Acleistorhinidae 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 ...
family of
Late Carboniferous and
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 (Son of Dave album), ''01'' (Son of Dave album), 2000
* 01 (Urban ...
-aged (
Moscovian
Moscovian may refer to:
*An inhabitant of Moscow, the capital of Russia
*Something of, from, or related to Moscow
*Moscovian (Carboniferous)
The Moscovian is in the International Commission on Stratigraphy, ICS geologic timescale a stage (strati ...
to
Kungurian stage)
parareptiles. Acleistorhinids are most diverse from the
Richards Spur locality of the
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 (Son of Dave album), ''01'' (Son of Dave album), 2000
* 01 (Urban ...
of
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 ...
. Richards Spur acleistorhinids include ''
Acleistorhinus'', ''
Colobomycter'', and possibly ''
Delorhynchus'' and ''
Feeserpeton
''Feeserpeton'' is an extinct genus of parareptile from the Early Permian of Richard's Spur, Oklahoma. It is known from a single species, ''Feeserpeton oklahomensis'', which was named in 2012 on the basis of a nearly complete skull. ''Feeserpet ...
''. Other taxa include ''
Carbonodraco'' from the
Late Carboniferous of
Ohio and ''
Karutia
''Karutia'' is an extinct genus of parareptile known from the Early Permian Pedra de Fogo Formation of Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South Americ ...
'' from the Early Permian of
Brazil.
Acleistorhinidae is commonly considered a subgroup of
lanthanosuchoids, related to taxa such as ''
Chalcosaurus'', ''
Lanthaniscus'' and ''
Lanthanosuchus''.
However, a re-examination of parareptile phylogeny conducted by Cisneros ''et al.'' (2021) argued that lanthanosuchids were not closely related to acleistorhinids. The phylogenetic analysis conducted by these authors recovered acleistorhinids as the
sister group
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree.
Definition
The expression is most easily illustrated by a cladogram:
Taxon A and t ...
of the clade
Procolophonia
The Procolophonia are a suborder of herbivorous reptiles that lived from the Middle Permian till the end of the Triassic period. They were originally included as a suborder of the Cotylosauria (later renamed Captorhinida Carroll 1988) but ar ...
, while lanthanosuchids were recovered within the procolophonian subgroup
Pareiasauromorpha.
Acleistorhinidae is notable for being the oldest-known parareptilian clade. The family is diagnosed by the presence two
synapomorphies
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have ...
: (1) the largest
tooth is located far anteriorly on the
maxilla; and (2)
cranial ornamentation consists of sparse and shallow circular dimples.
Diet
Two specimens of acleistorhinids described from the
Richards Spur fissure-fill locality 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 ...
have provided compelling evidence of the diet of acleistorhinids. One specimen,
OMNH 73362, was later referred to ''
Delorhynchus cifellii'', a species named in 2014. The other specimen, OMNH 73364, has not been formally described. Fragments of
arthropod cuticle
A cuticle (), or cuticula, is any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticle" are non- homologous, differing in their origin, structu ...
s are present in between the many
palatal teeth of both skulls. The fragments in OMNH 73362 are thought to be the segments of an
antenna
Antenna ( antennas or antennae) may refer to:
Science and engineering
* Antenna (radio), also known as an aerial, a transducer designed to transmit or receive electromagnetic (e.g., TV or radio) waves
* Antennae Galaxies, the name of two collid ...
, while the fragments in OMNH 73364 are thought to be part of a
cercus.
In acleistorhinids, the marginal teeth, which are small and recurved, are suggestive of an insectivorous diet, as they probably were used for gripping and piercing arthropod cuticle. The denticulated palate, with three pairs of tooth fields and smaller teeth in between the fields, is seen as an adaptation for holding food in the oral cavity.
[
The teeth, which possess cutting edges, may also have been suitable for a carnivorous diet in which vertebrate flesh may have been consumed.][ It is likely that one acleistorhinid, ''Colobomycter pholeter'', specialized either on invertebrates with hard cuticles or on small tetrapods.]
References
Procolophonomorphs
Prehistoric reptile families
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