''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 of

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 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 during the upper Permian 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 Events January * January 1 – The Bornean Sultanate of Brunei gains full independence from the United Kingdom, having become a British protectorate in 1888. * January 7 – Brunei becomes the sixth member of the Association of Southeast A ...

. According to classification by Michel Laurin and

Robert R. Reisz Robert Rafael Reisz is a Canadian paleontologist and specialist in the study of early amniote and tetrapod evolution. Research career Reisz received his B.Sc. (1969), M.Sc. (1971) and Ph.D. (1975) from McGill University as Robert L. Carroll ...

, the genus is a parareptile, belonging to the same branch as Millerettidae, Procolophonidae and other generalized anapsid reptiles. The type species 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 UCMP 143 277) was originally thought to be a reptile-like amphibian and assigned to the genus '' Seymouria''. 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