Dissorophoidea
Dissorophoidea | ||||||||||
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Temporal occurrence | ||||||||||
Upper Carboniferous ( Pennsylvania ) to Lower Triassic | ||||||||||
318.1 to 245.9 million years | ||||||||||
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Systematics | ||||||||||
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Scientific name | ||||||||||
Dissorophoidea | ||||||||||
Bolt , 1969 |
The Dissorophoidea are an extinct group of terrestrial vertebrates belonging to the Temnospondyli group . They were small to medium-sized animals that played a significant role in the vertebrate community for approximately 80 million years. There were several sub-taxa, which included both aquatic and terrestrial forms. The group is systematically important because, according to some scientists, it is the ancestors of today's amphibians .
Micromelerpetontidae and Branchiosauridae
The earliest dissorophoidea are the Micromelerpetontidae and the pedomorphic Branchiosauridae . Their fossils were found in freshwater deposits from the Pennsylvania 318 to 299 million years ago in the American Midwest and in the Czech Republic .
Dissorophoidae
The Dissorophoidae lived in the Unterperm and were probably exclusively terrestrial . They were small to medium-sized, massively built animals with short skulls, large eyes and middle ears. They differed from all other Dissorophoidea by a bony back armor.
Trematopidae
The Trematopidae appeared in the late Pennsylvania and lived until the early Permian. Like the Dissorophoidae, they are a group that lives primarily on land. They had typical keyhole-shaped nostrils extended backwards and large fangs on the maxillary (an upper jawbone).
Amphibamidae
The Amphibamidae lived from the late Pennsylvania to the early Triassic, existed for over 60 million years and were the longest living taxon of the Dissorophoidea. They were small animals that, as can be seen from the ossification of the limbs, lived mainly in the country. Their larvae lived in the water, had external gills and resembled the Branchiosauridae. This group is also assigned to Gerobatrachus hottoni , a small, only eleven centimeters long Temnospondyle, which was only described in 2008 and which combines common features of the frog amphibian and the tail amphibian , so that it could be close to the common ancestor of both taxa.
Systematics
Within the Temnospondyli, the Dissorophoidea belong to the Euskelia and are the sister group of the Eryopidae .
The group probably developed from a small Eryops -like ancestor. Of their five families, the Trematopidae and Dissorophidae are seen more in a basal position, while Branchiosauridae, Amphibamidae, and Lissamphibia (the modern amphibians) form the crown group .
literature
- Michael J. Benton : Paleontology of the vertebrates. Translation of the 3rd English edition by Hans-Ulrich Pfretzschner. Pfeil, Munich 2007, ISBN 978-3-89937-072-0 .
Web links
- Huttenlocker, Adam. 2007: Dissorophoidea Bolt 1969. Version March 12, 2007. in The Tree of Life Web Project
- Palæos Dissorophoidea