Eoactinistia

• Australia (Victoria)

Eoactinistia is a genus of fossil coelacanth from the Early Devonian of Australia. He is the oldest known representative of this group of bony fishes ( Osteichthyes ). The only known type ( type species ) is Eoactinistia foreyi.

Fund and naming

A single fossil evidence of the genus have been discovered in about 409-407 million year old sedimentary rocks of the Fairy Formation in the southern Australian state of Victoria. They are 20 million years older than the oldest previously known coelacanth finds, whereupon also the genus name refers Eoactinistia ( " coelacanth of the Dawn "). The specific epithet honors Peter Forey. The first scientific description of the new genus and species based on a single complete mandible ( holotype NMV ( Museum Victoria, Melbourne) 218301 ).

Features

From other coelacanths can Eoactinistia basis of the mandible, which is rectangular and only about twice as long as wide, can be distinguished. At its rear end runs a characteristic notch. The teeth are fused to the lower jaw bone, a pore is present.

Documents

• Zerina Johanson, John A. Long, John A. Talent, Philippe Janvier, James W. Warren: Oldest coelacanth, from the Early Devonian of Australia. In: Biology Letters. 2, No. 3, 2006, pp. 443-446. doi: 10.1098/rsbl.2006.0470. (Article, PDF, 305 kB)