Alaskacephale
Encyclopedia
Alaskacephale was a genus
of pachycephalosaurid dinosaur
that lived in the late Campanian
stage of the Late Cretaceous
(around 80 to 70 million years ago).
Alaskacephale was named by Robert Sullivan in 2006
. The genus name refers to Alaska
, where the fossil was found in the Prince Creek Formation. The species name, gangloffi, honors paleontologist Roland Gangloff. The only known specimen of A. gangloffi is the holotype
, 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 prenes
, and about the same size as Prenocephale edmontonensis
and Prenocephale brevis
(Gangloff et al. 2005).
The specimen was previously described by Gangloff et al. (2005) as an unnamed pachycephalosaurid, possibly a Pachycephalosaurus
. Gangloff et al. described the squamosal as having a 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.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of pachycephalosaurid dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
that lived in the late Campanian
Campanian
The Campanian is, in the ICS' geologic timescale, the fifth of six ages of the Late Cretaceous epoch . The Campanian spans the time from 83.5 ± 0.7 Ma to 70.6 ± 0.6 Ma ...
stage of the Late Cretaceous
Late Cretaceous
The Late Cretaceous is the younger of two epochs into which the Cretaceous period is divided in the geologic timescale. Rock strata from this epoch form the Upper Cretaceous series...
(around 80 to 70 million years ago).
Alaskacephale was named by Robert Sullivan in 2006
2006 in paleontology
-Insects:-Tetrapodomorphs:-Newly named temnospondylians:-Newly named amphibians:-Ichthyosaurs:-Newly named basal lepidosauromorphs:-Newly named plesiosaurs:-Newly named squamates:-Newly named crurotarsans:-Newly named dinosaurs:...
. The genus name refers to Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
, where the fossil was found in the Prince Creek Formation. The species name, gangloffi, honors paleontologist Roland Gangloff. The only known specimen of A. gangloffi is the holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
, 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
Pachycephalosaurus
Pachycephalosaurus is a genus of pachycephalosaurid dinosaur. It lived during the Late Cretaceous Period of what is now North America. Remains have been excavated in Montana, South Dakota, and Wyoming. It was an herbivorous or omnivorous creature which is only known from a single skull and a few...
or three quarters the size of Prenocephale prenes
Prenocephale
Prenocephale was a small pachycephalosaurid dinosaur genus from the Late Cretaceous and was similar in many ways to its close relative, Homalocephale, which may simply represent Prenocephale juveniles. Adult Prenocephale probably weighed around and measured around long...
, and about the same size as Prenocephale edmontonensis
Prenocephale
Prenocephale was a small pachycephalosaurid dinosaur genus from the Late Cretaceous and was similar in many ways to its close relative, Homalocephale, which may simply represent Prenocephale juveniles. Adult Prenocephale probably weighed around and measured around long...
and Prenocephale brevis
Prenocephale
Prenocephale was a small pachycephalosaurid dinosaur genus from the Late Cretaceous and was similar in many ways to its close relative, Homalocephale, which may simply represent Prenocephale juveniles. Adult Prenocephale probably weighed around and measured around long...
(Gangloff et al. 2005).
The specimen was previously described by Gangloff et al. (2005) as an unnamed pachycephalosaurid, possibly a Pachycephalosaurus
Pachycephalosaurus
Pachycephalosaurus is a genus of pachycephalosaurid dinosaur. It lived during the Late Cretaceous Period of what is now North America. Remains have been excavated in Montana, South Dakota, and Wyoming. It was an herbivorous or omnivorous creature which is only known from a single skull and a few...
. Gangloff et al. described the squamosal as having a 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.