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Ferris Formation
The Ferris Formation is a Late Cretaceous (~66 Ma) to Paleocene (66-63 Ma), fluvial-deltaic geological formation in southern Wyoming. It contains a variety of trace and body fossils, preserved in sandy fluvial channel deposits and overbank units. Dinosaur remains are fragmentary, but include ''Triceratops'', ''Tyrannosaurus'', dromaeosaurids, ''Paronychodon'', '' Ricardoestesia'', ''Edmontosaurus'', ''Edmontonia'', ''Ankylosaurus'', and ''Pachycephalosaurus''.Wroblewski, 1995 Some of the fluvial channels contain evidence of tidal influence and brackish water, in the form of tidal facies, shark teeth, and shrimp burrows. This demonstrates that the western shoreline of the Western Interior Sea was still within a few hundred kilometers even during the latest Cretaceous. The local K-T boundary is contained within a sandy channel deposit made up of stacked bars. Reworked Cretaceous fossils are preserved at the base of the channel complex, associated with mud rip-up clasts, and Paleoc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by Abraham Gottlob Wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edmontonia
''Edmontonia'' is a genus of panoplosaurin nodosaurid dinosaur from the Late Cretaceous Period. It is part of the Nodosauridae, a family within Ankylosauria. It is named after the Edmonton Formation (now the Horseshoe Canyon Formation in Canada), the unit of rock where it was found. Description Size and general build ''Edmontonia'' was bulky, broad and tank-like. Its length has been estimated at about 6.6 m (22 ft). In 2010, Gregory S. Paul considered both main ''Edmontonia'' species, ''E. longiceps'' and ''E. rugosidens'', to be equally long at six metres and weigh three tonnes.Paul, G.S., 2010, ''The Princeton Field Guide to Dinosaurs'', Princeton University Press p. 238 ''Edmontonia'' had small, oval ridged bony plates on its back and head and many sharp spikes along its sides. The four largest spikes jutted out from the shoulders on each side, the second of which was split into subspines in ''E. rugosidens'' specimens. Its skull had a pear-like shape when viewed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basilemys
''Basilemys'' () is a large, terrestrial trionychoid turtle from the Upper Cretaceous. In Greek, the word "Basil" means royal or kingly and the word "Emys" means turtle. Therefore, ''Basilemys'' means King Turtle. ''Basilemys'' has been found in rocks dating to the Campanian and Maastrichtian subdivisions of the Late Cretaceous and is considered to be the largest terrestrial turtle of its time. ''Basilemys'' has solely been found in North America. The family Nanhsiungchelyidae, which is the family ''Basilemys'' belongs to, made its first appearance in the Lower Cretaceous, in what we now call Asia. Because of ''Basilemys,'' we know that this family appeared in North America in the Upper Cretaceous. It is possible that ''Basilemys'' and other nanhsiungchelyids are immigrants from Asia. They might have arrived in North America by passing through what we now call the Bering Strait somewhere during the Cretaceous. In an analysis made by Sukhanov et al. on a new Nansiunghelyid turtle fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lepisosteus
''Lepisosteus'' is a genus of gars in the family Lepisosteidae. Distribution While in the present day, ''Lepisosteus'' is only known across North America, fossil remains show it was much more widespread in the past, with specimens known from the Cretaceous of India and Brazil. Systematics Species The currently recognized species are: Extant species Fossil species * †''Lepisosteus aganus'' (Cope, 1877) * †''Lepisosteus bemisi'' Grande, 2010 * †''Lepisosteus bohemicus'' (Laube, 1901) * †''Lepisosteus cominatoi'' Santos, 1984 * †''Lepisosteus cycliferus'' (Cope, 1873) * †''Lepisosteus glaber'' Marsh, 1871 * †'' Lepisosteus indicus'' Woodward, 1908 * †'' Lepisosteus integer'' (Cope, 1877) * †'' Lepisosteus fimbriatus'' Wood, 1846 * †'' Lepisosteus knieskerni'' Fowler, 1911 * †'' Lepisosteus longus'' Lambe, 1908 * †'' Lepisosteus nahunticus'' (Cope, 1869) * †'' Lepisosteus notabilis'' Leidy, 1873 * †'' Lepisosteus occidentalis''Pearson ''et al.'', 20 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amia (genus)
''Amia'', commonly called bowfin, is a genus of bony fish related to gars in the infraclass Holostei. They are regarded as taxonomic relicts, being the sole surviving species of the order Amiiformes, which dates from the Jurassic to the Eocene, persisting to the present. There is one living species in ''Amia'', ''Amia calva'', and a number of extinct species which have been described from the fossil record. Evolution and phylogeny Competing hypotheses and debates continue over the evolution of ''Amia'' and relatives, including their relationship among basal extant teleosts, and organization of clades. Bowfin are the last remaining member of Halecomorphi, a group that includes many extinct species in several families. Halecomorphs were generally accepted as the sister group to Teleostei but not without question. While a halecostome pattern of neopterygian clades was produced in morphology-based analyses of extant actinopterygians, a different result was produced with fossil taxa w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretorectolobus
''Cretorectolobus'' is an extinct carpet shark. It was described by G.R. Case in 1978, and the type species is ''C. olsoni'', which existed during the Campanian in Canada and the United States. Another species, ''C. gracilis'', was described by Charlie J. Underwood and Mitchell in 1999, from the Hauterivian to Barremian strata of the Speeton Clay Formation of England. The Specific name (zoology), species epithet refers to the shark's teeth, which Underwood and Mitchell described as gracile and narrow in form.C.J. Underwood & Mitchell, 1999. ''Albian and Cenomanian selachian assemblages from north-east England.'' Special Papers in Palaeontology, 60, January 1999: 9-56. A new species, ''C. robustus'', was described from the Cenomanian of Canada by Underwood and Stephen L. Cumbaa in 2010.Charlie J. Underwood and Stephen L. Cumbaa (2010). "Chondrichthyans from a Cenomanian (Late Cretaceous) bonebed, Saskatchewan, Canada". Palaeontology 53 (4): 903–944. . Species * ''C. olsoni'' Cas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lissodus
''Lissodus'' is an extinct genus of freshwater shark. It lived from the Early Carboniferous stage to the Albian age of the Cretaceous. It was about long and had flat teeth that it used for eating clams Clam is a common name for several kinds of bivalve molluscs. The word is often applied only to those that are edible and live as infauna, spending most of their lives halfway buried in the sand of the seafloor or riverbeds. Clams have two .... References Prehistoric shark genera Mesozoic fish of Asia Jurassic sharks Mesozoic fish of Europe Hasle Formation {{Triassic-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myledaphus
''Myledaphus'' is a genus of Late Cretaceous cartilaginous fish whose fossils are known from Canada, the Midwest of the United States, Olmos Formation of the Difunta Group of Mexico, and the Beshtyubin and Bissekty Formations of Uzbekistan. It was a freshwater guitarfish that probably reached a length of , and had teeth adapted for a durophagous diet of animals such as clams. Most taxonomic authories place the genus in the Rhinobatidae. Two species are known: ''Myledaphus bipartitus'', the type species, and ''Myledaphus araucanus'', named in 2019. Fossils and age The most common remains of this fish are teeth and vertebra. A study performed on ''Myledaphus'' vertebra from Alberta in 2013 revealed that ''Myledaphus'' had an estimated maximum age of 16 years. This means that ''Myledaphus'' had a shorter lifespan than that of the modern common guitarfish, by a difference of 8 years. See also * List of prehistoric cartilaginous fish This list of prehistoric cartilaginous ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fox Hills Formation
The Fox Hills Formation is a Cretaceous geologic Formation (geology), formation in the northwestern Great Plains of North America. It is present from Alberta on the north to Colorado in the south. Fossil remains of dinosaurs, including tyrannosaurs, as well as large marine reptiles, such as mosasaurs, have been recovered from the formation. Lithology The Fox Hills Formation consists of marginal marine yellow to grey sandstone with shale interbeds. It was deposited as a regressive sequence of barrier islands during the retreat of the Western Interior Seaway in Late Cretaceous time. In its eastern extents, the formation is underlain by the marine Pierre Shale in the United States and by the equivalent Bearpaw Formation in Canada, while in western ranges in Montana and Wyoming it overlies the Lewis Shale. The Fox Hills is overlain by continental sediments of the Laramie Formation in Colorado and the Lance Formation in Wyoming, the later being the equivalent of the overlying Hell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lewis Shale
The Lewis Shale is a geologic formation in the Western United States. It preserves fossils dating back to the Campanian to Maastrichtian stages of the late Cretaceous period. Description The Lewis Shale is an olive-gray marine shale with some thin beds of claystone, siltstone, sandstone, and limestone. It was deposited in the Western Interior Seaway in the late Cretaceous. The formation crops out in the Bighorn Basin, Green River Basin, Powder River Basin, San Juan Basin, and Wind River Basin. In the San Juan Basin, the formation has a maximum thickness of over in the northern part of the basin, but pinches out in the southern part of the basin. It is the stratigraphically highest marine shale in the basin, and is a sandy siltstone rather than a true shale. The upper part of the formation contains the Huerfanito Bentonite Bed, long recognized in the subsurface but recently discovered to crop out near Regina, New Mexico. The bed lies in the upper ''Baculites scottii'' biostrati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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