''Oromycter'' is an extinct
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of
caseid
Caseidae are an extinct family of basal synapsids that lived from the Late Carboniferous to Middle Permian between about 300 and 265 million years ago. Fossils of these animals come from the south-central part of the United States (Texas, Oklaho ...
synapsid
Synapsida is a diverse group of tetrapod vertebrates that includes all mammals and their extinct relatives. It is one of the two major clades of the group Amniota, the other being the more diverse group Sauropsida (which includes all extant rept ...
s from the Early
Permian
The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...
of
Oklahoma
Oklahoma ( ; Choctaw language, Choctaw: , ) is a landlocked U.S. state, state in the South Central United States, South Central region of the United States. It borders Texas to the south and west, Kansas to the north, Missouri to the northea ...
. The sole and type species, ''Oromycter dolesorum'', was named in 2005 by
Robert R. Reisz.
[Reisz, R. R. 2005. ''Oromycter'', a New Caseid from the Lower Permian of Oklahoma. ''Journal of Vertebrate Paleontology'' 25 (4): 905-910.]
Description
''Oromycter'' was a small caseid characterized by its dentition, which lacked the distinct leaf-like serrations of other caseids and instead possessed broad, spatulate and roughened cutting edges. Its teeth were also more thoroughly attached to the bone of the skull and jaw than in other members of
Caseidae
Caseidae are an Extinction, extinct Family (biology), family of Basal (phylogenetics), basal synapsids that lived from the Late Carboniferous to Middle Permian between about 300 and 265 million years ago. Fossils of these animals come from the so ...
. The first and second teeth of the premaxilla show distinct wear facets which suggest that they occluded with the first and second teeth of the dentary, possibly to facilitate the cropping of vegetation. Its lacrimal bone, while clearly
caseid
Caseidae are an extinct family of basal synapsids that lived from the Late Carboniferous to Middle Permian between about 300 and 265 million years ago. Fossils of these animals come from the south-central part of the United States (Texas, Oklaho ...
in form, appears more primitive than in any other known caseid.
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Classification
''Oromycter'' is the oldest and most basal caseid known, and is the sister taxon of all other caseids.
Below is a cladogram based on the phylogenetic analysis of Maddin et al. in 2008.
See also
* List of pelycosaurs
This list of pelycosaurs is an attempt to create a comprehensive listing of all Genus, genera that have ever been included in the synapsida excluding therapsida and purely vernacular terms. The list includes all commonly accepted genera, but also g ...
References
The main groups of non-mammalian synapsids at Mikko's Phylogeny Archive
Caseidae
Prehistoric synapsid genera
Cisuralian synapsids of North America
Permian United States
Taxa named by Robert R. Reisz
Fossil taxa described in 2005
Cisuralian genus first appearances
Cisuralian genus extinctions
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