''Koilops'' 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 four-limbed

stem-tetrapod The Stem Tetrapoda are a cladistically defined group, consisting of all animals more closely related to extant four-legged vertebrates than to their closest extant relatives (the lungfish), but excluding the crown group Tetrapoda. They are thus ...

from the Mississippian (mid-

Tournaisian The Tournaisian is in the ICS geologic timescale the lowest stage or oldest age of the Mississippian, the oldest subsystem of the Carboniferous. The Tournaisian age lasted from Ma to Ma. It is preceded by the Famennian (the uppermost st ...

) of

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 ...

. It contains a single species, ''Koilops herma'', based on a

mold A mold () or mould () is one of the structures that certain fungus, fungi can form. The dust-like, colored appearance of molds is due to the formation of Spore#Fungi, spores containing Secondary metabolite#Fungal secondary metabolites, fungal ...

of an 8.0 cm (3.1 in.)-long skull from the

Ballagan Formation The Ballagan Formation is a Formation (geology), geologic formation in Scotland and England. It preserves fossils dating back to the early part of the Carboniferous Period (geology), period (Tournaisian – early Visean). Its name comes from the ...

. A

phylogenetic analysis 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 data ...

in its original description places ''Koilops'' as a close relative of '' Tulerpeton'' and colosteids. ''Koilops'' was described in a 2016 study which was devised to fill in the tetrapod and stem-tetrapod faunas of

Romer's gap Romer's gap is an apparent gap in the Paleozoic tetrapod fossil record noted in the studies of paleontology and evolutionary biology, which represent periods in the Early Carboniferous from which excavators have not yet found relevant transition ...

, an interval of the early

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 ...

with few vertebrate fossils. It was one of five new genera named in this study, along with ''

Aytonerpeton ''Aytonerpeton'' is an extinct genus of stem-tetrapod from the Ballagan Formation of Scotland. It was one of five new genera of early limbed vertebrates from the Ballagan Formation described by Clack ''et al.'' in 2016. These vertebrates were amo ...

'', ''

Diploradus ''Diploradus'' is an extinct genus of four-limbed stem-tetrapod from the Mississippian (mid-Tournaisian) of Scotland. It contains a single species, ''Diploradus austiumensis'', based on an incomplete skull and jaw fragments from the Ballagan F ...

'', ''

Ossirarus ''Ossirarus'' is an extinct genus of four-limbed stem-tetrapod from the Mississippian (mid-Tournaisian) of Scotland. It contains a single species, ''Ossirarus kierani'', based on a disarticulated skull and postcranial bones from the Ballagan For ...

'', and ''

Perittodus ''Perittodus'' is an extinct genus of four-limbed stem-tetrapod from the Mississippian (mid-Tournaisian) of Scotland. It contains a single species, ''Perittodus apsconditus'', based on disarticulated skull and postcranial bones from the Ballagan ...

''.

References

Stegocephali Tournaisian life Mississippian sarcopterygians of Europe Fossil taxa described in 2016 Taxa named by Jenny Clack {{Paleo-tetrapodomorph-stub