Osteolepis is a member of Order Osteolepiformes within Vertebrata
Class Sarcopterygii, the so-called lobe-finned fish. While they
are bony fish, they are formally considered in classical cladistics
to be terrestrial vertebrates and are among the many ancestors
of tetrapods that conquered
the land late in the Devonian Period (~ 360 million
years ago), making them important to Devonian
is noted for having scales and plates on its
head that were covered with a thin layer of cosmine scales (a
spongy but bony material).
is also included in an unranked (but believed monophyletic) clade
Rhipidistia made up of Tetrapoda and still extant lungfishes
and Coelacanths. Traits that place Osteolepis within the lobe-finned
fish are paired lobed fins and posterior nasal passages called
choanae between the nasal cavity and the throat in tetrapods,
including humans, that allow breathing when the mouth is closed.
Osteolepis is also noted for think rhombic-shaped as seem in
the fossil images here. These Devonian fish had many characteristics
that would be largely retained when the first fish walked ashore.
by permission from Fossil Mall
(CC BY-NC 4.0)
see: Sarcopterygii Fish
Fossils Osteolepis macrolepidotus