Eldeceeon
Encyclopedia
Eldeceeon is an extinct genus
of reptiliomorph from the Early Carboniferous of Scotland
. It is known from two fossil specimens found within the Viséan
-age East Kirkton Quarry
in West Lothian
. The type
and only species, E. rolfei, was named in 1994. Eldeceeon is thought to be closely related to embolomeres, but it has several distinguishing features including long limbs and a short trunk.
. 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
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 35 centimetres (1.1 ft). 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 tetrapod
s (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
.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of reptiliomorph from the Early Carboniferous of Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
. It is known from two fossil specimens found within the Viséan
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 345.3 ± 2.1 to 328.3 ± 1.6 Ma...
-age East Kirkton Quarry
East Kirkton Quarry
East Kirkton Quarry is a former limestone quarry, 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 the Carboniferous...
in West Lothian
West Lothian
West Lothian is one of the 32 unitary council areas in Scotland, and a Lieutenancy area. It borders the City of Edinburgh, Falkirk, North Lanarkshire, the Scottish Borders and South Lanarkshire....
. The type
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
and only species, E. rolfei, was named in 1994. Eldeceeon is thought to be closely related to embolomeres, but it has several distinguishing features including long limbs and a short trunk.
Description
In the East Kirkton Quarry, fossils of Eldeceeon were found alongside another reptiliomorph called SilvanerpetonSilvanerpeton
Silvanerpeton is an extinct genus of early reptiliomorph found in the East Kirkton Quarry of West Lothian, Scotland. The find is important, as the quarry represents terrestrial deposits from the Romer's gap, a period poor in fossils where the higher groups labyrinthodonts evolved...
. 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
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
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 35 centimetres (1.1 ft). 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 tetrapod
Tetrapod
Tetrapods are vertebrate animals having four limbs. Amphibians, reptiles, birds and mammals are all tetrapods; even snakes and other limbless reptiles and amphibians are tetrapods by descent. The earliest tetrapods evolved from the lobe-finned fishes in the Devonian...
s (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
Proterogyrinus
Proterogyrinus was an anthracosaur, a large group of reptilian reptiliomorphs. It is likely that the first reptiles, such as Petrolacosaurus, evolved from reptilomorphs...
.