disaster, like a volcanic eruption or flood. 

Their bodies were buried and remained in proximity to each other as they preserved, and today excavations uncover the remains of the unfortunate herd. Multiple other monospecific bonebeds have been found for other species of horned dinosaurs, such as Achelousaurus, causing researchers to suggest some groups of horned dinosaurs did exhibit herding behaviour— and that sometimes they met sudden unfortunate ends. But is sudden mass death from a natural disaster the only reason for monospecific bonebeds? ⁣

⁣Researchers say no. While the monospecific nature is still largely argued to represent herding in many cases, natural disaster is not always the cause of death. Sometimes large numbers of animals die from disease or starvation. Their carcasses could later be pushed together and buried by an event like a mudflow unrelated to their deaths. Their bones could also sit on the surface for years before an event that buries them. ⁣

⁣To understand the cause of a bonebed, researchers look at the bones themselves and the sediment that surrounds them. Bonebeds can tell us a lot about how these animals were living— but there is a lot to be learned from trying to figure out how they died, too. ⁣

Currie, P. J., & Padian, K. (Eds.). (1997). Encyclopedia of dinosaurs. Elsevier. • Rogers, R. R. (1989). Taphonomy of three monospecific dinosaur bone beds in the Late Cretaceous Two Medicine Formation northwestern Montana: Evidence for dinosaur mass mortality related to episodic drought. Graduate Student Theses, Dissertations, & Professional Papers. 5871. • Sampson, S. D. (1995). 

Two new horned dinosaurs from the Upper Cretaceous Two Medicine Formation of Montana; with a phylogenetic analysis of the Centrosaurinae (Ornithischia: Ceratopsidae). Journal of Vertebrate Paleontology, 15(4), 743-760. • Schmitt, J. G., Jackson, F. D., & Hanna, R. R. (2014). Debris flow origin of an unusual late Cretaceous hadrosaur bonebed in the Two Medicine Formation of western Montana. Hadrosaurs. Indiana Press, Bloomington, 486-501.

WOLVERINE RIVER: DINOSAUR SITE

No visit to BC's Peace Region is complete without a trip to the Tumbler Ridge Museum. In 2000, Mark Turner and Daniel Helm were tubing down the rapids of Flatbed Creek just below Tumbler Ridge. As they walked up the shoreline excitement began to build as they quickly recognized a series of regular depressions as dinosaur footprints.

Their discovery spurred an infusion of tourism and research in the area. The Hudson's Hope Museum has an extensive collection of terrestrial and marine fossils from the area. They feature ichthysaurs, a marine reptile and hadrosaur tracks.

At a British Columbia Paleontological Symposium in Tumbler Ridge, I joined Jen Becker for an impromtu late night tour of Wolverine River. There are two types of footprints at the Wolverine River Tracksite, carnivorous theropods and plant eating ankylosaurs.

During the day, the trackways at Wolverine are difficult to see. Many of the prints are so shallow that they can only be recognized by the skin impressions pressed into the tracks. By night, we filled them water and lit them by lamplight to make them stand out, reflecting the light.

PTEROSAURS: CATCHING PREY ON THE WING

Pterosaurs, the mighty winged-lizards, soared ancient skies expertly hunting for prey. Because they evolved from reptiles prior to modern birds, it was once believed that pterosaurs were primitive, passive fliers. They were seen as gliders, rather than skillfull hunters. Being the earliest vertebrates to have evolved powered flight, we now recognize that they were powerful fliers, chasing and catching their prey on the wing. One clue to this revelation is a small bone at the front of the wing bone which curves back towards the shoulder, roughly like an elongated thumb on a spread hand.

Modern birds have a small but vital feather, the aula, in this position. It shifts, acting like the leading edge on some airplane wings, redirecting the airflow over the wing, and allowing major changes in speed and angle in the air for comparatively little effort. It seems clear the pterosaurs’ extended thumb would have held a flap of membrane in a similar position at the front of the wing, and for a similar purpose. Their skulls hold the other clue; they have much larger brain cases in relation to their size than their earth-bound contemporaries. Co-ordination of flight requires tremendous brainpower, and co-ordination of active flight, with the constant shift in the shape and location of massive wings, even more so. Nature is extremely parsimonious, not frittering away investment in any organ where it is not needed.

Given the engineering challenges and the energy costs of getting each additional gram of weight off the ground, pterosaurs would never have developed such large and heavy “on board computers” unless they clearly paid their own way in faster, more nimble flight that would have allowed their owners to catch more prey and outmaneuver competing aerial hunters and scavengers.

ANKYLOSAUR TRACKWAY

FOSSILIZED DINOSAUR EGGS