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Altispinax: The Mysterious Meat-Eater of Early Cretaceous England

Introduction

There are many dinosaur species which have been identified based upon very scant remains, and this article concerns one of them: a meat-eating dinosaur named Altispinax dunkeri. If you’ve never heard of this animal before, you’re not alone. It’s not exactly a name that readily springs to mind when one thinks of dinosaurs. After all, Altispinax is only known from three vertebrae that were found back in the 1850s, and nothing else has been found since then which can be positively attributed to this animal. Other isolated fossils have been found here and there, but there’s really no way to tell if all of these isolated bones, teeth, and claws all belong to the same creature. Broadly, we are reasonably sure that it was a meat-eating dinosaur, but aside from that, there’s not much else to go on.

Discovery and Description

In 1855, a British lawyer and amateur fossil hunter named Samuel H. Beckles (April 12, 1814 – September 4, 1890) was prospecting for fossils in southeastern England. Not far from the site of the Hastings battlefield, he discovered a series of three vertebrae with unusually tall dorsal spines, measuring about 14 inches (35 centimeters) from the top of the centrum disk to the top of the spine (1).

The holotype specimen of Altispinax (collections ID code: BMNH R1828, or maybe it’s NHMUK R1828). Image from “Dinosaurs of Great Britain and the role of the Geological Society of London in their discovery: basal Dinosauria and Saurischia” by Darren Naish and David M. Martill (2007). Journal of the Geological Society, volume 164. Page 503, Figure #7 (Pages 493-510).
https://darrennaish.files.wordpress.com/2013/01/naish-martill-2007-gsl-british-dinosaurs-pt-i-saurischia.pdf.

The following year in 1856, the famous British paleontologist Sir Richard Owen wrote a description of this fossil in which he ascribed it to the genus Megalosaurus, which had been classified about thirty years earlier. The description of the fossil reads as follows:

“Three anterior dorsal vertebrae: p, parapophysis, or lower transverse process: t, accessory tubercle contributing some attachment to the head of the rib: d, diapophyses, or upper transverse process, fractured, which gave attachment to the tubercle of the rib: b, oblique buttress extending from the parapophysis to the diapophysis, and contributing to the support of the neural platform : z, the prozygapophysis, z’, the zygapophysis, forming the ends of the neural platform and articulating the neural arches of the vertebrae with each other, ns, the neural spine of the foremost of these vertebras, ns’, the neural spine of the second vertebra; it expands at its extremity, overhangs the anterior shorter spine, and developes a strong bony plate from its back part which fixes it to n”, the similarly developed and modified spine of the third vertebra. The extraordinary size and strength of the spines of these anterior dorsal vertebrae, indicate the great force with which the head and jaws of the Megalosaurus must have been used” (2).

This is a drawing (yes, that’s a drawing, not a photograph) of the vertebrae, made by Joseph Dinkel which accompanies Owen’s article. Public domain image, Wikimedia Commons.
https://commons.wikimedia.org/wiki/File:Becklespinax.jpg.

The fossil vertebrae were found in the rocks of the “Wealden Supergroup”. This is a multi-layer series of geological formations consisting largely of sandstones and mudstones which are spread throughout much of southeastern England and date to the early Cretaceous Period. This geological super-formation is divided into several sub-units called “groups”, and each of these groups are divided further into “formations”. These include the “Hastings Beds Group” (dated from the Berriasian to Valanginian Stages of the early Cretaceous Period), the “Weald Clay Group” (Hauterivian and Barremian, possibly extending into the Aptian), and the “Wealden Group” (Barremian to Aptian) (3).

The vertebrae fossils were found in the rock layers of the “Hastings Beds Group”. Specifically, the fossils were found in the Wadhurst Clay Formation of East Sussex. This formation dates to the Valanginian Stage of the early Cretaceous Period, and even more specifically to the early to middle Valanginian. This would place the vertebrae’s date range at about 138-135 million years ago. During this same time, iconic early Cretaceous dinosaurs such as Iguanodon and Baryonyx had not yet evolved. Instead, Altispinax shared its habitat with the armored ankylosaur Hylaeosaurus, the sauropods Pelorosaurus and Xenoposeidon, and the small ornithopods Valdosaurus and Echinodon. Isolated fossils of Iguanodon-like animals have also been found here, as well as fossils of frogs, crocodiles, and small mammals. Since no other large carnivorous dinosaurs are known from this place and time, Altispinax might have been the top predator within its environment (4).

Discussion

Altispinax is not a well-known dinosaur, but even though it is not a major star in dinosaur paleontology circles and it is not a creature well-known to the general public, largely due to the fact that the only evidence for it comes from a single fragmentary specimen found nearly 170 years ago, Altispinax has received a surprisingly high amount of academic attention. Every now and then, professional paleontologists dabble in Altispinax speculation, analyzing these three vertebrae for the umpteenth time and pondering where exactly it fits in the theropod family tree.

Unsurprisingly, because these finds are 170 years old and are known only from fragmentary remains, Altispinax’s position in the dinosaur family tree has been regularly shuffled around because nobody, it seems, can make up their minds about what sort of animal it was. When it was first discovered, Sir Richard Owen believed that these spines belonged to Megalosaurus bucklandi, one of the first dinosaurs to be discovered and named. During the 19th and 20th Centuries, the name “Megalosaurus” was considered a “wastebasket taxon” – any remains of a meat-eating dinosaur which could not be positively identified were classified as Megalosaurus. As a result, this genus name acquired a long list of species names. Indeed, early reconstructions of Megalosaurus incorporated these three tall-spined vertebrae into its anatomy. For example, the British sculptor Benjamin Waterhouse Hawkins created a statue of Megalosaurus for Crystal Palace Park in which it possessed a bison-like hump over its shoulders.

Middle 19th Century reconstruction of Megalosaurus by Benjamin Waterhouse Hawkins, on display in Crystal Palace Park. Note the prominent bison-like hump over the shoulder. Photo by C. G. P. Gray (2007). Creative Commons Attribution 3.0 Unported license.
https://commons.wikimedia.org/wiki/File:London_-Crystal_Palace-_Victorian_Dinosaurs_1.jpg
.

When Megalosaurus’ appearance was further refined during the late 1800s into a definitely dinosaurian appearance, but in an incorrect upright pose as championed by people such as Joseph Leidy and Louis Dollo, this reconstruction again showed Megalosaurus with tall neural spines, forming a low ridge running down the middle of its back.

Late 19th Century reconstruction of Megalosaurus by Christian Von Meyer, in which the animal is portrayed with tall neural spines on its dorsal and sacral vertebrae. Illustration from Extinct Monsters, 5th Edition, by Reverend Henry N. Hutchinson. London: Chapman and Hall, 1897. Page 78. https://archive.org/details/extinctmonsters00hutciala.

In 1923, the famed German paleontologist Friedrich Von Huene took a look at the three spines from southern England, as well as a single tooth that was discovered in Germany which had been given the name Megalosaurus dunkeri. Von Huene lumped these fossils together in the belief that they both came from the same species, and determined that they did not, in fact, come from Megalosaurus. So he gave these spines and the solitary tooth a new name – Altispinax dunkeri, “Dunker’s high-spined ruler” (5).

Later researchers justifiably felt that Von Huene had jumped the gun by assuming that the tooth from Germany and the vertebrae from England belonged to the same species. Furthermore, new species had been discovered since then. In the late 1940s in the United States, another large theropod was discovered with a prominent ridge running down its back which looked remarkably similar to the three vertebrae found in England. In 1950, the American dinosaur was named Acrocanthosaurus atokensis, and other paleontologists began to wonder if the mysterious vertebrae found in England came from a similar animal. In the 1980s, paleontologist and paleo-artist Gregory Paul felt that the three vertebrae represented a European version of Acrocanthosaurus, so he gave it a provisional name of “Acrocanthosaurus altispinax”, though he wasn’t absolutely certain if he was correct. In 1991, George Olshevsky stated that these three spines did not belong to Acrocanthosaurus, but belonged to a new genus, and so it was named Becklespinax altispinax, named in honor of Samuel Beckles who had discovered the vertebrae in 1855 (6).

Skeleton of Acrocanthosaurus on display at the North Carolina Museum of Natural Sciences. Photo by Famille Wielosz-Caron (August 4, 2007). Creative Commons Attribution 2.0 Generic license.

Illustration of Becklespinax made by the paleo-artist James Robins in the magazine Dinosaurs!, issue #46, page 1084. Durham: Atlas Editions Partworks, Inc., 1994.

The name Becklespinax remained in place for the next twenty-five years until 2016 when it was challenged by Michael Maisch. He said that since Friedrich Von Huene recognized this animal as a distinct species back in 1923, this pre-dated George Olshevsky’s recognition of this animal as a distinct species in 1991. Therefore, the name Altispinax held priority over the more recent name Becklespinax, and therefore the name Becklespinax should be discarded. So in 2016, the old name of Altispinax dunkeri was resurrected (7).

Just as its name has been altered over the years, Altispinax’s phylogeny has also changed. In 1856, Sir Richard Owen classified this animal as a megalosaur. Then, following the discovery of Acrocanthosaurus in the late 1940s, it was believed to be an allosaur (later, Acrocanthosaurus was re-classified as a carcharodontosaurid). In 1991, George Olshevsky classified Altispinax once again as a megalosaur, specifically in the family Eustreptospondylidae. By the late 1990s, it was re-classified again as being more closely-related to a Middle Jurassic allosaur from China called Sinraptor, and was therefore placed in the allosauroidean family Metriacanthosauridae, which includes Metriacanthosaurus, Sinraptor, and Yangchuanosaurus. These species measured 20-25 feet long (which was the same size estimate commonly seen for Altispinax), had curvaceous skulls, and unusually tiny hands with stubby fingers and claws. Allosaurus, with its gigantic hands and meat hook claws, was a rough-and-tumble attacking predator (numerous injuries on fossils prove this), but its cousin Sinraptor did not have such well-developed hands. In 2003, Darren Naish classified this creature as belonging to the more evolutionarily-advanced super-family Allosauroidea, but didn’t hazard placing it into a specific allosaur family (8). In a 2007 article, Darren Naish wrote “Several other tetanurans exhibit a similar pattern of neural arch laminae to Becklespinax, including Condorraptor, Piatnitzkysaurus and Sinraptor, and Sinraptor in particular exhibits a superficially similar morphology: this could mean that Becklespinax is a sinraptorid, but there are no uniquely shared characters that might demonstrate this. For now, pending further discoveries, Becklespinax remains an indeterminate tetanuran of unknown affinities. Its combination of characters, and uniquely expanded neural spines tips, mean that it is a valid, diagnosable taxon” (9).

Skeleton of Sinraptor. Photo by Ian Armstrong (April 17, 2005). Creative Commons Attribution-Share Alike 2.0 Generic license.

Some people wondered if Altispinax might have been a spinosaur or perhaps a carcharodontosaur, since species from both groups have been found in Europe, and especially considering that carcharodontosaurs like Acrocanthosaurus and spinosaurs like Suchomimus and Ichthyovenator were known to have tall neural spines on its vertebrae forming a dorsal ridge. In a 2007 article, back when the animal was still referred to as Becklespinax, Darren Naish wrote “there are no shared derived characters that might unite Becklespinax with either spinosaurids or carcharodontosaurids, and these suggestions can’t be supported”(10). But not long after this was written, Concavenator was discovered in Spain, and old questions were resurrected regarding Altispinax’s position on the theropod family tree. It was determined that Concavenator was a carcharodontosaurid, and there were several noticeable similarities between this animal and Altispinax. Now, many people are once again changing Altispinax’s phylogeny, saying that, yes, it is a carcharodontosaur, but as to whether or not it is, it’s anybody’s guess at this point. Darren Naish re-classified Altispinax as a carcharodontosaurid in 2011, and the science website Palaeos also classifies Altispinax (identified on the web-page as Becklespinax) as a member of the family Carcharodontosauridae (11).

Skeleton of Concavenator, a 20 foot carcharodontosaurid from Spain. Photograph by Santiago Torralba (August 22, 2008). Creative Commons Attribution 2.0 Generic license.

Reconstructed skeleton of Concavenator. (May 1, 2019). Creative Commons Attribution-Share Alike 4.0 International license.

Reconstruction

Well, time to reconstruct what the whole animal may have looked like. It is not yet clear if Altispinax was more closely related to Sinraptor or to Concavenator. Although both of these animals had different features to the structure of their skull, outwardly they would have looked very similar to each other. Both groups of animals also had short arms with small hands, and would have had an allosaur-ish body structure. One wonders if the carcharodontosaurids evolved directly from the metriacanthosaurids like Sinraptor, but this is just a guess on my part.

As for the sail, that was a bit difficult. For years, paleo-artists depicted sail-backed bipedal dinosaurs, like the old renditions of Spinosaurus, with a sail located on the back between the arms and the legs. But the best position for a theropod’s sail is directly over the hips, not between the front limbs and hind limbs as is often seen. Animals that have their sails positioned between the front legs and back legs are quadrupedal animals, like Dimetrodon, and also what we now know Spinosaurus to be like. In a four-legged animal, the body is held off of the ground in an arch, braced by the four legs, and as such the main body has the structural support necessary to carry a sail over the back. However, in a bipedal animal, the hips form a fulcrum which balances the animal. If a bipedal animal had a sail located in a Dimetrodon-like way, positioned between the arms and legs, it would make the animal front-heavy. Therefore, a sail would be better positioned over the hips. Of course, this discounts the possibility that the animal had an unusually long tail to counter-balance the weight in the front. This is with the assumption that Becklespinax’s sail was short, extending only a small distance along the length of its back. It’s possible that it may have had a skeleton similar to Acrocanthosaurus, which had raised dorsal spines running all along its back, from the base of the skull, and extending down to the tip of the tail. However, this cannot be definitively stated to be the case until more of this animal is discovered.

The drawing that you see below was made with No. 2 pencil.

Altispinax dunkeri. © Jason R. Abdale (May 3, 2021).

Source Citations:

  1. Everything Dinosaur. “Remembering Samuel Husbands Beckles (1814-1890)”, by Mike Walley (August 24, 2014).; I Know Dino podcast. Episode 54 – “Becklespinax” (December 8, 2015).
  2. Richard Owen (1856). “Monograph on the fossil Reptilia of the Wealden Formation. Part IV”. Palaeontographical Society Monographs, volume 10.
  3. Darren Naish, “Pneumaticity, the early years: Wealden Supergroup dinosaurs and the hypothesis of saurian pneumaticity”. In Richard T. J. Moody, E. Buffetaut, Darren Naish, and David M. Martill, eds., Geological Society Special Publication No. 343 – Dinosaurs and Other Extinct Saurians: A Historical Perspective. London: The Geological Society, 2010. Pages 229-230.
  4. David B. Weishampel, ‎Peter Dodson, ‎Halszka Osmólska, eds., The Dinosauria, Second Edition. Berkeley: University of California Press, 2004. Page 73; Darren Naish, “Pneumaticity, the early years: Wealden Supergroup dinosaurs and the hypothesis of saurian pneumaticity”. In Richard T. J. Moody, E. Buffetaut, Darren Naish, and David M. Martill, eds., Geological Society Special Publication No. 343 – Dinosaurs and Other Extinct Saurians: A Historical Perspective. London: The Geological Society, 2010. Page 230; Mindat. “Becklespinax”; British Geological Survey. “Wadhurst Clay Formation”; Oladapo Odunayo Akinlotan (October 2015), The Sedimentolody of the Ashdown Formation and the Wadhurst Clay Formation, Southeast England. PhD Thesis, University of Brighton. Page 1.
  5. Smithsonian Magazine. “B is for Becklespinax”, by Riley Black (October 22, 2012).
  6. Smithsonian Magazine. “B is for Becklespinax”, by Riley Black (October 22, 2012).
  7. Michael W. Maisch (2016), “The nomenclatural status of the carnivorous dinosaur genus Altispinax v. Huene, 1923 (Saurischia, Theropoda) from the Lower Cretaceous of England”. Neues Jahrbuch für Geologie und Paläontologie – Abhandlungen, volume 280, issue 2. Pages 215-219.
  8. George Olshevsky (1991). “A revision of the parainfraclass Archosauria Cope, 1869, excluding the advanced Crocodylia”. Mesozoic Meanderings, volume 2. Pages 22-23 (1-196); Theropod Database. “Carnosauria”; Dinosaur Mailing List. “Re: Becklespinax” (February 18, 1997); Darren Naish (2003), “A definitive allosauroid (Dinosauria; Theropoda) from the Lower Cretaceous of East Sussex”. Proceedings of the Geologists’ Association, volume 114. Pages 319-326; Darren Naish and David M. Martill (2007), “Dinosaurs of Great Britain and the role of the Geological Society of London in their discovery: basal Dinosauria and Saurischia”. Journal of the Geological Society, volume 164. Pages 502-503, Figure #7 (Pages 493-510).
  9. Tetrapod Zoology. “Of Becklespinax and Valdoraptor”, by Darren Naish (October 2, 2007).
  10. Tetrapod Zoology. “Of Becklespinax and Valdoraptor”, by Darren Naish (October 2, 2007).
  11. Theropod Database. “Carnosauria”; Naish, Darren (2011). “Theropod Dinosaurs”. In Batten, ed., English Wealden Fossils. The Palaeontological Association. Pages 526-559; Smithsonian Magazine. “B is for Becklespinax”, by Riley Black (October 22, 2012); Palaeos. “Theropoda: Avetheropoda: Carcharodontosauridae”.

Bibliography:

Brachiosaurus

There are some dinosaurs that everybody thinks of when they hear the word “dinosaur”. Among these is a very large sauropod which was the reptilian analog of a giraffe. I am, of course, talking about Brachiosaurus.

Brachiosaurus is one of the more famous dinosaurs. This animal was the iconic “giraffe of the Jurassic”, and for a while it held the record of being the largest dinosaur known. It has been featured in countless books and TV documentaries about dinosaurs, and got a major role in the 1993 movie Jurassic Park. But how much do we really know about it?

Brachiosaurus makes its debut appearance in Jurassic Park (1993).

Considering that Brachiosaurus is one of the more familiar dinosaur names, we actually know surprisingly little about it. This largely has to do with the fact that fossils of this animal are extremely rare. Our total knowledge about this animal’s anatomy comes from bits and pieces of several skeletons that were found here and there across much of the Rocky Mountains within the states of Wyoming, Utah, and Colorado, as well as one location in the extreme westernmost parts of the Oklahoma pan-handle. That’s it.

Map of locations where Brachiosaurus fossils have been found, as of 2020:
1) KU Quarry, Wyoming (KUVP 129724; KUVP 133862; KUVP 142200; KUVP 144767)
2) Freeze-out Hills, Wyoming (one caudal vertebra, undescribed)
3) Reed’s Quarry 13, Wyoming (undescribed specimen)
4) Jensen/Jensen Quarry, Utah (FHPR 17108)
5) Fruita, Colorado (undescribed specimen)
6) Riggs’ Quarry 13, Colorado (FMNH P 25107) (this is the holotype)
7) Dry Mesa Quarry, Colorado (BYU 9462; BYU 12866; BYU 12867; BYU 13023)
8) Potter Creek, Colorado (BYU 4744; USNM 21903)
9) Felch Quarry 1, Garden Park, Colorado (USNM 5730)
10) Kenton Pit 1, Oklahoma (OMNH 01138)

The discovery of Brachiosaurus dates back to the very beginning of the 20th Century. In 1900, a few very large bones were discovered in western Colorado near the small town of Fruita, located only a short distance away from the Utah-Colorado border. There wasn’t much to go on: some vertebrae, one hip bone, one femur, one humerus, and part of the shoulder. Still, the bones were distinctive enough from other sauropod dinosaurs known from the Morrison Formation to warrant classifying it as a new genus. In 1903, the creature was officially named Brachiosaurus altithorax, “arm lizard with a wide chest” by Elmer Riggs.

In 1909, a German paleontological expedition led by Wilhelm von Branca were exploring in the German colony of Tanzania when they discovered some large bones near a site called Tendaguru, meaning “steep hill” in the Mwera language. Excavations revealed that it was a partial skeleton, and similarities were soon observed between these bones and the bones that had been unearthed by Elmer Rigg’s team in Colorado several years earlier. In 1914, these bones were classified as another species of Brachiosaurus, named Brachiosaurus brancai. It helped that there was a lot more of the skeleton in this specimen, and for decades afterwards, the African species of Brachiosaurus served as the model for the North American species. However, beginning in the 1980s, doubts arose whether these animals were, in fact, two species of the same genus. A thorough compare-and-contrast analysis showed that there were actually more differences noted in each bone than similarities. Consequently in 1988, the African species was re-named as Giraffatitan brancai.

Both genera had similarities. Both Brachiosaurus and Giraffatitan were very large animals, both of them belonged to the sauropod group known as “Macronaria”, both of them had necks which could be held vertically or near-vertically rather than the horizontally-oriented necks of many other sauropods, both of them had arms which were longer than their legs (hence Brachiosaurus‘ name) which resulted in high shoulders and the back sloping downwards towards the hips, and the neck was longer than the tail. Now that we have established what they had in common with each other, how different was Brachiosaurus from Giraffatitan? Since neither skeleton is complete, and in fact Brachiosaurus is known from scant remains, it is impossible to do a comprehensive 100% compare-and-contrast analysis of both of their skeletons. However, based upon the remains which we do have, we can draw a few conclusions.

First, it appears that either A) Giraffatitan was larger, or B) Both animals were the exact same length but Giraffatitan was more physically massive. Brachiosaurus is estimated to have reached a length of 70 feet long or thereabouts with a 30 foot neck. By contrast, Giraffatitan may be the same length, but differences in body proportions (which I will describe later) meant that it was bulkier than its North American counterpart. Other estimates state that Giraffatitan exceeded Brachiosaurus in size, measuring 75 to 85 feet long.

Second, the skull shape was different. When most people imagine what the head of a Brachiosaurus looked like, they are actually imagining the head of a Giraffatitan, with its high firefighter-helmet crest. Only one partial skull of a Brachiosaurus has been found near Garden Park, Colorado; it was found in 1883, but it wasn’t identified as belonging to a Brachiosaurus until decades later. Although the skull is not complete, enough of it was preserved to indicate that it was not as tall as the skull of Giraffatitan. It appears to have had a much lower crest, sort of in-between the low curvaceous skull of an Apatosaurus and the tall crested skull of a Giraffatitan.

Skulls of Brachiosaurus altithorax (A) and Giraffatitan brancai (B). Carpenter, Kenneth; Tidwell, Virginia (1998). “Preliminary description of a Brachiosaurus skull from Felch Quarry 1, Garden Park, Colorado”. Modern Geology, volume 23. Page 73 (Pages 69–84).

Third, Brachiosaurus had larger and bulkier shoulders compared to Giraffatitan, despite the fact that Giraffatitan seems on the whole to have been larger and more robustly-built than Brachiosaurus. However, Brachiosaurus might (emphasis on “might”) have had a wider chest than its African counterpart.

Fourth, Brachiosaurus may have had a longer chest compared to Giraffatitan. This cannot be stated with 100% certainty because we have not yet found a complete vertebral column or a complete ribcage of Brachiosaurus which could give us a clear picture of the animal’s body proportions. However, if it is true that Brachiosaurus had a longer torso, it would mean that its back would have had a much gentler slope than its African counterpart.

Fifth, Brachiosaurus might have had a longer tail. Only one tail vertebra of Brachiosaurus has been found so far. However, based upon its features, it has been hypothesized that the tail would have been substantially longer than that of Giraffatitan.

The scarcity of remains hints that Brachiosaurus might have been a rare animal out on the Jurassic plains. Other sauropods such as Camarasaurus were far more common.

Like Camarasaurus, Brachiosaurus was a member of a group of sauropod dinosaurs called the “macronarians”, meaning “the large nostrils”. The skull likely acted as a resonating chamber, able to produce loud low frequency long-range noises, which would be very helpful for communicating over the vast expanses of the Morrison Formation plains. If it is true that Brachiosaurus was rare, or perhaps even a solitary animal by nature, it would still need to communicate with other members of its kind, especially during the mating season. Being able to produce such sound, which could travel over long distances, would help these animals to communicate with each other even if individuals were located miles apart from one another.

Unlike the diplodocid sauropods of the Morrison Formation such as Apatosaurus, Barosaurus, and Diplodocus, Brachiosaurus did not hold its neck in a horizontal position. Instead, it held its neck either vertically or at a diagonal angle. The act of the head sticking far above the ground would minimize the chance that the sounds that it produced would be broken up and dissipated due to ground clutter, such as rocks, trees, and even other dinosaurs. This head attached to a long vertical neck would act like a submarine’s periscope, enabling it to see for long distances, and also enabling other members of its kind to spot it from a long distance away. To make sure that it could be seen from long distances away, it is possible that the head and the neck were very brightly and vividly colored while the rest of the body was comparatively drab. It’s also possible that the head might have sported some type of decoration to further ensure that it could be spotted from miles away by other members of its species – perhaps a frill or a mane of quills or baleen-like bristles. However, color and adornment are only hypothetical conjecture and should not be taken as fact.

Below are a pair of drawings that I made of Brachiosaurus altithorax. I have adorned the top part of the neck with a series of long quills forming a mane, and I also made its head bright red in order to stand out amidst the Morrison landscape. As to the remaining colors of grey with blue stripes, I based this on the Brachiosaurus model made for the Carnegie Collection in the 1980s. The drawings were made with No. 2 pencil, No. 3 pencil, and assorted Crayola and Prismacolor colored pencils.

Brachiosaurus altithorax. © Jason R. Abdale (April 26, 2021).

Keep your pencils sharp, everyone.

List of Articles about the Morrison Formation

The Morrison Formation of western North America is my favorite geological / paleontological formation to study. Within these rock layers, which are dated to the late Jurassic Period from approximately 155 to 145 million years ago, are found the fossils of some of the most famous dinosaurs known, such as Allosaurus, Brachiosaurus, Stegosaurus, and Diplodocus. However, dinosaurs were not the only animals which lived here. This was a vibrant ecosystem home to all kinds of fish, amphibians, reptiles, and mammals.

Since I set up this website in 2013, I have written several articles concerning the animals which lived in the Morrison Formation. It can be a bit difficult for me to keep track of what I’ve already written about and what I haven’t yet, so I’ve decided to compile all of my articles here into a comprehensive list. That way, it’s easy for myself and indeed anybody to quickly use this as a reference guide to look up info about the animals of late Jurassic North America.

FISH

REPTILES

MEAT-EATING DINOSAURS

PLANT-EATING DINOSAURS

Liopleurodon

The middle to late 19th Century can arguably be seen as the glory days of paleontology. While this time frame is often associated with the discovery of dinosaurs and the so-called “Bone Wars” of the American West, discoveries were also being made elsewhere during this time and concerning the remains of prehistoric life other than those creatures that inhabit every child’s fantasies.

Europeans had known about the fossilized remains of prehistoric marine life ever since the Middle Ages. In the superstitious societies of those times, shells of prehistoric mollusks were often believed to be the nails and horns of devils. During the late 18th Century, grander discoveries were made, notably by the English paleontologist Mary Anning. Due to the impressive finds made by her and others, creatures like ichthyosaurs, plesiosaurs, and mosasaurs made their entrance into our collective knowledge of life.

During the middle 1800s, some isolated teeth were discovered in northern France. In 1873, these teeth were ascribed the name Liopleurodon, meaning “smooth-sided tooth” by the French paleontologist and biologist Henri Émile Sauvage. It was evident that the teeth belonged to a large prehistoric marine reptile, and it was established that this creature belonged to a group known as the pliosaurs, which had been named by Sir Richard Owen in the 1840s. The pliosaurs were close relatives of their more famous long-necked plesiosaur cousins; in fact, pliosaurs are sometimes referred to as “short-necked plesiosaurs”. The pliosaurs had the same general body plan as their plesiosaur relatives – a rounded stocky body with four large flippers and a short tail – but they had short muscular necks and long crocodile-like heads which were very large in proportion with their bodies. The pliosaurs seem to have emerged during the early Jurassic Period, and quickly rose to be apex predators of their environment. Some species, such as the eponymous Pliosaurus and its cousin Kronosaurus grew to be some of the largest marine reptiles in Earth’s history, with their size commonly stated to be 40 feet long, just as big as Tyrannosaurus rex.

The remains of Liopleurodon have been found in Britain, France, and Germany within rocks dated to the middle Jurassic/late Jurassic boundary, approximately 165-155 million years ago. Phylogenic analysis suggests that it was an advanced member of the pliosaur family. However, it was only half the size of its gargantuan relatives. Only partial remains of this animal have been discovered so far, so it is difficult to gauge an accurate size. However, the most common size estimates for Liopleurodon are between 20 to 25 feet in length. Even though it wasn’t as big as Pliosaurus or Kronosaurus, Liopleurodon was likely the top predator in the shallow sea that once covered Europe during the Jurassic Period.

Liopleurodon first came to my attention in 1994 when it was featured in issue #85 of Dinosaurs! magazine. In the article, it was mistakenly stated that it grew to be 39 feet (12 meters) long, a much larger size than the one it was likely in life. It was also portrayed, remarkably, as being mostly toothless except for a crescent of curved fangs extending from the front of both jaws.

Liopleurodon afterwards came to mass public attention in 1999 when it was featured in Episode 3 of the BBC series Walking With Dinosaurs. In this TV show, the creature bears only a general resemblance to the real animal. Firstly, there was a drastic difference in size. As said earlier, many paleontologists think that Liopleurodon had a maximum size of 25 feet. However, in Walking With Dinosaurs, Liopleurodon was portrayed as being three times larger, measuring 80 feet long, a truly gargantuan size indeed! This inflated size estimate was based upon a single fragmentary specimen uncovered in Mexico which was attributed to Liopleurodon and was believed to represent a gigantic individual. Although the evidence was flimsy, the producers took this as a cue and exaggerated Liopleurodon’s size to absurd proportions, claiming that it was the largest marine reptile that ever lived – it wasn’t. Secondly, the head was the wrong shape, with it being given a much more curvaceous high-arched skull. In reality, the skull was much lower and flatter. Thirdly, the body proportions were incorrect. It was stated in the episode that Liopleurodon’s head measured one-fourth the total length of its body. However, an article from 2003 stated that it was likely that the head measured one-fifth the total length of its body. This would have made its head seem somewhat smaller in relation to its body.

A reconstructed Liopleurodon skeleton can be seen in the Museum of Paleontology in Tübingen, Germany – you can see a photo of it here. Granted, much of the skeleton is fictitious, since only partial remains of Liopleurodon have been found in Europe, so the blank spaces were filled in with reconstructions based upon what we know about pliosaur anatomy. The first thing that one is struck by is that it is obviously much, much smaller than the size given in Walking With Dinosaurs. The skull is also much flatter than you would expect. This might be due to compression caused by the fossilization process rather than being an accurate portrayal of its natural appearance. However, there are other pliosaur species that have flat crocodilian-like skulls, so I’ll give it the benefit of the doubt. The front teeth in both jaws are enormous, while the majority of teeth that line its mouth were only one-half or one-third the size of the front teeth, and most of them are missing. This is probably the reason why Liopleurodon was portrayed as having only front teeth in a largely toothless mouth in the Dinosaurs! article. The front end of the lower jaw is noticeably spoon or scoop-shaped – it is pronounced in relation to the rest of the dentary bone, and it has an obvious upward swoop. Like the 2003 article states, the head isn’t as large in proportion with the rest of the body as the BBC series showed. The neck is longer, and it has a much more pot-bellied barrel chest. All in all, this looks very little like its representation in Walking With Dinosaurs. Given the character’s well-known imagery from that show, you might be forgiven in thinking that the specimen on display in the museum was actually a completely different species.

Finally comes the issue of color. Ever since its appearance on Walking With Dinosaurs, reconstructions of Liopleurodon, either two-dimensional images or rendered into three-dimensional sculptures and toys, have portrayed it with a piebald black-and-white color pattern. While the repeated use of this color scheme may seem to be becoming over-used to the point of being trite, there may be scientific foundation to it, since it was claimed in a scientific study that prehistoric marine reptiles were probably darkly-colored in order to absorb as much heat as possible. Furthermore, this color pattern has become widely recognizable as the most identifiable and therefore definitive Liopleurodon appearance, and this motif is unlikely to go away anytime soon.

Seeing this reconstructed skeleton left an impression on me, and I decided to make a series of illustrations of what Liopleurodon would have looked like in real life. In contrast to my usual style, which is highly detailed and would take me weeks or even months to finish, I decided to knock out a few quick black-and-white line drawings made with an ordinary black ballpoint pen.

First is a basic line drawing showing how Liopleurodon would look as it swam through the Jurassic ocean.

Second is another line drawing showing the iconic Walking With Dinosaurs color pattern, rendered to look like something that you’d see in a coloring book.

Finally is a colorized portrayal showing the classic black-and-white piebald color pattern.

I realize that these pictures may not be what you’d expect, especially given our engrained perceptions of what we think Liopleurodon ought to look like based upon its appearance in WWD, but holy heck, look at the size of those front choppers!!! It looks like something out of a nightmarish Wayne Barlowe painting! I hope you enjoy these pictures. Please like and leave any comments below.

Dinosaur Day 2015 at the Garvies Point Museum

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Well, it was that time of year again! Every April or so, at around the time of Easter, the Garvies Point Museum and Preserve, located in Glen Cove, Nassau County, New York, holds it annual “Dinosaur Day”. This is one of the days that I really look foward to for a few reasons. First, I get to work at a place that I absolutely love and meet with some good friends. Secondly, I get to be out of NYC for a little while, which is something that I ALWAYS look foward to. Third, I get to talk about a subject that has fascinated me since my earliest days – paleontology.

Veronica, the museum’s de facto head of administration, did a wonderful job along with other members of the museum staff of setting up the classroom where the day’s major activities would be taking place. Recently, the museum’s library was substantially increased. The Sands Point Museum and Preserve had closed down its library a short while ago, and all of the books and papers were sent to the GPM. I should state, though, that almost all of these documents were originally part of the GPM collections anyway, and they just got them back, that’s all. However, Louis (one of the workers at the Garvies Point Museum, but works primarily at the Old Bethpage Village – another place that I really love) has been working hard to re-catalogue all of these books and papers back into the museum’s database.

The name of the event was somewhat misleading, as it concerned all prehistoric life, not just dinosaurs. We had exhibits on primitive mammal-like-reptiles, dinosaurs, and prehistoric mammals.

Here are some pictures of what the room looked like both during and after the hoards of kids showed up.

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Most of the really young children gravitated immediately towards the dino toy area and the fossil digsite. The older children and a lot of the adults were interested in the information that I and others were giving. They were especially interested in Dimetrodon, the famous sail-backed pelycosaur from the early Permian Period. I don’t think that I have ever had to say the name”Dimetrodon” so many times within the course of a single day! It seemed to be the only thing that many of them wanted to talk about!

Some of the major topics of interest on this day were: the Permian Mass Extinction, which occured about 251 million years ago, when an estimate 95% of all life was wiped out; of course, T. rex was a favorite; as too was Allosaurus, who competed with its larger relative for attention from the crowds. This was helped in no small part to the fact that we had a lot of Allosaurus “stuff” arrayed for them: a picture of the skull, a hand model, bone casts, a model, and my drawing which you might recognize from an earlier post on this blog.

Finally, here’s a picture of me, “the Dinosaur Man” as several members of the museum staff call me, dressed up as an amateur paleontologist. In addition to my olive drab Garvies Point Museum shirt, I also wore a khaki utility vest, because apparently ALL paleontologists wear khaki utility vests! I thought that wearing it would help to enhance my ethos with the audience, and by my reckoning, it worked.

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