Osteology, phylogeny, taphonomy, and ontogenetic histology of Oryctodromeus cubicularis, from the middle Cretaceous (Albian-Cenomanian) of Montana and Idaho

dc.contributor.advisorChairperson, Graduate Committee: David Varricchioen
dc.contributor.authorKrumenacker, L. J.en
dc.contributor.otherDavid J. Varricchio, Chris Organ, Clint Boyd and Brooks Britt were co-authors of the article, 'Osteology and phylogeny of the neornithischian dinosaur Oryctodromeus cubicularis from the middle Cretaceous (Albian-Cenomanian) of Montana and Idaho' submitted to the journal 'Journal of vertebrate paleontology' which is contained within this thesis.en
dc.contributor.otherDavid J. Varricchio, John Wilson and Ashley Ferguson were co-authors of the article, 'Taphonomy of Oryctodromeus cubicularis from the mid-Cretaceous (Albian-Cenomanian) of Idaho, and additional Oryctodromeus burrows from Idaho and Montana' submitted to the journal 'Palaeogeography, palaeoclimatology, palaeoecology' which is contained within this thesis.en
dc.contributor.otherDavid J. Varricchio, John R. Horner and Kelli Taddy were co-authors of the article, 'Ontogenetic histology and growth of the neornithischian dinosaur Oryctodromeus cubicularis from the middle Cretaceous (Albian-Cenomanian) of Montana and Idaho' submitted to the journal 'Journal of vertebrate paleontology' which is contained within this thesis.en
dc.coverage.spatialBlackleaf Formation (Mont.)en
dc.coverage.spatialWayan Formation (Idaho)en
dc.coverage.temporalCretaceousen
dc.date.accessioned2017-12-27T21:26:59Z
dc.date.available2017-12-27T21:26:59Z
dc.date.issued2017en
dc.description.abstractOryctodromeus is a small bipedal dinosaur known from middle Cretaceous (95-100 My) Wayan Formation of Idaho and the Vaughn Member of the Blackleaf Formation of Montana. This taxon is hypothesized to be a burrowing dinosaur, which cared for its young within these burrows. This dissertation is a broad three-part treatment of this taxon, and excepting the introductory and concluding chapters this dissertation consists of three main chapters. Chapter two describes the osteology and phylogenetic relationships of this animal. Notable features of the Oryctodromeus skeleton described include a network of ossified tendons along the vertebral column that completely ensheath the tail, a long tail that forms more than half the length of the animal, and unusual femoral heads whose morphology may be related to burrowing behavior. The first full skeletal and skull reconstructions of this animal are presented. Chapter three investigates patterns of preservation of Oryctodromeus. Data suggests that preservation of single to multiple individuals of this taxon typically occurred in burrows that may be difficult to impossible to recognize in the fossil record. New examples of burrows from Oryctodromeus from the Vaughn and Wayan, as well as additional evidence for social behavior, are also described. A third chapter details the ontogenetic histology, growth rates and patterns of skeletal fusion based on seven limb elements (femora and tibiae) from different individuals. Based on the data in this dissertation, three growth stages can be recognized in Oryctodromeus based on bone histology. Juveniles are defined by more rapidly growing fibrolamellar tissue, sub-adults are defined by a cortex of inner fibrolamellar tissue and outer zonal parallel fibered tissue, and near-adult individuals have tissue similar to sub adults with dense avascular bone in the outermost cortex that signals a decrease in growth rate. LAG's suggest a minimum age of six to seven years for more mature individuals. Patterns of neurocentral fusion in Oryctodromeus appear similar to those of crocodylians and some other small ornithischians, while the growth rates of Oryctodromeus appear slower than those of some dinosaurs, but similar to taxa such as Orodromeus and Tenontosaurus.en
dc.identifier.urihttps://scholarworks.montana.edu/handle/1/13100en
dc.language.isoenen
dc.publisherMontana State University - Bozeman, College of Letters & Scienceen
dc.rights.holderCopyright 2017 by Laurel James Krumenackeren
dc.subject.lcshOrnithischiaen
dc.subject.lcshPaleontologyen
dc.subject.lcshTaphonomyen
dc.subject.lcshBonesen
dc.subject.lcshPhylogenyen
dc.titleOsteology, phylogeny, taphonomy, and ontogenetic histology of Oryctodromeus cubicularis, from the middle Cretaceous (Albian-Cenomanian) of Montana and Idahoen
dc.typeDissertationen
mus.data.thumbpage100en
thesis.degree.committeemembersMembers, Graduate Committee: Chris Organ; Thaddeus S. Dyman; David W. Bowen.en
thesis.degree.departmentEarth Sciences.en
thesis.degree.genreDissertationen
thesis.degree.namePhDen
thesis.format.extentfirstpage1en
thesis.format.extentlastpage282en

Files

Original bundle
Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
KrumenackerL0817.pdf
Size:
10.89 MB
Format:
Adobe Portable Document Format
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
826 B
Format:
Plain Text
Description:
Copyright (c) 2002-2022, LYRASIS. All rights reserved.