{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/50855"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/50855","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Paleobiology of the Early Cambrian Yanjiahe Formation in Hubei Province of South China","abstract":"Fossils 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.","abstract_html":"Fossils 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.","abstract_has_math":false,"creators":["Broce, Jesse"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Geosciences","degree_department":"Geosciences","school":null,"contributors":[],"advisors":[],"committee_chairs":["Xiao, Shuhai"],"committee_members":["Gill, Benjamin C.","Schiffbauer, James Daniel"],"year":2013,"date_issued":"2013-05-23","date_published":"2013-05-23","updated_at":"2026-07-22T22:20:11Z","subjects":["Acetic","Acid","Annulations","Calcite","Cambrian","China","Diagenesis","Embryo","Fossil","Limestone","Maceration","Markuelia","Micro-CT","Mic"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:500"],"render_values":[{"text":"vt_gsexam:500","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/50855","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Xiao, Shuhai"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Gill, Benjamin C.","Schiffbauer, James Daniel"]},{"key":"dc:contributor.department","label":"Department","values":["Geosciences"]},{"key":"dc:creator","label":"Author","values":["Broce, Jesse"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-11-15T07:00:30Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-11-15T07:00:30Z"]},{"key":"dc:date.issued","label":"Date","values":["2013-05-23"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Geosciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Acetic","Acid","Annulations","Calcite","Cambrian","China","Diagenesis","Embryo","Fossil","Limestone","Maceration","Markuelia","Micro-CT","Mic"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:500"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/50855"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Fossils 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."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["ETD"]},{"key":"dc:title","label":"Title","values":["Paleobiology of the Early Cambrian Yanjiahe Formation in Hubei Province of South China"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Xiao, Shuhai"],"dc:contributor.committeemember":["Gill, Benjamin C.","Schiffbauer, James Daniel"],"dc:contributor.department":["Geosciences"],"dc:creator":["Broce, Jesse"],"dc:date.accessioned":["2014-11-15T07:00:30Z"],"dc:date.available":["2014-11-15T07:00:30Z"],"dc:date.issued":["2013-05-23"],"dc:description.abstract":["Fossils 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."],"dc:description.degree":["Master of Science"],"dc:format.medium":["ETD"],"dc:identifier.other":["vt_gsexam:500"],"dc:identifier.uri":["http://hdl.handle.net/10919/50855"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Acetic","Acid","Annulations","Calcite","Cambrian","China","Diagenesis","Embryo","Fossil","Limestone","Maceration","Markuelia","Micro-CT","Mic"],"dc:title":["Paleobiology of the Early Cambrian Yanjiahe Formation in Hubei Province of South China"],"dc:type":["Thesis"],"thesis:degree_discipline":["Geosciences"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:11Z"}