''"Haptodus" garnettensis'' 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 ...

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of basal sphenacodont from the Late Carboniferous ( Pennsylvanian) of Kansas, USA.

Taxonomy

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 ...

of ''"Haptodus" garnettensis'' is RM 14156, a partially articulated

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 ...

(

cranial 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 ...

and

postcranial 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 ...

) of immature individual. More than 16 well-preserved specimen of various

ontological In metaphysics, ontology is the philosophical study of being, as well as related concepts such as existence, becoming, and reality. Ontology addresses questions like how entities are grouped into categories and which of these entities exis ...

states were referred to this species. All specimens came from the Garnett Quarry, located in the Anderson County of

Kansas Kansas () is a state in the Midwestern United States. Its capital is Topeka, and its largest city is Wichita. Kansas is a landlocked state bordered by Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the ...

. They were collected from the Rock Lake Member of the Stanton Formation (Lansing Group), dating to the late

Kasimovian The Kasimovian is a geochronology, geochronologic age (geology), age or chronostratigraphy, chronostratigraphic stage (stratigraphy), stage in the International Commission on Stratigraphy, ICS geologic timescale. It is the third stage in the Penn ...

stage of the late Pennsylvanian

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 in ...

, about 304 million years old. Laurin (1993, 1994) suggested that ''Haptodus garnettensis'' would have to be renamed because he saw ''Haptodus baylei'' as a possible ''nomen dubium''. In his dissertation revising taxa assigned to ''

Haptodus ''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, feedin ...

'', Spindler (2015) proposed that ''"Haptodus" garnettensis'' is not congeneric with the ''Haptodus'' type species, giving it the ''nomen ex dissertationae'' ''Eohaptodus''. He also concluded that two specimens referred to ''garnettensis'', ROM 43608 and ROM 43601, represent new genera and species, the former specimen being named ''

Kenomagnathus ''Kenomagnathus'' (meaning "gap jaw", in reference to the diastema in its upper tooth row) is a genus of synapsid belonging to the Sphenacodontia, which lived during the Pennsylvanian subperiod of the Carboniferous in what is now Garnett, Kansas ...

'' by Spindler (2020) and latter specimen being given the ''nomen ex dissertationae'' '' Tenuacaptor reiszi''.Spindler, Frederik. 2020. A faunivorous early sphenacodontian synapsid with a diastema. Palaeontologia Electronica, 23(1):a01. https://doi.org/10.26879/1023 palaeo-electronica.org/content/2020/2905-early-sphenacodontian-diastema

References

{{Taxonbar, from=Q21129936 Prehistoric sphenacodonts Carboniferous synapsids Carboniferous synapsids of North America