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Decapodiformes
Decapodiformes is a superorder of Cephalopoda comprising all cephalopod species with ten limbs, specifically eight short arms and two long tentacles. It is hypothesized that the ancestral coleoid had five identical pairs of limbs, and that one branch of descendants evolved a modified arm pair IV to become the Decapodiformes, while another branch of descendants evolved and then eventually lost its arm pair II, becoming the Octopodiformes. The Decapodiformes include: *Order Spirulida: ram's horn squid *Order Sepiida: cuttlefish, pygmy, bobtail and bottletail squid *Order Myopsida: coastal squid *Order Oegopsida Oegopsida is one of the two orders of squid in the superorder Decapodiformes, in the class Cephalopoda. Together with the Myopsina, it was formerly considered to be a suborder of the order Teuthida, in which case it was known as Oegopsina. Th ...: neritic squid References Further reading *abstract External links The Taxonomicon: Superorder Decapodiformes Cole ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belemnite
Belemnitida (or the belemnite) is an extinct order of squid-like cephalopods that existed from the Late Triassic to Late Cretaceous. Unlike squid, belemnites had an internal skeleton that made up the cone. The parts are, from the arms-most to the tip: the tongue-shaped pro-ostracum, the conical phragmocone, and the pointy guard. The calcitic guard is the most common belemnite remain. Belemnites, in life, are thought to have had 10 hooked arms and a pair of fins on the guard. The chitinous hooks were usually no bigger than , though a belemnite could have had between 100 and 800 hooks in total, using them to stab and hold onto prey. Belemnites were an important food source for many Mesozoic marine creatures, both the adults and the planktonic juveniles, and likely played an important role in restructuring marine ecosystems after the Triassic–Jurassic extinction event. They may have laid between 100 and 1,000 eggs. Some species may have been adapted to speed and swam in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coleoidea
Subclass Coleoidea, or Dibranchiata, is the grouping of cephalopods containing all the various taxa popularly thought of as "soft-bodied" or "shell-less" (i.e., octopuses, squid and cuttlefish). Unlike its extant sister group, Nautiloidea, whose members have a rigid outer shell for protection, the coleoids have at most an internal cuttlebone, gladius, or shell that is used for buoyancy or support. Some species have lost their cuttlebone altogether, while in some it has been replaced by a chitinous support structure. A unique trait of the group is the ability to edit their own RNA. The major divisions of Coleoidea are based upon the number of arms or tentacles and their structure. The extinct and most primitive form, the Belemnoidea, presumably had ten equally-sized arms in five pairs numbered dorsal to ventral as I, II, III, IV and V. More modern species either modified or lost a pair of arms. The superorder Decapodiformes has arm pair IV modified into long tentacles wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coleoid
Subclass Coleoidea, or Dibranchiata, is the grouping of cephalopods containing all the various taxa popularly thought of as "soft-bodied" or "shell-less" (i.e., octopuses, squid and cuttlefish). Unlike its extant sister group, Nautiloidea, whose members have a rigid outer shell for protection, the coleoids have at most an internal cuttlebone, gladius, or shell that is used for buoyancy or support. Some species have lost their cuttlebone altogether, while in some it has been replaced by a chitinous support structure. A unique trait of the group is the ability to edit their own RNA. The major divisions of Coleoidea are based upon the number of arms or tentacles and their structure. The extinct and most primitive form, the Belemnoidea, presumably had ten equally-sized arms in five pairs numbered dorsal to ventral as I, II, III, IV and V. More modern species either modified or lost a pair of arms. The superorder Decapodiformes has arm pair IV modified into long tentacles with su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boletzkyida
Boletzkyida is a primitive order of teuthid coleoid cephalopod: the boletzkyids are thought to be the earliest forms of coleoid cephalopods, and appear to form a link between nautiloid orthocerids and more advanced coleoids. Boletzkyida was named and described by Bandel, Reitner, and Sturmer in 1983 (B.R.&S) from specimens found in the Lower Devonian black slate ("Hunsrück Slate") in Germany. Taxonomy Bandel, ''et al'' (1983) divided the Boletzkyida into two, not too dissimilar families, each based on a single genus. They are the Boletzkyidae based on the genus ''Boletzkya'' and the Naefiteuthidae based on the genus ''Naefiteuthis''. The main difference between ''Boletzkya'' and ''Naefiteuthis'' is the length of the phragmocone at which time the living chamber becomes gladius-like and dominates the shell. Ontogeny Boletzkyd shells grew to as long as 16 cm. The juvenile portion is a phragmocone that closely resembles that of Silurian orthocerid ''Michelinoceras'' with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalopoda
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 ide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octopodiformes
Octopodiformes is a superorder of the subclass Coleoidea, comprising the octopuses and the vampire squid. All living members of Octopodiformes have eight arms, either lacking the two tentacles of squid (as is the case in octopuses) or modifying the tentacles into thin filaments (as in vampire squid). Octopodiformes is often considered the crown group of octopuses and vampire squids, including all descendants of their common ancestor. Some authors use the term Vampyropoda for the same general category, though others use "Vampyropoda" to refer to the total group (all cephalopods closer to octopods than to true squid). Another term is Octobranchia, referring to cephalopods without prominent tentacles. '' Pohlsepia'', originally described as earliest octopod is considered as dubious for this group in later study. The oldest unambiguous vampyropod is ''Syllipsimopodi'', a squid-like cephalopod from the Mississippian-age Bear Gulch Lagerstätte of Montana. ''Syllipsimopodi'' has a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalopod Limb
All cephalopods possess flexible limbs extending from their heads and surrounding their beaks. These appendages, which function as muscular hydrostats, have been variously termed arms, legs or tentacles. Description In the scientific literature, a cephalopod ''arm'' is often treated as distinct from a ''tentacle'', though the terms are sometimes used interchangeably, often with the latter acting as an umbrella term for cephalopod limbs. Generally, arms have suckers along most of their length, as opposed to tentacles, which have suckers only near their ends.Young, R.E., M. Vecchione & K.M. Mangold 1999Cephalopoda Glossary Tree of Life web project. Barring a few exceptions, octopuses have eight arms and no tentacles, while squid and cuttlefish have eight arms (or two "legs" and six "arms") and two tentacles.Norman, M. 2000. ''Cephalopods: A World Guide''. ConchBooks, Hackenheim. p. 15. "There is some confusion around the terms ''arms'' versus ''tentacles''. The numerous l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oegopsida
Oegopsida is one of the two orders of squid in the superorder Decapodiformes, in the class Cephalopoda. Together with the Myopsina, it was formerly considered to be a suborder of the order Teuthida, in which case it was known as Oegopsina. This reclassification is due to Oegopsina and Myopsina not being demonstrated to form a clade. The Oegopsida are an often pelagic squid, with some nerito-oceanic species associated with sea mounts. They consist of 24 families and 69 genera. They have these characters in common: the head is without tentacle pockets, eyes lack a corneal covering, arms and tentacle clubs may have hooks, the buccal supports are without suckers, and oviducts in females are paired. Two families, the Bathyteuthidae and Chtenopterygidae, which have features characteristic of the Myopsida while retaining others common to the Oegopsina, are sometimes placed in the Bathyteuthoidea. The Oegopsida differ from the coastal Myopsida, characterised by the genus ''Lolig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spirulida
Spirulida is an order of cephalopods comprising one extant species (''Spirula spirula'') and several extinct taxa. Fossil record * Oldest representative: Carboniferous, though contested: see ''Shimanskya'' * Oldest uncontested representative: Late Jurassic Classification *Order Spirulida **?Family †Shimanskyidae **Suborder †Groenlandibelina Khromov, 1990 ***Family †Groenlandibelidae Groenlandibelidae is a family of coleoid cephalopods believed to belong to the spirulids. Morphologically, its taxa seem to have some belemnoid characteristics, suggesting a possible intermediate relationship. Genera ''Groenlandibelus '' Je ... ***Family † Adygeyidae **Suborder †Belopterina Engeser, 1998 ***Family † Belemnoseidae ***Family † Belopteridae **Suborder Spirulina Pompeckj, 1912 ***Family † Spirulirostridae ***Family † Spirulirostrinidae ***Family Spirulidae References Tree of Life: Spirulida [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myopsida
Myopsida is one of the four orders of squid. It consists of two families: the monotypic '' Australiteuthis'' and the diverse and commercially important Loliginidae (~50 species). Some taxonomists classify this taxon as a suborder of the order Teuthida, in which case it is known as Myopsina. This reclassification is due to Myopsina and Oegopsina not being demonstrated to form a clade. A number of morphological features distinguish members of Myopsida from those of its sister group, Oegopsida. Some of the most obvious differences are found in the structure of the eyes: those of myopsid squids lack a secondary eyelid and are instead covered by a transparent corneal membrane, the opening of which is reduced to a microscopic anterior pore in most species. The arms and tentacles are ornamented with simple suckers (hooks are never present), with additional suckers usually borne on the buccal lappets. The carpal ("wrist") portion of the tentacular club lacks a locking apparatus, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superorder
Order ( la, ordo) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized by the nomenclature codes. An immediately higher rank, superorder, is sometimes added directly above order, with suborder directly beneath order. An order can also be defined as a group of related families. What does and does not belong to each order is determined by a taxonomist, as is whether a particular order should be recognized at all. Often there is no exact agreement, with different taxonomists each taking a different position. There are no hard rules that a taxonomist needs to follow in describing or recognizing an order. Some taxa are accepted almost universally, while others are recognized only rarely. The name of an order is usually written with a capital letter. For some groups of organisms, their orders may foll ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sepiida
Cuttlefish or cuttles are marine molluscs of the order Sepiida. They belong to the class Cephalopoda which also includes squid, octopuses, and nautiluses. Cuttlefish have a unique internal shell, the cuttlebone, which is used for control of buoyancy. Cuttlefish have large, W-shaped pupils, eight arms, and two tentacles furnished with denticulated suckers, with which they secure their prey. They generally range in size from , with the largest species, the giant cuttlefish (''Sepia apama''), reaching in mantle length and over in mass. Cuttlefish eat small molluscs, crabs, shrimp, fish, octopus, worms, and other cuttlefish. Their predators include dolphins, sharks, fish, seals, seabirds, and other cuttlefish. The typical life expectancy of a cuttlefish is about 1–2 years. Studies are said to indicate cuttlefish to be among the most intelligent invertebrates. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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