Guest Author: Sophie Pollard
Palaeobiology MSc Student
While citizens of the city of Bristol and the rest of the UK will remember the summer of 2022 for its record-breaking heatwave, records of a different kind have been set in the Bristol Bay area of Alaska, with sockeye salmon returning in higher numbers than any recorded before. This is great news for the fauna of Katmai National Park, and by extension, for fans of Katmai National Park’s Fat Bear Week, an annual event in which the bears of Katmai compete to see who best drags the competition, by how much their bellies drag along the ground.
Dinosaurs were famously stupid, but what about Theco, the Bristol dinosaur? In a new study, just published (October 2021), Bristol PhD students Antonio Ballel and Logan King, certainly don’t revise that view; there is no evidence (i’m afraid to say) that Thecodontosaurus was any more brainy (or any more stupid) than any other dinosaur of its size. However, their study does show two things: Theco held its head steady while moving, maintaining a steady gaze, and it had pretty good hearing.
The new study is based on CT scans and detailed digital reconstruction from the amazing Thecodontosaurus braincase in the collections at Yale University. In the image, you can see the braincase (top left), the reconstructed key bones (top right) and images showing the semi-circular canals, highlighted in pink (bottom left and right).
The steady gaze evidence comes from bumps on the side of the Theco brain called flocculi: in modern animals these assist the animals in keeping their head steady as they run and duck and dive, using two responses – one to keep the eyes fixed on any object in their field of view, and the other to keep the head steady. This new finding confirms that Thecodontosaurus was adept at moving bipedally, on its hind legs, and the fixed gaze adaptations would have helped it if it occasionally hunted prey. We’ve always said Theco was a herbivore, and it primarily was, but many early dinosaurs seem to have mixed and matched, and would have grabbed a juicy beetle or small lizard if they had a chance.
It might also seem amazing to be able to estimate the hearing ability of a dinosaur. This can be done using standard formulas based on measuring parts of the braincase and cochlear duct buried in the bone of the skull. It was specialized to hear low and middle frequencies of sounds, similar to other dinosaurs and early birds. These sounds could have included chirping and grunting from other Thecos, and so provides some evidence for group living and some social behaviour where they chattered to each other.
News story here and the new paper is here.
Guest Author: James Ormiston
Palaeontology MSci Graduate
Disclaimer: The sketches made for this article were drawn before the extensive re-description of Dilophosaurus specimens by Marsh & Rowe (2020). As such they may no longer be as anatomically accurate, particularly regarding the robustness of the skull and shape of the crests.
You can find the “new look” for Dilophosaurus here.
Dilophosaurus: my favourite dinosaur and one of Jurassic Park’s only celebrity species to actually come from the Jurassic period. This is a dinosaur which, perhaps more so than any other to appear on screen, has suffered a persistent identity crisis thanks to some major creative liberties taken by Crichton and Spielberg to make it more intimidating (and it worked on me, as a child it was by far the one that scared me the most). But that part is already addressed in a previous article on the blog. Today we’re going to take a look at another intriguing aspect of Dilophosaurus which could tell us a lot about what it was like to walk in its…um…dino-shoes? Di-loafers-aurus? Maybe let’s leave the palaeo-puns in the ground…
When going from school to school talking about dinosaurs, it’s only natural that one of the most commonly asked questions I get is; “What is your favourite dinosaur?” Perhaps, being as I am part of the Bristol Dinosaur Project, I should say Thecodonotosaurus, but that wouldn’t be true. If I absolutely had to pick just one, my favourite dinosaur would be Baryonyx walkeri. (more…)
Guest Author – Jack Lovegrove
Palaeontology & Evolution MSci Graduate
Ichthyosaurs are one of those groups of prehistoric animals that always seem to play second fiddle to dinosaurs in popular science (with the notable exception of the BBC series ‘Walking with Dinosaurs’). They are usually only mentioned as a way of demonstrating convergent evolution with fish rather than as fascinating and varied animals on their own right. (more…)