''Haptodus'' 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 living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of basal

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' ...

, member of the clade that includes

therapsid Therapsida is a major group of eupelycosaurian synapsids that includes mammals, their ancestors and relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including limbs that were oriented more ...

s and hence, mammals. It was at least in length. It lived in present-day France during the Early

Permian The Permian ( ) is a geologic period and 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 251.9 Mya. It is the last period of the Paleo ...

. It was a medium-sized

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill t ...

, feeding on

insects Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of j ...

and small

vertebrates Vertebrates () comprise all animal taxa within the subphylum Vertebrata () (chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, with ...

Discovery and history

''Haptodus baylei''

''Haptodus baylei'', 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 specim ...

of ''Haptodus'', is known only from a single, badly preserved specimen hosted in the

Muséum National d'Histoire Naturelle The French National Museum of Natural History, known in French as the ' (abbreviation MNHN), is the national natural history museum of France and a ' of higher education part of Sorbonne Universities. The main museum, with four galleries, is loc ...

of Paris. It was collected at Les Télots, near

Autun Autun () is a subprefecture of the Saône-et-Loire department in the Bourgogne-Franche-Comté region of central-eastern France. It was founded during the Principate era of the early Roman Empire by Emperor Augustus as Augustodunum to give a Ro ...

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

, from a terrestrial horizon dating to the

Asselian In the geologic timescale, the Asselian is the earliest geochronologic age or lowermost chronostratigraphic stage of the Permian. It is a subdivision of the Cisuralian Epoch or Series. The Asselian lasted between and million years ago (Ma) ...

stage of the

Cisuralian The Cisuralian 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 Mountains in Russia and Kazakhstan and ...

series, about 299-296.4 million years old. The taxonomy of many

pelycosaur Pelycosaur ( ) is an older term for basal or primitive Late Paleozoic synapsids, excluding the therapsids and their descendants. Previously, the term ''mammal-like reptile'' had been used, and pelycosaur was considered an order, but this is ...

s was revised in details by Alfred Sherwood Romer & Llewellyn Price (1940). They synonymized many genera, including '' Callibrachion'' (from Margenne near Autun, France), '' Datheosaurus'' (from Nowa Ruda of

Poland Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populou ...

), ''

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 ver ...

'' and ''

Pantelosaurus ''Pantelosaurus'' (meaning "complete lizard") is an extinct genus of basal sphenacodonts known from the Early Permian period (Asselian stage) of Saxony, Germany. It contains a single species, ''Pantelosaurus saxonicus''. Discovery ''Pantelos ...

'' (both from

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwee ...

), with ''Haptodus'', but retained these taxa as distinct species. After describing ''H. garnettensis'' in 1977, Currie (1979) synonymized all European haptodontines, as well as '' Cutleria wilmarthi'', with the type of the genus, ''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 conver ...

grade of basal

s, and revalidated ''Cutleria'', ''Palaeohatteria'' and ''Pantelosaurus'', while ''Callibrachion'' was considered to be a

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium'' it may be impossible to determine whether a s ...

and ''Datheosaurus'' was not examined. Laurin also suggested that the type species of the genus ''H. baylei'' might be a nomen dubium. His revision has been accepted by subsequent authors.

Other species

''Haptodus garnettensis'' was named based on 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 seve ...

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 prov ...

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 s ...

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

ontogenetic Ontogeny (also ontogenesis) is the origination and development of an organism (both physical and psychological, e.g., moral development), usually from the time of fertilization of the egg to adult. The term can also be used to refer to the s ...

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

Kansas Kansas () is a U.S. state, state in the Midwestern United States, Midwestern United States. Its Capital city, capital is Topeka, Kansas, Topeka, and its largest city is Wichita, Kansas, Wichita. Kansas is a landlocked state bordered by Nebras ...

. They were collected from the

Rock Lake Member Rock most often refers to: * Rock (geology), a naturally occurring solid aggregate of minerals or mineraloids * Rock music, a genre of popular music Rock or Rocks may also refer to: Places United Kingdom * Rock, Caerphilly, a location in Wales ...

of the

Stanton Formation The Stanton Formation is a geologic formation of limestone in Iowa, Nebraska, Missouri and Kansas. It preserves fossils dating back to the Carboniferous period. It is in the Upper Pennsylvanian series, forming the top of the Lansing Group. Loca ...

(Lansing Group), dating to the late Kasimovian stage of the late Pennsylvanian series, about 305-303.9 million years old. Another species, ''Haptodus grandis'', was named from a

maxilla The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. T ...

(Gz 1071) found in Pennsylvanian to

deposits in

Kenilworth Kenilworth ( ) is a market town and civil parish in the Warwick District in Warwickshire, England, south-west of Coventry, north of Warwick and north-west of London. It lies on Finham Brook, a tributary of the River Sowe, which joins the ...

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe ...

, by Roberta Paton in 1974. In his 2015 dissertation revising the basal Sphenacodontia, Frederik Spindler demonstrated that ''H. garnettensis'' and ''H. grandis'' do not belong in the same genus as ''H. baylei'' and instead represent distinct genera. Spindler referred ''"H." grandis'' to a new genus ''

Hypselohaptodus ''Hypselohaptodus'' is a genus of sphenacodont synapsid from the Cisuralian of England. It contains a single species, ''Hypselohaptodus grandis'', and is known only from a single specimen, a partial left maxilla, which is hosted at the Warwick ...

'' in 2019. He also showed that some specimens referred to ''"H." garnettensis'' belong to different taxa; one of these, ROM 43608, was named by Spindler in 2020 as a new genus and species, '' Kenomagnathus scottae''.

References

{{Taxonbar, from=Q631703 Prehistoric sphenacodonts Prehistoric synapsid genera Cisuralian synapsids of Europe Fossil taxa described in 1886