Name:
Akainacephalus
(spike head).
Phonetic: Ah-kane-ah-sef-ah-lus.
Named By: Jelle P. Wiersma & Randall B.
Irmis - 2018.
Classification: Chordata, Reptilia, Dinosauria,
Ornithischia, Ankylosauridae, Ankylosaurini.
Species: A. johnsoni (type).
Diet: Herbivore.
Size: Holotype roughly about 3.75 meters long.
Known locations: USA, Utah - Kaiparowits
Formation.
Time period: Campanian of the Cretaceous.
Fossil representation: Skull and partial postcranial
skeleton.
Akainacephalus
is a genus of ankylosaur
that lived in North America during the late
Cretaceous. During this time, the central portion of North
America was submerged by the Western Interior Seaway, carving North
America into two landmasses; Appalacia to the East, and Laramidia
to the West. Akainacephalus hails from the
southern portion of
Laramidia, and at the time of the genus description, is the best
preserved ankylosaur from this area. Akainacephalus
however was not
the first ankylosaur discovered in this region, another ankylosaur
named Nodocephalosaurus
is also known. Both of these two genera are
noted for having similar skull structure, though the original
describers are confident in Akainacephalus being a
distinct genus after
testing between known skull elements of Akainacephalus
and
Nodocephalosaurus.
Additionally,
both Akainacephalus and Nodocephalosaurus
have skulls that appear to
be more similar to Asian ankylosaurid genera such as Tarchia
and
Saichania
than to those seen in other North American ankylosaurid
dinosaurs that are known from the Northern portion of Laramidia. This
reinforces the idea of species radiations between Asia and North
America, but then this has also been indicated elsewhere. Both Asia
and North America had similar kinds of late Cretaceous dinosaurs as
one another, with remains of hadrosaurs,
ankylosaurs, dromaeosuars,
tyrannosaurs,
ceratopsians
and ornithomimosaurs
amongst others known
from both continents during same time periods.
Further reading
- A new southern Laramidian
ankylosaurid, Akainacephalus johnsoni gen. et
sp. nov., from
the upper Campanian Kaiparowits Formation of southern Utah, USA. -
PeerJ. 6: e5016. - Jelle P. Wiersma & Randall B.
Irmis - 2018.