''Archegosaurus'' is a

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 ...

temnospondyl Temnospondyli (from Greek language, Greek τέμνειν, ''temnein'' 'to cut' and σπόνδυλος, ''spondylos'' 'vertebra') or temnospondyls is a diverse ancient order (biology), order of small to giant tetrapods—often considered Labyrinth ...

amphibian Amphibians are ectothermic, anamniote, anamniotic, tetrapod, four-limbed vertebrate animals that constitute the class (biology), class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all Tetrapod, tetrapods, but excl ...

which lived during the Asselian to

Wuchiapingian In the geologic timescale, the Wuchiapingian or Wujiapingian (from in the Liangshan area of Hanzhong, Shaanxi Province ) is an age or stage of the Permian. It is also the lower or earlier of two subdivisions of the Lopingian Epoch or S ...

stages of the

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 ...

, 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, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

. The name ''Archegosaurus'' was coined by Goldfuss in 1847. ''Archegosaurus'' is a member of Archegosauridae and is that

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

type genus In biological taxonomy, the type genus (''genus typica'') is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearin ...

Classification

In 1938, paleontologist Margaret C. Steen described a temnospondyl from the Permian-age Ruprechtice assemblage in northeast

Bohemia Bohemia ( ; ; ) is the westernmost and largest historical region of the Czech Republic. In a narrow, geographic sense, it roughly encompasses the territories of present-day Czechia that fall within the Elbe River's drainage basin, but historic ...

. 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 rachitomi. 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''.

Biology

Water balance of the Archegosaurus model

''Archegosaurus'' was a fully aquatic animal. A study regarding its metabolism, gas exchange, osmoregulation, and digestion suggest that it was rather similar to

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

, rather than modern aquatic amphibians like salamanders.Florian Witzmann; Elizabeth Brainerd (2017). "Modeling the physiology of the aquatic temnospondyl Archegosaurus decheni from the early Permian of Germany". Fossil Record. 20 (2): 105–127. doi:10.5194/fr-20-105-2017.

References

External links

Archegosauroidea
from Palaeos.com {{Taxonbar, from=Q748733 Permian temnospondyls of Europe Stereospondylomorpha Fossil taxa described in 1847 Prehistoric amphibian genera Taxa named by Georg August Goldfuss