''Macroleter'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

nycteroleterid Nycteroleteridae is a family of procolophonian parareptilians (extinct early reptiles) from the Middle to Late Permian of Russia and North America. They are sometimes classified as a sister group to pareiasaurids (but see ''Classification)'' ...

parareptile Parareptilia ("at the side of reptiles") is a subclass or clade of basal sauropsids (reptiles), typically considered the sister taxon to Eureptilia (the group that likely contains all living reptiles and birds). Parareptiles first arose near th ...

which existed in

Oklahoma Oklahoma (; Choctaw language, Choctaw: ; chr, ᎣᎧᎳᎰᎹ, ''Okalahoma'' ) is a U.S. state, state in the South Central United States, South Central region of the United States, bordered by Texas on the south and west, Kansas on the nor ...

and

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

during the upper

Permian The Permian ( ) is a geologic period and 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 251.9 Mya. It is the last period of the Paleoz ...

period. It was a quite generalized primitive reptile, in many ways resembling their amphibian ancestors. It was first named by paleontologists Tverdochlebova and Ivachnenko in 1984. According to classification by

Michel Laurin Michel Laurin is a Canadian-born French vertebrate paleontologist whose specialities include the emergence of a land-based lifestyle among vertebrates, the evolution of body size and the origin and phylogeny of lissamphibians. He has also made impo ...

and Robert R. Reisz, the genus is a

, belonging to the same branch as

Millerettidae Millerettidae is an extinct family of parareptiles from the Middle Permian to the Late Permian period (Capitanian - Changhsingian stages) of South Africa. The millerettids were small insectivores and probably resembled modern lizards in appearanc ...

Procolophonidae Procolophonidae is an extinct family of small, lizard-like parareptiles known from the Late Permian to Late Triassic that were distributed across Pangaea, having been reported from Europe, North America, China, South Africa, South America, Anta ...

and other generalized

anapsid An anapsid is an amniote whose skull lacks one or more skull openings (fenestra, or fossae) near the temples. Traditionally, the Anapsida are the most primitive subclass of amniotes, the ancestral stock from which Synapsida and Diapsida evolve ...

reptiles. The

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

is ''Macroleter poezicus'' from

Upper Permian The Permian ( ) is a geologic period and 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 251.9 Mya. It is the last period of the Paleoz ...

of Russia. ''Macroleter'' had an 8 cm skull, and an overall length of 75 cm. It was generally lizard-like in build with a rather flat and broad skull. The teeth were small and pointy, indication it predominantly hunted insects and other small invertebrates. ''Seymouria agilis'' (Olson, 1980) that is known from only one specimen (

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

UCMP 143 277) was originally thought to be a reptile-like amphibian and assigned to the genus ''

Seymouria ''Seymouria'' is an extinct genus of seymouriamorpha, seymouriamorph from the Early Permian of North America and Europe. Although they were amphibians (in a biological sense), ''Seymouria'' were well-adapted to life on land, with many reptile, re ...

''. The find consists of a nearly complete

skeleton A skeleton is the structural frame that supports the body of an animal. There are several types of skeletons, including the exoskeleton, which is the stable outer shell of an organism, the endoskeleton, which forms the support structure inside ...

from the

Chickasha Formation The Chickasha Formation is a geologic formation in Oklahoma. It preserves fossils dating back to the Permian period. See also * List of fossiliferous stratigraphic units in Oklahoma * Paleontology in Oklahoma Paleontology in Oklahoma refers ...

. In 2001, the find was reassigned by Laurin and Reisz to ''Macroleter''. ''Tokosaurus'', another parareptile thought to be closely related to ''Macroleter'', has also been reassigned to ''Macroleter'' and considered to be a juvenile of ''M. poezicus'' as they are known from the same locality.

References

Pareiasauromorphs Permian reptiles Extinct animals of Russia Prehistoric reptile genera {{paleo-reptile-stub