Dickosteus, Heterosteus, Homosteus, Cladoselache kepleri, Ramirosuarezia and Aquilolamna

Dickosteus threiplandi (Miles and Westoll 1963; Middel Devonian) is similar to Coccosteus with a distinct suture pattern. Here a specimen is traced in DGS colors and reconstructed revealing an early mandible.

Gladbachus, Dickosteus and Cladoselache kepleri

Cladoselache kepleri (Newberry 1889; Dean 1909, Late Devonian; AMNH FF7328, skull lengh about 26cm) has a shorter, wider skull than Cladoselache fyleri. Currently it nests closer to smaller flat-head sharks and placoderms, like Gladbachus and Dickosteus.

Aquilolamna milarcae (Vullo et al. 2021; 1.6m; Tuorcian, Early Cretaceous, INAH 2544 P.F.17) was described as a manta-like plankton feeder with wide terminal jaws. Here Aquilolamna nests with Cladoselache kepleri (above). Skull labels provided by Vullo et al. are reinterpreted here.

Heidtke UHJ and Krätschmer K 2001. Gladbachus adentatus nov. gen. et sp., ein primitiver Hai aus dem Oberen Givetium (Oberes Mitteldevon) der Bergisch Gladbach – Paffrath-Mulde (Rheinisches Schiefergebirge). Mainzer geowiss. Mitt. 30, 105–122.

Miles RS and Westoll TS 1963. Two new genera of coccosteid Arthrodira from the Middle Old Red Sandstone of Scotland, and their stratigraphical distribution. Trans. R. Soc. Edinb, 65, 179–210.

Newberry JS 1889. On the fossil fishes of the Eerie shale of Ohio (Abstract). Transactions of the New York Academy of Sciences, 7, 178– 180.

Vullo R, Frey E, Ifrim C, Gonzalez Gonzalez MA, Stinnesbeck ES and Stinnesbeck W 2021. Manta-like planktivorous sharks in Late Cretaceous oceans. Science 371(6535): 1253-1256. DOI: 10.1126/science.abc1490

wiki/Aquilolamna
wiki/Dickosteus
wiki/Placodermi
wiki/Cladoselache