Aspinothoracidi is a clade of placoderms, extinct armored fish most diverse during the

Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, w ...

. The gigantic

apex predator An apex predator, also known as a top predator, is a predator at the top of a food chain, without natural predators of its own. Apex predators are usually defined in terms of trophic dynamics, meaning that they occupy the highest trophic le ...

'' Dinichthys'', is the best-known member of this group. Many other

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial ...

, such as the infamous '' Dunkleosteus'', were previously thought to be close relatives of ''Dinichthys'' and were grouped together in the family Dinichthyidae, though more recent studies have restricted that family to only its type species.

Phylogeny

Eubrachythoraci is divided into the clades Coccosteomorphi and Pachyosteomorphi, the latter of which can be further sub-divided into Aspinothoracidi and Dunkleosteoidea, as shown in the

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

below:

References

Arthrodires {{Placoderm-stub