page_title: Probrachylophosaurus
section_title: Phylogeny
hierarchical_section_title: Probrachylophosaurus / Phylogeny
caption_attribution_description: Probrachylophosaurus bergei gen. et sp. nov. cervical and dorsal vertebrae. MOR 2919 vertebrae are pictured in anterior view in their approximate order within their series. Serial position of vertebrae is not listed because the complete series of cervicals and dorsals were not preserved, and so their exact serial positions cannot be determined with confidence. However, the last cervical vertebra pictured, “C14”, is consistent with the morphology of cervical 14 in CMN 8893, the holotype of Brachylophosaurus canadensis [23]. Atlas fragments and other vertebral fragments not pictured.
context_page_description: Probrachylophosaurus bergei is a species of large herbivorous brachylophosaurin hadrosaurid dinosaur known from the Late Cretaceous Campanian Judith River Formation, of Montana.
  The significance of this particular hadrosaur taxon is that it is a transitional species between the genera Acristavus and Brachylophosaurus evolving from a crestless ancestor to its crested descendant while changing the morphology of its nasal bones.
context_section_description: Probrachylophosaurus was, within the Hadrosaurinae, placed in the Brachylophosaurini by the describing authors. Adding the traits of Probrachylophosaurus to two earlier datasets of cladistic analyses, resulted in slightly conflicting positions. In one analysis it was recovered as the sister species of Brachylophosaurus; in the other as a sister species of a clade consisting of Brachylophosaurus and Maiasaura. In both evolutionary trees Acristavus was in a more basal position. The authors suggested that Acristavus might have been a direct ancestor of Probrachylophosaurus and the latter, in view of its intermediate smaller crest form, again an ancestor of Brachylophosaurus that lived about 1.5 million years later.
  The revised analysis of Albert Prieto-Márquez resulted in the following evolutionary tree:
caption: Cervical and dorsal vertebrae
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