A new genus and species of Ptyctodont (Placodermi) from the Late Devonian Gneudna Formation, Western Australia, and an analysis of Ptyctodont phylogeny.

Abstract

An almost complete but predominantly disarticulated ptyctodont fish, Kimbryanodus williamburyensis n. gen., n.sp. from the Late Devonian Gneudna Formation, is described. The fossils occur as three-dimensionally preserved isolated plates, and this has allowed the reconstruction of the fish. A taxonomic revision of the ptyctodonts was undertaken based on recently described Australian taxa and new reconstructions of Australian, American and European specimens. The phylogenetic analysis supports a threefold division of the ptyctodonts, with Rhamphodopsis being the most basal taxon and the other ptyctodonts divided into those possessing a median dorsal spine, spinal plate and simple V-shaped overlap of the anterior lateral and anterior dorsolateral plates and those taxa which do not.