Looking Inside — Australia’s Smallest Fossil Crocodile Species
The crocs seem more closely related to its northern relatives
A strange and extremely small species of crocodile lived in north-west Queensland about 13.5 million years ago; scientists are now learning more about it.
Modern technology has enabled University of Queensland researchers to uncover previously hidden anatomical information about the prehistoric Trilophosuchus rackhami.
Jorgo Ristevski, a PhD candidate at the faculty of science, claimed it was the most in-depth analysis of the skull anatomy of an ancient Australian crocodile ever done.
We were able to digitally isolate each bone by micro-CT scanning the well preserved cranium — according to Mr. Ristevski. In comparison to most modern crocodiles, Trilophosuchus rackhami was quite small as an adult, measuring about 70 to 90 centimeters long and weighing one to two kilograms.
This crocodile had a small snout and three distinct ridges on the top of its skull, giving it a genuinely unusual appearance.
The 1993 name Trilophosuchus rackhami, which translates to “Rackham’s three-crested croc,” was given in honor of Alan Rackham, who currently oversees the Riversleigh Fossil Discovery Centre in Mount Isa.
Paleoneurology, a field that examines the brain and nervous system of extinct species, according to Mr. Ristevski, can shed important light on the morphology, behavior, and evolution of the animal.
For one of the research, Mr. Ristevski said, “I digitally recreated the Trilophosuchus rackhami brain cavity and found that it matches that of other distantly related and potentially extinct terrestrial crocodiles from Africa and South America.”
The results are startling. Trilophosuchus rackhami, appeared more closer to modern crocodiles. This suggest Trilophosuchus rackhami spent more time on land than the majority of current crocodiles.
The discoveries, according to Mr. Ristevski, will be helpful in interpreting the evolutionary links of extinct crocodiles, a topic that will be studied in the future.
According to Associate Professor Steve Salisbury, Australia had an astounding variety of ancient crocodiles until quite recently.
He said, “Trilophosuchus rackhami was definitely one of the prettiest.”
“Crocodiles would not only need to be avoided at the water’s edge, but you would also need to be careful not to step on them in the forest, if we could travel back in time to north Queensland 13 million years ago,” said the researcher.
Reference:
- Jorgo Ristevski, Vera Weisbecker, John D. Scanlon, Gilbert J. Price, Steven W. Salisbury. Cranial anatomy of the mekosuchine crocodylian Trilophosuchus rackhami Willis, 1993. The Anatomical Record, 2022; DOI: 10.1002/ar.25050
- Jorgo Ristevski. Neuroanatomy of the mekosuchine crocodylian Trilophosuchus rackhami Willis, 1993. Journal of Anatomy, 2022; DOI: 10.1111/joa.13732
- https://www.uq.edu.au/news/article/2022/08/inside-head-of-one-of-australia%E2%80%99s-smallest-fossil-crocs
Originally published at https://www.mbiology.com.
