Dunkleosteidae Temporal range: Late Emsian to Late Famennian, ~
Dunkleosteus terrelli skull, Queensland Museum
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	†Placodermi
Order:	†Arthrodira
Suborder:	†Brachythoraci
Clade:	†Eubrachythoraci
Clade:	†Pachyosteomorphi
Superfamily:	†Dunkleosteoidea
Family:	†Dunkleosteidae Stensiö, 1963
Type species
Dinichthys terrelli Newberry, 1873
Genera
Dunkleosteus Eastmanosteus Golshanichthys Heterosteus Kiangyousteus Xiangshuiosteus?

Dunkleosteidae is an extinct family of arthrodire placoderms that lived during the Devonian period. The gigantic apex predator Dunkleosteus terrelli is the best known member of this group.

Phylogeny

While members of Dunkleosteidae were previously thought to be close relatives of the genus Dinichthys (when they were not synonymized as each other) and grouped together in the family Dinichthyidae, more recent phylogenetic studies have shown that the two taxa represent two very distinct clades within Arthrodira.^[1] Dunkleosteidae was then established as the sister taxon to the family Panxiosteidae, which together comprised the superfamily Dunkleosteoidea (one of the three major clades of Eubrachythoraci).^[1] Dunkleosteidae was thus cladistically defined as including the type genus Dunkleosteus and all other genera in Dunkleosteoidea more closely related to Dunkleosteus than to Panxiosteus.^[2]

The phylogeny of Dunkleosteidae from the 2013 Zhu & Zhu study is shown in the cladogram below:^[2]

However, the subsequent 2016 Zhu et al. study using a larger morphological dataset recovered Panxiosteidae well outside of Dunkleosteoidea, leaving the status of Dunkleosteidae as a clade grouping separate from Dunkleosteoidea in doubt, as shown in the cladogram below:^[3]

Genera

Dunkleosteus

Restoration of D. terrelli

The type genus, Dunkleosteus, is known from Late Frasnian and Famennian-aged marine strata from Europe, Morocco, and North America. The best known species, D. terrelli, is famous as the "world's first vertebrate apex predator," and is estimated to be up to 6 m (20 ft) in length: other species, however, such as D. raveri, are estimated to be 1 m (3.3 ft) in length.

Kiangyousteus

Kiangyousteus yohii

This Middle Devonian genus represents the first arthrodire described from China. Fossils are known from the Late Givetian to Early Frasnian-aged Guanwu Formation in Sichuan province.

References