''Cutleria'' 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 ...

of basal

sphenacodontid Sphenacodontidae (Greek: "wedge point tooth family") is an extinct family of small to large, advanced, carnivorous, Late Pennsylvanian to middle Permian pelycosaurs. The most recent one, ''Dimetrodon angelensis'', is from the late Kungurian or e ...

s or derived stem- sphenacodontoid known from 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 ...

period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept ...

(

Sakmarian In the geologic timescale, the Sakmarian is an age or stage of the Permian. It is a subdivision of the Cisuralian Epoch or Series. The Sakmarian lasted between 293.52 and million years ago (Ma). It was preceded by the Asselian and followed by t ...

stage) of the

Colorado Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of t ...

, United States. It contains a single species, ''Cutleria wilmarthi''.

Discovery

''Cutleria'' is known only from the

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 ...

specimen

USNM The National Museum of Natural History is a natural history museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C., United States. It has free admission and is open 364 days a year. In 2021, with 7. ...

22099, a fractured but three-dimensionally preserved, a nearly complete

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, the ...

and articulated partial

postcrania Postcrania (postcranium, adjective: postcranial) in zoology and vertebrate paleontology is all or part of the skeleton apart from the skull. Frequently, fossil remains, e.g. of dinosaurs or other extinct tetrapods, consist of partial or isolated sk ...

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 ...

(including

vertebral column The vertebral column, also known as the backbone or spine, is part of the axial skeleton. The vertebral column is the defining characteristic of a vertebrate in which the notochord (a flexible rod of uniform composition) found in all chordata, ...

rib In vertebrate anatomy, ribs ( la, costae) are the long curved bones which form the rib cage, part of the axial skeleton. In most tetrapods, ribs surround the chest, enabling the lungs to expand and thus facilitate breathing by expanding the ches ...

s and several girdle and limb elements). It was collected at locality 3, near Placerville of

San Miguel County, Colorado San Miguel County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 8,072. The county seat is Telluride. The county is named for the San Miguel River. History San Miguel County was given the Spanish ...

, from the

Cutler Formation The Cutler Formation or Cutler Group is a rock unit that is exposed across the U.S. states of Arizona, northwest New Mexico, southeast Utah and southwest Colorado. It was laid down in the Early Permian during the Wolfcampian epoch. Descript ...

, dating to the

stage of the

Cisuralian The Cisuralian is the first Series (stratigraphy), series/Epoch (geology), epoch of the Permian. The Cisuralian was preceded by the Pennsylvanian (geology), Pennsylvanian and followed by the Guadalupian. The Cisuralian Epoch is named after the w ...

series Series may refer to: People with the name * Caroline Series (born 1951), English mathematician, daughter of George Series * George Series (1920–1995), English physicist Arts, entertainment, and media Music * Series, the ordered sets used i ...

. MCZ 2987, a tip of the

rostrum Rostrum may refer to: * Any kind of a platform for a speaker: **dais **pulpit * Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects * Rostrum (ship), a form of bow on naval ships * Ros ...

and some teeth collected 2.5 km from the type locality (from localities 11-13), was originally referred to ''C. wilmarthi'' by Lewis and Vaughn (1965). A redescription of

sphenacodont Sphenacodontia is a stem-based clade of derived synapsids. It was defined by Amson and Laurin (2011) as "the largest clade that includes ''Haptodus baylei'', ''Haptodus garnettensis'' and '' Sphenacodon ferox'', but not ''Edaphosaurus pogonias'' ...

s 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 imp ...

(1993 and 1994), revealed that it can't be assigned to any named sphenacodont genus. Although its teeth also bear cutting edges without serrations, they are more

bulbous In botany, a bulb is structurally a short stem with fleshy leaves or leaf basesBell, A.D. 1997. ''Plant form: an illustrated guide to flowering plant morphology''. Oxford University Press, Oxford, U.K. that function as food storage organs durin ...

, not as strongly compressed

lateral Lateral is a geometric term of location which may refer to: Healthcare *Lateral (anatomy), an anatomical direction *Lateral cricoarytenoid muscle *Lateral release (surgery), a surgical procedure on the side of a kneecap Phonetics *Lateral cons ...

ly and not curved

distal Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...

ly. A new genus wasn't erected for MCZ 2987, as it is very fragmentary and lacks sufficient diagnostic features.

Description

''Cutleria'' was assigned to the

Haptodontinae ''Haptodus'' is an extinct genus of basal sphenacodont, member of the clade that includes therapsids and hence, mammals. It was at least in length. It lived in present-day France during the Early Permian. It was a medium-sized predator, feedi ...

by Lewis and Vaughn (1965) on the basis of similarities to ''

Haptodus baylei ''Haptodus'' is an extinct genus of basal (phylogenetics), basal sphenacodont, member of the clade that includes therapsids and hence, mammals. It was at least in length. It lived in present-day France during the Early Permian. It was a medium-s ...

'' and '' H. longicaudata'' (now ''

Palaeohatteria ''Palaeohatteria'' is an extinct genus of basal sphenacodonts known from the Early Permian period (Sakmarian stage) of Saxony, Germany. It contains a single species, ''Palaeohatteria longicaudata''. Discovery ''Palaeohatteria'' is based on v ...

''). Currie (1977) described the second haptodontine from

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

, ''

Haptodus garnettensis ''"Haptodus" garnettensis'' is an extinct species of basal sphenacodont from the Late Carboniferous ( Pennsylvanian) of Kansas, USA. Taxonomy The holotype of ''"Haptodus" garnettensis'' is RM 14156, a partially articulated skeleton (cra ...

''. In 1979, he synonymized all European haptodontines, as well as ''C. wilmarthi'', with ''H. baylei''. Later, Laurin (1993 and 1994) considered Haptodontinae to represent a

polyphyletic A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of converg ...

grade of basal

s, and revalidated ''Cutleria'' among other genera and species. His revision has been accepted since. Only three

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

analyses included ''Cutleria''. Laurin (1994) and Fröbisch ''et al.'' (2011) recovered ''Cutleria'' as the sister taxon of Sphenacodontoidea, while the significantly larger analysis of Benson (in press) recovered it as the

basalmost In phylogenetics, basal is the direction of the ''base'' (or root) of a rooted phylogenetic tree or cladogram. The term may be more strictly applied only to nodes adjacent to the root, or more loosely applied to nodes regarded as being close to th ...

. Benson (in press) listed three

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 ...

between ''Cutleria'' and more derived sphenacodontids: their frontal is more than 2.5 times the length of the parietal (as it was noted by Laurin in 1994), a strongly posteroventrally inclined temporal roof (absent in ''

Secodontosaurus ''Secodontosaurus'' (meaning "cutting-tooth lizard") is an extinct genus of "pelycosaur" synapsids that lived from between about 285 to 272 million years ago during the Early Permian. Like the well known ''Dimetrodon'', ''Secodontosaurus'' is a c ...

''), and a lateral centrale that covers the proximal ends of the first-third distal carpals. However, only one additional step was required to place ''Cutleria'' outside Sphenacodontidae, as the sister taxon of Sphenacodontoidea (which is the node "Therapsida + Sphenacodontidae"). The

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...

below shows ''Cutleria'' phylogenetic position among other synapsids following Benson (2012).

Etymology

''Cutleria'' was first described and named by George Edward Lewis and

Peter Paul Vaughn Peter may refer to: People * List of people named Peter, a list of people and fictional characters with the given name * Peter (given name) ** Saint Peter (died 60s), apostle of Jesus, leader of the early Christian Church * Peter (surname), a sur ...

1965 Events January–February * January 14 – The Prime Minister of Northern Ireland and the Taoiseach of the Republic of Ireland meet for the first time in 43 years. * January 20 ** Lyndon B. Johnson is Second inauguration of Lyndo ...

and 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 ''Cutleria wilmarthi''. The generic name is derived from the name of the

in which the holotype was found. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

honors Wilmarth for finding the holotype.

References

{{Taxonbar, from=Q5196889 Sphenacodontidae Fossil taxa described in 1965 Cisuralian synapsids of North America Prehistoric synapsid genera Cisuralian genus first appearances