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Cirrate Shell
Cirrate octopuses possess a well-developed internal shell that supports their muscular swimming fins. This is in contrast to the more familiar, finless, incirrate octopuses, in which the shell remnant is either present as a pair of stylets or absent altogether. The cirrate shell is quite unlike that of any other living cephalopod group and has its own dedicated set of descriptive terms. It is usually roughly arch- or saddle-shaped and is rather soft, being similar in consistency to cartilage. Each of the eight extant cirrate genera is characterised by a distinct shell morphology outlined below (below taxonomy updated per WoRMS): *Superfamily Cirroteuthoidea ** Cirroteuthidae ***'' Cirroteuthis'' — saddle-shaped, with large wings ***'' Cirrothauma'' — butterfly-shaped ** Stauroteuthidae ***'' Stauroteuthis'' — U-shaped *Superfamily Opisthoteuthoidea ** Opisthoteuthidae ***'' Opisthoteuthis'' (also '' Exsuperoteuthis'' & '' Insigniteuthis'')— U-shaped, lateral wings usu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grimpoteuthis Innominata 73 Mm ML
''Grimpoteuthis'' is a genus of pelagic cirrate (finned) octopods known as the dumbo octopus. The name "dumbo" originates from their resemblance to the title character of Disney's 1941 film ''Dumbo'', having two prominent ear-like fins which extend from the mantle above each eye. There are 17 species recognized in the genus. The Dumbo octopus has a gelatinous body and uses fin propulsion for movement, which also helps it to conserve energy in its extreme deep-sea environment. These unique physical traits distinguish it from other octopuses, which primarily rely on jet propulsion. Prey include crustaceans, bivalves, worms and copepods. The average life span of various ''Grimpoteuthis'' species is 3 to 5 years. Range and habitat Species of ''Grimpoteuthis'' are assumed to have a worldwide distribution, living in the cold, abyssal depths ranging from . Specimens have been found off the coasts of Oregon, the Philippines, Martha's Vineyard, the Azores, New Zealand, A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stylet (octopus)
Stylet may refer to: *An archaeological term for a type of flint tool found in Lebanon, also known as a Minet ed Dhalia point *Stylet (anatomy) A stylet is a hard, sharp, anatomical structure found in some invertebrates. For example, the word ''stylet'' or stomatostyle is used for the primitive piercing mouthparts of some nematodes and some nemerteans. In these groups the stylet is a h ..., a hard, sharp anatomical structure *In the medical industry a stylet is a slender medical probe or device. **For example, stylets used to facilitate tracheal intubation – see * French destroyer ''Stylet'', a ship of the French Navy 1905–1921 {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palaeoctopus Newboldi
''Palaeoctopus'' is an extinct genus of octopuses that lived during the Late Cretaceous. It contains one valid species, ''P. newboldi'', which has been found in Lebanon. Taxonomy ''Calais newboldi'' was named by Henry B. Woodward in 1896 for a nearly-complete specimen from the Sahel Alma lagerstätte of Lebanon. However, that genus name was preoccupied by the beetle ''Calais''. Woodward named ''Palaeoctopus'' as a replacement later the same year. Embrik Strand proposed the alternate replacement name ''Calaita'' in 1928. '' Beloteuthis libanotica'' was named by Adolf Naef in 1922 for a supposed teudopsid gladius from Sahel Alma. It was moved to a new genus, ''Parateudopsis'', by Theo Engeser and Joachim Reitner in 1986. The specimen was eventually reidentified as an isolated gladius vestige of ''P. newboldi''. A second species, ''P. pelagicus'', was named by Dirk Fuchs and colleagues in 2008 for an alleged gladius vestige from the Vallecillo lagerstätte of Mexico. It was s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Aus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Derived Trait
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have evolved in their most recent common ancestor. ) In cladistics, synapomorphy implies homology. Examples of apomorphy are the presence of erect gait, fur, the evolution of three middle ear bones, and mammary glands in mammals but not in other vertebrate animals such as amphibians or reptiles, which have retained their ancestral traits of a sprawling gait and lack of fur. Thus, these derived traits are also synapomorphies of mammals in general as they are not shared by other vertebrate animals. Etymology The word —coined by German entomologist Willi Hennig—is derived from the Ancient Greek words (''sún''), meaning "with, together"; (''apó''), meaning "away from"; and (''morphḗ''), meaning "shape, form". Determining ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plesiomorphy
In phylogenetics, a plesiomorphy ("near form") and symplesiomorphy are synonyms for an ancestral Phenotypic trait, character shared by all members of a clade, which does not distinguish the clade from other clades. Plesiomorphy, symplesiomorphy, apomorphy and synapomorphy, apomorphy, and synapomorphy all mean a trait shared between species because they share an ancestral species. Apomorphic and synapomorphic characteristics convey much information about evolutionary clades and can be used to define taxa. However, plesiomorphic and symplesiomorphic characteristics cannot. The term ''symplesiomorphy'' was introduced in 1950 by German Entomology, entomologist Willi Hennig. Examples A backbone is a plesiomorphic trait shared by birds and mammals, and does not help in placing an animal in one or the other of these two clades. Birds and mammals share this trait because both clades are descended from the same far distant ancestor. Other clades, e.g. snakes, lizards, turtles, fish, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptoteuthis
''Cryptoteuthis brevibracchiata'', the short-arm flapjack octopod, is a deepwater species of octopod. It is the only species in the monotypic genus ''Cryptoteuthis'' one of the cirrate octopuses of the family Grimpoteuthidae, the umbrella octopuses. It is known from a single specimen which was collected in the northeastern Atlantic Ocean. It has characteristics which are shared with two other genera, '' Opisthoteuthis'' and ''Grimpoteuthis'', but is sufficiently distinctive from either of these to warrant the erection of a new genus. Description ''Cryptoteuthis brevibracchiata'' is a bell-shaped octopus with a semi-gelatinous, semi-transparent body, except for the dark tips of the oral web and the tips of the fins. The fins are small and round, and their length is equal to half the width of the head. It has short arms, each with a single row of small, broad suckers and with a double row of cirri which are of moderate length, with each cirrus just longer than the diameter of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luteuthis
''Luteuthis'' is a small genus of Cirrata, cirrate octopuses currently placed in the Family (biology), family Grimpoteuthidae. There are two species classified in this genus one from waters west of New Zealand and the other from the South China Sea. Taxonomy ''Luteuthis'' are characterized by several unique features. The body is relatively elongate, extensively gelatinous and lacking areolar spots. The paired fins are laterally placed, and supported by a W-shaped internal shell with the shell wings bearing in-rolled margins and tapering to acute points. The arms are narrow and connected by simple webbing, there is no web nodule acting as a web attachment point. The Suckers (cephalopod anatomy), suckers are crenulated (around the aperture opening) and are flanked by rows of short cirri (cirri about half as long as the sucker diameter). The gills resemble a "half-orange" and have seven lamellae. ''Luteuthis'' species have a well developed radula as well as palatine teeth on the pal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molluscan Research
''Molluscan Research'' is a quarterly peer-reviewed scientific journal covering the field of malacology with a preference for studies focusing on Australia and surrounding regions. The journal was established in 1957 as the ''Journal of the Malacological Society of Australia'', obtaining its current name in 1994. It was published by CSIRO from 2002 to 2004 (volumes 22 to 24), then from 2004 to 2012 by Magnolia Press (volumes 25 to 32). Since 2013 the journal has been published by Taylor & Francis and the editor-in-chief is D.J. Colgan (Australian Museum). Abstracting and indexing The journal is abstracted and indexed in: According to the ''Journal Citation Reports'', the journal has a 2021 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a type of journal ranking. Journals with higher impact factor values are considered more prestigious or important within their field. The Impact Factor of a journa ... of 0.803. References Exter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grimpoteuthis
''Grimpoteuthis'' is a genus of pelagic Cirrina, cirrate (finned) octopods known as the dumbo octopus. The name "dumbo" originates from their resemblance to the title character of Disney's 1941 film ''Dumbo'', having two prominent ear-like fins which extend from the Mantle (mollusc), mantle above each eye. There are 17 species recognized in the genus. The Dumbo octopus has a gelatinous body and uses fin propulsion for movement, which also helps it to conserve energy in its extreme deep-sea environment. These unique physical traits distinguish it from other octopuses, which primarily rely on jet propulsion. Prey include crustaceans, bivalves, worms and copepods. The average life span of various ''Grimpoteuthis'' species is 3 to 5 years. Range and habitat Species of ''Grimpoteuthis'' are assumed to have a worldwide distribution, living in the cold, Abyssal plain, abyssal depths ranging from . Specimens have been found off the coasts of Oregon, the Philippines, Marth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grimpoteuthidae
Grimpoteuthidae are a family of bentho-pelagic octopuses, comprising three currently accepted genera. They have extensive arm webbing and relatively large fins allowing for powerful fin swimming. Description Grimpoteuthidae have a strongly U-, V-, W-shaped internal shell (gladius remnant) that supports muscles for large fins. These fins are proportionally much larger than in the related Opisthoteuthidae, and allow for much stronger swimming using the fins alone (unlike Opisthoteuthids that mostly use the arm webbing for swimming). Unlike Cirroctopodidae and Opisthoteuthidae, Grimpoteuthids also have the optic nerves heading to each eye as a single bundle (in the other families this occurs as multiple separated nerve bundles). The extensive arm webbing is shared with Opisthoteuthidae and Cirroctopodidae. Taxonomy The following genera and 19 species are currently accepted in this family. The family has consistently been supported in molecular studies as distinct from Opistho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
