A Review of the North American Squalodontidae (Mammalia, Cetacea).
All available North American specimens of squalodont whales were examined to determine species assignments, and to determine functional aspects and ecological implications. Only two existing species of the 17 referred to Squalodontidae from North America are members of that family, Squalodon atlanti...
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ftlouisianastuir:oai:digitalcommons.lsu.edu:gradschool_disstheses-7824 2023-06-11T04:13:42+02:00 A Review of the North American Squalodontidae (Mammalia, Cetacea). Dooley, Alton Cline, Jr 1998-01-01T08:00:00Z application/pdf https://digitalcommons.lsu.edu/gradschool_disstheses/6825 https://doi.org/10.31390/gradschool_disstheses.6825 https://digitalcommons.lsu.edu/context/gradschool_disstheses/article/7824/viewcontent/9922074.pdf English eng LSU Digital Commons https://digitalcommons.lsu.edu/gradschool_disstheses/6825 doi:10.31390/gradschool_disstheses.6825 https://digitalcommons.lsu.edu/context/gradschool_disstheses/article/7824/viewcontent/9922074.pdf LSU Historical Dissertations and Theses Paleontology Paleozoology Biology zoology text 1998 ftlouisianastuir https://doi.org/10.31390/gradschool_disstheses.6825 2023-05-28T18:38:45Z All available North American specimens of squalodont whales were examined to determine species assignments, and to determine functional aspects and ecological implications. Only two existing species of the 17 referred to Squalodontidae from North America are members of that family, Squalodon atlanticus and Squalodon calvertensis. Of these two species, only S. calvertensis is based on adequate material for consideration as a valid species. Squalodon calvertensis is redescribed, based on the material which has been collected since 1923. These specimens indicate that the species is found from New Jersey to North Carolina, in the Miocene Kirkwood, Calvert, and Pungo River Formations. One specimen questionably comes from the Oligocene Old Church Formation in Virginia. A new species of squalodont, Squalodon whitmorei, is also described. This is the largest known squalodont, but it is much less common than S. calvertensis. The two species are found in the same stratigraphic units. Based on tooth shape and wear, squalodonts seem to have been opportunistic predators of fish, small mammals, and squid, like the larger modem dolphins such as the false killer whale. The weak squalodont skull structure suggests that they were not feeding on animals significantly larger than themselves, as do killer whales. The dental differences between squalodonts; and their modem analogs is probably due to the constraint in tooth form in modem species, which evolved from fish-eating ancestors which had simplified conical teeth. It appears that squalodonts exhibited sexual dimorphism both in body size and incisor morphology, reminiscent of modem beaked whales. The temporal and geographic distribution of squalodonts suggests that members of the family dispersed in the Oligocene from Tethys, to North America, and then to Europe and through Panama to Oregon. The lack of squalodonts in Japan, and their disappearance from the north Atlantic when ocean temperatures dropped in the middle Miocene, indicate that squalodonts were limited to warmer ... Text Killer Whale North Atlantic LSU Digital Commons (Louisiana State University) Kirkwood ENVELOPE(-68.975,-68.975,-68.338,-68.338) |
institution |
Open Polar |
collection |
LSU Digital Commons (Louisiana State University) |
op_collection_id |
ftlouisianastuir |
language |
English |
topic |
Paleontology Paleozoology Biology zoology |
spellingShingle |
Paleontology Paleozoology Biology zoology Dooley, Alton Cline, Jr A Review of the North American Squalodontidae (Mammalia, Cetacea). |
topic_facet |
Paleontology Paleozoology Biology zoology |
description |
All available North American specimens of squalodont whales were examined to determine species assignments, and to determine functional aspects and ecological implications. Only two existing species of the 17 referred to Squalodontidae from North America are members of that family, Squalodon atlanticus and Squalodon calvertensis. Of these two species, only S. calvertensis is based on adequate material for consideration as a valid species. Squalodon calvertensis is redescribed, based on the material which has been collected since 1923. These specimens indicate that the species is found from New Jersey to North Carolina, in the Miocene Kirkwood, Calvert, and Pungo River Formations. One specimen questionably comes from the Oligocene Old Church Formation in Virginia. A new species of squalodont, Squalodon whitmorei, is also described. This is the largest known squalodont, but it is much less common than S. calvertensis. The two species are found in the same stratigraphic units. Based on tooth shape and wear, squalodonts seem to have been opportunistic predators of fish, small mammals, and squid, like the larger modem dolphins such as the false killer whale. The weak squalodont skull structure suggests that they were not feeding on animals significantly larger than themselves, as do killer whales. The dental differences between squalodonts; and their modem analogs is probably due to the constraint in tooth form in modem species, which evolved from fish-eating ancestors which had simplified conical teeth. It appears that squalodonts exhibited sexual dimorphism both in body size and incisor morphology, reminiscent of modem beaked whales. The temporal and geographic distribution of squalodonts suggests that members of the family dispersed in the Oligocene from Tethys, to North America, and then to Europe and through Panama to Oregon. The lack of squalodonts in Japan, and their disappearance from the north Atlantic when ocean temperatures dropped in the middle Miocene, indicate that squalodonts were limited to warmer ... |
format |
Text |
author |
Dooley, Alton Cline, Jr |
author_facet |
Dooley, Alton Cline, Jr |
author_sort |
Dooley, Alton Cline, Jr |
title |
A Review of the North American Squalodontidae (Mammalia, Cetacea). |
title_short |
A Review of the North American Squalodontidae (Mammalia, Cetacea). |
title_full |
A Review of the North American Squalodontidae (Mammalia, Cetacea). |
title_fullStr |
A Review of the North American Squalodontidae (Mammalia, Cetacea). |
title_full_unstemmed |
A Review of the North American Squalodontidae (Mammalia, Cetacea). |
title_sort |
review of the north american squalodontidae (mammalia, cetacea). |
publisher |
LSU Digital Commons |
publishDate |
1998 |
url |
https://digitalcommons.lsu.edu/gradschool_disstheses/6825 https://doi.org/10.31390/gradschool_disstheses.6825 https://digitalcommons.lsu.edu/context/gradschool_disstheses/article/7824/viewcontent/9922074.pdf |
long_lat |
ENVELOPE(-68.975,-68.975,-68.338,-68.338) |
geographic |
Kirkwood |
geographic_facet |
Kirkwood |
genre |
Killer Whale North Atlantic |
genre_facet |
Killer Whale North Atlantic |
op_source |
LSU Historical Dissertations and Theses |
op_relation |
https://digitalcommons.lsu.edu/gradschool_disstheses/6825 doi:10.31390/gradschool_disstheses.6825 https://digitalcommons.lsu.edu/context/gradschool_disstheses/article/7824/viewcontent/9922074.pdf |
op_doi |
https://doi.org/10.31390/gradschool_disstheses.6825 |
_version_ |
1768390964834992128 |