Sinotubulites
Encyclopedia
Sinotubulites is a genus
of small, tube-shaped shelly fossils from the Ediacaran
period. It is often found in association with Cloudina.
Its tube has a "tube-in-tube" structure composed of several thin layers. It bears prominent longitudinal sculptures and / or irregular rings, which were formed by the wrinkles of tube layers, and weaken gradually towards the inner layers.
The organism probably had a sessile life-style, lying on the sea floor.
Sinotubulites and Cloudina (discovered in 1972) are currently the two earliest known fossils of organisms that mineralized shells when alive, and are often found in the same fossil beds. It is remarkable that Cloudina specimens often have tiny holes bored in them, which are attributed to predators, while no such borings have been found in Sinotubulites. This suggests that Sinotubulites had evolved features that made it a much less attractive target than Cloudina. As a result both organisms are important in analyses of the Cambrian explosion
, as predation and the appearance of mineralised components are often cited as possible causes of the "explosion".
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of small, tube-shaped shelly fossils from the Ediacaran
Ediacaran
The Ediacaran Period , named after the Ediacara Hills of South Australia, is the last geological period of the Neoproterozoic Era and of the Proterozoic Eon, immediately preceding the Cambrian Period, the first period of the Paleozoic Era and of the Phanerozoic Eon...
period. It is often found in association with Cloudina.
Its tube has a "tube-in-tube" structure composed of several thin layers. It bears prominent longitudinal sculptures and / or irregular rings, which were formed by the wrinkles of tube layers, and weaken gradually towards the inner layers.
The organism probably had a sessile life-style, lying on the sea floor.
Sinotubulites and Cloudina (discovered in 1972) are currently the two earliest known fossils of organisms that mineralized shells when alive, and are often found in the same fossil beds. It is remarkable that Cloudina specimens often have tiny holes bored in them, which are attributed to predators, while no such borings have been found in Sinotubulites. This suggests that Sinotubulites had evolved features that made it a much less attractive target than Cloudina. As a result both organisms are important in analyses of the Cambrian explosion
Cambrian explosion
The Cambrian explosion or Cambrian radiation was the relatively rapid appearance, around , of most major phyla, as demonstrated in the fossil record, accompanied by major diversification of other organisms, including animals, phytoplankton, and calcimicrobes...
, as predation and the appearance of mineralised components are often cited as possible causes of the "explosion".