Caseidae
Caseidae | ||||||||||||
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Life picture of Cotylorhynchus |
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Temporal occurrence | ||||||||||||
Pennsylvania (Upper Carbon) to Middle Perm ( Capitanium ) | ||||||||||||
300 to 260 million years | ||||||||||||
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Systematics | ||||||||||||
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Scientific name | ||||||||||||
Caseidae | ||||||||||||
Williston , 1912 |
The Caseidae were herbivorous synapsids from the group of pelycosaurs . According to the classical view, they are " reptiles ", but related to the animals from which the " mammal-like reptiles " and finally the mammals developed. They lived in the late Pennsylvania and Permian about 290 to 260 million years ago.
description
The body size of the Caseidae varies considerably, the smaller representatives were around one meter, while the larger species reached a length of over four meters and an estimated weight of 500 kilograms.
The skull of these animals was short and had a basic shape bent forward. The skull window , which is typical of the synapsids, was very large to allow space for strong masticatory muscles . The nostrils were also greatly enlarged. The teeth were uniform ( homodont ), they had a blunt shape with wavy edges. There was a row of smaller teeth on the roof of the mouth , which - since there are no corresponding structures on the lower jaw - probably worked together with a rough, muscular tongue and thus made it possible to pick up hard plant parts. The body skeleton was barrel-shaped, probably to make room for a well-developed digestive tract for the fermentation of plant food. The limbs were strong, the head very small and the neck short compared to the rest of the body.
Spatial and temporal classification
The oldest finds come from the early Permian and they are among the few pelycosaurs that are not only known from North America - for example, fossils of these animals have also been discovered in France and Kazakhstan . The most recent finds come from the late Middle Permian.
Systematics
The Caseidae and the Eothyrididae systematically form the group of Caseasauria , which stands at the base of the synapsids and forms the sister group of the Eupelycosauria , from which the therapsids (the "mammal-like reptiles") and finally the mammals have developed.
Genera
- Alierasaurus
- Angelosaurus
- Casea
- Caseopsis
- Caseoides
- Cotylorhynchus
- Ennatosaurus
- Eocasea
- Knoxosaurus
- Oromycter
literature
- TS Kemp: The Origin & Evolution of Mammals. Oxford University Press, Oxford 2005. ISBN 0-19-850761-5
Individual evidence
- ↑ a b Reisz RR, Fröbisch J (2014) The Oldest Caseid Synapsid from the Late Pennsylvanian of Kansas, and the Evolution of Herbivory in Terrestrial Vertebrates. PLoS ONE 9 (4): e94518. doi: 10.1371 / journal.pone.0094518
- ↑ Marco Romano & Umberto Nicosia: Alierasaurus ronchii, gen. Et sp. nov., A Caseid from the Permian of Sardinia, Italy. Journal of Vertebrate Paleontology, July, 34 (4): 900-913. 2014, doi: 10.1080 / 02724634.2014.837056
Web links
- Caseidae in Mikko's Phylogeny Archive
- Caseidae on Palaeos.com