''Saarina'' are tube fossils from the
Ediacaran (
Vendian
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 the ...
) and
Early Cambrian
The Cambrian Period ( ; sometimes symbolized Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million years ago ...
marine deposits of
European Russia. These fossils are comparable to the dwelling tubes of
worm
Worms are many different distantly related bilateral animals that typically have a long cylindrical tube-like body, no limbs, and no eyes (though not always).
Worms vary in size from microscopic to over in length for marine polychaete wo ...
s or
cnidaria
Cnidaria () is a phylum under kingdom Animalia containing over 11,000 species of aquatic animals found both in freshwater and marine environments, predominantly the latter.
Their distinguishing feature is cnidocytes, specialized cells that ...
ns.
Occurrence
Fossils of the type species, ''S. tenera'', were found in a core from the
Gatchina
The town of Gatchina ( rus, Га́тчина, , ˈɡatːɕɪnə, links=y) serves as the administrative center of the Gatchinsky District in Leningrad Oblast, Russia. It lies south-south-west of St. Petersburg, along the E95 highway which ...
No.13 borehole in the
Leningrad Region, Russia. The most conspicuous deposits associated with these fossils are referred to as the Lomonosov Fm., Lontova Horizon, and lower
Tommotian
Stage 2 of the Cambrian is the unnamed upper stage of the Terreneuvian Series. It lies atop the Fortunian and below Stage 3 of the Cambrian. It is commonly referred to as the Tommotian, after the Cambrian stratigraphy of Siberia. Neither the upp ...
(=
Cambrian Stage 2
Stage 2 of the Cambrian is the unnamed upper stage of the Terreneuvian Series. It lies atop the Fortunian and below Stage 3 of the Cambrian. It is commonly referred to as the Tommotian, after the Cambrian stratigraphy of Siberia. Neither the uppe ...
).
''S. kirsanovi'' fossils were found in a core from the Vorob'evo No.1 borehole,
Moscow Region
Moscow Oblast ( rus, Моско́вская о́бласть, r=Moskovskaya oblast', p=mɐˈskofskəjə ˈobləsʲtʲ), or Podmoskovye ( rus, Подмоско́вье, p=pədmɐˈskovʲjə, literally "under Moscow"), is a federal subject of Rus ...
and in a core from the Malinovka borehole, near
Obozersky in the
Arkhangelsk Region
Arkhangelsk Oblast (russian: Арха́нгельская о́бласть, ''Arkhangelskaya oblast'') is a federal subject of Russia (an oblast). It includes the Arctic archipelagos of Franz Josef Land and Novaya Zemlya, as well as the Solovet ...
.
''S. juliae'' was found in a core from the
Gavrilov-Yam
Gavrilov-Yam (russian: Гаври́лов-Ям) is a town and the administrative center of Gavrilov-Yamsky (or Gavrilov-Yamskiy) District in Yaroslavl Oblast, Russia, located on the Kotorosl River. Population:
History
The first mention of a set ...
No.5 borehole,
Yaroslavl Region
Yaroslavl Oblast (russian: Яросла́вская о́бласть, ''Yaroslavskaya oblast'') is a federal subject of Russia (an oblast), which is located in the Central Federal District, surrounded by Tver, Moscow, Ivanovo, Vladimir, Kostroma ...
. The deposites with ''S. kirsanovi'' and ''S. juliae'' are referred to the Redkino Horizon, Upper Vendian (Ediacaran), and are about 558 mya old.
Description
''Saarina'' was a tube-dwelling organism of unknown biological affinity, known from its
siliciclastic
Siliciclastic (or ''siliclastic'') rocks are clastic noncarbonate sedimentary rocks that are composed primarily of silicate minerals, such as quartz or clay minerals. Siliciclasic rock types include mudrock, sandstone, and conglomerate
Conglomera ...
deposits dating to the late
Ediacaran (Vendian) and lowest
Cambrian of the Russian Platform. It was funnel-shaped, consisting of dense, thinly-walled and annulated, ringlike segments. The fossils are preserved in the substrate as a result of superficial mineralization during the early stages of decomposition.
The fossils are typically found in
mudstone and preserved in the form of flat
pyrite
The mineral pyrite (), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Fe S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral.
Pyrite's metallic luster and pale brass-yellow hue giv ...
ribbons as a result of superficial pyritization in the early stage of organic decomposition.
''Saarina'' tubes were cylindrical in form, conical at the base, consisting of funnel-shaped narrow rings. The wall of the tube was thin, originally organic-walled, not chitinous. The tubes attained widths up to 7 mm.
The species of the ''Saarina'' differ mainly in the forms of the funnels:
* ''S. tenera'' have straight conical funnels.
* ''S. juliae'' have conical funnels, curved outward.
* ''S. kirsanovi'' have funnels curved inward.
See also
* ''
Cloudina''
* ''
Corumbella''
* ''
Sinotubulites''
* ''
Somatohelix''
List of Ediacaran genera
This is a list of all described Ediacaran genera, including the Ediacaran biota. It contains 227 genera.
References
{{reflist, 30em
*
Ediacaran
The Ediacaran Period ( ) is a geological period that spans 96 million years from the end ...
References
*
{{Taxonbar, from=Q7395696
Ediacaran life
Fossils of Russia
Fortunian
Cambrian genus extinctions