''Asaphestera'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

of a

tetrapod Tetrapods (; ) are four-limb (anatomy), limbed vertebrate animals constituting the superclass Tetrapoda (). It includes extant taxon, extant and extinct amphibians, sauropsids (reptiles, including dinosaurs and therefore birds) and synapsids (p ...

described on the basis of fossils from the Carboniferous of the Joggins locality in

Nova Scotia, Canada Nova Scotia ( ; ; ) is one of the thirteen provinces and territories of Canada. It is one of the three Maritime provinces and one of the four Atlantic provinces. Nova Scotia is Latin for "New Scotland". Most of the population are native Eng ...

. It was originally described as an undetermined lepospondyl and subsequently classified as a microsaur within the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Tuditanidae. A study published in May 2020 found that specimens referred to ''Asaphestera'' represented several unrelated species. Steen (1934)'s original species name ''Asaphestera platyris'' was retained for a skull which has been re-evaluated as the earliest known

synapsid Synapsids + (, 'arch') > () "having a fused arch"; synonymous with ''theropsids'' (Greek, "beast-face") are one of the two major groups of animals that evolved from basal amniotes, the other being the sauropsids, the group that includes rep ...

. The type species of ''Asaphestera'' is ''Asaphestera platyris'', named by Steen (1934) based on three skulls. Carroll & Gaskill (1978) noted that one of the skulls was briefly named as the species ''" Hylerpeton" intermedium'' by Dawson (1894), though it is no longer consider related to the genus ''Hylerpeton''. According to Dawson's species name, they renamed ''Asaphestera platyris'' to ''Asaphestera intermedia''. Mann ''et al.'' (2020) re-evaluated purported Joggins microsaurs and found several unusual results. One of the skulls assigned the name ''Asaphestera platyris'' by Steen appeared to be a valid taxon, but instead of a microsaur it was the oldest known synapsid, possibly an eothyridid. Dawson's ''"Hylerpeton" intermedium'' was determined to be an indeterminate tetrapod and a ''

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium'' it may be impossible to determine whether a s ...

''. Additional ''Asaphestera'' material was named as a new genus of microsaur, '' Steenerpeton''.

References

Prehistoric synapsid genera Paleozoic life of Nova Scotia Fossil taxa described in 1934 {{paleo-synapsid-stub