Stephanospondylus is an extinct genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of diadectid reptiliomorph from the Early Permian of Germany

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

. Fossils have been found in deposits of the Lower Rotliegend

Rotliegend

The Rotliegend or Rotliegendes is a lithostratigraphic unit of Cisuralian age that is found in the subsurface of large areas in western and central Europe. The Rotliegend mainly consists of sandstone layers...

 near Dresden

Dresden

Dresden is the capital city of the Free State of Saxony in Germany. It is situated in a valley on the River Elbe, near the Czech border. The Dresden conurbation is part of the Saxon Triangle metropolitan area....

. The type species

Type species

In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...

 S. pugnax was originally referred to the genus Phanerosaurus

Phanerosaurus

Phanerosaurus is an extinct genus of diadectid reptiliomorph from the Early Permian of Germany. Fossils are known from the Leukersdorf Formation near Zwickau. German paleontologist Christian Erich Hermann von Meyer named the type species P. naumanni in 1860 on the basis of several sacral and...

in 1882 but was placed in its own genus in 1905.

Description

Stephanospondylus is known only from several vertebrae and fragments of the upper and lower jaws. It was named in 1882 on the basis of two slabs, the fossils in which were thought to represent two individuals. With the erection of a new genus in 1905, the fossils were considered to be part of a single individual. In 1925, Alfred Romer

Alfred Romer

Alfred Sherwood Romer was an American paleontologist and comparative anatomist and a specialist in vertebrate evolution.-Biography:...

 determined that only parts of the jaws and some vertebrae belonged to Stephanospondylus; the other material belonged to the temnospondyl amphibian

Amphibian

Amphibians , are a class of vertebrate animals including animals such as toads, frogs, caecilians, and salamanders. They are characterized as non-amniote ectothermic tetrapods...

 Onchiodon

Onchiodon

Onchiodon is an extinct genus of temnospondyl amphibian....

.

Stephanospondylus has spade-shaped teeth adapted to cutting plant material. The vertebrae are distinct from those of other diadectids in that they lack hyposphene-hypantrum articular surfaces. The holotype

Holotype

A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...

specimen may represent a juvenile form of another diadectid. Because so little is known of the genus, the relationship of Stephanospondylus to other diadectids is poorly known.