''Vendia'' is an extinct
vendiamorph from the late
Ediacaran
The Ediacaran ( ) is a geological period of the Neoproterozoic geologic era, Era that spans 96 million years from the end of the Cryogenian Period at 635 Million years ago, Mya to the beginning of the Cambrian Period at 538.8 Mya. It is the last ...
, estimated to be around 567 - 550 Ma years old, it contains two species, ''V. sokolovi'' and ''V. rachiata'', both of which are restricted to the
Ust' Pinega Formation in Northwestern
Russia
Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...
.
Discovery and naming
The first fossil materials of ''Vendia'' were found in a core from a Yarensk borehole that was collected from the Ust' Pinega Formation of the
Arkhangelsk Oblast
Arkhangelsk Oblast ( rus, Архангельская область, p=ɐrˈxanɡʲɪlʲskəjə ˈobɫəsʲtʲ) is a federal subjects of Russia, federal subject of Russia (an oblast). It includes the Arctic Ocean, Arctic archipelagos of Franz ...
, northwestern Russia in 1963,
[V. V. Menner. (1963). "The Other Problematical Organic Remains". In: "Stratigraphy of the USSR: Upper Precambrian" Gos. Nauchno-Tekh. Izd., Moscow. pp. 504-507. (In Russian)] and was formally described and named in 1969 as ''Vendia sokolovi''.
[B. M. Keller. (1969). "Imprint of unknown animal from Valdai Series of Russian Platform". In: A. Y. Rozanov and et al. (Eds.), "Tommotian Stage and the Cambrian lower boundary problem". ''Geol. Inst. Trans''. Vol. 206, p. 175. (In Russian)] A Further two species were found and named in 2001 and 2004, that being ''V. janae'',
(Redescribed as ''
Paravendia janae'' in 2004) and ''V. rachiata''.
The generic name ''Vendia'' is derived from the older Russian name for the Ediacaran, ''Vendian''. The specific name ''sokolovi'' is derived from the surname of
Boris Sokolov, a well-known Russian geologist and paleontologist, and who also created the concept of the Vendian period itself, which ''Vendia'' takes its name from.
[ The specific name ''rachiata'' is derived from the ]Latin
Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
word ''rachis'', to mean "stem", in reference to the preserved internal organs found in most specimens.[
]
Description
All species of ''Vendia'' are oval in shape, ranging from in overall length. As with all proarticulates, their bodies consist of segmented isomers
In chemistry, isomers are molecules or polyatomic ions with identical molecular formula – that is, the same number of atoms of each element – but distinct arrangements of atoms in space. ''Isomerism'' refers to the existence or possibili ...
, which are arranged in a glide reflection
In geometry, a glide reflection or transflection is a geometric transformation that consists of a reflection across a hyperplane and a translation ("glide") in a direction parallel to that hyperplane, combined into a single transformation. Bec ...
along a central axis. Unlike other proarticulates, the larger isomers nearer to the front wrap round to cover the smaller isomers nearer the back, with the most extreme case of this being seen in ''V. rachiata'', and the now separate genus '' Paravendia''.[ The initial right isomer extends over to the left side, forming a 'head-like' structure, which has been noted to be similar to ]cephalization
Cephalization is an evolutionary trend in animals that, over a sufficient number of generations, concentrates the special sense organ (biology), organs and nerve ganglia towards the front of the body where the mouth is located, often producing a ...
.[
]
Taxonomy
Three ''Vendia'' species have been described to date, although only two remain as ''Vendia'' with one being reassigned, with the following differentiating characteristics:
* ''V. sokolovi'', represented by only one specimen that is in length, has 7 isomers per side. The lateral appendages of the internal system extend almost along the full length of each isomer.[
* ''V. rachiata'' differs from ''V. sokolovi'' in the smaller number of isomers. The largest specimens are up to in length, with all specimens having 5 isomers per side, with the length of each isomer quickly decreasing posteriorly. The lateral appendages are much shorter. This species has been found only in the Solza River locality, ]Onega Peninsula
The Onega Peninsula is located in Arkhangelsk Oblast, Russia. It protrudes into the White Sea, with Onega Bay to the south-west, and Dvina Bay to the north-east. The length of the peninsula is about , and the width varies between and .
Geogr ...
of the White Sea
The White Sea (; Karelian language, Karelian and ; ) is a southern inlet of the Barents Sea located on the northwest coast of Russia. It is surrounded by Karelia to the west, the Kola Peninsula to the north, and the Kanin Peninsula to the nort ...
area, Arkhangelsk Oblast.
* The third species, ''V. janae''[ was reassigned to the separate genus ''Paravendia''.][ It differs from the genus ''Vendia'' in the shape and relative position of the isomers, with the larger initial isomers curving around and meeting at the 'tail' point, completely covering the smaller isomers nearer to the rear. It is also known to grow much larger, with the largest specimen coming in at in length. It is from Zimnie Gory locality, White Sea.
]
See also
* List of Ediacaran genera
The existence of life, especially that of animals, before the Cambrian had long been the subject of debate in paleontology. The apparent suddenness of the Cambrian explosion had no firm explanation, and Charles Darwin himself recognized the chal ...
References
{{Taxonbar, from=Q1649128
Vendiamorpha
Ediacaran life
Fossils of Russia
White Sea fossils
Prehistoric bilaterian genera