Archegosaurus
Encyclopedia
Archegosaurus is a genus
of temnospondyl amphibian
which lived during the Asselian
to Wuchiapingian
stages of the Permian
, around 299-253 million years ago. The remains of this animal, consisting of at least 90 partial skeletons (mostly skulls), have been found in Germany
. The name Archegosaurus was coined by Goldfuss in 1847. Archegosaurus is a member of Archegosauridae
and gives its name to the family
.
. Steen named it Memonomenos dyscriton on the basis of a skull that was narrower than others in the Ruprechtice. It was classified as an anthracosaur, a group closely related to reptiles. Both Memonomenos and embolomere anthracosaurs had vertebrae that were divided into several parts, including a pleurocentrum and intercentrum. Animals with this type of divided vertebrae were said to be rhachitomous. During the early twentieth century, paleontologists considered rhachitomous temnospondyls to be the descendants of embolomeres, and Steen considered Memonomenos to be a link between these two groups. Steen also noted that Memonomenos had large tabular horns, a feature shared with anthracosaurs. Temnospondyls and anthracosaurs were later found to be two distantly related groups, and paleontologist Alfred Romer
placed Memonomenos within Anthracosauria. This placement was accepted until 1978 when Memonomenos was reassigned to the genus Archegosaurus and classified as a temnospondyl. Memonomenos dyscriton became a second species of Archegosaurus, A. dyscriton.
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 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...
which lived during the Asselian
Asselian
In the geologic timescale, the Asselian is the earliest geochronologic age or lowermost chronostratigraphic stage of the Permian. It is a subdivision of the Cisuralian epoch or series. The Asselian lasted between 299.0 ± 0.8 and 294.6 ± 0.8 million years ago...
to Wuchiapingian
Wuchiapingian
In the geologic timescale, the Wuchiapingian or Wujiapingian is an age or stage of the Permian. It is also the lower or earlier of two subdivisions of the Lopingian epoch or series. The Wuchiapingian spans the time between 260.4 ± 0.7 and 253.8 ± 0.7 million years ago...
stages of the Permian
Permian
The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...
, around 299-253 million years ago. The remains of this animal, consisting of at least 90 partial skeletons (mostly skulls), have been found in 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...
. The name Archegosaurus was coined by Goldfuss in 1847. Archegosaurus is a member of Archegosauridae
Archegosauridae
Archegosauridae is a family of relatively large and long snouted temnospondyls that lived in the Permian period. Most appeared and probably behaved like crocodiles.-References:...
and gives its name to the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
.
Classification
In 1938, paleontologist Margaret C. Steen described a temnospondyl from the Permian-age Ruprechtice assemblage in northeast BohemiaBohemia
Bohemia is a historical region in central Europe, occupying the western two-thirds of the traditional Czech Lands. It is located in the contemporary Czech Republic with its capital in Prague...
. Steen named it Memonomenos dyscriton on the basis of a skull that was narrower than others in the Ruprechtice. It was classified as an anthracosaur, a group closely related to reptiles. Both Memonomenos and embolomere anthracosaurs had vertebrae that were divided into several parts, including a pleurocentrum and intercentrum. Animals with this type of divided vertebrae were said to be rhachitomous. During the early twentieth century, paleontologists considered rhachitomous temnospondyls to be the descendants of embolomeres, and Steen considered Memonomenos to be a link between these two groups. Steen also noted that Memonomenos had large tabular horns, a feature shared with anthracosaurs. Temnospondyls and anthracosaurs were later found to be two distantly related groups, and paleontologist Alfred Romer
Alfred Romer
Alfred Sherwood Romer was an American paleontologist and comparative anatomist and a specialist in vertebrate evolution.-Biography:...
placed Memonomenos within Anthracosauria. This placement was accepted until 1978 when Memonomenos was reassigned to the genus Archegosaurus and classified as a temnospondyl. Memonomenos dyscriton became a second species of Archegosaurus, A. dyscriton.
External links
- Archosauroidea from Palaeos.com