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It is claimed to be the oldest animal fossil, being found in rock aged between 760 and 550 million years ago. The genus was named after the Otavi Group in Namibia in which the fossils were found. The oldest fossils are from the Tonian period, before the Cryogenian glaciations, but the latest found were from the Nama Group rocks, which are from ...
Pleurotomariidae, common name the "slit snails", is a family of large marine gastropods in the superfamily Pleurotomarioidea of the subclass Vetigastropoda. [1] This family is a very ancient lineage; there were numerous species in the geological past.
This list of marine gastropod genera in the fossil record is an attempt to list all the genera of sea snails or marine gastropod mollusks which have been found in the fossil record. Nearly all of these are genera of shelled forms, since it is relatively rare for gastropods without a shell ( sea slugs ) to leave any recognizable traces.
Index fossils must have a short vertical range, wide geographic distribution and rapid evolutionary trends. Another term, "zone fossil", is used when the fossil has all the characters stated above except wide geographical distribution; thus, they correlate the surrounding rock to a biozone rather than a specific time period.
One variety of "Turritella agate", that from the Green River Formation in Wyoming, is a fossiliferous rock which does indeed contain numerous high-spired snail shells. However, contrary to the common name, these snails are not in the marine genus Turritella , instead they are freshwater snails in the species Elimia tenera , family Pleuroceridae ...
The algific talus slope habitat that harbors the snail is a landscape cooled by air and water emerging from masses of subterranean ice. The ground temperature rarely exceeds 10 °C (50 °F), even in summer. Here the snail feeds on leaf litter from trees (mainly birch, maple and dogwood) and shrubs. During the winter, it burrows underground and ...
Life restoration of E. tenera. E. tenera occurs in fossil beds that are 46 to 51 million years old, in the Laney Member of the Green River Formation. [4] Evidence suggests that the Elimia tenera were deposited nearshore in a series of shallow lakes, which geologists have named the Fossil, Uinta and Gosiute Lakes. [5]
The fossil range of Cerion is possibly from the Upper Cretaceous of Montana, or the early Miocene of Florida. [1] Records of Cerion in Pleistocene are rare. [ 1 ] Fossil records , particularly from the Quaternary period , reveal patterns and trends that provide insights into these evolutionary processes.