''Amazichthys'' is an extinct genus of selenosteid

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 Middle Famennian of the

Late Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era during the Phanerozoic eon, spanning 60.3 million years from the end of the preceding Silurian period at million years ago ( Ma), to the beginning of the succeeding ...

of the Anti-Atlas Mountains of

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 ...

. It contains a single species, ''Amazichthys trinajsticae''. It is one of a few example of

placoderm Placoderms (from Ancient Greek πλάξ 'plax'', ''plakos'''Plate (animal anatomy), plate' and δέρμα 'derma'''skin') are vertebrate animals of the class (biology), class Placodermi, an extinct group of prehistoric fish known from Pal ...

known from whole body shape, including cartilaginous axial and fin elements.

Description

''Amazichthys'' had a profile similar to that of fast-moving pelagic fishes, with lateral keels for stability, and a lunate caudal fin, suggesting it could reach and maintain high speed. The

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

, AA.MEM.DS.8, is long.

Etymology

''Amazichthys trinajsticae'' was named after the North African ethnic group

Amazigh Berbers, or the Berber peoples, also known as Amazigh or Imazighen, are a diverse grouping of distinct ethnic groups indigenous to North Africa who predate the arrival of Arabs in the Maghreb. Their main connections are identified by their u ...

(Berbers), and Australian palaeontologist

Kate Trinajstic Kate Trinajstic or Katherine M. Trinajstic is an Australian palaeontologist, evolutionary biologist, and winner of the Dorothy Hill Award. She is the Dean of Research, Faculty of Science and Engineering at Curtin University. Early life and care ...

Taxonomy

''Amazichthys'' is part of

Selenosteidae Selenosteidae is an extinct family of small to large-sized arthrodire placoderms from the Late Devonian. With the exception of the Chinese '' Phymosteus'', selenosteids lived in shallow seas in what is now Eastern North America (the Cleveland S ...

, a family inside the clade

Aspinothoracidi Aspinothoracidi is a clade of placoderms, extinct armored fish most diverse during the Devonian. The gigantic apex predator ''Dinichthys'', is the best-known member of this group. Many other genera, such as the infamous ''Dunkleosteus'', were pre ...

, inside of

Pachyosteomorphi Pachyosteomorphi is an extinct clade of arthrodire placoderms within the Eubrachythoraci (of the suborder Brachythoraci), armored fish most diverse during the Devonian. Most are considered to be pelagic (open ocean) long-distance swimmers, leadi ...

, along with Dunkleosteoidea. The

cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

shown here is based on Jobbins ''et al'', 2022.

References

Arthrodire genera Placoderms of Africa Selenosteidae {{Placoderm-stub Devonian fish of Africa Famennian genera Fossils of Morocco Fossil taxa described in 2022