''Kirktonecta'' 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 ...

microsaur Microsauria 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 considered paraphyletic, as s ...

known from the

Carboniferous The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the ...

West Lothian West Lothian (; ) is one of the 32 council areas of Scotland, bordering (in a clockwise direction) the City of Edinburgh council area, Scottish Borders, South Lanarkshire, North Lanarkshire and Falkirk (council area), Falkirk. The modern counci ...

Scotland Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac ...

Discovery

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

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 the

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 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 ( or , ) is a town in West Lothian, Scotland, west of Livingston, Scotland, Livingston and adjacent to the M8 motorway (Scotland), M8 motorway. Nearby towns are Linlithgow, Livingston, and West Calder. A number of villages fall under ...

, from "Bed 82" East Kirkton Limestone of the Bathgate Hills Volcanic Formation, 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 ...

stage Stage, stages, or staging may refer to: Arts and media 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 Brit ...

, of the

Dinantian The Dinantian is a series or epoch from the Lower Carboniferous system in western Europe between 359.2 and 326.4 million years ago. It can stand for a series of rocks in Europe or the time span in which they were deposited. The Dinantian is eq ...

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: Places in the United States * Early, Iowa, a city * Early, Texas, a city * Early Branch, a stream in Missouri * Early County, Georgia * Fort Early, Georgia, an early 19th century fort Music * Early B, stage name of Jamaican d ...

), about 333–328.3

million years ago Million years ago, abbreviated as Mya, Myr (megayear) or Ma (megaannum), is a unit of time equal to (i.e. years), or approximately 31.6 teraseconds. Usage Myr is in common use in fields such as Earth science and cosmology. Myr is also used w ...

. 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 Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...

and the earliest occurrence of a microsaur in the fossil record. The next oldest being ''

Utaherpeton ''Utaherpeton'' is an extinct genus of lepospondyl amphibian from the Carboniferous of Utah. It is one of the oldest and possibly one of the most basal ("primitive") known lepospondyls. The genus is monotypic, including only the type species ''U ...

'' 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 rough ...

of Goreville,

Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. It borders on Lake Michigan to its northeast, the Mississippi River to its west, and the Wabash River, Wabash and Ohio River, Ohio rivers to its ...

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 ...

: "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 synapsid 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 ...

'', ''

Saxonerpeton ''Saxonerpeton'' is an extinct genus of microsaur in the family Hapsidopareiidae. Fossils have been found from Early Permian strata near Dresden, Germany. References External links''Saxonerpeton''in the Paleobiology Database The Paleobiology ...

'', ''

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''.

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 The year marked the start of a Arab Spring, series of protests and revolutions throughout the Arab world advocating for democracy, reform, and economic recovery, later leading to the depositions of world leaders in Tunisia, Egypt, and Yemen ...

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

East Kirkton Quarry East Kirkton Quarry, or simply East Kirkton, is a former limestone quarry in West Lothian, Scotland, now a renowned fossil site. The quarry is known for terrestrial and freshwater fossils up to 341 million years old, from the Viséan stage of ...

, where the holotype was found, and

Greek Greek may refer to: 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 of all kno ...

''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 as palaeontology or palæontology, is the scientific study of the life of the past, mainly but not exclusively through the study of fossils. Paleontologists use fossils as a means to classify organisms, measure geolo ...

Angela C. Milner.

References

{{Taxonbar, from=Q6415854 Microsauria Mississippian tetrapods Carboniferous tetrapods of Europe Carboniferous Scotland Fossils of Scotland Fossil taxa described in 2011 Taxa named by Jenny Clack