Skip to main content

Coelophysis bauri

I'm going to start using this blog not only for my technical comments but also to introduce my attempts at life-restorations of theropod dinosaurs. Left is the famous Coelophysis bauri. Coelophysis is one of the best preserved theropods with numerous complete specimens.

One interesting thing about this animals is the supposed evidence of cannibalism. Two specimens have been long considered to have
remains of members of its own species in their thoracic cavities. This view has been recently challenged by Sterling Nesbitt et al. A closer reinspection of the specimens revealed that in one specimen (AMNH FR 7223) the gut contents were actually not even inside the ribcage but underneath it. The second specimen (AMNH FR 7224) on the other hand was shown to actually have bone materials within its thoracic cavity. However, detailed histological study has shown that none of these bones had any diagnostic characters to suggest they were Coelophysis but were more likely to be from a small crocodylomorph.

So, there is no compelling evidence of cannibalism in Coelophysis.


Mike said…
Thank you for your comments on Coelophysis bauri, I was trying to explain to one of the young dinosaur fans that I meet in the course of my work that not everything seen on Walking with Dinosaurs is the gospel truth, but such programmes are based on the best guesses made by palaeontologists reviewing the evidence at the time. However, I suspect that theropods such as Coelophysis were probably capable of turning cannibalistic when environmental pressures could stresses amongst populations.

Nice blog, and I really appreciate the line drawings, we have made some attempts at drawing prehistoric animals as well, but I think yours are better than my efforts.

Best wishes

Popular posts from this blog

R for beginners and intermediate users 3: plotting with colours

For my third post on my R tutorials for beginners and intermediate users, I shall finally touch on the subject matter that prompted me to start these tutorials - plotting with group structures in colour.

If you are familiar with R, then you may have noticed that assigning group structure is not all that straightforward. You can have a dataset that may have a column specifically for group structure such as this:

B0 B1 B2 Family
Acrocanthosaurus 0.308 -0.00329 3.28E-05 Allosauroidea
Allosaurus 0.302 -0.00285 2.04E-05 Allosauroidea
Archaeopteryx 0.142 -0.000871 2.98E-06 Aves
Bambiraptor 0.182 -0.00161 1.10E-05 Dromaeosauridae
Baryonychid 0.189 -0.00238 2.20E-05 Basal_Tetanurae
Carcharodontosaurus 0.369 -0.00502 5.82E-05 Allosauroidea
Carnotaurus 0.312 -0.00324 2.94E-05 Neoceratosauria
Ceratosaurus 0.377 -0.00522 6.07E-05 Neoceratosauria
Citipati 0.278 -0.00119 5.08E-06 Oviraptorosauria

The difference between Lion and Tiger skulls

A quick divergence from my usual dinosaurs, and I shall talk about big cats today. This is because to my greatest delight, I had discovered today a wonderful book. It is called The Felidæ of Rancho La Brea (Merriam and Stock 1932, Carnegie Institution of Washington publication, no. 422). As the title suggests it goes into details of felids from the Rancho La Brea, in particular Smilodon californicus (probably synonymous with S. fatalis), but also the American Cave Lion, Panthera atrox. The book is full of detailed descriptions, numerous measurements and beautiful figures. However, what really got me excited was, in their description and comparative anatomy of P. atrox, Merriam and Stock (1932) provide identification criteria for the Lion and Tiger, a translation of the one devised by the French palaeontologist Marcelin Boule in 1906. I have forever been looking for a set of rules for identifying lions and tigers and ultimately had to come up with a set of my own with a lot of help fro…

Spinosaurus, the gigantic pangolin of the Cretaceous?

I was made aware of this not long ago - it kind of looks creepy, but it gave me an idea:

Did Spinosaurus walk like a pangolin?

That is, with it's hands low to the ground but not touching the ground - so no knuckle walking - and maintaining balance as a biped...

This pangolin seems to maintain balance on its hind legs even though, on cursory glance, its centre of mass seems too far forward for that.

Spinosaurus is supposed to have had a dense femur, so maybe its centre of gravity was farther back than you'd think from overall proportions. Maybe the sail helped tip the scale back?

...or maybe it was a giant ant-eater? Those giant claws look particularly suited to breaking open termite mounds?

Who knows. This is me being silly, but thought it was hilarious enough to share...