''Gehlingia dibrachida'' is a species of enigmatic

Ediacaran The Ediacaran Period ( ) is a geological period that spans 96 million years from the end of the Cryogenian Period 635 million years ago (Mya), to the beginning of the Cambrian Period 538.8 Mya. It marks the end of the Proterozoic Eon, and th ...

organism from

South Australia South Australia (commonly abbreviated as SA) is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest of Australia's states and territories ...

described in 1998. ''Gehlingia'' has been described as having many characteristics of petalonamids, although it has been classified as a rather close relative of the ''

Tribrachidium ''Tribrachidium heraldicum'' is a tri-radially symmetric fossil animal that lived in the late Ediacaran (Vendian) seas. In life, it was hemispherical in form. ''T. heraldicum'' is the best known member of the extinct group Trilobozoa. Etymology ...

''. The overall shape of ''Gehlingia'' contradicts this affinity, however, with its shape being a more

Bilaterally symmetrical Symmetry in biology refers to the symmetry observed in organisms, including plants, animals, fungi, and bacteria. External symmetry can be easily seen by just looking at an organism. For example, take the face of a human being which has a pla ...

one although the basic structure similar to that of Tribrachidium appears in ''Gehlingia'' as separate branches extending into bifurcating minor branches along with "thumb structures" that are apparent in Tribrachidium in the form of side bulges on an axis.

Etymology

The name of the genus, "Gehlingia", is in honour of the Australian palaeontologist specialising in Ediacaran fossils, James G. Gehling.

Description

''Gehlingia dibrachida'' represents a frond-like bilaterally symmetric organism with two fronds with each half of them having a swollen axis on an inner edge. The organism's axis bifurcated once and bifurcates towards the outer edge of its two fronds. Similar deformations occur in both Tribrachidium and ''Gehlingia'' some notable ones being delaying of the bifurcation and tubular structures being visible between the striae. A number of tubular structures emanate from the axis and are often either straight or curved. A deep groove separates the two axes. The entire animal is estimated to have been in length and in width. The tubular structures of the two "fronds" end abruptly and in turn form a smooth edge to the organism. In ''Gehlingia'' (as well as Tribrachidium) there are "thumb" structures that appear to have been positioned on the left and right side of the main branch. In Tribrachidium, the thumb structures are visible as side bulges which extend out of an axis.

References

{{Taxonbar, from=Q110245502 Ediacaran Ediacaran life Ediacaran first appearances Enigmatic prehistoric animal genera Prehistoric animal genera Fossil taxa described in 1998 Fossils of Australia Trilobozoa

Etymology

Description

Further reading

See also

References