Open AccessThe first complete description of the holotype of Brachylophosaurus canadensis Sternberg, 1953 (Dinosauria: Hadrosauridae) with comments on intraspecific variation
Author(s) -
CUTHBERTSON ROBIN S.,
HOLMES ROBERT B.
Publication year - 2010
Publication title -
zoological journal of the linnean society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.148
H-Index - 83
eISSN - 1096-3642
pISSN - 0024-4082
DOI - 10.1111/j.1096-3642.2009.00612.x
Subject(s) - holotype , anatomy , biology , foramen , vomer , theropoda , quadrate bone , crest , mandible (arthropod mouthpart) , paleontology , cretaceous , zoology , taxonomy (biology) , genus , physics , quantum mechanics
The holotype of Brachylophosaurus canadensis was collected by C.M. Sternberg in 1936 from the Oldman Formation (Upper Cretaceous) of Alberta, Canada, with a brief description focusing on the cranium following in 1953. A re‐description of the holotype skeleton confirms its position as a hadrosaurine dinosaur exhibiting the following unique combination of characters: paddle‐like solid nasal crest; posteriorly elongated prefrontal; only the anterior tip of the lacrimal contacting maxilla; extremely elongated anterior maxillary process; and a quadratojugal with a noncrescentic posterior margin variably forming a paraquadratic foramen with the quadrate. Comparison of the holotype with other specimens assigned to the taxon reveals numerous morphological differences. These variable features include the presence/absence of an accessory premaxillary foramen, the number of maxillary/dentary vertical tooth rows, the number of functional teeth per tooth row contributing to the dental occlusal surface, the bones forming the mandibular glenoid, the presence/absence of a nasal foramen, nasal crest morphology, the number of cervical vertebrae, and axis morphology. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society , 2010, 159 , 373–397.