Australia’s rivers, which flow through Australia’s now-arid interior, were once home to a variety of strange animals, including smooth predatory fish with large teeth and bony scales. Flinders University paleontologist Dr. An international research team led by Brian Chu has named a newly identified fish fossil discovered at a remote fossil site west of Alice Springs. Harajicadectes zhumini.

The fossil takes its name from the Harajica Sandstone, where the fossils are found in Australia’s “Red Centre”, and from the Ancient Greek word dersēs (“biter”). This is also a tribute to Professor Ming Zhu, now at the Chinese Academy of Sciences in Beijing, who made major contributions to the study of early vertebrates. One of the ancient species of tetrapodomorphs, some of which became the ancestors of four-legged molluscs with limbs and later humans. Harajicadectes It is distinguished by its large holes, especially in the upper part of the skull.

Studying the most complete example of the species, Flinders Paleontology Laboratory researcher Dr. “Since modern African fish have similar structures for sucking in air from the surface of the water, these respiratory structures are thought to facilitate breathing of surface air,” says Brian Chu. recently announced Harajicadectes It grew to about 40 cm.

“This trait appears simultaneously in several tetrapomomorph lineages during the Middle-Late Devonian.

“In addition Harajicadectes Large breathers also emerged from central Australia gogonasus from Western Australia and such as elpistostegallis Tiktaalik (closest relatives of four-legged animals). It also appears in unrelated places Pickeringius – A ray-finned fish from Western Australia, first described in 2018.”

Evolutionary context and impact of the study

Flinders Professor John Long, Australia’s leading fossil fish expert and co-author of the new discovery, said: Journal of Vertebrate PaleontologyThe simultaneous emergence of this air-breathing adaptation may have coincided with a period of reduced atmospheric oxygen in the mid-Devonian, he says.

“The ability to supplement gill respiration with air oxygen likely provided an adaptive advantage,” says Professor Long.

“We found this new form of paddlefish at one of Australia’s most remote fossil sites; the Harajica Sandstone in the Northern Territory, about 200 km west of Alice Springs, dating to the Middle-Late Devonian period, approximately 380 million years ago.” . years

“It’s hard to say exactly where Harajicadectes “It belongs to this group of fish because it appears to have convergently acquired the mosaic of special features characteristic of quite different branches of the tetrapodomorph radiation.”

This publication is the result of 50 years of discovery and research. ANU Professor Gavin Young first discovered the detrital specimens in 1973, and many other fossils discovered in 1991 were examined by the Melbourne Museum and Geosciences Australia in Canberra. Attempts to study these fossils proved elusive until a Flinders University expedition in 2016 found a nearly complete specimen.

From Flinders College of Science and Technology, Dr. “This fossil showed that all the isolated fragments collected over the years belonged to a new type of ancient fish,” Chu says. The 2016 example was donated to the Northern Territory Museum and Art Galleries in Darwin.