''Proterogyrinus'' is an extinct genus of early tetrapods from the order Embolomeri. Fossil remains of ''Proterogyrinus'' have been found in Scotland, UK, and West Virginia, United States, and date back to the Serpukhovian (mid-

Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ...

period), which is from about 331 to 323 million years ago. The genus was originally named by renowned vertebrate paleontologist Alfred Sherwood Romer in 1970. A comprehensive redescription was later published by Canadian paleontologist Robert Holmes in 1984. The generic name "''Proterogyrinus''" is Greek for "earlier wanderer" or "earlier tadpole". This name was chosen by Romer in keeping with a trend of naming long-bodied early tetrapods (such as ''

Eogyrinus ''Pholiderpeton'' (from el, φολῐ́δος , 'horny scale' and el, ἑρπετόν , 'creeping thing') is an extinct genus of embolomere amphibian which lived in the Late Carboniferous period ( Bashkirian) of England. The genus was first ...

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Crassigyrinus ''Crassigyrinus'' (from la, crassus, 'thick' and el, γυρίνος el, gyrínos, 'tadpole') is an extinct genus of carnivorous stem tetrapod from the Early Carboniferous Limestone Coal Group of Scotland and possibly Greer, West Virginia. ...

'') with the suffix "-''gyrinus''". Romer hesitated from designating ''Proterogyrinus'' as a true embolomere, because its intercentra (the forward portion of each vertebra) were smaller than its pleurocentra (the rear portion). He used the group Anthracosauria to encompass embolomeres and their close relatives such as ''Proterogyrinus''. However, other sources prefer a wider definition of Embolomeri similar in usage to Romer's Anthracosauria, thus counting ''Proterogyrinus'' as an embolomere.

Description

In most respects ''Proterogyrinus'' resembled other embolomeres such as '' Archeria'', with a moderately elongated skull that was taller than that of other early tetrapods such as colosteids and temnospondyls. Members of the genus had strong limbs with several fully- ossified ankle and wrist bones. This would have given ''Proterogyrinus'' the ability to walk and hunt on land. However, the presence of lateral line grooves and otic notches which likely held

spiracle Spiracle or spiraculum may refer to: * Spiracle (arthropods), opening in the exoskeletons of some arthropods * Spiracle (vertebrates), openings on the surface of some vertebrates * Spiraculum, a genus of land snails in family Cyclophoridae Cycl ...

s show that they were probably more well-adapted for the water. The tail was long and tall, and was likely a powerful method of locomotion. The eyes were positioned high on the skull, supporting the idea that ''Proterogyrinus'' had an active lifestyle near the surface of the water.

References

{{Taxonbar, from=Q134526 Extinct animals of North America Embolomeres Carboniferous reptiliomorphs Transitional fossils Taxa named by Alfred Romer Fossil taxa described in 1970