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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 ...
Volborthella, some fossils of which predate , was long thought to be a cephalopod, but discoveries of more detailed fossils showed its shell was not secreted, but built from grains of the mineral silicon dioxide (silica), and it was not divided into a series of compartments by septa as those of fossil shelled cephalopods and the living Nautilus are.
Fossil orthoconic nautiloid from the Ordovician of Kentucky; an internal mold showing siphuncle and half-filled camerae, both encrusted.. Understanding of early cephalopod origins is by necessity biased by the available fossil material, which on the whole consists of shelly fossils.
This genus is known in the fossil records from the Cretaceous to the Quaternary (age range: from 125.45 to 0.0 million years ago). Fossils of species within this genus have been found all over the world. There are about 25 known extinct species. [4] Murex altispira Fossil shell of Murex spinicosta from Pliocene of Italy
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. The genus includes several hundred fossil forms, mostly Paleozoic.
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.
Naticidae, common name moon snails or necklace shells, is a family of medium to large-sized predatory sea snails, marine gastropod molluscs in the clade Littorinimorpha. The shells of the species in this family are mostly globular in shape. Naticidae is the only family in the superfamily Naticoidea.
The oldest fossil cerionid is C. acherontis from the Upper Cretaceous Hell Creek Formation, in Montana, northwestern USA. [5] The second oldest record is the genus Brasilennea from the Brazilian Paleocene Itaboraí Basin , in Rio de Janeiro.