| Inoceramus | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Bivalvia |
| Order: | Pteriida |
| Family: | † Inoceramidae |
| Genus: | † Inoceramus Sowerby, 1814 |
| Species | |
See text | |
Inoceramus (Greek: translation "strong pot") is an extinct genus of fossil marine pteriomorphian bivalves that superficially resembled the related winged pearly oysters of the extant genus Pteria . They lived from the Early Jurassic to latest Cretaceous. [1] [2]
The taxonomy of the inoceramids is disputed, with genera such as Platyceramus sometimes classified as subgenus within Inoceramus. Also the number of valid species in this genus is disputed.
Inoceramids had thick shells composed of "prisms" of calcite deposited perpendicular to the surface, and unweathered fossils commonly preserve the mother-of-pearl luster the shells had in life. [3] Most species have prominent growth lines which appear as raised semicircles concentric to the growing edge of the shell. [3]
In 1952, the huge specimen of Inoceramus steenstrupi 187 cm long, was found in Qilakitsoq, the Nuussuaq Peninsula, Greenland. This fossil is 83 Ma old, the Upper Santonian or Lower Campanian stage. [4] Paleontologists suggest that the giant size of some species was an adaptation for life in the murky bottom waters, with a correspondingly large gill area that would have allowed the animal to survive in oxygen-deficient waters. [3]
Species of Inoceramus had a worldwide distribution during the Cretaceous and Jurassic periods (from 189.6 to 66.043 Ma). [1] Many examples are found in the Pierre Shale of the Western Interior Seaway in North America. Inoceramus can also be found abundantly in the Cretaceous Gault Clay that underlies London. Other locations for this fossil include Vancouver Island, [3] British Columbia, Colombia (Hiló Formation, Tolima and La Frontera Formation, Boyacá, Cundinamarca and Huila), [6] Spain, France, Germany, Afghanistan, Albania, Algeria, Angola, Antarctica, Argentina, Australia, Austria, Brazil, Bulgaria, Canada (Alberta, Northwest Territories, Nunavut, Saskatchewan, Yukon), Chile, China, Cuba, the Czech Republic, Denmark, Ecuador, Egypt, Hungary, India, Indian Ocean, Iran, Italy, Jamaica, Japan, Jordan, Kenya, Libya, Madagascar, Mexico, Morocco, Mozambique, Nepal, New Caledonia, New Zealand, Nigeria, Papua New Guinea, Peru, Poland, the Russian Federation, Saudi Arabia, Serbia and Montenegro, South Africa, Sweden, Switzerland, Tunisia, Turkey, Turkmenistan, the United Kingdom, United States (Alabama, Alaska, Arizona, Arkansas, California, Colorado, Delaware, Idaho, Iowa, Kansas, Maryland, Minnesota, Mississippi, Montana, Nebraska, New Jersey, New Mexico, North Carolina, North Dakota, Oregon, South Carolina, South Dakota, Tennessee, Texas, Utah, Washington, Wyoming), and Venezuela. [1]
The Western Interior Seaway was a large inland sea that split the continent of North America into two landmasses for 34 million years. The ancient sea, which existed from the early Late Cretaceous to the earliest Paleocene, connected the Gulf of Mexico to the Arctic Ocean. The two land masses it created were Laramidia to the west and Appalachia to the east. At its largest extent, it was 2,500 feet (760 m) deep, 600 miles (970 km) wide and over 2,000 miles (3,200 km) long.
Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock strata by using the fossil assemblages contained within them. The primary objective of biostratigraphy is correlation, demonstrating that a particular horizon in one geological section represents the same period of time as another horizon at a different section. Fossils within these strata are useful because sediments of the same age can look completely different, due to local variations in the sedimentary environment. For example, one section might have been made up of clays and marls, while another has more chalky limestones. However, if the fossil species recorded are similar, the two sediments are likely to have been laid down around the same time. Ideally these fossils are used to help identify biozones, as they make up the basic biostratigraphy units, and define geological time periods based upon the fossil species found within each section.
Baculites is an extinct genus of heteromorph ammonite cephalopods with almost straight shells. The genus, which lived worldwide throughout most of the Late Cretaceous, and which briefly survived the K-Pg mass extinction event, was named by Lamarck in 1799.
Scaphites is a genus of heteromorph ammonites belonging to the Scaphitidae family. They were a widespread genus that thrived during the Late Cretaceous period.
The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous Epoch, or a stage in the Upper Cretaceous Series. It spans the time between 93.9 ± 0.8 Ma and 89.8 ± 1 Ma. The Turonian is preceded by the Cenomanian Stage and underlies the Coniacian Stage.
Ostrea is a genus of edible oysters, marine bivalve mollusks in the family Ostreidae, the oysters.
Nucula is a genus of very small saltwater clams. They are part of the family Nuculidae.
The Pierre Shale is a geologic formation or series in the Upper Cretaceous which occurs east of the Rocky Mountains in the Great Plains, from Pembina Valley in Canada to New Mexico.
The Kaskapau Formation is a geological formation in North America whose strata date back to the Late Cretaceous.
The Matanuska Formation consists of more than 3 km (1.9 mi) of sedimentary strata exposed in the northern Chugach Mountains, Matanuska Valley, and southern Talkeetna Mountains of south-central Alaska. The Matanuska Formation contains strata from Early Cretaceous (Albian) to Late Cretaceous (Maestrichtian). Parts of the formation contain abundant marine mollusks, foraminifera, and radiolaria. Fossils of nonmarine plants are found in some beds. Fossils of two dinosaurs have been recovered from marine mudstones in the formation. The lower Matanuska Formation (MF) is several hundred meters thick and includes nonmarine and marine sediments. Campanian-Maastrichtian graded sandstone, conglomerate, and mudstone comprise the upper 2000 m of the Formation.
The Menefee Formation is an upper Santonian to lower Campanian geologic formation found in Colorado and New Mexico, United States.
The Straight Cliffs Formation is a stratigraphic unit in the Kaiparowits Plateau of south central Utah. It is Late Cretaceous in age and contains fluvial, paralic, and marginal marine (shoreline) siliciclastic strata. It is well exposed around the margin of the Kaiparowits Plateau in the Grand Staircase – Escalante National Monument in south central Utah. The formation is named after the Straight Cliffs, a long band of cliffs creating the topographic feature Fiftymile Mountain.
The Inoceramidae are an extinct family of bivalves ("clams") in the Class Mollusca. Fossils of inoceramids are found in marine sediments of Permian to latest Cretaceous in age. Inoceramids tended to live in upper bathyal and neritic environments. Many species of inoceramid are found all over the world, demonstrating the wide distribution of their preferred ecosystems, and possibly long-lived planktotrophic larvae. Despite their wide distribution, the pace of evolution of inoceramids was great, with species ranges commonly averaging 0.2-0.5 Ma.
Paleontology in North Dakota refers to paleontological research occurring within or conducted by people from the U.S. state of North Dakota. During the early Paleozoic era most of North Dakota was covered by a sea home to brachiopods, corals, and fishes. The sea briefly left during the Silurian, but soon returned, until once more starting to withdraw during the Permian. By the Triassic some areas of the state were still under shallow seawater, but others were dry and hot. During the Jurassic subtropical forests covered the state. North Dakota was always at least partially under seawater during the Cretaceous. On land Sequoia grew. Later in the Cenozoic the local seas dried up and were replaced by subtropical swamps. Climate gradually cooled until the Ice Age, when glaciers entered the area and mammoths and mastodons roamed the local woodlands.
Paleontology in Alaska refers to paleontological research occurring within or conducted by people from the U.S. state of Alaska. During the Late Precambrian, Alaska was covered by a shallow sea that was home to stromatolite-forming bacteria. Alaska remained submerged into the Paleozoic era and the sea came to be home to creatures including ammonites, brachiopods, and reef-forming corals. An island chain formed in the eastern part of the state. Alaska remained covered in seawater during the Triassic and Jurassic. Local wildlife included ammonites, belemnites, bony fish and ichthyosaurs. Alaska was a more terrestrial environment during the Cretaceous, with a rich flora and dinosaur fauna.
Cimoliopterus is a genus of pterosaur that lived during the Late Cretaceous in what is now England and the United States. The first known specimen, consisting of the front part of a snout including part of a crest, was discovered in the Grey Chalk Subgroup of Kent, England, and described as the new species Pterodactylus cuvieri in 1851. The specific name cuvieri honours the palaeontologist George Cuvier, whereas the genus Pterodactylus was then used for many pterosaur species that are not thought to be closely related today. It was among the first pterosaurs to be depicted as sculptures, in Crystal Palace Park in the 1850s. The species was subsequently assigned to various other genera, including Ornithocheirus and Anhanguera. In 2013, the species was moved to a new genus, as Cimoliopterus cuvieri; the generic name Cimoliopterus is derived from the Greek words for "chalk" and "wing". Other specimens and species have also been assigned to or synonymised with the species with various levels of certainty. In 2015, a snout discovered in the Britton Formation of Texas, US, was named as a new species in the genus, C. dunni; the specific name honours its collector, Brent Dunn.
The Cliff House Sandstone is a late Campanian stratigraphic unit comprising sandstones in the western United States.
The Graneros Shale is a geologic formation in the United States identified in the Great Plains as well as New Mexico that dates to the Cenomanian Age of the Cretaceous Period. It is defined as the finely sandy argillaceous or clayey near-shore/marginal-marine shale that lies above the older, non-marine Dakota sand and mud, but below the younger, chalky open-marine shale of the Greenhorn. This definition was made in Colorado by G. K. Gilbert and has been adopted in other states that use Gilbert's division of the Benton's shales into Carlile, Greenhorn, and Graneros. These states include Kansas, Texas, Oklahoma, Nebraska, and New Mexico as well as corners of Minnesota and Iowa. North Dakota, South Dakota, Wyoming, and Montana have somewhat different usages — in particular, north and west of the Black Hills, the same rock and fossil layer is named Belle Fourche Shale.
Watinoceras is a genus of acanthoceratid ammonite that lived during the early Turonian stage of the Late Cretaceous.
This list 2019 in paleomalacology is a list of new taxa of ammonites and other fossil cephalopods, as well as fossil gastropods, bivalves and other molluscs that are scheduled to be described during the year 2019, as well as other significant discoveries and events related to molluscan paleontology that are scheduled to occur in the year 2019.
