''Nyctiphruretus'' (meaning "Guardian of the Night") is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

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 ...

nyctiphruretid Nyctiphruretidae is an extinct family of hallucicranian parareptiles known from the late Early to the late Middle Permian of European Russia and south-central United States. Nyctiphruretidae was named by Efremov in 1938. The type genus is '' N ...

parareptile Parareptilia ("near-reptiles") is an extinct group of Basal (phylogenetics), basal Sauropsida, sauropsids ("Reptile, reptiles"), traditionally considered the sister taxon to Eureptilia (the group that likely contains all living reptiles and birds ...

known from the

Guadalupian The Guadalupian is the second and middle Series (stratigraphy), series/Epoch (geology), epoch of the Permian. The Guadalupian was preceded by the Cisuralian and followed by the Lopingian. It is named after the Guadalupe Mountains of New Mexico an ...

series (middle

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 ...

) of

European Russia European Russia is the western and most populated part of the Russia, Russian Federation. It is geographically situated in Europe, as opposed to the country's sparsely populated and vastly larger eastern part, Siberia, which is situated in Asia ...

Many

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

s of the type species, ''N. acudens'', were found well preserved near the

Mezen River The Mezen (; Komi: ''n'') is a river in Udorsky District of the Komi Republic and in Leshukonsky and Mezensky Districts of Arkhangelsk Oblast in Russia. Its mouth is located in the Mezen Bay of the White Sea. Mezen is one of the biggest rivers ...

of European Russia in various stages of growth. The dentition identified that ''Nyctiphruretus'' is a

herbivore A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat ...

. Based on the large numbers of individuals found and the sediment that they were found in, it appears that their diet consisted of

aquatic plant Aquatic plants, also referred to as hydrophytes, are vascular plants and Non-vascular plant, non-vascular plants that have adapted to live in aquatic ecosystem, aquatic environments (marine ecosystem, saltwater or freshwater ecosystem, freshwater ...

s. Adults discovered averaged 36 cm in length with a 4.4 cm skull that was crushed but recognisable. ''Nyctiphruretus'' was first named by Efremov in

1938 Events January * January 1 – state-owned enterprise, State-owned railway networks are created by merger, in France (SNCF) and the Netherlands (Nederlandse Spoorwegen – NS). * January 20 – King Farouk of Egypt marries Saf ...

and the

type species In International_Code_of_Zoological_Nomenclature, 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 spe ...

is ''Nyctiphruretus acudens''. In 2002, a second species was named by V. V. Bulanov. ''N. optabilis'' is known from a single

jaw The jaws are a pair of opposable articulated structures at the entrance of the mouth, typically used for grasping and manipulating food. The term ''jaws'' is also broadly applied to the whole of the structures constituting the vault of the mouth ...

, also from Russia, Eastern Europe. Lee (1997) named the order Nyctiphruretia and the family Nyctiphruretidae, to include ''Nyctiphruretus''. While the family was defined to be

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

, the order was defined to include both nyctiphruretids and

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)''. The ...

s. However, recent

cladistic Cladistics ( ; from Ancient Greek 'branch') is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is ...

analyses suggest that

s are more closely related to the

Pareiasauria Pareiasaurs (meaning "cheek lizards") are an extinct clade of large, herbivorous parareptiles. Members of the group were armoured with osteoderms which covered large areas of the body. They first appeared in southern Pangea during the Middle Per ...

instead, thus making ''Nyctiphruretus'' the only genus of its order. In 2014, MacDougall & Reisz described and named a second genus of Nyctiphruretidae, ''

Abyssomedon ''Abyssomedon'' (meaning "Guardian of the Abyss") is an extinct genus of a nyctiphruretid parareptile known from Early Permian ( Artinskian age) fissure fills at Richards Spur in Comanche County, Oklahoma, south-central United States. It conta ...

'', from the middle Leonardian stage of the late

Early Permian 01 or 01 may refer to: * The year 2001, or any year ending with 01 * The month of January * 1 (number) Music * '01 (Richard Müller album), ''01'' (Richard Müller album), 2001 * 01 (Urban Zakapa album), ''01'' (Urban Zakapa album), 2011 * ''01011 ...

Comanche County, Oklahoma Comanche County is a County (United States), county located in the U.S. state of Oklahoma. As of the 2020 United States census, 2020 census, the population was 121,125, making it the fifth-most populous county in Oklahoma. Its county seat is L ...

, south-central United States. It contains a single species, ''A. williamsi'', which represents the first nyctiphruretid known from North America, and the oldest species of the family.

References

{{Taxonbar, from=Q2425306 Procolophonomorpha Guadalupian reptiles of Europe Prehistoric reptile genera