Perinatal specimens of Maiasaura from the Upper Cretaceous of Montana (USA) : Insights into the early ontogeny of saurolophine hadrosaurid dinosaurs
Prieto-Marquez, Albert (Institut Català de Paleontologia Miquel Crusafont)
Guenther, Merrilee F. (Elmhurst College (USA))

Date:	2018
Abstract:	Perinatal specimens of hadrosaurids discovered in the late 1970's by field crews from Princeton University were significant in providing evidence of the early ontogenetic stages in North American dinosaurs. These specimens from the Campanian (Upper Cretaceous) Two Medicine Formation of Montana consist of over a dozen skeletons referable to the saurolophine hadrosaurid Maiasaura peeblesorum, but never fully figured or described. Here, we provide a more complete documentation of the morphology of these specimens, along with an examination of variation during a large span of the development of saurolophine hadrosaurids. Many ontogenetic changes in the available facial and mandibular elements are associated with the progressive elongation of the preorbital region of the skull and mandible. In the postcranium, limb bones change nearly isometrically, with exception of certain elements of the forelimb. Some cranial and postcranial characters commonly used for inferring hadrosaurid phylogenetic relationships remain invariable during the ontogeny of M. peeblesorum. This indicates that early ontogenetic stages may still provide a limited amount of character information useful for systematics and phylogenetic inference.
Grants:	Ministerio de Economía y Competitividad RyC-2015-17388
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Evolution ; Dinosaur ; Cretaceous ; Growth ; Ontogeny ; Anatomy ; Hadrosaurid
Published in:	PeerJ, Vol. 6 (May 2018) , p. e4734, ISSN 2167-8359

DOI: 10.7717/peerj.4734
PMID: 29785343

31 p, 4.2 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Institut Català de Paleontologia Miquel Crusafont (ICP)
Articles > Research articles
Articles > Published articles