Oldest coelacanth, from the Early Devonian of Australia.
Coelacanths are well-known sarcopterygian (lobe-finned) fishes, which together with lungfishes are the closest extant relatives of land vertebrates (tetrapods). Coelacanths have both living representatives and a rich fossil record, but lack fossils older than the late Middle Devonian (385-390 Myr ago), conflicting with current phylogenies implying coelacanths diverged from other sarcopterygians in the earliest Devonian (410-415 Myr ago). Here, we report the discovery of a new coelacanth from the Early Devonian of Australia (407-409 Myr ago), which fills in the approximately 20 Myr 'ghost range' between previous coelacanth records and the predicted origin of the group. This taxon is based on a single lower jaw bone, the dentary, which is deep and short in form and possesses a dentary sensory pore, otherwise seen in Carboniferous and younger taxa.
Johanson
Zerina
Z
Department of Biological Sciences, Macquarie University, Sydney, New South Wales, Australia. zjohanso@bio.mq.edu.au
Long
John A
JA
Talent
John A
JA
Janvier
Philippe
P
Warren
James W
JW
D000818:Animals; D001315:Australia; D005075:Biological Evolution; D002965:Classification; D005399:Fishes / Q000235:genetics* / Q000502:physiology*; D005580:Fossils; D010163:Paleontology; D010802:Phylogeny; D013997:Time Factors