Bone histology of the graviportal dinocephalian therapsid Jonkeria from the middle Permian Tapinocephalus Assemblage Zone of the Karoo Basin of South Africa
Here we examine the bone histology of multiple skeletal elements of three individuals of Jonkeria from the middle Permian Tapinocephalus Assemblage Zone of the Karoo Basin of South Africa. Our histological results reveal a predominance of highly vascularized, uninterrupted fibrolamellar bone tissu...
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| Format: | Article |
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Institute of Paleobiology PAS
2021-12-01
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| Series: | Acta Palaeontologica Polonica |
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| Online Access: | https://www.app.pan.pl/archive/published/app66/app008722021.pdf |
| _version_ | 1798022083651829760 |
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| author | MOHD SHAFI BHAT CHRISTEN D. SHELTON ANUSUYA CHINSAMY |
| author_facet | MOHD SHAFI BHAT CHRISTEN D. SHELTON ANUSUYA CHINSAMY |
| author_sort | MOHD SHAFI BHAT |
| collection | DOAJ |
| description | Here we examine the bone histology of multiple skeletal elements of three individuals of Jonkeria from the middle
Permian Tapinocephalus Assemblage Zone of the Karoo Basin of South Africa. Our histological results reveal a predominance of highly vascularized, uninterrupted fibrolamellar bone tissue, which suggests rapid periosteal bone deposition
and an overall fast growth. However, in a rib, the periosteal bone deposition periodically stops abruptly, resulting in the
deposition of several lines of arrested growth. The absence of bone growth marks in the limb bones (except for an annulus
in a radius) suggests a young ontogenetic status for all specimens of the studied sample. All the skeletal elements are characterized by thick bone walls, extensive secondary reconstruction and the complete infilling of the medullary cavity by
bony trabeculae. The latter condition is different to observations of contemporaneous graviportal terrestrial pareiasaurs,
but similar to the observations in the modern semi-aquatic Hippopotamus, and suggests a possible semi-aquatic lifestyle
for Jonkeria. On the basis of our histological findings, we assert that during early ontogeny Jonkeria experienced rapid
sustained rates of growth, whereas later in ontogeny they experienced cyclical rates of growth. |
| first_indexed | 2024-04-11T17:24:02Z |
| format | Article |
| id | doaj.art-f1d735f496694d5083f72b9e474215a7 |
| institution | Directory Open Access Journal |
| issn | 0567-7920 1732-2421 |
| language | English |
| last_indexed | 2024-04-11T17:24:02Z |
| publishDate | 2021-12-01 |
| publisher | Institute of Paleobiology PAS |
| record_format | Article |
| series | Acta Palaeontologica Polonica |
| spelling | doaj.art-f1d735f496694d5083f72b9e474215a72022-12-22T04:12:24ZengInstitute of Paleobiology PASActa Palaeontologica Polonica0567-79201732-24212021-12-0166470572110.4202/app.00872.2021Bone histology of the graviportal dinocephalian therapsid Jonkeria from the middle Permian Tapinocephalus Assemblage Zone of the Karoo Basin of South AfricaMOHD SHAFI BHAT0CHRISTEN D. SHELTON1ANUSUYA CHINSAMY2Department of Biological Sciences, University of Cape Town, Private Bag X3, Rhodes Gift 7701, South AfricaDepartment of Biological Sciences, University of Cape Town, Private Bag X3, Rhodes Gift 7701, South Africa; current address: Biology/Mathematics & Physical Science Departments, Rogers State University, Claremore, OK 74017-3252, USA and Natural History Department, New Jersey State Museum, Trenton, NJ 08625-0530, USADepartment of Biological Sciences, University of Cape Town, Private Bag X3, Rhodes Gift 7701, South AfricaHere we examine the bone histology of multiple skeletal elements of three individuals of Jonkeria from the middle Permian Tapinocephalus Assemblage Zone of the Karoo Basin of South Africa. Our histological results reveal a predominance of highly vascularized, uninterrupted fibrolamellar bone tissue, which suggests rapid periosteal bone deposition and an overall fast growth. However, in a rib, the periosteal bone deposition periodically stops abruptly, resulting in the deposition of several lines of arrested growth. The absence of bone growth marks in the limb bones (except for an annulus in a radius) suggests a young ontogenetic status for all specimens of the studied sample. All the skeletal elements are characterized by thick bone walls, extensive secondary reconstruction and the complete infilling of the medullary cavity by bony trabeculae. The latter condition is different to observations of contemporaneous graviportal terrestrial pareiasaurs, but similar to the observations in the modern semi-aquatic Hippopotamus, and suggests a possible semi-aquatic lifestyle for Jonkeria. On the basis of our histological findings, we assert that during early ontogeny Jonkeria experienced rapid sustained rates of growth, whereas later in ontogeny they experienced cyclical rates of growth.https://www.app.pan.pl/archive/published/app66/app008722021.pdftherapsidasynapsidabone microstructuremiddle permianbeaufort groupabrahamskraal formationsouth africa |
| spellingShingle | MOHD SHAFI BHAT CHRISTEN D. SHELTON ANUSUYA CHINSAMY Bone histology of the graviportal dinocephalian therapsid Jonkeria from the middle Permian Tapinocephalus Assemblage Zone of the Karoo Basin of South Africa Acta Palaeontologica Polonica therapsida synapsida bone microstructure middle permian beaufort group abrahamskraal formation south africa |
| title | Bone histology of the graviportal dinocephalian therapsid Jonkeria from the middle Permian Tapinocephalus Assemblage Zone of the Karoo Basin of South Africa |
| title_full | Bone histology of the graviportal dinocephalian therapsid Jonkeria from the middle Permian Tapinocephalus Assemblage Zone of the Karoo Basin of South Africa |
| title_fullStr | Bone histology of the graviportal dinocephalian therapsid Jonkeria from the middle Permian Tapinocephalus Assemblage Zone of the Karoo Basin of South Africa |
| title_full_unstemmed | Bone histology of the graviportal dinocephalian therapsid Jonkeria from the middle Permian Tapinocephalus Assemblage Zone of the Karoo Basin of South Africa |
| title_short | Bone histology of the graviportal dinocephalian therapsid Jonkeria from the middle Permian Tapinocephalus Assemblage Zone of the Karoo Basin of South Africa |
| title_sort | bone histology of the graviportal dinocephalian therapsid jonkeria from the middle permian tapinocephalus assemblage zone of the karoo basin of south africa |
| topic | therapsida synapsida bone microstructure middle permian beaufort group abrahamskraal formation south africa |
| url | https://www.app.pan.pl/archive/published/app66/app008722021.pdf |
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