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Aethoceras
''Aethoceras'' is a genus of Tarphycerida Nautiloidea, nautiloids included in the family Estonioceratidae for which the shell is a loosely coiled, gradually expanding dextral torticone with a slightly depressed whorl section. Siphuncle small, ventral, submarginal. Whorl section somewhat resembles early stages of ''Estonioceras'' in being laterally fanged. Trochoidal coiling brings to mind the later Trocholitidae. ''Aethoceras'' was originally found in the lower Ordovician of Western Australia. References * Furnish & Glennster, 1964, Nautiloidea - Tarphycerida. Treatise on Invertetrate Paleontology, Part C. University of Kansas Press, Lawrence, Ka. ''Aethoceras'' in Fossilworks. 1/5/15 Prehistoric nautiloid genera {{paleo-nautiloidea-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician
The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. The Ordovician, named after the Celtic Britons, Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same Rock (geology), rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed Stratum, strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Union of Geological Sciences, Intern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motility, able to move, can Sexual reproduction, reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of Cell (biology), cells, the blastula, during Embryogenesis, embryonic development. Over 1.5 million Extant taxon, living animal species have been Species description, described—of which around 1 million are Insecta, insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have Ecology, complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a Symmetry in biology#Bilate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 estimated between 60,000 and 100,000 additional species. The proportion of undescribed species is very high. Many taxa remain poorly studied. Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. Numerous molluscs also live in freshwater and terrestrial habitats. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat. The phylum is typically divided into 7 or 8 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurologically advanced of all invertebrates—and either the giant squid or the colossal squid is the largest known invertebrate species. The gastropods ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalopod
A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles (muscular hydrostats) modified from the primitive molluscan foot. Fishers sometimes call cephalopods "inkfish", referring to their common ability to squirt ink. The study of cephalopods is a branch of malacology known as teuthology. Cephalopods became dominant during the Ordovician period, represented by primitive nautiloids. The class now contains two, only distantly related, extant subclasses: Coleoidea, which includes octopuses, squid, and cuttlefish; and Nautiloidea, represented by ''Nautilus'' and ''Allonautilus''. In the Coleoidea, the molluscan shell has been internalized or is absent, whereas in the Nautiloidea, the external shell remains. About 800 living species of cephalopods have been ident ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nautiloidea
Nautiloids are a group of marine cephalopods (Mollusca) which originated in the Late Cambrian and are represented today by the living ''Nautilus'' and ''Allonautilus''. Fossil nautiloids are diverse and speciose, with over 2,500 recorded species. They flourished during the early Paleozoic era, when they constituted the main predatory animals. Early in their evolution, nautiloids developed an extraordinary diversity of shell shapes, including coiled morphologies and giant straight-shelled forms ( orthocones). Only a handful of rare coiled species, the nautiluses, survive to the present day. In a broad sense, "nautiloid" refers to a major cephalopod subclass or collection of subclasses (Nautiloidea ''sensu lato''). Nautiloids are typically considered one of three main groups of cephalopods, along with the extinct ammonoids (ammonites) and living coleoids (such as squid, octopus, and kin). While ammonoids and coleoids are monophyletic clades with exclusive ancestor-descendant rela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tarphycerida
The Tarphycerida were the first of the coiled cephalopods, found in marine sediments from the Lower Ordovician (middle and upper Canad) to the Middle Devonian. Some, such as '' Aphetoceras'' and '' Estonioceras'', are loosely coiled and gyroconic; others, such as '' Campbelloceras'', '' Tarphyceras'', and '' Trocholites'', are tightly coiled, but evolute with all whorls showing. The body chamber of tarphycerids is typically long and tubular,Furnish and Glenister 1964; Nautiloidea - Tarphycerida; In the ''Treatise on Invertebrate Paleontology'' Vol K; Teichert and Moore, (eds) GSA and U of Kansas Press 1964 as much as half the length of the containing whorl in most, greater than in the Silurian Ophidioceratidae. The Tarphycerida evolved from the elongated, compressed, exogastric Bassleroceratidae, probably ''Bassleroceras'', around the end of the Gasconadian through forms like ''Aphetoceras''. Close coiling developed rather quickly, and both gyroconic and evolute forms are fou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estonioceratidae
The Estonioceratidae are a family of loosely coiled tarphycerids in which the inner side of the whorls, which forms the dorsum, is rounded or flat with no impression, and in which the siphuncle, composed of thick tubular segments, is located ventrally. The Estonioceratidae seem to form a link between the ancestral Bassleroceratidae and the more tightly coiled Tarphyceratidae The Tarphyceratidae are tightly coiled, evolute Tarphycerida with ventral siphuncles. The dorsum is characteristically impressed where the whorl presses against the venter of the previous. The Tarphyceratidae are derived from ''Bassleroceras'' or ....Furnish, W. M, and Glenister, Brian F. 1964. Nautiloidea – Tarphycerida; Treatise on Invertebrate Paleontology, Part K, Geol. Soc. of America, Teichert and Moore (eds.) References {{Taxonbar, from=Q16965822 Cephalopod families Nautiloids Ordovician cephalopods ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estonioceras
''Estonioceras'' is an extinct genus of tarphyceridan nautiloids from the Ordovician of Europe. Sources * ''Dinosaur Encyclopedia'' by Jayne Parsons * ''Fossils'' (Smithsonian Handbooks) by David Ward External links''Estonioceras''in the Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals, plants, and microorganisms. History The Paleobiology Database (PBDB) originated in the NCEAS-funded Phanerozoic Marine Pale ... Prehistoric nautiloid genera Ordovician cephalopods of Europe Fossil taxa described in 1883 {{paleo-Nautiloidea-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trocholitidae
The Trocholitidae are Tarphycerida with whorls in close contact as with the Tarphyceratidae, but in which the siphuncle, similar in structure, becomes dorsal. The Trocholitidae are derived from the Tarphyceratidae, perhaps from different tarphyceratids. Members of the Trocholitidae vary in whorl section and siphuncle position. Most are tightly coiled with the dorsum impressed to some degree. As exceptions ''Arkoceras'' and ''Wichitoceras'' have their whorls touching but without a dorsal impression. '' Discoceras'' and '' Curtoceras'' have somewhat subquadrate whorl sections and are moderately impressed. In ''Graftonoceras'' and ''Jasperoceras'' the venter is rounded and continues smoothly through the flanks to a broad dorsum which in each is moderately impressed. The siphuncle in ''Graftonoceras'' is on the dorsal margin, in ''Jasperoceras'' it is between the center and dorsum. Whorls in T''rocholites'' have a wide cross section and low profile, in ''Wichitoceras'' they are lat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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