Reuniting the “head hunted” Corythosaurus excavatus (Dinosauria: Hadrosauridae) holotype skull with its dentary and postcranium

Abstract

A Corythosaurus skull (UALVP 13) was collected in 1920 from what is now Dinosaur Provincial Park in southern Alberta, Canada and was designated the holotype of Corythosaurus excavatus, a new hadrosaur species by Gilmore (1923). In 1992, a previously uncovered, weathered, headless skeleton was found. This was collected in 2012 by the University of Alberta as there was potential it could belong to the holotype skull. In addition, an isolated hadrosaur dentary had been found in 1992 close to the articulated postcranial skeleton and may be one of the missing jaws of Corythosaurus excavatus. The hypothesis that it may be the skeleton of the holotype of Corythosaurus excavatus is tested using anatomical information and statistical analyses. Statistical comparisons suggest it is possible that the skull and dentary belong to the same specimen. Furthermore, bivariate plots and percentage prediction errors also indicate that the postcranial material could belong to the UALVP 13 skull. Because many large vertebrate fossil specimens (even types) are not always collected in their entirety, this method may be used as a line of evidence to determine whether independently collected specimens potentially belong to the same individual. The problems described herein highlight the need to collect specimens in their entirety, and for good field documentation, including the spatial and stratigraphic context of all finds.