Yorgiidae is an extinct
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
of
cephalozoa
Cephalozoa are an extinct class of primitive segmented marine organisms within the Phylum Proarticulata from the Ediacaran period. They possessed bilateral symmetry and were characterized by a thin, rounded body.
Description
Unlike the other cl ...
ns, which lived 635 million years ago.
[Distribution age in the paleontology database](_blank)
/ref> They were filter fed.
Description
Like most proarticulates, they present semi-bilateral symmetry
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 ...
. They had a discoid appearance, with the body segmented by isomers
In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers.
...
.
Distribution
Ediacaran of Russian Federation
Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...
and 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 ...
.
Gallery
Archaeaspinus_fedonkini.jpg , ''Archaeaspinus fedonkini
''Archaeaspinus fedonkini'' is an extinct proarticulatan organism from the Late Precambrian ( Ediacaran) period.
Background
''Archaeaspinus'' was discovered in Zimnii Bereg, the Winter Coast of the White Sea in Russia, by A. Yu. Ivantsov in 20 ...
''
Photo_of_"Archaeaspinus_fedonkini"_fossil_Ivantsov_2007.png , ''Other fossil of Archaeaspinus fedonkini''
Yorgia_trace.jpg , ''Epibaion
''Epibaion'' is a trace fossil imprint of the Ediacaran animals of the phylum Proarticulata, which became extinct in the Precambrian. Imprints often occurring in chains, that is interpreted as a feeding trace; some chains terminate in a body foss ...
waggoneri, possible ichnofossil of Yorgia waggoneri
''Yorgia waggoneri'' is a discoid Ediacaran organism. It has a low, segmented body consisting of a short wide "head", no appendages, and a long body region, reaching a maximum length of . It is classified within the extinct animal phylum Proart ...
''
See also
* Cephalozoa
Cephalozoa are an extinct class of primitive segmented marine organisms within the Phylum Proarticulata from the Ediacaran period. They possessed bilateral symmetry and were characterized by a thin, rounded body.
Description
Unlike the other cl ...
References
Cephalozoa
Yorgiidae
Ediacaran life
Fossils of Russia
{{Ediacaran-stub