Acanthostega gunnari, a Devonian tetrapod from Greenland; the snout, palate and ventral parts of the braincase, with a discussion of their significance
The snout, including the naris and choana, and the palate, ventral parts of the brain case and suspensorium of Acanthostega gunnari are described from three-dimensional specimens and sections. The naris is low on the snout, and the choana and vomerine dentition resemble those of osteolepiform fishes...
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The Commission for Scientific Research in Greenland /Danish Polar Center
1994
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Online Access: | https://tidsskrift.dk/meddrgroenland_geosci/article/view/140691 |
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ftsbaarhusojs:oai:ojs.tidsskrift.dk:article/140691 2024-01-28T10:06:10+01:00 Acanthostega gunnari, a Devonian tetrapod from Greenland; the snout, palate and ventral parts of the braincase, with a discussion of their significance Clack, J. A. 1994-04-19 application/pdf https://tidsskrift.dk/meddrgroenland_geosci/article/view/140691 eng eng The Commission for Scientific Research in Greenland /Danish Polar Center https://tidsskrift.dk/meddrgroenland_geosci/article/view/140691/184557 https://tidsskrift.dk/meddrgroenland_geosci/article/view/140691 Meddelelser om Grønland. Geoscience; Vol. 31 (1994): Meddelelser om Grønland. Geoscience; 24 pp. Meddelelser om Grønland. Geoscience; Årg. 31 (1994): Meddelelser om Grønland, Geoscience; 24 pp. 1600-4590 0106-1046 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 1994 ftsbaarhusojs 2024-01-03T23:59:20Z The snout, including the naris and choana, and the palate, ventral parts of the brain case and suspensorium of Acanthostega gunnari are described from three-dimensional specimens and sections. The naris is low on the snout, and the choana and vomerine dentition resemble those of osteolepiform fishes. The braincase is ossified in two portions in ventral view, with the ventral cranial fissure still evident. Dorsally, however, the otic region and sphenethmoid are co-ossified, so there was no movement possible between them. The palate is "closed" as in osteolepi forms and primitive tetrapods, and the parasphenoid is grooved as in some osteolepiforms. It is argued that the low naris and divided braincase represent the primitive condition for tetrapods, and that the condition of the naris and choana most closely resemble those of panderichthyid fishes among sarcopterygians. Article in Journal/Newspaper Greenland Aarhus University: OJS at The State and University Library Greenland |
institution |
Open Polar |
collection |
Aarhus University: OJS at The State and University Library |
op_collection_id |
ftsbaarhusojs |
language |
English |
description |
The snout, including the naris and choana, and the palate, ventral parts of the brain case and suspensorium of Acanthostega gunnari are described from three-dimensional specimens and sections. The naris is low on the snout, and the choana and vomerine dentition resemble those of osteolepiform fishes. The braincase is ossified in two portions in ventral view, with the ventral cranial fissure still evident. Dorsally, however, the otic region and sphenethmoid are co-ossified, so there was no movement possible between them. The palate is "closed" as in osteolepi forms and primitive tetrapods, and the parasphenoid is grooved as in some osteolepiforms. It is argued that the low naris and divided braincase represent the primitive condition for tetrapods, and that the condition of the naris and choana most closely resemble those of panderichthyid fishes among sarcopterygians. |
format |
Article in Journal/Newspaper |
author |
Clack, J. A. |
spellingShingle |
Clack, J. A. Acanthostega gunnari, a Devonian tetrapod from Greenland; the snout, palate and ventral parts of the braincase, with a discussion of their significance |
author_facet |
Clack, J. A. |
author_sort |
Clack, J. A. |
title |
Acanthostega gunnari, a Devonian tetrapod from Greenland; the snout, palate and ventral parts of the braincase, with a discussion of their significance |
title_short |
Acanthostega gunnari, a Devonian tetrapod from Greenland; the snout, palate and ventral parts of the braincase, with a discussion of their significance |
title_full |
Acanthostega gunnari, a Devonian tetrapod from Greenland; the snout, palate and ventral parts of the braincase, with a discussion of their significance |
title_fullStr |
Acanthostega gunnari, a Devonian tetrapod from Greenland; the snout, palate and ventral parts of the braincase, with a discussion of their significance |
title_full_unstemmed |
Acanthostega gunnari, a Devonian tetrapod from Greenland; the snout, palate and ventral parts of the braincase, with a discussion of their significance |
title_sort |
acanthostega gunnari, a devonian tetrapod from greenland; the snout, palate and ventral parts of the braincase, with a discussion of their significance |
publisher |
The Commission for Scientific Research in Greenland /Danish Polar Center |
publishDate |
1994 |
url |
https://tidsskrift.dk/meddrgroenland_geosci/article/view/140691 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland |
genre_facet |
Greenland |
op_source |
Meddelelser om Grønland. Geoscience; Vol. 31 (1994): Meddelelser om Grønland. Geoscience; 24 pp. Meddelelser om Grønland. Geoscience; Årg. 31 (1994): Meddelelser om Grønland, Geoscience; 24 pp. 1600-4590 0106-1046 |
op_relation |
https://tidsskrift.dk/meddrgroenland_geosci/article/view/140691/184557 https://tidsskrift.dk/meddrgroenland_geosci/article/view/140691 |
_version_ |
1789332868645781504 |