''Glaucosaurus'' is an extinct genus of edaphosaurid

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 ...

from the

Early Permian 01 or 01 may refer to: * The year 2001, or any year ending with 01 * The month of January * 1 (number) Music * '01 (Richard Müller album), ''01'' (Richard Müller album), 2001 * 01 (Urban Zakapa album), ''01'' (Urban Zakapa album), 2011 * ''01011 ...

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

. The type species, ''G. megalops'', was named in 1915.S. W. Williston. 1915. New genera of Permian reptiles. ''The American Journal of Science'', series 4 39(233):575-579

Classification

''Glaucosaurus'' is known only from its holotype, a partial

skull The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

and

jaw The jaws are a pair of opposable articulated structures at the entrance of the mouth, typically used for grasping and manipulating food. The term ''jaws'' is also broadly applied to the whole of the structures constituting the vault of the mouth ...

. Almost all of the sutures have been obliterated. Nevertheless, there is broad agreement that ''Glaucosaurus'' is not only an edaphosaurid, but a close relative of ''

Edaphosaurus ''Edaphosaurus'' (, meaning "pavement lizard" for dense clusters of its teeth) is a genus of extinct edaphosaurid synapsids that lived in what is now North America and Europe around 303.4 to 272.5 million years ago, during the Late Carboniferous ...

'' itself. All of the known

sphenacodonts Sphenacodontia is a stem-based clade of derived synapsids. It was defined by Amson and Laurin (2011) as "the largest clade that includes ''Haptodus baylei'', ''Haptodus garnettensis'' and '' Sphenacodon ferox'', but not '' Edaphosaurus pogonias' ...

are

carnivore A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they ar ...

s except for certain therapsids. ''Glaucosaurus'' is plainly not a therapsid, e.g. because the lacrimal reaches the

naris A nostril (or naris , : nares ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called turbinates, ...

, the septo

maxilla In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxil ...

is large, there are no

incisor Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, wher ...

s, etc. And it is just as plainly not a carnivore, since it lacks cutting edges on the teeth or canine-like teeth. So, it is very likely to be an edaphosaur. Assuming that this is the case, it is very close to ''Edaphosaurus'', because only ''Glaucosaurus'' and ''Edaphosaurus'' completely lack both canine teeth and a canine buttress, lack the transverse flange of the pterygoid, and have prefrontal with a ventral (descending) process which is expanded toward the middle of the skull, forming an anterior housing for the eyeball. However, ''Glaucosaurus'' differs from any of the known sorts of ''Edaphosaurus'' in have an incredibly long maxilla, and in the equally extreme length of the prefrontal's ventral process.

References

External links

The main groups of non-mammalian synapsids at Mikko's Phylogeny Archive
Edaphosauridae Prehistoric synapsid genera Cisuralian synapsids of North America Taxa named by Samuel Wendell Williston Fossil taxa described in 1915 Cisuralian genus first appearances Cisuralian genus extinctions {{Paleo-synapsid-stub

Classification

See also

References

External links