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Yezoteuthis
''Yezoteuthis'' (" Yezo squid") is an extinct genus of very large oegopsid squid that inhabited the seas around Japan in the Late Cretaceous period. It contains a single species, ''Y. giganteus'' from the early Campanian Osousyunai Formation of the Yezo Group in Hokkaido. It is possibly the largest fossil coleoid ever described. ''Yezoteuthis'' is known from a single upper jaw that shares close similarities with those of oegopsids, hence its assignment to that order. These jaws are very large, and a comparison to modern squid indicates that ''Yezoteuthis'' would have rivalled the extant giant squid (''Architeuthis'') in size, reaching about in mantle length, and more than in total length. ''Yezoteuthis'' was likely a major predator of its ecosystem and existed at a high trophic level. A second set of oegopsid jaws closely resembling those of ''Yezoteuthis'' was described from the Yezo Group in 2023, but was found to be even larger and have different proportions of those fro ... [...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] |
Yezo Group
The Yezo Group is a stratigraphic group in Hokkaido, Japan and Sakhalin, Russia which is primarily Late Cretaceous in age (Aptian to Earliest Paleocene). It is exposed as roughly north–south trending belt extending 1,500 kilometres through central Hokkaido from Urakawa, Hokkaido, Urakawa to Cape Sōya and Sakhalin from the south coast to Alexandrovsk-Sakhalinsky District. It consists of marine forearc basin sediments, typically turbiditic and Bioturbation, bioturbated mudstones and sandstones with subordinate conglomerate primarily deposited on the continental shelf and continental slope, slope of the ancient Yezo Subduction, subduction margin. It forms a continuous depositional sequence with the Sorachi Group, which overlies the Horokanai Ophiolite. The sequence gradually shallows upwards with the terminal Hakobuchi Formation representing a fluvial-inner shelf environment. Numerous fossils are known from the unit, mostly ammonites and bivalves, but also marine vertebrates such a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giant Squid
The giant squid (''Architeuthis dux'') is a species of deep-ocean dwelling squid A squid (: squid) is a mollusc with an elongated soft body, large eyes, eight cephalopod limb, arms, and two tentacles in the orders Myopsida, Oegopsida, and Bathyteuthida (though many other molluscs within the broader Neocoleoidea are also ... in the family (biology), family Architeuthidae. It can grow to a tremendous size, offering an example of deep-sea gigantism, abyssal gigantism: recent estimates put the maximum body size at around for females, with males slightly shorter, from the cephalopod fin, posterior fins to the tip of its long cephalopod limb, arms. This makes it longer than the colossal squid at an estimated , but substantially lighter, as it is less robust and its arms make up much of the length. The Mantle (mollusc), mantle of the giant squid is about long (longer for females, shorter for males), and the feeding tentacles of the giant squid, concealed in life, are . Clai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Campanian
The Campanian is the fifth of six ages of the Late Cretaceous epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian spans the time from 83.6 (± 0.2) to 72.1 (± 0.2) million years ago. It is preceded by the Santonian and it is followed by the Maastrichtian. The Campanian was an age when a worldwide sea level rise covered many coastal areas. The morphology of some of these areas has been preserved: it is an unconformity beneath a cover of marine sedimentary rocks. Etymology The Campanian was introduced in scientific literature by Henri Coquand in 1857. It is named after the French village of Champagne in the department of Charente-Maritime. The original type locality was a series of outcrops near the village of Aubeterre-sur-Dronne in the same region. Definition The base of the Campanian Stage is defined as a place in the stratigraphic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalopod Beak
All extant taxon, extant cephalopods have a two-part beak, or Rostrum (anatomy), rostrum, situated in the buccal mass and surrounded by the muscular Cephalopod limb, head appendages. The Dorsal (anatomy), dorsal (upper) mandible fits into the ventral (lower) mandible and together they function in a scissor-like fashion.Young, R.E., M. Vecchione & K.M. Mangold (1999)Cephalopoda Glossary Tree of Life Web Project. The beak may also be referred to as the mandibles or jaws.Tanabe, K., Y. Hikida & Y. Iba (2006). Two coleoid jaws from the Upper Cretaceous of Hokkaido, Japan. ''Journal of Paleontology'' 80(1): 138–145. These beaks are different from Beak, bird beaks because they crush bone while most bird beaks do not. Fossilized remains of beaks are known from a number of cephalopod-groups, both extant and extinct, including squids, octopus, octopodes, belemnites, and vampyromorphs. Aptychus, Aptychi - paired plate-like structures found in ammonites - may also have been jaw elements. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous Japan
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 77.1 million years, it is the ninth and longest geological period of the entire Phanerozoic. The name is derived from the Latin , 'chalk', which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation . The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was largely ice-free, although there is some evidence of brief periods of glaciation during the cooler first half, and forests extended to the poles. Many of the dominant taxonomic groups present in modern times can be ultimately traced back to origins in the C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossils Of Japan
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Though the fossil record is incomplete, numerous studies have demonstrated that there is enough information available to give a good understanding of the pattern of diversification of life on Earth. In addition, the record can predict and fill gaps such as the discovery of ''Tiktaalik'' in the arctic of Canada. Paleontology includes the study of fossils: their age, method of formation, and evolutionary significance. Specimens are sometimes considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years to 4.1 billion years old. Early edition, published online before print. The ob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous Cephalopods
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 77.1 million years, it is the ninth and longest geological period of the entire Phanerozoic. The name is derived from the Latin , 'chalk', which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation . The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was largely ice-free, although there is some evidence of brief periods of glaciation during the cooler first half, and forests extended to the poles. Many of the dominant taxonomic groups present in modern times can be ultimately traced back to origins in the C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotypic Prehistoric Cephalopod Genera
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispecific" or "monospecific" is sometimes preferred. In botanical nomenclature, a monotypic genus is a genus in the special case where a genus and a single species are simultaneously described. Theoretical implications Monotypic taxa present several important theoretical challenges in biological classification. One key issue is known as "Gregg's Paradox": if a single species is the only member of multiple hierarchical levels (for example, being the only species in its genus, which is the only genus in its family), then each level needs a distinct definition to maintain logical structure. Otherwise, the different taxonomic ranks become effectively identical, which creates problems for organizing biological diversity in a hierarchical system. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haboroteuthis
''Haboroteuthis'' is an extinct genus of squid that lived during the Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ... period. The only species that has been classified in the genus is ''H. poseidon''. References {{Taxonbar, from=Q56232842 Monotypic prehistoric cephalopod genera Squid Cretaceous cephalopods ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hokkaido
is the list of islands of Japan by area, second-largest island of Japan and comprises the largest and northernmost prefectures of Japan, prefecture, making up its own list of regions of Japan, region. The Tsugaru Strait separates Hokkaidō from Honshu; the two islands are connected by railway via the Seikan Tunnel. The largest city on Hokkaido is its capital, Sapporo, which is also its only cities designated by government ordinance of Japan, ordinance-designated city. Sakhalin lies about to the north of Hokkaidō, and to the east and northeast are the Kuril Islands, which are administered by Russia, though the four most southerly are Kuril Islands dispute, claimed by Japan. The position of the island on the northern end of the archipelago results in a colder climate, with the island seeing significant snowfall each winter. Despite the harsher climate, it serves as an agricultural breadbasket for many crops. Hokkaido was formerly known as ''Ezo'', ''Yezo'', ''Yeso'', or ''Yes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coleoidea
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 w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
