An ancient fish with a nose for business

Australian palaeontologists have reconstructed a pair of fragmented 400-million-year-old fossil skulls and made a remarkable discovery.

“This was one strange looking fish,” says Benedict King, formerly of Flinders University in South Australia and now based at the Naturalis Biodiversity Centre in Leiden in The Netherlands.

The fossil pieces were originally found in the 1980s, but had not been reassembled until now. The items were found in limestone near Lake Burrinjuck in New South Wales, an area well known for containing the remains of some 70 species of the world’s earliest known reef fish.

None of those discovered to date, however, looked like this one.

“The eyes were on top of the head, and the nostrils came out of the eye sockets,” says King. “There was this long snout at the front, and the jaws were positioned very far forward.”

Indeed, the fish head looked coincidentally not unlike that of another, much more famous, Australian oddity: the monotreme, egg-laying platypus (Ornithorhynchus anatinus). The resemblance has earned the fossil species the nickname “platyfish”.

Its formal name, however, is Brindabellaspis stensioi, the genus referencing the Brindabella Range, a mountainous feature not far from where the fragments were found.

Examining the skull, King and his colleagues were able to identify another unusual feature – a kind of pressure-sensor on the snout, a modified form of which is found in a wide variety of modern fish.

This, along with the skull shape, leads the researchers to infer that Brindabellaspis shared more than appearance with the monotreme mammal.

“We suspect that this animal was a bottom-dweller,” says co-author John Long. “We imagine it used the bill to search for prey, somewhat like a platypus, while the eyes on top of the head looked out for danger from above.”

The research is published in the journal Royal Society Open Science.