Weird dinosaur discovery in Mongolia


This video says about itself:

22 October 2014

This computer animation shows Deinocheirus mirificus walking. Deinocheirus had unusually large forearms and several features that seem cobbled together from a variety of other dinosaurs.

From daily The Independent in Britain:

Fossils reveal very awkward dinosaur once roamed the Earth

Christopher Hooton

Thursday 23 October 2014

Palaeontologists in Mongolia’s Gobi Desert have discovered new fossils that allow them to create a picture of what one of the most unusually-shaped dinosaurs looked like.

Deinocheirus mirificus, which means “unusual horrible hand” in Latin, was a bipedal dinosaur with a hump-back and a big belly that stood almost as tall as the Tyrannosaurus rex.

The fossils were described in a study in the journal Nature, with vertebrate palaeontologist Thomas Holtz, Jr commenting: “This is definitely an unusual animal.

“It had more of a ‘beer belly’ than your typical ornithomimosaur.”

Palaeontologists recovered fossils from three individuals from the species in the Gobi Desert, and were able to combine them with some previously stolen by poachers to create a 95% complete skeleton of the dinosaur.

Its unusual combination of features has scientists puzzled.

“This creature wasn’t built for speed,” said Stephen Brusatte a palaeontologist at the University of Edinburgh. “That’s pretty obvious.”

Deinocheirus had wide hips and large toes, which made for an awkward gait as seen in the animation above.

Stegosaurus killed allosaurus, 147 million years ago


This video says about itself:

The Smell of Prey – Walking With Dinosaurs – BBC

An insight into the hunting habits of one of the most successful breeds of Dinosaur, the Allosaurus.

From Science News:

Stegosaurus landed a low blow in dino brawl

Fossil shows that allosaurus was maimed by tail spike attack

Thomas Sumner

3:19pm, October 22, 2014

VANCOUVER — In a story worthy of CSI: Jurassic Period, researchers have solved the mystery of what killed a predatory allosaurus dinosaur 147 million years ago.

The allosaurus fossil contains a circular hole in its pelvis flanked by a well-preserved, fist-sized abscess where the infected wound spread. The only murder weapon around that time that would create the circular hole is a tail spike on a stegosaurus.

The plant-eating dinosaur used its flexible body to whip its barbed tail into the allosaurus’s crotch during a fight, proposed paleontologist Robert Bakker of the Houston Museum of Natural Science on October 21 at the Geological Society of America‘s annual meeting. The allosaurus didn’t die right away, probably limping for weeks expelling pus, Bakker said.

The research could help scientists learn the fighting styles of the two dinos and reconstruct how the two species might have interacted.

Tyrannosaurs, what we don’t know


This video is called Tyrannosaur Rivalry – Planet Dinosaur – Episode 3 – BBC One.

From the Things We Don’t Know blog:

Tuesday, 23 September 2014

Ten Things We Don’t Know about Tyrannosaurs

Tyrannosaurus rex and its closest relatives, the tyrannosaurs, are among the best known and most popular dinosaurs – and yet there is still plenty we don’t know about these fascinating creatures…

1. What age could T. rex live to?
It’s possible to work out how old a tyrannosaur was when it died, by looking at growth rings inside its bones – just like counting the rings of a tree. The oldest T. rex yet examined in this way has been nicknamed Sue, and is on display at the Field Museum. It’s thought that Sue was 28 years old[1] when it died. Only about a dozen skeletons have been cut up to determine their age, and there are other T. rex’s that look like they might be older than Sue, but haven’t had their growth rings counted. This means that we really don’t exactly know the maximum age of T. rex; it’s possible that it will turn out to be much more than 28 years once the sample of adults has increased.

2. How were tyrannosaurs related?
Evolutionary trees are diagrams that can be drawn to show how animals are related to each other. Researchers gather data and use this to try to reconstruct the evolutionary history of a group of species – but it isn’t always simple. At the moment there are two versions of the evolutionary tree of tyrannosaurs[2][3] which differ in which species they include, and where they appear on the tree. As more data is collected, trees produced by different groups of researchers usually become more similar. It is likely that with more time and research we will, eventually, find a history that all of the available data supports. Until then though, how tyrannosaurs evolved remains something we don’t know.

3. What did their eggs, embryos, & hatchlings look like?
Despite the popularity of tyrannosaurs, we don’t know anything about the earliest growth stages of any tyrannosaur species. Currently, there are no skulls or skeletons of embryos or juveniles up to a year old. We don’t even know what a tyrannosaur eggshell looks like – very few embryos have been discovered inside fossilised eggs, which is the only way we could be certain of the species the egg belonged to, so the number of dinosaur species identified in this way is very low. It could be that tyrannosaur eggs have already been collected (among those that currently lack embryonic bones) but we just haven’t realised it yet! Hopefully this situation, at least for eggs and embryos, will change very soon as dinosaur eggs are being discovered all the time in places such as China.

4. Were there two groups of Tyrannosaurs in Laramidia?

It has been suggested that tyrannosaurs in the Late Cretaceous of western North America (Laramidia) can be divided into a northern group and a southern group[3]. However the fact that the fossil record from that period is incomplete throws doubt on this hypothesis. The far north and the far south of this region are virtually blank slates in terms of tyrannosaur fossils, and no fossils have yet been found from the 20 million years following the split of North America into the subcontinents of Laramidia and Appalachia. Once specimens have been found to fill the gaps, there is a chance that the proposed two groups will lose support and be replaced by something more complex.

5. What Tyrannosaurs lived in Appalachia?
It is extremely rare to find tyrannosaur fossils in the eastern region of North America, which existed as an island continent called Appalachia during the Late Cretaceous. In fact, only two species have been found, we only know of one skeleton for each of them, and neither is complete. We can tell from these that the eastern tyrannosaurs are more primitive than their western counterparts; they have shallow snouts and large arms, in contrast to the deep snouts and short arms seen in the Laramidian and Asian species. Finding out more about these animals would give clues as to what the ancestors of tyrannosaurs looked like in North America before it was split into two, but the rarity of these fossils means that Appalachia may remain the ‘dark continent’ of tyrannosaur history.

6. How long ago did the Nemegt species live?
The Nemegt Formation in the Mongolian People’s Republic is a rich source of fossils, and includes well-known tyrannosaurs such as Tyrannosaurus bataar (Tarbosaurus) and Alioramus. It is clear from looking at these fossils that they are closely related to those found in Laramidia, which suggests animals moved from one area to the other. Currently, however, we don’t know when, or in which direction, the exchange occurred. It is thought the Nemegt fauna occurred close to the end of the age of dinosaurs, but before the last slice of time that included T. rex. Often, the age of rocks can be determined by looking for the presence of certain radioactive materials, but unfortunately this hasn’t been possible in the Nemegt Formation as the materials aren’t present. This means we only have a rough idea of how long ago the rocks formed[4]. To narrow it down from the current estimate of 80-66 million years ago, we need to find a new area of rock that is possible to date but, unfortunately, this seems unlikely.

7. Did advanced tyrannosaurs have scales?
We have all seen pictures and models of T. rex looking like a giant lizard, but in reality we don’t know what covered the skin of advanced tyrannosaurs. More and more types of dinosaurs, and their relatives the flying pterosaurs (including Pterodactylus), are being found with feathers and hair-like structures on their skin, which would make them appear very different to the images in popular media. However, in some lineages such as sauropods, duckbilled dinosaurs and horned dinosaurs, feathers were lost, and scales reappeared. When it comes to tyrannosaurs, the picture is less clear. The most ancient tyrannosaurs were feathery in species big (Yutyrannus) and small (Dilong), but the presence of scales is known from patches in a handful of specimens of advanced tyrannosaurs, although these have only been reported in passing without detailed description[5]. Most specimens aren’t well enough preserved to get a full picture of their external appearance. If, however, tyrannosaur mummies are found one day, this would cast light on this aspect of their appearance.

8. What happened in the middle Jurassic period?
Unfortunately, we can only discover what the fossil record allows, and there are periods of time where there is little to work with. One of these is the Middle Jurassic, which was between 176 and 161 million years ago. This means there is a gap in our knowledge of tyrannosaur evolution, and it is difficult to determine how they developed from so called ‘basal’ forms to the more ‘advanced’ tyrannosaurs, or if these forms are even related. Hopefully, the discovery of more fossils from this interval will help fill in the gaps and give us a better picture of the history of tyrannosaurs.

9. Why did the alioramins have such long, low snouts?
Tyrannosaur workers have recently seen the addition of a new lineage, the alioramins[6]. The species in this group, Alioramus and Qianzhousaurus, have long and low snouts, in contrast to the short and deep snouts seen in, say, T. rex. T rex used its snout to deliver powerful bites to its prey, so while it is likely the longer snouts of the alioramins are an adaptation to a different kind of prey, its exact function is presently unknown.

10. Were there any tyrannosaurs in Siberia?
So far, fossils of several types of Late Cretaceous dinosaurs have been found in the far northeast of Russia, but no tyrannosaurs[7]. It is thought that dinosaurs dispersed across Northeastern Siberia and the north slope of Alaska, when moving between between Asia and Laramidia during the Late Cretaceous, so it is likely there are specimens here waiting to be found. Whatever tyrannosaur species are found in Siberia, they will be entirely new to science and they will certainly jostle the family tree.

This article was written by Dr Thomas Carr PhD, a vertebrate paleontologist who specializes in the growth and evolution of tyrannosaurs. He has named three new genera of tyrannosaurs, namely Appalachiosaurus (Alabama), Bistahieversor (New Mexico), and Teratophoneus (Utah), and he was part of the team who named Alioramus altai (Mongolia). Dr. Carr was the first to publish growth series of dinosaurs using cladistic analysis, a method usually used for recovering evolutionary relationships, for Tyrannosaurus rex and Albertosaurus sarcophagus. He collects dinosaur fossils with his students and volunteers each summer on federally regulated lands in southeastern Montana. Dr. Carr is an Associate Professor of Biology at Carthage College (Kenosha, WI), the Director of the Carthage Institute of Paleontology, and the Senior Scientific Adviser to the Dinosaur Discovery Museum (Kenosha, WI). You can visit Dr. Carr’s blog, Tyrannosauroidea Central, and follow his tweets at @Tyrannosaurcarr.

References
why don’t all references have links?

[1] Erickson, Gregory M et al. “Gigantism and comparative life-history parameters of tyrannosaurid dinosaurs.” Nature 430.7001 (2004): 772-775. doi:10.1038/nature02699
[2] Brusatte, S. L., Norell, M. A., Carr, T. D., Erickson, G. M., Hutchinson, J. R., Balanoff, A. M., Bever, G. S., Choiniere, J. N., Makovicky, P. J., and Xu, X. 2010. “Tyrannosaur paleobiology: New research on ancient exemplar organisms.” Science 329: 1481-1485.
[3] Loewen MA, Irmis RB, Sertich JJW, Currie PJ, Sampson SD (2013) “Tyrant Dinosaur Evolution Tracks the Rise and Fall of Late Cretaceous Oceans.” PLoS ONE 8(11): e79420. doi:10.1371/journal.pone.0079420
[4] Shuvalov, V. F. 2000. “The Cretaceous stratigraphy and paleobiogeography of Mongolia.” In Benton, M. J., Shichkin, M. A., Unwin, D. M., and Kurochkin, E. N. (eds.) The Age of Dinosaurs in Russia and Mongolia, pp. 256-278. Cambridge University Press, Cambridge.
[5] Currie, P. J. 2004. “Theropods, Including Birds.” In Currie, P. J. and Koppelhus, E. B. (eds.) Dinosaur Provincial Park: A spectacular ancient ecosystem revealed; pp. 367-397. Indiana University Press, Bloomington and Indianapolis.
[6] Lu, J., Yi, L., Brusatte, S. L., Yang, L., Li, H., and Chen, L. 2014. “A new clade of Asian Late Cretaceous long-snouted tyrannosaurids.” Nature Communications 5, article number: 3788. doi:10.1038/ncomms4788
[7] Weishampel, D. B., Barrett, P. M., Coria, R. A., Le Loeuff, J., Xing, X., Xijin, Z., Sahni, A., Gomani, E. M. P., and Noto, C. “Dinosaur Distribution.” In Weishampel, D. B., Dodon, P., and Osmolska, H. (eds.) The Dinosauria Second Edition, pp. 517-606. University of California Press, Berkeley.
[8] Horner, John R.; Weishampel, David B.; Forster, Catherine A (2004). “Hadrosauridae”. In Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.). The Dinosauria (2nd ed.). Berkeley: University of California Press. pp. 438–463. ISBN 0-520-24209-2.

Dinosaur with big nose discovery


This video is about hadrosaurs.

From North Carolina State University in the USA:

Hadrosaur with huge nose discovered: Function of dinosaur’s unusual trait a mystery

September 19, 2014

Call it the Jimmy Durante of dinosaurs — a newly discovered hadrosaur with a truly distinctive nasal profile. The new dinosaur, named Rhinorex condrupus by paleontologists from North Carolina State University and Brigham Young University, lived in what is now Utah approximately 75 million years ago during the Late Cretaceous period.

Rhinorex, which translates roughly into “King Nose,” was a plant-eater and a close relative of other Cretaceous hadrosaurs like Parasaurolophus and Edmontosaurus. Hadrosaurs are usually identified by bony crests that extended from the skull, although Edmontosaurus doesn’t have such a hard crest (paleontologists have discovered that it had a fleshy crest). Rhinorex also lacks a crest on the top of its head; instead, this new dinosaur has a huge nose.

Terry Gates, a joint postdoctoral researcher with NC State and the North Carolina Museum of Natural Sciences, and colleague Rodney Sheetz from the Brigham Young Museum of Paleontology, came across the fossil in storage at BYU. First excavated in the 1990s from Utah’s Neslen formation, Rhinorex had been studied primarily for its well-preserved skin impressions. When Gates and Sheetz reconstructed the skull, they realized that they had a new species.

“We had almost the entire skull, which was wonderful,” Gates says, “but the preparation was very difficult. It took two years to dig the fossil out of the sandstone it was embedded in — it was like digging a dinosaur skull out of a concrete driveway.”

Based on the recovered bones, Gates estimates that Rhinorex was about 30 feet long and weighed over 8,500 lbs. It lived in a swampy estuarial environment, about 50 miles from the coast. Rhinorex is the only complete hadrosaur fossil from the Neslen site, and it helps fill in some gaps about habitat segregation during the Late Cretaceous.

“We’ve found other hadrosaurs from the same time period but located about 200 miles farther south that are adapted to a different environment,” Gates says. “This discovery gives us a geographic snapshot of the Cretaceous, and helps us place contemporary species in their correct time and place. Rhinorex also helps us further fill in the hadrosaur family tree.”

When asked how Rhinorex may have benefitted from a large nose Gates said, “The purpose of such a big nose is still a mystery. If this dinosaur is anything like its relatives then it likely did not have a super sense of smell; but maybe the nose was used as a means of attracting mates, recognizing members of its species, or even as a large attachment for a plant-smashing beak. We are already sniffing out answers to these questions.”

The scientific dewscription of this new species is here.

See also here.

Spinosaurus bigger than Tyrannosaurus, new research


This video is called Bigger Than T. rex: Spinosaurus.

From the University of Chicago in the USA:

Massive hunter prowled water’s edge

UChicago collaboration rediscovers African dinosaur Spinosaurus, 9 feet longer than T. rex

By Claire Gwatkin Jones

Scientists have unveiled what appears to be the first truly semiaquatic dinosaur, Spinosaurus aegyptiacus. New fossils of the massive Cretaceous-era predator reveal it adapted to life in the water some 95 million years ago, providing the most compelling evidence to date of a dinosaur able to live and hunt in an aquatic environment.

The fossils also indicate that Spinosaurus was the largest known predatory dinosaur to roam the Earth, measuring more than 9 feet longer than the world’s largest Tyrannosaurus rex specimen. These findings, published online Sept. 11 on the Science Express website, also are featured in the October National Geographic magazine cover story.

An international research team—including paleontologists Nizar Ibrahim and Paul Sereno from the University of Chicago; Cristiano Dal Sasso and Simone Maganuco from the Natural History Museum in Milan, Italy; and Samir Zouhri from the Université Hassan II Casablanca in Morocco—found that Spinosaurus developed a variety of previously unknown aquatic adaptations. The researchers came to their conclusions after analyzing new fossils uncovered in the Moroccan Sahara and a partial Spinosaurus skull and other remains housed in museum collections around the world. They also used historical records and images from the first reported Spinosaurus discovery in Egypt more than 100 years ago. According to lead author Ibrahim, a 2014 National Geographic Emerging Explorer, “Working on this animal was like studying an alien from outer space; it’s unlike any other dinosaur I have ever seen.”

Aquatic adaptations of Spinosaurus

The aquatic adaptations of Spinosaurus differ significantly from earlier members of the spinosaurid family that lived on land but were known to eat fish. These adaptations include:

Small nostrils located in the middle of the skull. The small size and placement of the nostrils farther back on the skull allowed Spinosaurus to breathe when part of its head was in water.
Neurovascular openings at the end of the snout. Similar openings on crocodile and alligator snouts contain pressure receptors that enable them to sense movement in water. It’s likely these openings served a comparable function in Spinosaurus.
Giant, slanted teeth that interlocked at the front of the snout. The conical shape and location of the teeth were well-suited for catching fish.
A long neck and trunk that shifted the dinosaur’s center of mass forward. This made walking on two legs on land nearly impossible, but facilitated movement in water.
Powerful forelimbs with curved, blade-like claws. These claws were ideal for hooking or slicing slippery prey.
A small pelvis and short hind legs with muscular thighs. As in the earliest whales, these adaptations were for paddling in water and differ markedly from other predatory dinosaurs that used two legs to move on land.
Particularly dense bones lacking the marrow cavities typical to predatory dinosaurs. Similar adaptations, which enable buoyancy control, are seen in modern aquatic animals like king penguins.
Strong, long-boned feet and long, flat claws. Unlike other predators, Spinosaurus had feet similar to some shorebirds that stand on or move across soft surfaces rather than perch. In fact, Spinosaurus may have had webbed feet for walking on soft mud or paddling.
Loosely connected bones in the dinosaur’s tail. These bones enabled its tail to bend in a wave-like fashion, similar to tails that help propel some bony fish.
Enormous dorsal spines covered in skin that created a gigantic “sail” on the dinosaur’s back. The tall, thin, blade-shaped spines were anchored by muscles and composed of dense bone with few blood vessels. This suggests the sail was meant for display and not to trap heat or store fat. The sail would have been visible even when the animal entered the water.

Discovery more than century in making

More than a century ago, German paleontologist Ernst Freiherr Stromer von Reichenbach first discovered evidence of Spinosaurus in the Egyptian Sahara. Sadly, all of Stromer’s fossils were destroyed during the April 1944 Allied bombing of Munich, Germany. Ibrahim, however, was able to track down Stromer’s surviving notes, sketches and photos in archives and at the Stromer family castle in Bavaria to supplement Stromer’s surviving publications.

The new Spinosaurus fossils were discovered in the Moroccan Sahara along desert cliffs known as the Kem Kem beds. This area was once a large river system, stretching from present-day Morocco to Egypt. At the time, a variety of aquatic life populated the system, including large sharks, coelacanths, lungfish and crocodile-like creatures, along with giant flying reptiles and predatory dinosaurs.

The most important of the new fossils, a partial skeleton uncovered by a local fossil hunter, was spirited out of the country. As a result, critical information about the context of the find was seemingly lost, and locating the local fossil hunter in Morocco was nearly impossible. Remarked Ibrahim, “It was like searching for a needle in a desert.” After an exhaustive search, Ibrahim finally found the man and confirmed the site of his original discovery.

To unlock the mysteries of Spinosaurus, the team created a digital model of the skeleton with funding provided by the National Geographic Society. The researchers CT scanned all of the new fossils, which will be repatriated to Morocco, complementing them with digital recreations of Stromer’s specimens. Missing bones were modeled based on known elements of related dinosaurs. According to Maganuco, “We relied upon cutting-edge technology to examine, analyze and piece together a variety of fossils. For a project of this complexity, traditional methods wouldn’t have been nearly as accurate.”

The researchers then used the digital model to create an anatomically precise, life-size 3-D replica of the Spinosaurus skeleton. After it was mounted, the researchers measured Spinosaurus from head to tail, confirming their calculation that the new skeleton was longer than the largest documented Tyrannosaurus by more than 9 feet. According to Sereno, head of the University of Chicago’s Fossil Lab, “What surprised us even more than the dinosaur’s size were its unusual proportions. We see limb proportions like this in early whales, not predatory dinosaurs.”

Added Dal Sasso, “In the last two decades, several finds demonstrated that certain dinosaurs gave origins to birds. Spinosaurus represents an equally bizarre evolutionary process, revealing that predatory dinosaurs adapted to a semiaquatic life and invaded river systems in Cretaceous North Africa.”

Other authors of the Science paper are David Martill, University of Portsmouth, United Kingdom; Matteo Fabbri, University of Bristol, United Kingdom; Nathan Myhrvold, Intellectual Ventures; and Dawid Iurino, Sapienza Università di Roma in Italy. Important contributors to the making of the digital Spinosaurus include Tyler Keillor, Lauren Conroy and Erin Fitzgerald of the Fossil Lab at the University of Chicago.

Originally published on September 11, 2014.

How dinosaurs are depicted


This video is called Dinosaur Art Gallery Part 1.

From Tetrapod Zoology blog:

The changing life appearance of dinosaurs

By Darren Naish

September 1, 2014

Anyone who knows anything about Mesozoic dinosaurs will be – or certainly should be – familiar with the fact that our view of what these animals looked like in life has changed substantially within the last several decades. The ‘dinosaur renaissance’ of the late 1960s and 70s saw the flabby-bodied, tail-dragging behemoths of earlier decades be replaced by sprightly, athletic animals with big, bulging limb muscles, erect tails, and dashing patterns and colour schemes. This ‘new look’ for dinosaurs was initiated by (sometime Tet Zoo reader) Robert Bakker and then taken forwards by Greg Paul and Mark Hallett; several other artist-writers of the 1970s and 80s also helped perpetuate ‘new look’ dinosaurs, including John McLoughlin, Peter Zallinger and Doug Henderson (arguably the greatest palaeoartist of them all).

The influence of Greg Paul in particular has been so significant that the majority of ‘modern’ dinosaur renditions – those of Jurassic Park and numerous artworks, museum installations and so on – are, effectively, ‘Greg Paul dinosaurs’. Many palaeontologists don’t like crediting Greg Paul’s influence, in part because they dislike or disagree with the arguments, proposals and contentions he has made in his many technical articles and books. I think that ‘Greg Paul the publishing scientist’ is a different entity from ‘Greg Paul the technical artist’, and that’s Greg’s influence on how we imagine and reconstruct fossil dinosaurs needs to be fairly credited (see comments in Naish 2008, Conway et al. 2012). So, ‘Revolution # 1’ as goes the portrayal of Mesozoic dinosaurs* was instigated by Bakker, Paul, Hallett and their contemporaries, with Greg Paul being of pre-eminent importance.

* Because birds are dinosaurs, it should be noted that articles like the one you’re reading now are specifically about those dinosaurs that lived during the Mesozoic Era. Early birds are included in this general subject area, meaning that ‘Mesozoic dinosaurs’ and ‘non-avialan dinosaurs’ (= non-bird dinosaurs) are not synonymous.

I should say, by the way, that all of what I’ve just said is very familiar stuff to those interested in the world of palaeoart. However, many things that are ‘common knowledge’ for certain sets of people are not necessarily familiar to interested parties at large.

Moving on… So, those of us interested in the life appearance of fossil animals grew up with svelte, muscular, sometimes fuzzy or feathery ‘Paulian’ dinosaurs. Blubbery, fat-limbed dinosaurs that somehow persisted into the artwork of the mid-1980s – produced by artists, and presumably given the ok by palaeontologists, who shall remain nameless (some of you will know who I have in mind) – looked weirdly anachronistic when published, and their existence during the 1980s and persistence beyond them has always been inexplicable. What? You mean you hadn’t seen the Paulian dinosaurs that everyone else was drawing by now? Huh. Anyway…

This video is called Dinosaur pictures and Oil Paintings by Dinosaur Corporation.

Fast forward to the early decades of the 21st century. As ridiculous as it would have seemed to the palaeontologists and palaeoartists of the 1980s and before, feathered non-bird dinosaurs are now “commonplace” (to quote one study), and integumentary fuzz has been discovered on ornithischians and numerous theropods (including big tyrannosaurs). Assorted studies have shed substantial light on dinosaur facial tissues, forelimb orientation, posture, locomotion, muscle size, and tail shape. We have learnt enough for ‘Revolution # 2’ to occur – the ‘soft dinosaur revolution’ (hat-tip to Jason Brougham for this term).

With Paulian dinosaurs as the framework or bedrock, we have entered the age whereby people are able to add a more realistic amount of musculature, skin and other integumentary structures… to make the animals less shrink-wrapped. The concept of shrink-wrapped dinosaur syndrome (SWDS) arose sometime round about 2010 and has since been widely used in discussions of dinosaur life appearance. I’m not sure who originated the term, since it was used approximately simultaneously by sauropod expert Matt Wedel and palaeoartist John Conway.

We really need to talk about palaeoart. A new, augmented edition of All Yesterdays will appear in time.

Whatever, the concept emerged among several interested parties. The ‘All Yesterdays Movement’ – which has rigorous skeletomuscular reconstructive work at its core – has emerged from a desire to portray dinosaurs (and other fossil animals) with the right amount of soft stuff (Conway et al. 2012). It’s really not, as some seem to have assumed, built on the idea that anything goes. Muscles may sometimes be more extensive and more voluminous than illustrated within the ‘Paulian’ paradigm (Hutchinson et al. 2011, Persons & Currie 2011), dinosaurs may sometimes or often have sported wattles, dewlaps, soft frills and other epidermal features, and fuzzy and feathery coatings of various species were frequently thick and extensive, not sparse.

In the rest of this article I want to say a few brief things about the life appearance of Mesozoic dinosaurs. The old, chunky, tail-dragging dinosaurs of the 1950s and before are dead, but the shrink-wrapped, sparse-feathered ones of the 1980s should be, too. Again, this idea is familiar to those who keep up to speed on dinosaur life appearance, but I get the impression that it’s not that appreciated overall.

A very brief guide to dinosaur life appearance

Articulated skeletons, trackways, and the way bones fit together show that dinosaurs generally walked and ran with horizontal bodies and tails that were approximately parallel to the ground. Tail-tips might have drooped or dangled, but tails only really sloped downwards in horned dinosaurs, and to a degree in therizinosaurs and brachiosaur-like sauropods. This doesn’t mean that all dinosaurs were all horizontal all the time. Bipedal species of many sorts likely stood with diagonal or even near-vertical bodies when scanning the landscape, testing for odours, or showing off to other animals. And quadrupedal species like certain sauropods (most notably diplodocids) and stegosaurs were also almost certainly capable of semi-erect poses too. Therizinosaurs must have walked and stood with a perpetual diagonal body posture.

Theropods – the predatory dinosaurs and birds – did not walk around with ‘bunny hands’ as used to be shown (that is, with their palms facing the ground). Rather, the arms and hands were articulated such that the palms faced inwards and the hand could not be pronated – that is, it could not be rotated to face downwards (e.g., Gishlick 2001, Senter & Robins 2005). This raises all manner of issues as goes hand function and predatory behaviour, but that’s an issue I can’t cover here. ‘Palms-inward’ hands were also present in bipedal sauropodomorphs (the plateosaurs and their kin) (Bonnan & Senter 2007).

The idea that bird-like non-avialan coelurosaurs were feathered has been popular in some circles since the late 1980s at least. That’s right, feathered (non-avialan) dinosaurs are not a new thing, but were ‘normal’ and oft-illustrated by a whole generation of people interested in the life appearance of dinosaurs. Bakker, Hallett and Paul were all illustrating feathered theropods throughout the late 1970s and 80s but it was Paul’s 1988 book Predatory Dinosaurs of the World (Paul 1988) that launched the idea into mainstream dinofandom (see also Paul 1987). Paul’s arguments were pretty sensible: they basically hinged on the fact that non-bird maniraptorans like Velociraptor are extremely similar in form and anatomical detail to indisputably feathered Archaeopteryx. While quite a few palaeontologists agreed that the notion of a feathery Velociraptor was at least plausible, what I remember from the 1980s and early 90s is those palaeontologists who declared this idea unlikely and overly speculative. Nope, it’s scales scales scales until proven otherwise, they said. Of course, it turns out that Paul and those other palaeoartists were actually right all along.

Well, actually: now that we have lots of feathered non-bird theropods, it turns out that Paul and his followers were too conservative. These animals didn’t have a thin or sparse veneer of feathers on just part of their bodies. Rather, they were thickly clothed in them just as birds are, with fuzz covering much of the face and snout, long feathers obscuring the arms and hands and much of the legs, and fan-like arrangement of large feathers sprouting from the tail. You can do your bit to help spread the news as goes properly feathered non-avialan theropods by backing Rebecca Groom’s Palaeoplushie Velociraptor project or by purchasing my new “Just say NO to unfeathered non-avialan maniraptoran theropod dinosaurs” t-shirt at the Tet Zoo Redbubble shop!

Sauropods with softer faces

Moving on to sauropods… Sauropods were mostly covered in non-overlapping scales but some had osteoderms and tubercles across the back. Diplodocids – and maybe others – had a row of triangular, laterally compressed spines running along the dorsal midline (Czerkas 1992). The hands of ‘advanced’ sauropods were columnar, semi-circular structures where the thumb claw was the only claw present (and even this was reduced and lost in the largest, most speciose sauropod clade: Titanosauria). Hindfeet were oval, backed by a giant fat-pad, and with three (sometimes two, sometimes four) laterally compressed claws on the innermost toes.

Debate continues over the neck posture of sauropods. I’m one of several researchers who thinks – based in part on data from living animals – that sauropods (and other sauropodomorphs) routinely held their necks in high, raised poses, not horizontal or downward-sloping ones (Taylor et al. 2009). Sauropods have traditionally been illustrated with sunken, skeletal faces and nostrils perched high up in the bony nostril openings. However, work on sauropod facial tissues (Witmer 2001) means that we should imagine them with ‘softer’ faces where tissues obscured much of the underlying bony anatomy, and the fleshy nostrils were located down on the muzzle and not well up and back in the bony nostril opening [adjacent illustration take from this SV-POW! article on the life appearance of sauropods]. The notion that sauropods might have had tapir- or elephant-like trunks has been suggested a few times but is not consistent with any aspect of skull anatomy, nor with the tooth wear seen in the group. It’s also contradicted by data on nerve anatomy (animals need big facial nerves to operate a trunk) (Knoll et al. 2006). I’ve written about this idea before – see the links below.

Ornithischians, fuzzy and otherwise

Finally, what about ornithischians – the third great group of dinosaurs, the one that includes stegosaurs, ankylosaurs, ornithopods, ceratopsians and pachycephalosaurs? Beak tissue definitely sheathed the anterior parts of the jaws in these dinosaurs (this is actually preserved in some hadrosaurs) but several other aspects of their facial anatomy have been controversial. The idea that skin and other soft tissue spanned the side of the mouth cavity – this is typically termed ‘cheek’ tissue even though this is very likely technically incorrect – has been popular but occasionally contested. The distribution of nutrient foramina on the jaw bones of these dinosaurs supports the idea that an extensive amount of tissue did indeed cover the sides of their jaws (Morhardt et al. 2009), and the presence of ossifications that fit in the space between the upper and lower jaws of some ankylosaurs show that a tissue web of some sort really was present.

Preserved skin impressions show that many ornithischians possessed polygonal scales over most or all of their bodies; at least some hadrosaurs also had serrated or ribbon-like frills along the back and tail. The gigantic, complex bony nostrils of hadrosaurs and ceratopsians almost certainly housed erectile or inflatable structures of some sort. Soft crests, dewlaps and other structures are suspected or known to have been present in hadrosaurs and other ornithischians, and the horns of ceratopsians, and plates and spines of stegosaurs and ankylosaurs, were certainly enlarged in size (sometimes substantially) by keratinous coverings.

The big deal about ornithischian life appearance right now concerns the presence of filamentous integumentary structures in several taxa: in the heterodontosaurid Tianyulong, the ceratopsian Psittacosaurus, and in Kulindadromeus, a bipedal ornithischian that would once have been identified as an ornithopod but is actually outside the clade that includes ornithopods and marginocephalians. Kulindadromeus is remarkable in that it is partially covered in simple filaments but also in parallel fibres that emerge from broad, plate-like structures, and in bundles of parallel, ribbon-like filaments (Godefroit et al. 2014). None of these structures are longer than 2 or 3 cm. Scales cover the feet and imbricated, rectangular scales – arranged in several longitudinal rows – are present across the dorsal surface of the tail.

The question now is how widespread such filamentous structures were across Ornithischia, and across Dinosauria in general. Were they restricted to one or two lineages, were they normal across the small-bodied members of all lineages, or were they present across diverse small-bodied and large-bodied lineages? And are the structures in ornithischians homologous with the filaments of theropods and pterosaurs? We simply need more data from more fossils before we can go further with this.

Finding information is hard – so, what to do?

Needless to say, there’s a ton more that could be said about dinosaur life appearance. What I’ve done here is merely overview, in very brief fashion, some of the more easily summarised subject areas. What do people do when they need up-to-date information on these sorts of issues? That’s not an easy question to answer. The only competent and comprehensive review of dinosaur life appearance is Paul’s 1987 book chapter (Paul 1987), and it’s now woefully out of date.

Your other recourse is to scour through the vast primary literature, or to team up with a friendly expert (and don’t go assuming that palaeontologists are necessarily useful on this sort of stuff. Those who work on phylogenetics, diversity across time, histology and so on are often not up to speed on soft tissue anatomy. Exhibit A: all those execrable and hopelessly inaccurate dinosaur images published in books that were supposedly authenticated by august working scientists). So, what’s needed? The answer: a grand new illustrated work that provides a comprehensive guide to the life appearance of fossil dinosaurs. The good news: plans to produce just such a project are underway right now. Watch this space…

For previous Tet Zoo articles on palaeoart and the life appearance of Mesozoic dinosaurs, see…

And – entirely coincidentally – today all sees the publication of my colleague Mark Witton’s article on palaeoart Patterns in Palaeontology: Palaeoart – fossil fantasies or recreating lost reality?

Refs – -

Bonnan, M. F. & Senter, P. 2007. Were the basal sauropodomorph dinosaurs Plateosaurus and Massospondylus habitual quadrupeds. Special Papers in Palaeontology 77, 139-155.

Conway, J., Kosemen, C. M., Naish, D. & Hartman, S. 2012. All Yesterdays: Unique and Speculative Views of Dinosaurs and Other Prehistoric Animals. Irregular Books.

Czerkas, S. A. 1992. Discovery of dermal spines reveals a new look for sauropod dinosaurs. Geology 20, 1068-1070.

Gishlick, A. D. 2001. The function of the manus and forelimb of Deinonychus antirrhopus and its importance for the origin of avian flight. In Gauthier, J. & Gall, L. F. (eds) New perspectives on the origin and early evolution of birds: proceedings of the international symposium in honor of John H. Ostrom. Peabody Museum of Natural History, Yale University (New Haven), pp. 301-318.

Godefroit, P., Sinitsa, S. M.,  Dhouailly, D., Bolotsky, Y. L., Sizov, A. V., McNamara, M. E., Benton, M. J. & Spagna, P. 2014. A Jurassic ornithischian dinosaur from Siberia with both feathers and scales. Science 345, 451-455

Hutchinson, J. R., Bates, K. T., Molnar, J., Allen, V. & Makovicky, P. J. 2011. A computational analysis of limb and body dimensions in Tyrannosaurus rex with implications for locomotion, ontogeny, and growth. PLoS ONE 6(10): e26037. doi:10.1371/journal.pone.0026037

Knoll, F., Galton, P. M. & López-Antoñanzas, R. 2006. Paleoneurological evidence against a proboscis in the sauropod dinosaur Diplodocus. Geobios 39, 215-221.

Morhardt, A. C., Bonnan M. F. & Keillor, T. 2009. Dinosaur smiles: correlating premaxilla, maxilla, and dentary foramina counts with extra-oral structures in amniotes and its implications for dinosaurs. Journal of Vertebrate Paleontology 29 (supplement to 3), 152A.

Naish, D. 2008. The Great Dinosaur Discoveries. University of California Press, Berkeley.

Naish, D. 2014. Rediscovering the dinosaurs. Science Uncovered 7 (June 2014), 68-72.

Paul, G. S. 1987. The science and art of restoring the life appearance of dinosaurs and their relatives – a rigorous how-to guide. In Czerkas, S. J. & Olson, E. C. (eds) Dinosaurs Past and Present Vol. II. Natural History Museum of Los Angeles County/University of Washington Press (Seattle and London), pp. 4-49.

1988. Predatory Dinosaurs of the World. Simon & Schuster, New York.

Persons, W. S. & Currie, P. J. 2011. The tail of Tyrannosaurus: reassessing the size and locomotive importance of the M. caudofemoralis in non-avian theropods. The Anatomical Record 294, 119-131.

Senter, P. & Robins, J. H. 2005. Range of motion in the forelimb of the theropod dinosaur Acrocanthosaurus atokensis, and implications for predatory behaviour. Journal of Zoology 266, 307-318.

Taylor, M. P., Wedel, M. J. & Naish, D. 2009. Head and neck posture in sauropod dinosaurs inferred from extant animals. Acta Palaeontologica Polonica 54, 213-220.

Witmer, L. M. 2001. Nostril position in dinosaurs and other vertebrates and its significance for nasal function. Science 293, 850-853.

Darren NaishAbout the Author: Darren Naish is a science writer, technical editor and palaeozoologist (affiliated with the University of Southampton, UK). He mostly works on Cretaceous dinosaurs and pterosaurs but has an avid interest in all things tetrapod. His publications can be downloaded at darrennaish.wordpress.com. He has been blogging at Tetrapod Zoology since 2006. Check out the Tet Zoo podcast at tetzoo.com! Follow on Twitter @TetZoo.

Utah dinosaur tracks site open to the public


This video from the USA is called Dinosaur Footprints Set For Public Display In Utah.

From Associated Press:

Site of dinosaur tracks to be unveiled

by Brady Mccombs

SALT LAKE CITY, UTAH – A dry wash full of 112-million-year-old dinosaur tracks that include an ankylosaurus, dromaeosaurus and a menacing ancestor of the Tyrannosaurus rex, is set to open to the public this fall in Utah.

There are more than 200 tracks near the city of Moab from 10 different ancient animals that lived during the early Cretaceous period, said Utah Bureau of Land Management paleontologist ReBecca Hunt-Foster.

They were first discovered in 2009 by a resident. Since then, paleontologists led by a team at the University of Colorado at Denver have studied them and prepared them to go on display for the general public.

The tracks include a set of 17 consecutive footprints left by [a] Tyrannosaurus rex ancestor and the imprint of an ancient crocodile pushing off into the water.

The site is one of the largest areas of dinosaur tracks from the early Cretaceous period known to exist in North America, she said.

“We don’t usually get this,” said Hunt-Foster, a paleontologist for 16 years. “It is a beautiful track site, one of the best ones I’ve ever seen.”

There are footprints from duckbilled dinosaurs, prehistoric birds, long-necked plant eaters and a dromaeosaur similar to a velociraptor or Utahraptor that had long, sharp claws.

In one rock formation, a footprint left behind by a large plant eater is right in the middle of prints from a meat-eating theropod, Hunt-Foster said.

The imprint of an ancient crocodile shows the chest, body, tail and one foot. Paleontologists believe it was made while the crocodile was pushing off a muddy bank into water.

Paleontologists believe the tracks were made over several days in what was a shallow lake. They likely became covered by sediment that filled them up quickly enough to preserve them but gently enough not to scour them out, Hunt-Foster said. Over time, as more sediment built up, they became rock. They’re near a fault line, where the land has moved up and down over the years, she said. Rain slowly eroded away layers of the rock, exposing the footprints.