''Eldeceeon'' is an extinct genus of reptiliomorph from the

Mississippian Mississippian may refer to: * Mississippian (geology), a subperiod of the Carboniferous period in the geologic timescale, roughly 360 to 325 million years ago *Mississippian culture, a culture of Native American mound-builders from 900 to 1500 AD ...

(early

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 ...

) of Scotland. It is known from two fossil specimens found within the Viséan-age East Kirkton Quarry in

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 ...

. The

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * Ty ...

and only species, ''E. rolfei'', was named in 1994. ''Eldeceeon'' is thought to be closely related to

embolomere Embolomeri is an Order (biology), order of Tetrapod, tetrapods or Stem-group, stem-tetrapods, possibly members of Reptiliomorpha. Embolomeres first evolution, evolved in the Early Carboniferous (Mississippian age, Mississippian) Period and were th ...

s, but it has several distinguishing features including long limbs and a short trunk. Initially known from two crushed partial skeletons, additional specimens have been reported by Ruta & Clack (2006).

Description

In the East Kirkton Quarry, fossils of ''Eldeceeon'' were found alongside another reptiliomorph called '' Silvanerpeton''. These genera are closely related to each other but represent an unusual group of reptiliomorphs that cannot be placed in any of the major reptiliomorph

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

s, but may be related to the earliest embolomeres. The shapes of some bones in their skulls Unlike most embolomeres, which could grow over a meter long, ''Eldeceeon'' has a much smaller body length of . Compared to embolomeres, it has fewer dorsal vertebrae and much larger limbs relative to its body. The shortened spine and robust limbs of ''Eldeceeon'' suggest it had a terrestrial lifestyle, distinguishing it from the primarily aquatic embolomeres which have relatively long bodies and short limbs. These adaptations also distinguish it from ''Silvanerpeton'', which is presumed to have been aquatic. The ribs of ''Eldeceeon'' are restricted to the front half of the spine, a characteristic that is not present in any tetrapods (four-limbed vertebrates) except mammals and their relatives. Each vertebra is divided into a U-shaped pleurocentrum and a smaller intercentrum, like the vertebrae of the embolomere '' Eoherpeton''. The pectoral and pelvic girdles resemble those of the embolomere '' Proterogyrinus''.

References

{{Taxonbar, from=Q5353913 Basal tetrapods of Europe Carboniferous reptiliomorphs