Placodermi is a class of armoured prehistoric fish, known from fossils, which lived from the Silurian to the end of the Devonian period. Their head and thorax were covered by articulated armoured plates and the rest of the body was scaled or naked, depending on the species. Placoderms were among the first jawed fish; their jaws likely evolved from the first of their gill arches.
Bothriolepis was a widespread, abundant and diverse genus of antiarch placoderms that lived during the Middle to Late Devonian period of the Paleozoic Era. Historically, Bothriolepis resided in an array of paleo-environments spread across every paleocontinent, including near shore marine and freshwater settings. Most species of Bothriolepis were characterized as relatively small, benthic, freshwater detritivores, averaging around 30 centimetres (12 in) in length. However, the largest species, B. rex, had an estimated bodylength of 170 centimetres (67 in). Although expansive with over 60 species found worldwide, comparatively Bothriolepis is not unusually more diverse than most modern bottom dwelling species around today.
Groenlandaspis is an extinct genus of arthrodire from the Late Devonian. Fossils of the different species are found in late Devonian strata in all continents except eastern Asia. The generic name commemorates the fact that the first specimens of the type species were found in Greenland.
Acanthothoraci is an extinct group of chimaera-like placoderms closely related to the rhenanid placoderms. Superficially, the acanthoracids resembled scaly chimaeras and (relatively) heavily armored ptyctodonts. They were distinguished from chimaeras by their large scales and plates, a pair of large spines that emanate from their chests, tooth-like beak plates, and the typical bone-enhanced placoderm eyeball. They were distinguished from other placoderms by differences in skull anatomy and by patterns on the skull plates and thoracic plates that are unique to this order.
Brindabellaspis stensioi is a placoderm with a flat, platypus-like snout from the Early Devonian of the Taemas-Wee Jasper reef in Australia. When it was first discovered in 1980, it was originally regarded as a Weejasperaspid acanthothoracid due to anatomical similarities with the other species found at the reef.
Weejasperaspididae is a family of three extinct acanthothoracid placoderms indigenous to the Early Devonian of Victoria and New South Wales, Australia.
Mandageria fairfaxi is an extinct lobe-finned fish that lived during the Late Devonian period. It is related to the much larger Hyneria; although Mandageria was smaller, it probably hunted in the same way.
Lunaspis is an extinct genus of armor-plated petalichthyid placoderm fish that lived in shallow marine environments of the Early Devonian period, from approximately 409.1 to 402.5 million year ago. Fossils have been found in Germany, China and Australia. There are three different identified species of within the genus Lunaspis: L. broilii, L. heroldi, and L. prumiensis.
Phyllolepis is the type genus of Phyllolepida, an extinct taxon of arthrodire placoderm fish from the middle to late Devonian. The species of Phyllolepis, themselves, are restricted to the Famennian-aged freshwater strata of the Late Devonian, around 360 million years ago. Fossils of this genus have been found primarily in Europe and North America. The end of the Devonian saw them disappear in a mass extinction.
Buchanosteus is an extinct genus of arthrodire placoderm. Its fossils have been found in Early Devonian-aged marine strata throughout Asia and Australia. It contains the following species:
Buchanosteidae is a family of arthrodire placoderms that lived from the Early to Middle Devonian. Fossils appear in various strata in Russia, Central Asia, Australia, and China.
Arenipiscis westolli is an extinct buchanosteid arthrodire placoderm. Its fossils have been found in Emsian-aged marine strata of New South Wales, Australia.
Parabuchanosteus murrumbidgeensis is an extinct buchanosteid arthrodire placoderm. Its fossils have been found in the Late Emsian-aged marine strata of New South Wales, Australia.
Taemasosteus is an extinct genus of arthrodire placoderm. Its fossils have been found in Emsian-aged marine strata in New South Wales, Australia. It contains two species, T. novaustrocambricus, and T. maclartiensis.
Goodradigbeeon is an extinct genus of buchanosteid arthrodire placoderm. Its fossils have been found in Emsian-aged marine strata from the Taemas-Wee Jasper reef of New South Wales, Australia and the type species is G. australianum.
Burrinjucosteus asymmetricus is an extinct buchanosteid arthrodire placoderm. Its fossils have been found in Emsian-aged marine strata of New South Wales, Australia.
Placolepis is an extinct genus of phyllolepid placoderm first discovered in New South Wales. Placolepis was the most widespread phyllolepid genus, with fossils found in Australia, Turkey, Venezuela and Antarctica.
Yurammia is a placoderm from what is now the Pambula River in New South Wales. Unlike all other known phyllolepids, Yurammia's plates had no external grooves.
Cowralepis is an extinct genus of phyllolepid placoderm of Givetian Cowra, New South Wales, and several juveniles of various stages of growth have also been discovered. Cowralepis grew to 35 centimeters.
Cobandrahlepis is an extinct genus of phyllolepid placoderm found in New South Wales, Australia.
