''Kirktonecta'' 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 ...

microsaur Microsauria ("small lizards") is an extinct, possibly polyphyletic order of tetrapods from the late Carboniferous and early Permian periods. It is the most diverse and species-rich group of lepospondyls. Recently, Microsauria has been considere ...

known from the

Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ...

West Lothian West Lothian ( sco, Wast Lowden; gd, Lodainn an Iar) is one of the 32 council areas of Scotland, and was one of its shires of Scotland, historic counties. The county was called Linlithgowshire until 1925. The historic county was bounded geogra ...

Scotland Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ...

Discovery

''Kirktonecta'' is known 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 UMZC 2002, a and b, an almost complete

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 the

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 preserved evidence for soft tissues, in part (slab a) and counterpart (slab b). The holotype was collected in the East Kirkton Quarry, near

Bathgate Bathgate ( sco, Bathket or , gd, Both Chèit) is a town in West Lothian, Scotland, west of Livingston and adjacent to the M8 motorway. Nearby towns are Armadale, Blackburn, Linlithgow, Livingston, West Calder and Whitburn. Situated sout ...

, from "Bed 82" East Kirkton Limestone of the

Bathgate Hills Volcanic Formation Bathgate ( sco, Bathket or , gd, Both Chèit) is a town in West Lothian, Scotland, west of Livingston, Scotland, Livingston and adjacent to the M8 motorway (Scotland), M8 motorway. Nearby towns are Armadale, West Lothian, Armadale, Blackburn, ...

, dating to the Brigantian substage, of the late

Viséan The Visean, Viséan or Visian is an age in the ICS geologic timescale or a stage in the stratigraphic column. It is the second stage of the Mississippian, the lower subsystem of the Carboniferous. The Visean lasted from to Ma. It follows the ...

stage Stage or stages may refer to: Acting * Stage (theatre), a space for the performance of theatrical productions * Theatre, a branch of the performing arts, often referred to as "the stage" * ''The Stage'', a weekly British theatre newspaper * Sta ...

, of the

Dinantian Dinantian is the name of a series (stratigraphy), series or Epoch (reference date), epoch from the Lower Carboniferous system (stratigraphy), system in Europe. It can stand for a series of rocks in Europe or the time span in which they were deposit ...

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 ...

(

Early Carboniferous Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early Christianity ** Early modern Europe Places in the United States * Early, Iowa * Early, Texas * Early ...

), about 333–328.3

million years ago The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds. Usage Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (million years ago). ...

. It represents the first microsaur to be discovered in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...

and the earliest occurrence of a microsaur in the fossil record. The next oldest being '' Utaherpeton'' and an unnamed taxon from the

Chesterian The Mississippian ( , also known as Lower Carboniferous or Early Carboniferous) is a subperiod in the geologic timescale or a subsystem of the geologic record. It is the earlier of two subperiods of the Carboniferous period lasting from roughly ...

of Goreville,

Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolita ...

Description

''Kirktonecta'' is diagnosed by the following

autapomorphies In phylogenetics, an autapomorphy is a distinctive feature, known as a derived trait, that is unique to a given taxon. That is, it is found only in one taxon, but not found in any others or outgroup taxa, not even those most closely related to t ...

: "deep tail, long, posteriorly directed, round-ended haemal spines in contact along their anterior and posterior margins distally, combined with low rounded neural spines; large pes, with tarsus breadth equivalent to the length of 3.5 or 4 presacral vertebrae." Jennifer A. Clack, who named this genus, found it to be most closely related to basal

s, such as ''

Asaphestera ''Asaphestera'' is an extinct genus of a tetrapod described on the basis of fossils from the Carboniferous of the Joggins locality in Nova Scotia, Canada. It was originally described as an undetermined lepospondyl and subsequently classified as a ...

'', ''

Saxonerpeton ''Saxonerpeton'' is an extinct genus of microsaur of the family Hapsidopareiontidae. Fossils have been found from Early Permian strata near Dresden, Germany. See also * List of prehistoric amphibians This list of prehistoric amphibians is an ...

'', ''

Hyloplesion ''Hyloplesion'' is an extinct genus of microbrachomorph microsaur. It is the type and only genus within the family Hyloplesiontidae. Fossils have been found from the Czech Republic near the towns of Plzeň, Nýřany, and Třemošná, and da ...

'' and ''

Llistrofus ''Llistrofus'' is an extinct genus of early Permian microsaur within the family Hapsidopareiidae that is known from Oklahoma. Discovery ''Llistrofus'' was described by Canadian paleontologists Robert Carroll and Pamela Gaskill in 1978. The ...

''.

Etymology

''Kirktonecta'' was first named by

Jennifer A. Clack Jennifer Alice Clack, (''née'' Agnew; 3 November 1947 – 26 March 2020) was an English palaeontologist and evolutionary biologist. She specialised in the early evolution of tetrapods, specifically studying the "fish to tetrapod" transition: ...

2011 File:2011 Events Collage.png, From top left, clockwise: a protester partaking in Occupy Wall Street heralds the beginning of the Occupy movement; protests against Libyan dictator Muammar Gaddafi, who was killed that October; a young man celebrate ...

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 ''Kirktonecta milnerae''. The generic name is derived from the name of the

East Kirkton Quarry East Kirkton Quarry is a former limestone quarry in West Lothian, Scotland (East Kirkton Limestone), now better known as a fossil site known for terrestrial fossils from the fossil-poor Romer's gap, a 15 million year period at the beginning of th ...

, where the holotype was found, and

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

''necta'', "swimmer". 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 ...

honours the

paleontologist Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...

Angela C. Milner Angela Cheryl Milner (3 October 1947 – 13 August 2021) was a British paleontologist who, in 1986 alongside Alan Charig, described the dinosaur ''Baryonyx''. Early life Milner was born Angela Girven in Gosforth, daughter of Cyril and Luc ...

References

{{Taxonbar, from=Q6415854 Carboniferous amphibians of Europe Carboniferous reptiliomorphs Fossil taxa described in 2011