''Alaskacephale'' was a

genus 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 n ...

pachycephalosaurid Pachycephalosauria (; from Greek παχυκεφαλόσαυρος for 'thick headed lizards') is a clade of ornithischian dinosaurs. Along with Ceratopsia, it makes up the clade Marginocephalia. With the exception of two species, most pachycep ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

from the Prince Creek Formation, that lived in the early

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interv ...

stages of the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

(around 71 to 69 million years ago).

Discovery

''Alaskacephale'' was named by Robert Sullivan in 2006. The genus name refers to

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S ...

, where the holotype was discovered, combined with the Greek ''kephale'', meaning head. The species name, ''gangloffi'', honors paleontologist Roland Gangloff. The only known specimen of ''A. gangloffi'' is the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of seve ...

UAM AK-493-V-001, found in 1999, a nearly complete left squamosal with a characteristic array of polygonal nodes. The dimensions of this bone suggest that ''A. gangloffi'' was about half the size of '' Pachycephalosaurus wyomingensis'' or three quarters the size of '' Prenocephale'', and about the same size as '' Sphaerotholus edmontonensis'' and '' Foraminacephale''. The specimen was previously described by Gangloff ''et al.'' (2005) as an unnamed pachycephalosaurid, possibly a ''

Pachycephalosaurus ''Pachycephalosaurus'' (; meaning "thick-headed lizard", from Greek ''pachys-/'' "thick", ''kephale/'' "head" and ''sauros/'' "lizard") is a genus of pachycephalosaurid dinosaurs. The type species, ''P. wyomingensis'', is the only known species ...

''. Gangloff ''et al.'' described the squamosal as having an interdigitated suture with the quadrate, a feature previously described only in ''Pachycephalosaurus''. Sullivan (2006) opined that this "suture" is instead a breakage point in both ''Alaskacephale'' and ''Pachycephalosaurus'', so it could not be used to unite the two taxa.

Classification

Within the tribe

Pachycephalosaurini Pachycephalosauria (; from Greek παχυκεφαλόσαυρος for 'thick headed lizards') is a clade of ornithischian dinosaurs. Along with Ceratopsia, it makes up the clade Marginocephalia. With the exception of two species, most pachycephal ...

, ''Alaskacephale'' is very closely related to '' Pachycephalosaurus wyomingensis''. Below is a cladogram from Evans ''et al.'', 2021.

References

{{Taxonbar, from=Q132965 Late Cretaceous dinosaurs of North America Fossil taxa described in 2006 Pachycephalosaurs Paleontology in Alaska Campanian genus extinctions Campanian genus first appearances Ornithischian genera

Discovery

Classification

See also

References