''Cutleria'' 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 ...

of basal

sphenacodontid Sphenacodontidae (Greek: "wedge point tooth family") is an extinct family of sphenacodontoid synapsids. Small to large, advanced, carnivorous, Late Pennsylvanian to middle Permian "pelycosaurs". The most recent one, ''Dimetrodon angelensis'', is ...

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 (Urban Zakapa album), ''01'' (Urban Zakapa album), 2011 * ''01011 ...

period (

Sakmarian In the geologic timescale, the Sakmarian is an age or stage of the Permian period. 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 fo ...

stage) of

Colorado Colorado is a U.S. state, state in the Western United States. It is one of the Mountain states, sharing the Four Corners region with Arizona, New Mexico, and Utah. It is also bordered by Wyoming to the north, Nebraska to the northeast, Kansas ...

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

Discovery

''Cutleria'' is known only from the

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

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

skull The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

and articulated partial

postcrania The postcranium ("behind the cranium"; plural: postcrania) or postcranial skeleton in zoology and vertebrate paleontology is the skeleton apart from the skull. The postcranium encompasses the axial skeleton, which includes the entirety of the verte ...

skeleton A skeleton is the structural frame that supports the body of most animals. There are several types of skeletons, including the exoskeleton, which is a rigid outer shell that holds up an organism's shape; the endoskeleton, a rigid internal fra ...

(including

vertebral column The spinal column, also known as the vertebral column, spine or backbone, is the core part of the axial skeleton in vertebrates. The vertebral column is the defining and eponymous characteristic of the vertebrate. The spinal column is a segmente ...

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

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 Spanis ...

, from the

Cutler Formation The Cutler Formation or Cutler Group is a stratigraphic unit 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. Desc ...

, dating to the

stage of the

Cisuralian The Cisuralian, also known as the Early Permian, is the first series/epoch of the Permian. The Cisuralian was preceded by the Pennsylvanian and followed by the Guadalupian. The Cisuralian Epoch is named after the western slopes of the Ural Mou ...

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 ** podium * 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 ...

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 pogonia ...

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 impo ...

(1993 and 1994), revealed that it cannot 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 a short underground 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 duri ...

, not as strongly compressed

lateral Lateral is a geometric term of location which may also refer to: Biology and healthcare * Lateral (anatomy), a term of location meaning "towards the side" * Lateral cricoarytenoid muscle, an intrinsic muscle of the larynx * Lateral release ( ...

ly and not curved

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

ly. A new genus was not 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 sphenacodonts, a 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, fe ...

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

Haptodus baylei ''Haptodus'' is an extinct genus of basal sphenacodonts, a 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, fe ...

'' 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 ve ...

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

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

, ''

Haptodus garnettensis ''Haptodus'' is an extinct genus of basal sphenacodonts, a 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, fe ...

''. 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 that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies ...

grade of basal

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

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

analyses included ''Cutleria''. Laurin (1994) and Fröbisch ''et al.'' (2011) recovered ''Cutleria'' as the sister taxon of

Sphenacodontoidea Sphenacodontoidea is a node-based clade that is defined to include the most recent common ancestor of Sphenacodontidae and Therapsida and its descendants (including mammals). Sphenacodontoids are characterised by a number of synapomorphies co ...

, while the significantly larger analysis of Benson (in press) recovered it as the basalmost

. 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 ...

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 language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

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 in

1965 Events January–February * January 14 – The First 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 Lynd ...

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 ''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 Verl Richard Wilmarth for finding the holotype, together with Rollin Vickers.

References

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