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dc.contributor.authorBroce, Jesseen
dc.date.accessioned2014-11-15T07:00:30Zen
dc.date.available2014-11-15T07:00:30Zen
dc.date.issued2013-05-23en
dc.identifier.othervt_gsexam:500en
dc.identifier.urihttp://hdl.handle.net/10919/50855en
dc.description.abstractFossils recovered from limestones of the lower Cambrian (Stage 2-3) Yanjiahe Formation in Hubei Province, South China, recovered using acetic acid maceration, fracturing, and thin sectioning techniques were examined using a combination of analytical techniques, including energy dispersive spectroscopic (EDS) elemental mapping and micro-focus X-ray computed tomography (micro-CT). One important fossil recovered and analyzed with these techniques is a fossilized embryo. Fossilized animal embryos from lower Cambrian rocks provide a rare opportunity to study the ontogeny and developmental biology of early animals during the Cambrian explosion. The fossil embryos in this study exhibit a phosphatized outer envelope (interpreted as the chorion) that encloses a multicelled blastula-like embryo or a calcitized embryo marked by sets of grooves on its surface. The arrangement of these grooves resembles annulations found on the surface of the Cambrian-Ordovician fossil embryo Markuelia. Previously described late-stage Markuelia embryos exhibit annulations and an introvert ornamented by scalids, suggesting a scalidophoran affinity. In the Yanjiahe fossils illustrated herein, however, the phosphatized chorions and blastulas are not taxonomically or phylogenetically diagnostic, and the late-stage embryo is secondarily calcitized and thus poorly preserved, with only vague grooves indicative of Markuelia-type annulations. Consequently, their taxonomic assignment to the genus Markuelia is uncertain. If they indeed belong to the genus Markuelia, they are the oldest known Markuelia fossils from China, and represent both a new occurrence and possibly a new species.en
dc.format.mediumETDen
dc.publisherVirginia Techen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectAceticen
dc.subjectAciden
dc.subjectAnnulationsen
dc.subjectCalciteen
dc.subjectCambrianen
dc.subjectChinaen
dc.subjectDiagenesisen
dc.subjectEmbryoen
dc.subjectFossilen
dc.subjectLimestoneen
dc.subjectMacerationen
dc.subjectMarkueliaen
dc.subjectMicro-CTen
dc.subjectMicen
dc.titlePaleobiology of the Early Cambrian Yanjiahe Formation in Hubei Province of South Chinaen
dc.typeThesisen
dc.contributor.departmentGeosciencesen
dc.description.degreeMaster of Scienceen
thesis.degree.nameMaster of Scienceen
thesis.degree.levelmastersen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.disciplineGeosciencesen
dc.contributor.committeechairXiao, Shuhaien
dc.contributor.committeememberGill, Benjamin C.en
dc.contributor.committeememberSchiffbauer, James Danielen


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