New data on the enigmatic Ocruranus-Eohalobia group of Early Cambrian small skeletal fossils
The Ocruranus-Eohalobia group, whose members were variously considered to be brachiopods, bivalves, chitons, tommotiids and coeloscleritophorans, are difficult to classify because of lack of morphological detail and evidence for skeletal reconstruction. New specimens from South China reveal more inf...
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2009
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ftchinacscnigpas:oai:ir.nigpas.ac.cn:332004/267 2023-05-15T16:29:51+02:00 New data on the enigmatic Ocruranus-Eohalobia group of Early Cambrian small skeletal fossils Vendrasco, Michael J. Li, Guoxiang (李国祥) Porter, Susannah M. Fernandez, Christine Z. 2009-11-01 http://ir.nigpas.ac.cn/handle/332004/267 https://doi.org/10.1111/j.1475-4983.2009.00913.x 英语 eng WILEY-BLACKWELL PUBLISHING, INC PALAEONTOLOGY http://ir.nigpas.ac.cn/handle/332004/267 doi:10.1111/j.1475-4983.2009.00913.x Cambrian Mollusc Ocruranus Eohalobia Meishucun Chiton Polyplacophora Stem Group Brachiopod Small Shelly Fossils Polyplacophoran Mollusks Northeast Greenland South-australia Planktotrophy Chitons Origin China Microstructures Paleontology 期刊论文 2009 ftchinacscnigpas https://doi.org/10.1111/j.1475-4983.2009.00913.x 2019-10-11T00:03:06Z The Ocruranus-Eohalobia group, whose members were variously considered to be brachiopods, bivalves, chitons, tommotiids and coeloscleritophorans, are difficult to classify because of lack of morphological detail and evidence for skeletal reconstruction. New specimens from South China reveal more information about Ocruranus-Eohalobia and allow progress towards deciphering the skeletal reconstruction and phylogenetic affinity of this enigmatic group. Many specimens have a phosphatic inner and outer coat (mould) with empty space in between that resulted from dissolution of the original shell. Moreover, many of the internal moulds show a previously unknown type of shell microstructure that consisted of stacked layers of highly organized, acicular crystallites that radiated from the apex of the shell towards the aperture. The dissolved shell and needle-like crystals suggest an original calcareous, probably aragonitic, shell mineralogy. A few specimens also show a polygonal texture in regions that suggests the shell had a thin, prismatic inner shell microstructure. Ocruranus and Eohalobia belong to the same skeleton, and we herein synonymize Eohalobia with the older Ocruranus. Moreover, new specimens from Meishucun reveal a third type of shell plate, similar in form and inferred placement to intermediate valves of chitons. Ocruranus is likely a mollusc, and possibly a member of the chiton stem lineage. If so, then the beginning of the known record of chitons would be extended back from late Cambrian (Saukia Zone; Furongian) to early Cambrian (Meishucunian; Series 1). Report Greenland Nanjing Institute of Geology and Palaeontology: NIGPAS OpenIR (Chinese Academy of Sciences) Greenland Palaeontology 52 6 1373 1396 |
institution |
Open Polar |
collection |
Nanjing Institute of Geology and Palaeontology: NIGPAS OpenIR (Chinese Academy of Sciences) |
op_collection_id |
ftchinacscnigpas |
language |
English |
topic |
Cambrian Mollusc Ocruranus Eohalobia Meishucun Chiton Polyplacophora Stem Group Brachiopod Small Shelly Fossils Polyplacophoran Mollusks Northeast Greenland South-australia Planktotrophy Chitons Origin China Microstructures Paleontology |
spellingShingle |
Cambrian Mollusc Ocruranus Eohalobia Meishucun Chiton Polyplacophora Stem Group Brachiopod Small Shelly Fossils Polyplacophoran Mollusks Northeast Greenland South-australia Planktotrophy Chitons Origin China Microstructures Paleontology Vendrasco, Michael J. Li, Guoxiang (李国祥) Porter, Susannah M. Fernandez, Christine Z. New data on the enigmatic Ocruranus-Eohalobia group of Early Cambrian small skeletal fossils |
topic_facet |
Cambrian Mollusc Ocruranus Eohalobia Meishucun Chiton Polyplacophora Stem Group Brachiopod Small Shelly Fossils Polyplacophoran Mollusks Northeast Greenland South-australia Planktotrophy Chitons Origin China Microstructures Paleontology |
description |
The Ocruranus-Eohalobia group, whose members were variously considered to be brachiopods, bivalves, chitons, tommotiids and coeloscleritophorans, are difficult to classify because of lack of morphological detail and evidence for skeletal reconstruction. New specimens from South China reveal more information about Ocruranus-Eohalobia and allow progress towards deciphering the skeletal reconstruction and phylogenetic affinity of this enigmatic group. Many specimens have a phosphatic inner and outer coat (mould) with empty space in between that resulted from dissolution of the original shell. Moreover, many of the internal moulds show a previously unknown type of shell microstructure that consisted of stacked layers of highly organized, acicular crystallites that radiated from the apex of the shell towards the aperture. The dissolved shell and needle-like crystals suggest an original calcareous, probably aragonitic, shell mineralogy. A few specimens also show a polygonal texture in regions that suggests the shell had a thin, prismatic inner shell microstructure. Ocruranus and Eohalobia belong to the same skeleton, and we herein synonymize Eohalobia with the older Ocruranus. Moreover, new specimens from Meishucun reveal a third type of shell plate, similar in form and inferred placement to intermediate valves of chitons. Ocruranus is likely a mollusc, and possibly a member of the chiton stem lineage. If so, then the beginning of the known record of chitons would be extended back from late Cambrian (Saukia Zone; Furongian) to early Cambrian (Meishucunian; Series 1). |
format |
Report |
author |
Vendrasco, Michael J. Li, Guoxiang (李国祥) Porter, Susannah M. Fernandez, Christine Z. |
author_facet |
Vendrasco, Michael J. Li, Guoxiang (李国祥) Porter, Susannah M. Fernandez, Christine Z. |
author_sort |
Vendrasco, Michael J. |
title |
New data on the enigmatic Ocruranus-Eohalobia group of Early Cambrian small skeletal fossils |
title_short |
New data on the enigmatic Ocruranus-Eohalobia group of Early Cambrian small skeletal fossils |
title_full |
New data on the enigmatic Ocruranus-Eohalobia group of Early Cambrian small skeletal fossils |
title_fullStr |
New data on the enigmatic Ocruranus-Eohalobia group of Early Cambrian small skeletal fossils |
title_full_unstemmed |
New data on the enigmatic Ocruranus-Eohalobia group of Early Cambrian small skeletal fossils |
title_sort |
new data on the enigmatic ocruranus-eohalobia group of early cambrian small skeletal fossils |
publisher |
WILEY-BLACKWELL PUBLISHING, INC |
publishDate |
2009 |
url |
http://ir.nigpas.ac.cn/handle/332004/267 https://doi.org/10.1111/j.1475-4983.2009.00913.x |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland |
genre_facet |
Greenland |
op_relation |
PALAEONTOLOGY http://ir.nigpas.ac.cn/handle/332004/267 doi:10.1111/j.1475-4983.2009.00913.x |
op_doi |
https://doi.org/10.1111/j.1475-4983.2009.00913.x |
container_title |
Palaeontology |
container_volume |
52 |
container_issue |
6 |
container_start_page |
1373 |
op_container_end_page |
1396 |
_version_ |
1766019563891195904 |