''Antineosteus'' is an extinct genus of homostiid

arthrodire Arthrodira (Greek for "jointed neck") is an Order (biology), order of extinct armored, jawed fishes of the class Placodermi that flourished in the Devonian period before their sudden extinction, surviving for about 50 million years and penetratin ...

from the

Emsian The Emsian is one of three faunal stages in the Early Devonian Epoch. It lasted from 410.62 ±1.95 million years ago to 393.47 ±0.99 million years ago. It was preceded by the Pragian Stage and followed by the Eifelian Stage. It is named after ...

Early Devonian The Early Devonian is the first of three Epoch (geology), epochs comprising the Devonian period, corresponding to the Lower Devonian Series (stratigraphy), series. It lasted from and began with the Lochkovian Stage , which was followed by the Pr ...

Kess-Kess Mounds, in the eastern

Anti-Atlas Mountains The Anti-Atlas, also known as Lesser Atlas or Little Atlas, is a mountain range in Morocco, a part of the Atlas Mountains in the northwest of Africa. The Anti-Atlas extends from the Atlantic Ocean in the southwest toward the northeast, to the heig ...

Morocco Morocco, officially the Kingdom of Morocco, is a country in the Maghreb region of North Africa. It has coastlines on the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to Algeria–Morocc ...

, and the Barrandian area of the

Czech Republic The Czech Republic, also known as Czechia, and historically known as Bohemia, is a landlocked country in Central Europe. The country is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the south ...

Description

''Antineosteus lehmani'' is rather fragmentary, known from a left anterior dorsolateral plate, a left paranuchal plate, and an inferognathal. ''A. rufus'' is known from a nearly-complete right head shield plate, and a right anterior dorsolateral plate. ''A. rufus'' is estimated to exceed , from measuring the plates with the ones from better-preserved, related taxa.

Diet

''Antineosteus'', like many other members of

Homostiidae Homostiidae (alternatively spelled Homosteidae) is a family (biology), family of flattened arthrodire placoderms from the Early Devonian, Early to Middle Devonian. Fossils appear in various strata in Europe, Russia, Morocco, Australia, Canada and ...

, lacked bladed dentition on their

jaw The jaws are a pair of opposable articulated structures at the entrance of the mouth, typically used for grasping and manipulating food. The term ''jaws'' is also broadly applied to the whole of the structures constituting the vault of the mouth ...

s, and was large in size. These traits all in one animal support a

planktivorous A planktivore is an aquatic organism that feeds on planktonic food, including zooplankton and phytoplankton. Planktivorous organisms encompass a range of some of the planet's smallest to largest multicellular animals in both the present day and i ...

lifestyle, like

baleen whale Baleen whales (), also known as whalebone whales, are marine mammals of the order (biology), parvorder Mysticeti in the infraorder Cetacea (whales, dolphins and porpoises), which use baleen plates (or "whalebone") in their mouths to sieve plankt ...

s, or the

whale shark The whale shark (''Rhincodon typus'') is a slow-moving, filter feeder, filter-feeding carpet shark and the largest known Extant taxon, extant fish species. The largest confirmed individual had a length of . The whale shark holds many records for ...

, as supported by Denison, 1978, suggesting similar lifestyles for

arthrodires Arthrodira (Greek for "jointed neck") is an order of extinct armored, jawed fishes of the class Placodermi that flourished in the Devonian period before their sudden extinction, surviving for about 50 million years and penetrating most marine eco ...

like ''Homostius'', making it reasonable for many homostiids to be suspension-feeders like the later '' Titanichthys''.

Phylogeny

''Antineosteus'' is a homostiid, closest related to Homostius. Taxonomy shown here is based on "FISH FROM THE EMSIAN OF ARAGÓN". {{Clade, style={{Clade , 1=''

Taemasosteus ''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''. The genus (and a ...

'' , 2={{Clade , 1=''

Tityosteus ''Tityosteus'' is an extinct genus of homostiid arthrodire from the Early Emsian of the Early Devonian, with fossils known from Germany, the Ibero-Armorican Trough, and southern Siberia. It attained a length of 2.5 meters. Description ''Ti ...

'' , 2={{Clade , 1=''Antineosteus'' , 2='' Homostius''

References

{{Arthrodira, state=E. {{Taxonbar, from=Q21416371 Homostiidae Arthrodire genera Placoderms of Africa Placoderms of Europe