In Depth
Although the last part of the name, suchus, translates to English as crocodile, Ornithosuchus was actually an archosaur. These were the dominant reptiles of the Triassic some of which would diverge into true crocodiles, while others would take different paths to evolve into the dinosaurs. In fact the long hind legs that would have allowed for a bipedal stance were once taken as a sign that Ornithosuchus was a very primitive dinosaur, although modern analysis places it more firmly within the Archosauria. This identification is based upon the five towed feet, the number of skull fenestra (holes) as well as the joints of the ankles and spine to the hips.
Because the long hind legs were directly underneath the hips Ornithosuchus was easily able to attain a bipedal stance. However it’s more likely that the typical resting posture of Ornithosuchus was quadrupedal, with bipedal posture only taking over when Ornithosuchus was chasing after and attacking prey. This would have allowed for greater speed as well as reach for Ornithosuchus to find a weaker spot on the prey. This high bite angle could explain why the archosaurs developed bony armour along their backs, particularly in herbivorous members such as as Desmatosuchus.
Ornithosuchus was roughly the smaller average in size for the archosaurs and since it was larger than many of the other known archosaurs. However Ornithosuchus probably had to mind its step when dealing with other larger members of the group which could grow up to five to six meters long as seen with the Polish archosaur Smok.
Further Reading
– Triassic reptiles from the Elgin area: Ornithosuchus and the origin of carnosaurs – Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences, 248(744): 53-134. – A. D. Walker – 1964. – Taxonomy of the archosaur Ornithosuchus: reassessing Ornithosuchus woodwardi Newton, 1894 and Dasygnathoides longidens (Huxley 1877). – Earth and Environmental Science Transactions of the Royal Society of Edinburgh 106(3): 199-205. – M. Bel�n von Baczko & Mart�n D. Ezcurra – 2016.
