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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. Taxonomy The following orders are recognised in the superorder Decapodiformes: * Bathyteuthida * †Belemnitida * † Diplobelida * Idiosepida – pygmy squid * Myopsida – coastal squid * Oegopsida – neritic squid * Sepiida Cuttlefish, or cuttles, are marine molluscs of the suborder Sepiina. 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 ... – cuttlefish, bobtail and bottletail squid * Spirulida – ram's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belemnitida
Belemnitida (or belemnites) is an extinct order (biology), order of squid-like cephalopods that existed from the Late Triassic to Late Cretaceous (And possibly the Eocene). 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 calcite, 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 they 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Idiosepida
Idiosepiidae, also known as the pygmy squids, is a family of squids in the superorder Decapodiformes. They are the smallest known squids. It is the only family in the monotypic order Idiosepida and the monotypic superfamily Idiosepioidea. Phylogenomic analyses have shown that species in the family Idiosepiidae are sister to all other Decapodiformes. Description Idiosepiidae are the smallest known squids: males can grow to about and females to about in mantle length. The mantle is elongate, obovate to cigar-shaped, with its posterior margin bluntly pointed at the distal tip. Their internal chitinous shell is vestigial, and the dorsal surface of the mantle has a unique oval adhesive organ, which secretes a sticky substance and is used to attach itself to seaweed or seagrass blades. The head is prominent while the arms are short. In males, both ventral arms are differentiated, but they are also different from each other. Females are generally larger and achieve sexual maturity la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coleoid
Coleoidea or Dibranchiata is one of the two subclasses of cephalopod molluscs containing all the various taxa popularly thought of as "soft-bodied" or "shell-less" (i.e. octopus, 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 shell called cuttlebone or gladius that is used for buoyancy or as muscle anchorage. Some species, notably incirrate octopuses, have lost their internal shell altogether, while in some it has been replaced by a chitinous support structure. 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 sucker ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neocoleoidea
Neocoleoidea is a large group of marine cephalopods. This cohort contains two extant groups: Decapodiformes (squid, cuttlefish, and relatives) and Octopodiformes (octopuses and the vampire squid). Species within this group exist in all major habitats in the ocean, in both the southern and northern polar regions, and from intertidal zones to great depths. Whilst conventionally held to be monophyletic, the only morphological character for the group is the presence of suckers: although the presence of these features in the belemnites suggests that they do not support the Neocoleoidea, and hence that the group may be paraphyletic. Taxonomy *Superorder Decapodiformes **Order Bathyteuthida **Order † Belemnitida **Order † Diplobelida **Order Idiosepida - pygmy squid **Order Myopsida - coastal squid **Order Oegopsida - neritic squid **Order Sepiolida - bobtail squid **Order Spirulida - ram's horn squid **Order Sepiida - cuttlefish and bottletail squid *Superorder Octopo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oegopsida
Oegopsida is one of the four 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, were formerly placed in the family, but are now placed in their own order Bathyteuthida. The Oegopsida differ from the coastal My ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bathyteuthida
Bathyteuthida is an order of cephalopods, consisting of small, mesopelagic to bathypelagic squid that in some ways resemble myopsid squid, such as ''Loligo'' and in others the pelagic oegopsid squid. Its two families, the Bathyteuthidae and Chtenopterygidae, each containing a single genus, have previously been included with the oegopsids. As with the oegopsids, the Bathyteuthida lack corneal membranes covering their eyes, something common to myopsid squid, and have paired oviducts, lacking in myopsids. As with the myopsids, bathyteuthids have tentacle pockets in the head and small suckers on the buccal supports, found only in this group, Loliginidae, and Sepiidae; neither is found in true oegopsids. The Bathyteuthida do share the open ocean pelagic habitat with the oegopsid squid, uniting them in that way with that diverse group. The Bathyteuthidae and Chtenopterygidae differ in body conformation, the internal shell, and in the manner in which buccal supports attach to the ... [...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'' wi ... [...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 iden ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paralarva
Coleoidea or Dibranchiata is one of the two subclasses of cephalopod molluscs containing all the various taxa popularly thought of as "soft-bodied" or "shell-less" (i.e. octopus, 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 shell called cuttlebone or gladius that is used for buoyancy or as muscle anchorage. Some species, notably incirrate octopuses, have lost their internal shell altogether, while in some it has been replaced by a chitinous support structure. 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 suckers gener ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
