''Rugoconites'' is a

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 ...

Ediacaran biota The Ediacaran (; formerly Vendian) biota is a taxonomic period classification that consists of all life forms that were present on Earth during the Ediacaran Period (). These were enigmatic tubular and frond-shaped, mostly sessile, organis ...

found as

fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

in the form of a circular or oval-like impression preserved in high relief, six or more centimeters in diameter. The fossils are surrounded by frills that have been interpreted ( Wade 1972) as sets of

tentacle In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work main ...

s. The bifurcating radial ribs, spreading from a central dome, serve to distinguish this

from the

sponge Sponges or sea sponges are primarily marine invertebrates of the animal phylum Porifera (; meaning 'pore bearer'), a basal clade and a sister taxon of the diploblasts. They are sessile filter feeders that are bound to the seabed, and a ...

'' Palaeophragmodictya'', and may represent the channels of the gastrovascular system. Fossils of ''Rugoconites'' have been interpreted as early

s, although this is countered by Sepkoski ''et al.'' (2002), who interpreted the organism as a free-swimming jellyfish-like

cnidaria Cnidaria ( ) is a phylum under kingdom Animalia containing over 11,000 species of aquatic invertebrates found both in fresh water, freshwater and marine environments (predominantly the latter), including jellyfish, hydroid (zoology), hydroids, ...

n; similar to '' Ovatoscutum''. However, the fossil is consistently preserved as a neat circular form and its general morphology does not vary, therefore a benthic and perhaps slow-moving or sessile lifestyle is more likely. Ivantstov & Fedonkin (2002), suggest that ''Rugoconites'' may possess tri-radial

symmetry Symmetry () in everyday life refers to a sense of harmonious and beautiful proportion and balance. In mathematics, the term has a more precise definition and is usually used to refer to an object that is Invariant (mathematics), invariant und ...

and be a member of the

Trilobozoa Trilobozoa, from Ancient Greek τρεῖς (''treîs''), meaning "three", λοβός (''lobós''), meaning "lobe", and ζῷον (''zôion''), meaning "animal", is a phylum of extinct, sessile animals that were originally classified into the Cnid ...

. ''Rugoconites'' have been reported in clusters; this may represent a social/colonial way of life, or simply accumulation by the action of currents, sea-floor processes, or possibly preservational conditions. The ''Rugoconites'' genus may contain two species: ''Rugoconites enigmaticus'' and ''Rugoconites tenuirugosus'', the latter being less dome-shaped and having smaller and more numerous radial ridges than the former. However, due to the dubious nature of ''R. tenuirugosus'', its taxonomy is still unclear, and it has been suggested that a new genus named ''Wadea'' should be erected for ''''R." tenuirugosus''. In 1966, Martin Glaessner along with Mary Wade unearthed the external mold of a form which possessed a small central disc that had eleven radiating lobes from its center that they named ''Lorenzinites rarus''. This form was also compared to the top of some ''Rugoconites'' specimens. The fossil of ''Lorenzinites rarus'' was, however, reconsidered to be a ''Rugoconites enigmaticus'' specimen despite his original observations and placed it along with the genus in the synonymy of ''Rugoconites''. The genus was then forgotten about and needs further examination.

References

* * * * * * *

External links

* http://www.yuzonakano-secretmemory.com/life3.c.html contains a low-quality image. {{Taxonbar, from=Q3942574 Trilobozoa species described in 1966 species described in 1992 Ediacaran life Cryogenian life Enigmatic prehistoric animal genera

See also

References

External links