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Pleurotomariacea
Pleurotomariacea is one of two names that are used for a taxonomic superfamily of sea snails that are an ancient lineage and are well represented in the fossil record. The name Pleurotomariacea is used by paleontologists, who, because they usually have only the hard parts of mollusks to study, often use a slightly different scheme of classification from that used by scientists who study living mollusks. The name Pleurotomariacea is based on Swainson, 1840 (Pleurotomariae) and was described in 1960 in the Treatise on Invertebrate Paleontology, (I197)Treatise on Invertebrate Paleontology Part I, R.C. Moore (ed) Geol Soc of America and Univ. Kansas Press, 1960. The taxon was established for mostly conispiral, but also discoidal and auriform (ear-like) shells which have a nacreous, aragonite, inner layer. The Pleurotomariacea, now often seen as Pleurotomarioidea, has been included in the Archaegastropoda. although more recent classifications put it in a more restricted sense in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleurotomarioidea
Pleurotomarioidea is a superfamily of small to large marine gastropods included in the order Pleurotomariida of the subclass Vetigastropoda. These are the slit shells, originally named Pleurotomariacea, in keeping with the convention for naming superfamilies at the time. This updated version of the name for the taxon is usually used by students of the living Mollusca. Paleontologists often still use the name Pleurotomariacea instead. Evolutionary history Forming the first evidence of crown-group gastropods when they appeared in the Upper Cambrian, the fossil record of the Pleurotomarioideans has no substantial gaps until today. The group took quite a hit at the Cretaceous–Paleogene boundary (K–T boundary), with only the Pleurotomariidae surviving the Cretaceous–Paleogene extinction event – and then only in deep waters. Living representatives of the group were first discovered in the mid-19th century, and their unusual mix of primitive and derived characters perple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeogastropoda
Archaeogastropoda (also known as Aspidobranchia) was a taxonomic order of sea snails used in older classifications of gastropods, i.e. snails and slugs. Archeogastropoda are marine prosobranch gastropod mollusks, mainly herbivores, typically having two gills and a double-chambered heart, with the eggs and sperm discharged directly into the water. They were traditionally regarded as a relatively primitive group. This older classification of the gastropods is based on the classification of Johannes Thiele (1925). This classification was not based on true phylogenetic relationships, but on more general affinities between the groups. In the last few years, two new cladistic taxonomies of the gastropods have been published (in 1997 and 2005). This has led to an extensive reclassification of gastropod taxa. The taxon Archaeogastropoda was found to be a paraphyletic group, and therefore unacceptable in a strictly cladistic classification. In the 1997 classification, most of the former ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambrian
The Cambrian Period ( ; sometimes symbolized C with bar, 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 (mya) to the beginning of the Ordovician Period mya. Its subdivisions, and its base, are somewhat in flux. The period was established as "Cambrian series" by Adam Sedgwick, who named it after Cambria, the Latin name for 'Cymru' (Wales), where Britain's Cambrian rocks are best exposed. Sedgwick identified the layer as part of his task, along with Roderick Murchison, to subdivide the large "Transition Series", although the two geologists disagreed for a while on the appropriate categorization. The Cambrian is unique in its unusually high proportion of sedimentary deposits, sites of exceptional preservation where "soft" parts of organisms are preserved as well as their more resistant shells. As a result, our understanding of the Ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helcionellacea
The Helcionellacea is one of two taxonomic superfamilies of extinct primitive marine molluscs within the order Bellerophontida. This superfamily is thought to be the more primitive of the two superfamilies, the other being the Bellerophontacea. These molluscs are thought to be sea snails, marine gastropod mollusks, rather than monoplacophorans. Diagnosis Helcionellaceans are characterised by cap-shaped to bellerophontiform shells; commonly with strong rugae, (transverse plications) clearly defined on both the interior and exterior of the shell; with a septum or septa partitioning off the apex, but lacking the anal emargination that is characteristic of the Bellerophontacea. Taxonomy The Helcionellacea includes two families according to the Treatise, 1960, the Helcionellidae, which is the more primitive, and the Coreospiridae, which is the more derived. The Helconellidae (Wenz, 1938) represented by the genus '' Helcionella'' (Grabau & Shimer, 1909) more closely resembles the m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phanerotrematidae
Phanerotrematidae is an extinct family of fossil sea snails, marine gastropod mollusks in the clade Vetigastropoda Vetigastropoda is a major Taxonomy (biology), taxonomic group of sea snails, marine (ocean), marine gastropod mollusc, mollusks that form a very ancient lineage (evolution), lineage. Taxonomically the Vetigastropoda are sometimes treated as an O ... (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005). This family has no subfamilies. Genera References {{paleo-gastropod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luciellidae
Luciellidae is an extinct family of fossil sea snails, marine gastropod mollusks in the clade Vetigastropoda Vetigastropoda is a major Taxonomy (biology), taxonomic group of sea snails, marine (ocean), marine gastropod mollusc, mollusks that form a very ancient lineage (evolution), lineage. Taxonomically the Vetigastropoda are sometimes treated as an O ... (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005). This family has no subfamilies. Genera Genera within the family Luciellidae include* '' Luciella'', the type genus and * '' Echinocirrus'' * '' Epiptychia'' * '' Platyconus'' * '' Playfordia'' * '' Prosolarium'' * '' Zhuslennngospira'' References External links PaleoBiology Database info, February 16, 2010 {{paleo-gastropod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lophospiridae
Lophospiridae is an extinct taxonomic family of sea snails, marine gastropod mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...s. This family has no subfamilies. Genera Lophospiridae contains the following genera: References {{paleo-gastropod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laubellidae
Laubellidae is an extinct family of sea snails, marine gastropod mollusks in the clade Vetigastropoda Vetigastropoda is a major Taxonomy (biology), taxonomic group of sea snails, marine (ocean), marine gastropod mollusc, mollusks that form a very ancient lineage (evolution), lineage. Taxonomically the Vetigastropoda are sometimes treated as an O ... (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005). This family has no subfamilies. Genera Genera within the family Laubellidae include: * '' Laubella'' Kittl, 1891Kittl (1891) ''Ann. Hofmus. Wien'' 6: 207. - the type genus of the family References {{paleo-gastropod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kittlidiscidae
Kittlidiscidae is an extinct family of Middle Triassic gastropods in the superfamily Pleurotomarioidea, named to contain the genus ''Kittlidiscus''Treatise on Invertebrate Paleontology Part I, R.C. Moore (ed) Geol Soc of America and Univ. Kansas Press, 1960. and included in the Vetigastropoda Vetigastropoda is a major Taxonomy (biology), taxonomic group of sea snails, marine (ocean), marine gastropod mollusc, mollusks that form a very ancient lineage (evolution), lineage. Taxonomically the Vetigastropoda are sometimes treated as an O .... Note that Bouchet & Rocroi, 2005 gives Vetigastropoda simply as a clade, which not being paraphyletic, it also is, leaving taxonomic ranking to a future date. Other gastropod classifications, including those subsequent, have determined that the Vetigastropoda is a superorder. Genera The Kittlidiscidae includes the genus ''Kittlidiscus''. References Gastropod families {{paleo-gastropod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haliotidae
''Haliotis'', common name abalone, is the only genus in the family Haliotidae. This genus once contained six subgenera. These subgenera have become alternate representations of ''Haliotis''. The genus consists of small to very large, edible, herbivorous sea snails, marine gastropod molluscs. The number of species recognized worldwide ranges between 30 and 130, with over 230 species-level taxa described. The most comprehensive treatment of the family considers 56 species valid, with 18 additional subspecies. Other common names are ear shells, sea ears, and, rarely, muttonfish or muttonshells in parts of Australia, ormer in the UK, perlemoen in South Africa, and the Maori name for three species in New Zealand is pāua. Description The shells of abalones have a low, open, spiral structure, and are characterized by having several open respiratory pores in a row near the shell's outer edge. The thick inner layer of the shell is composed of nacre, which in many species of abalone i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
