Chimaeroid from Early Cretaceous reassessed in light of new data

A paper went out in Journal of Vertebrate Paleontology.

The basis for this new take on the classification was laid in 1985, when John Long attributed a fossil tooth plate to a new species, Edaphodon eyrensis. The species was named after Lake Eyre, near which the tooth was found in 1978.

Asscoiate Professor Evgeny Popov had his doubts about the attribution. However, he had to study the fossil personally to advance his theory. The opportunity presented itself during a trip to Australia in 2010. The tooth plate was stored in a museum in Adelaide, South Australia.

"I didn't plan to go there, but I was able to negotiate a temporary transfer of the fossil to Victoria, where I was working with another collection of chimaeroid fossils. The tooth plate was photographed, drawn, measured and studied under a microscope," says Popov.

To further solidify his takeaways, Popov also visited Brisbane, Queensland, where he studied more chimaeroid specimens. As a result, the plate was attributed to Ptyktoptychion Lees, and the species received a new name—Ptyktoptychion eyrensis.

Interestingly, the place of discovery, which is now in the Australian moderate climate, was in polar latitudes during the Aptian age of the Cretaceous (125 to 113 Ma). The changes of polar day and night and frosty weather were not a hindrance for this fish in the shallow waters of prehistoric Australian seas.

More information:
Systematic reassessment of Edaphodon eyrensis Long, 1985 (Holocephali, Chimaeroidei) from the Early Cretaceous of South Australia

www.tandfonline.com/doi/abs/10 … 2724634.2020.1884564

Provided by Kazan Federal University