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Cephalopod Egg Fossil
Cephalopod egg fossils are the fossilized remains of eggs laid by cephalopods. The fossil record of cephalopod eggs is scant since their soft, gelatinous eggs decompose quickly and have little chance to fossilize. Eggs laid by ammonoids are the best known and only a few putative examples of these have been discovered. The best preserved of these were discovered in the Jurassic Kimmeridge Clay of England. Currently no belemnoid egg fossils have ever been discovered although this may be because scientists have not properly searched for them rather than an actual absence from the fossil record. Taphonomy Ammonite eggs in well-aerated sea bottoms probably would have quickly been broken down by scavengers and aerobic bacteria. Fossil evidence supports this general idea since swarms of hatchling ammonitellae fossils are known although there are no associated egg fossils. One of the eggs preserved in the Kimmeridge Clay ammonite egg cluster K1486 bears crystalline phosphate on its sur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aulacostephanidae - Aulacostephanus Yo
Aulacostephanidae is an extinct ammonoid cephalopod family belonging to the superfamily Perisphinctoidea. These fast-moving nektonic carnivores lived during the Upper Jurassic period, from the Oxfordian to Tithonian ages. Genera Genera within this family include: Paleobiology Database *'''' *'''' *'' |
Living Chamber
The body whorl is part of the morphology of the shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk. In gastropods In gastropods, the body whorl, or last whorl, is the most recently formed and largest whorl (or revolution) of a spiral or helical shell, terminating in the aperture. It is called the "body whorl" because most of the body of the soft parts of the animal fits into this whorl. The proportional size of the body whorl in gastropod shells differs greatly according to the actual shell morphology. For shells in which the rate of whorl expansion of each revolution around the axis is very high, the aperture and the body whorl are large, and the shell tends to be low spired. The shell of the abalone is a good example of this kind of shell. The opposite tendency can sometimes create a high spire with very little whorl increase per revolution. In these instances, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lias Group
The Lias Group or Lias is a lithostratigraphic unit (a sequence of rock strata) found in a large area of western Europe, including the British Isles, the North Sea, the Low Countries and the north of Germany. It consists of marine limestones, shales, marls and clays. ''Lias'' is a Middle English term for hard limestone, used in this specific sense by geologists since 1833. In the past, geologists used ''Lias'' not only for the sequence of rock layers, but also for the timespan during which they were formed. It was thus an alternative name for the Early Jurassic epoch of the geologic timescale. It is now more specifically known that the Lias is Rhaetian to Toarcian in age (over a period of 20 million years between ) and thus also includes a part of the Triassic. The use of the name "Lias" for a unit of time is therefore slowly disappearing. Subdivisions In southern England, the Lias Group is often divided into Lower, Middle and Upper subgroups. In Southern England the Lias is d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger 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, Australia and Ant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desmophyllites
''Desmophyllites'' is a small desmoceratitid ammonite characterized by a smooth and very involute shell that lived during the Santonian to Maachstrictian stages of the Late Cretaceous. Shells of ''Desmophylites diphylloida'' from the upper Santonian are on order of 1.8 cm (0.7 in) in diameter. Those of ''Desmophylllites larteti'' from the upper Campanian are on order of 10.5 cm (~4 in) across. References * Arkell, et al, 1957. Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology'' (or ''TIP'') published by the Geological Society of America and the University of Kansas Press, is a definitive multi-authored work of some 50 volumes, written by more than 300 paleontologists, and co ..., Part L (L370-371). Geological Society of America. * ''Desmophyllites'' iDesmoceratinae {{Taxonbar, from=Q16466651 Cretaceous ammonites Ammonites of Europe Ammonitida ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kamchatka
The Kamchatka Peninsula (russian: полуостров Камчатка, Poluostrov Kamchatka, ) is a peninsula in the Russian Far East, with an area of about . The Pacific Ocean and the Sea of Okhotsk make up the peninsula's eastern and western coastlines, respectively. Immediately offshore along the Pacific coast of the peninsula runs the Kuril–Kamchatka Trench. The Kamchatka Peninsula, the Commander Islands, and the Karaginsky Island, constitute the Kamchatka Krai of the Russian Federation. The vast majority of the 322,079 inhabitants are ethnic Russians, although about 13,000 are Koryaks (2014). More than half of the population lives in Petropavlovsk-Kamchatsky (179,526 in 2010) and nearby Yelizovo (38,980). The Kamchatka peninsula contains the volcanoes of Kamchatka, a UNESCO World Heritage Site. Geography Politically, the peninsula forms part of Kamchatka Krai. The southern tip is called Cape Lopatka. (Lopatka is Russian for spade.) The circular bay to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triassic
The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic Period is subdivided into three epochs: Early Triassic, Middle Triassic and Late Triassic. The Triassic began in the wake of the Permian–Triassic extinction event, which left the Earth's biosphere impoverished; it was well into the middle of the Triassic before life recovered its former diversity. Three categories of organisms can be distinguished in the Triassic record: survivors from the extinction event, new groups that flourished briefly, and other new groups that went on to dominate the Mesozoic Era. Reptiles, especially archosaurs, were the chief terrestrial vertebrates during this time. A specialized subgroup of archo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anisian
In the geologic timescale, the Anisian is the lower stage or earliest age of the Middle Triassic series or epoch and lasted from million years ago until million years ago. The Anisian Age succeeds the Olenekian Age (part of the Lower Triassic Epoch) and precedes the Ladinian Age. Stratigraphic definitions The stage and its name were established by Austrian geologists Wilhelm Heinrich Waagen and Carl Diener in 1895. The name comes from ''Anisus'', the Latin name of the river Enns. The original type locality is at Großreifling in the Austrian state of Styria. The base of the Anisian Stage (also the base of the Middle Triassic series) is sometimes laid at the first appearance of conodont species '' Chiosella timorensis'' in the stratigraphic record. Other stratigraphers prefer to use the base of magnetic chronozone MT1n. There is no accepted global reference profile for the base, but one ( GSSP or golden spike) was proposed at a flank of the mountain Deşli Caira in the Roman ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated between the Baltic and North seas to the north, and the Alps to the south; it covers an area of , with a population of almost 84 million within its 16 constituent states. Germany borders Denmark to the north, Poland and the Czech Republic to the east, Austria and Switzerland to the south, and France, Luxembourg, Belgium, and the Netherlands to the west. The nation's capital and most populous city is Berlin and its financial centre is Frankfurt; the largest urban area is the Ruhr. Various Germanic tribes have inhabited the northern parts of modern Germany since classical antiquity. A region named Germania was documented before AD 100. In 962, the Kingdom of Germany formed the bulk of the Holy Roman Empire. During the 16th ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muschelkalk
The Muschelkalk (German for "shell-bearing limestone"; french: calcaire coquillier) is a sequence of sedimentary rock strata (a lithostratigraphic unit) in the geology of central and western Europe. It has a Middle Triassic (240 to 230 million years) age and forms the middle part of the tripartite Germanic Trias, that give the Triassic its name, lying above the older Buntsandstein and below the younger Keuper. The Muschelkalk (" mussel chalk") consists of a sequence of limestone and dolomite beds. In the past, the time span in which the Muschelkalk was deposited could also be called "Muschelkalk". In modern stratigraphy, however, the name only applies to the stratigraphic unit. Occurrence The name ''Muschelkalk'' was first used by German geologist Georg Christian Füchsel (1722-1773). In 1834, Friedrich August von Alberti included it into the Triassic system. The name indicates a characteristic feature of the unit, namely the frequent occurrence of lenticular banks composed o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceratites
''Ceratites'' is an extinct genus of ammonite cephalopods. These nektonic carnivores lived in marine habitats in what is now Europe, during the Triassic, from the upper-most Anisian to the lower Ladinian age.Sepkoski, JacSepkoski's Online Genus Database – Cephalopoda/ref> Description This ammonite has a ceratitic suture pattern on its shell (smooth lobes and frilly saddles). Evolution of the frilly saddles is thought to be due to increased pressure on the shell, at greater depth. The frilly pattern would increase the strength of the shell and allow ''Ceratites'' to dive deeper, possibly in search of food. Distribution Fossils of this genus are only known from the Germanic Basin, which formed a partially isolated shallow sea across much of Europe from eastern France north of the future Alps and into Poland, separated from the Tethys by 3 gates that variably opened. The salinity of the water in this partially isolated basin may have been one of the main factors keeping ammonoid a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macroconch
Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) than they are to shelled nautiloids such as the living ''Nautilus'' species. The earliest ammonites appeared during the Devonian, with the last species vanishing during the Cretaceous–Paleogene extinction event. Ammonites are excellent index fossils, and linking the rock layer in which a particular species or genus is found to specific geologic time periods is often possible. Their fossil shells usually take the form of planispirals, although some helically spiraled and nonspiraled forms (known as heteromorphs) have been found. The name "ammonite", from which the scientific term is derived, was inspired by the spiral shape of their fossilized shells, which somewhat resemble tightly coiled rams' horns. Pliny the Elder ( 79 AD near Pompe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
