Lanthanosuchidae
| Lanthanosuchidae | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Life picture of Chalcosaurus lukjanovae |
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| Temporal occurrence | ||||||||||||
| Guadalupium to Lopingium (Oberperm) | ||||||||||||
| 268 to 255 million years | ||||||||||||
| Locations | ||||||||||||
| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Lanthanosuchidae | ||||||||||||
| Yefremov , 1946 |
The Lanthanosuchidae are an extinct group of terrestrial vertebrates (Tetrapoda) from the Russian Upper Permian. They belong to the group of parareptiles . The fossils of several genera have been found in sedimentary rocks around 268 to 255 million years old . The Soviet paleontologist Ivan Yefremov ( Ivan Antonovich Efremov ) presented the taxon on the 1946th
description
The distinguishing feature of the Lanthanosuchiden is their broad, extremely flat skull . This was considered to be an adaptation to an aquatic way of life, later investigations question this interpretation. Perhaps the animals fed on insects and larvae and pushed their flattened skulls to forage in the litter of the forest floor under leaves and other material. The inside of the skull offered no space for jaw muscles , so the muscles were outside and connected to the jaw through an opening in the skull behind the bony eye socket .
Systematics
The systematic position of the Lanthanosuchidae in the phylogenetic family tree of terrestrial vertebrates has long been the subject of discussion. In the past they were considered to be members of the Seymouriamorpha , presumably because of the skull , which was sculpted in the Lanthanosuchidae by pronounced skin ossification from ridges and pits. These were probably used to reinforce the roof of the skull . Belonging to the Diadectomorpha was also suggested. Today they are considered to belong to the extinct amniote group Parareptilia , which was previously considered to be the parent group of turtles . According to recent studies, the Lanthanosuchiden are closely related to the early parareptile Acleistorhinus .
The strong sculpturing of the skull was not a specific feature ( autapomorphy ) of the Lanthanosuchids, it was widespread in the early Anapsids and Seymouriamorphs. A lateral temple window was also found in at least some taxa of the early anapsids.
Genera of the Lanthanosuchidae
Individual evidence
- ↑ a b Olivier Rieppel , Robert, R. Reisz: The origin and early evolution of turtles. In: Annual Review of Ecology and Systematics. Vol. 30, 1999, ISSN 0066-4162 , pp. 1-22, doi : 10.1146 / annurev.ecolsys.30.1.1 .
- ↑ a b c d e Introduction to Lanthanosuchidae. Last accessed: November 3, 2014.
- ↑ a b The Paleobiology Database . Last accessed: November 3, 2014.
- ↑ a b c d Lanthanosuchidae - Palaeos.com. Last accessed: November 3, 2014.
