Describer

Giffin, Gabriel & Johnson, 1987

Time

Cretaceous Late Maastrichtian

Classification

Ornithischia Genasauria Cerapoda Marginocephalia Pachycephalosauria Pachycephalosauridae

Diet

Herbivore

Fossilsite

Hell Creek Formation, McCone Country, MPM locality 3850, Montana, US

Fall Under

Stygimoloch spinifer

Info

Pachycephalosaurus (Brown& Schlaikjer, 1943) = Tylosteus (Leidy, 1872)

Pachycephalosaurus > Pachycephalosaurus wyomingensis (Gilmore, 1931) >> Troodon wyomingensis (Gilmore, 1931) >>> Tylosteus ornatus (Leidy, 1872), Pachycephalosaurus grangeri (Brown & Schlaikjer, 1943) Pachycephalosaurus reinheimeri (Brown & Schlaikjer, 1943)

Pachycephalosaurus (Brown& Schlaikjer, 1943) > Pachycephalosaurus wyomingensis (Gilmore, 1931) > Dracorex hogwartsia [Juvenile] (Bakker, Sullivan, Porter, Larson & Saulsbury, 2006) > Stygimoloch spinifer (Galton & Sues, 1983) >> Stenotholus kohleri (Giffin, Gabriel & Johnson, 1987)

Holotype

MPM 7111 a well-preserved frontoparital dome with partially preserved occipital and andocranial regions.

Etymology

[genus] Greek Steno = narrow plus Greek tholus = dome. [species]In honor of Terry and Mary Kohler, major sponsors of Milwaukee Public Museum field work.

MPM 7111 consists of a narrow, highly doomed frontoparietal region with nearly complete supraoccipital bone, and complete or fragmentary prefrontal, postorbital, presphenoid, orbotosphenoid, laterosphenoid, accessory sphenoidal, prootic, and opisthotic elements.

The doome reaches greatest height in the parietal region, and the occipital surface is rotated strongly ventrad. Clearly visable sutures, suggest that this individual had not attained maturity. The entire specimen is 203 mm in length and 144 mm in height. [Giffin, Gabriel and Johnson (1987)]