A new species of Polypterus has been found inside a lump of rock.
The fish, which is a member of the Cladistia's Polypteridae family, is the first complete fossil polypterid skeleton ever described.
The extinct species has been named Polypterus faraou in a paper in the Zoological Journal of the Linnean Society and was found in an area known as Toros-Menalla in western Djourab, Chad. "The articulated skeleton is preserved in three dimensions..."The articulated skeleton is preserved in three dimensions and has allowed the scientists who discovered it to determine, fairly accurately, where it lies in the fossil record.
The authors believe the species comes from the Late Miocene and they claim it's the only verifiable record for the genus Polypterus.
The species is said to closely resemble Polypterus bichir and P. endlicheri, which still live in the Chad and Chari river systems today.
They don't know exactly how this and other polypterids are interrelated, but they believe that Polypterus faraou has a primitive body shape and a primitive "shape of opening of the lateral line on the scales" which is also seen in P. bichir, P. ansorgii and P. endlicheri.
For more details see the paper: Otero O, A Likius, P Vignaud and M Brunet, 2006. A new polypterid fish: Polypterus faraou sp. nov. (Cladistia, Polypteridae) from the Late Miocene, Toros-Menalla, Chad. Zoological Journal of the Linnean Society 146: 227-237.