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Paleobiota Of The Hell Creek Formation
This is an overview of the fossil flora and fauna of the Maastrichtian-Danian Hell Creek Formation. Invertebrates Insects Insects from the groups Diptera, Zygoptera, and possibly Hemiphlebiidae have been unearthed in Hell Creek in amber. Fossils found in the Hell Creek Formation and the Fort Union Formation of these insects went extinct during the K-T Event. Molluscs Amphibians Fish Bony fish Cartilaginous fish Dinosaurs A paleo-population study is one of the most difficult of analyses to conduct in field paleontology. Here is the most recent estimate of the proportions of the eight most common dinosaurian families in the Hell Creek Formation, based on detailed field studies by White, Fastovsky and Sheehan. * Ceratopsidae 61% * Hadrosauridae 23% * Ornithomimidae 5% * Tyrannosauridae 4% * Hypsilophodontidae 3% * Dromaeosauridae 2% * Pachycephalosauridae 1% * Troodontidae 1% (represented only by teeth) Outcrops sampled by the Hell Creek Project were divid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hell Creek Formation
The Hell Creek Formation is an intensively studied division of mostly Upper Cretaceous and some lower Paleocene rocks in North America, named for exposures studied along Hell Creek, near Jordan, Montana. The formation stretches over portions of Montana, North Dakota, South Dakota, and Wyoming. In Montana, the Hell Creek Formation overlies the Fox Hills Formation. The site of Pompeys Pillar National Monument is a small isolated section of the Hell Creek Formation. In 1966, the Hell Creek Fossil Area was designated as a National Natural Landmark by the National Park Service. It is a series of fresh and brackish-water clays, mudstones, and sandstones deposited during the Maastrichtian and Danian (respectively, the end of the Cretaceous period and the beginning of the Paleogene) by fluvial activity in fluctuating river channels and deltas and very occasional peaty swamp deposits along the low-lying eastern continental margin fronting the late Cretaceous Western Interior Seawa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadrula Cylindricoides
''Quadrula'' is a genus of freshwater mussels, aquatic bivalve mollusks in the family Unionidae native to rivers of the American Midwest and mid-south. All have thick nacreous shells with well-developed hinge teeth, many also with external shell sculpturing of nodules or lumps. Species within the genus ''Quadrula'' In 2012, many species classified as ''Quadrula'' were moved to ''Rotundaria'' and ''Theliderma'' based on genetic and morphological evidence. Species currently in ''Quadrula'' now consist of: * ''Quadrula apiculata'' (Southern mapleleaf) * ''Quadrula fragosa'' (Winged mapleleaf) * ''Quadrula nobilis'' (Gulf mapleleaf) * ''Quadrula quadrula'' (Mapleleaf) * ''Quadrula rumphiana'' (Ridged mapleleaf) * ''Quadrula verrucosa ''Quadrula'' is a genus of freshwater mussels, aquatic bivalve mollusks in the family Unionidae native to rivers of the American Midwest and mid-south. All have thick nacreous shells with well-developed hinge teeth, many also with external she . ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadrula
''Quadrula'' is a genus of freshwater mussels, aquatic bivalve mollusks in the family Unionidae native to rivers of the American Midwest and mid-south. All have thick nacreous shells with well-developed hinge teeth, many also with external shell sculpturing of nodules or lumps. Species within the genus ''Quadrula'' In 2012, many species classified as ''Quadrula'' were moved to '' Rotundaria'' and ''Theliderma ''Theliderma'' is a genus of freshwater mussels, aquatic bivalve mollusks in the family Unionidae. They are native to North America. This genus is sometimes classified in an expanded ''Quadrula''. Species within the genus ''Theliderma'' Note: ...'' based on genetic and morphological evidence. Species currently in ''Quadrula'' now consist of: * '' Quadrula apiculata'' (Southern mapleleaf) * '' Quadrula fragosa'' (Winged mapleleaf) * '' Quadrula nobilis'' (Gulf mapleleaf) * '' Quadrula quadrula'' (Mapleleaf) * '' Quadrula rumphiana'' (Ridged mapleleaf) * '' Quadrula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plethobasus Biesopoides
''Plethobasus'' is a genus of freshwater mussels, aquatic bivalve mollusks in the family Unionidae, the river mussels. Species Species within the genus ''Plethobasus'' include: * '' Plethobasus cicatricosus'' (white warty-back pearly mussel) * ''Plethobasus cooperianus ''Plethobasus cooperianus'', the orange-footed pimpleback mussel or orangefoot pimpleback, is a rare species of freshwater mussel in the family Unionidae, the river mussels. This aquatic bivalve mollusk is native to the Tennessee, Cumberlan ...'' (orange-footed pimpleback mussel) * '' Plethobasus cyphyus'' (sheepnose mussel) References Bivalve genera Taxonomy articles created by Polbot {{Unionidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plethobasus Aesopiformis
''Plethobasus'' is a genus of freshwater mussels, aquatic bivalve mollusks in the family Unionidae, the river mussels. Species Species within the genus ''Plethobasus'' include: * '' Plethobasus cicatricosus'' (white warty-back pearly mussel) * ''Plethobasus cooperianus ''Plethobasus cooperianus'', the orange-footed pimpleback mussel or orangefoot pimpleback, is a rare species of freshwater mussel in the family Unionidae, the river mussels. This aquatic bivalve mollusk is native to the Tennessee, Cumberlan ...'' (orange-footed pimpleback mussel) * '' Plethobasus cyphyus'' (sheepnose mussel) References Bivalve genera Taxonomy articles created by Polbot {{Unionidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plethobasus
''Plethobasus'' is a genus of freshwater mussels, aquatic bivalve mollusks in the family Unionidae, the river mussels. Species Species within the genus ''Plethobasus'' include: * '' Plethobasus cicatricosus'' (white warty-back pearly mussel) * ''Plethobasus cooperianus ''Plethobasus cooperianus'', the orange-footed pimpleback mussel or orangefoot pimpleback, is a rare species of freshwater mussel in the family Unionidae, the river mussels. This aquatic bivalve mollusk is native to the Tennessee, Cumberlan ...'' (orange-footed pimpleback mussel) * '' Plethobasus cyphyus'' (sheepnose mussel) References Bivalve genera Taxonomy articles created by Polbot {{Unionidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleurobema Cryptorhynchus
''Pleurobema'' is a genus of freshwater mussels, aquatic bivalve mollusks in the family Unionidae, the river mussels. Species Species within the genus ''Pleurobema'' include: * '' Pleurobema altum'' (Highnut) * '' Pleurobema avellanum'' (Hazel pigtoe) * '' Pleurobema beadleianum'' (Mississippi pigtoe) * '' Pleurobema bournianum'' (Scioto pigtoe) * '' Pleurobema chattanoogaense'' (Painted clubshell) * ''Pleurobema clava'' (Club naiad) * '' Pleurobema collina'' (James River spinymussel) * '' Pleurobema cordatum'' (Ohio pigtoe) * '' Pleurobema curtum'' (Black clubshell) * '' Pleurobema decisum'' (Southern clubshell) * ''Pleurobema flavidulum'' (Yellow pigtoe) * '' Pleurobema furvum'' (Dark pigtoe) * '' Pleurobema georgianum'' (Southern pigtoe) * '' Pleurobema gibberum'' (Cumberland pigtoe) * '' Pleurobema hagleri'' (Brown pigtoe) * '' Pleurobema hanleyianum'' (Georgia pigtoe) * '' Pleurobema hartmanianum'' (Cherokee pigtoe) * ''Pleurobema johannis'' (Alabama pigtoe) * '' Pleurobema ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleurobema
''Pleurobema'' is a genus of freshwater mussels, aquatic bivalve mollusks in the family Unionidae, the river mussels. Species Species within the genus ''Pleurobema'' include: * '' Pleurobema altum'' (Highnut) * '' Pleurobema avellanum'' (Hazel pigtoe) * '' Pleurobema beadleianum'' (Mississippi pigtoe) * '' Pleurobema bournianum'' (Scioto pigtoe) * '' Pleurobema chattanoogaense'' (Painted clubshell) * ''Pleurobema clava'' (Club naiad) * '' Pleurobema collina'' (James River spinymussel) * '' Pleurobema cordatum'' (Ohio pigtoe) * '' Pleurobema curtum'' (Black clubshell) * '' Pleurobema decisum'' (Southern clubshell) * ''Pleurobema flavidulum'' (Yellow pigtoe) * '' Pleurobema furvum'' (Dark pigtoe) * '' Pleurobema georgianum'' (Southern pigtoe) * '' Pleurobema gibberum'' (Cumberland pigtoe) * '' Pleurobema hagleri'' (Brown pigtoe) * '' Pleurobema hanleyianum'' (Georgia pigtoe) * '' Pleurobema hartmanianum'' (Cherokee pigtoe) * ''Pleurobema johannis'' (Alabama pigtoe) * '' Pleurobema ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freshwater Bivalve
Freshwater bivalves are one kind of freshwater mollusc, along with freshwater snails. They are bivalves that live in fresh water as opposed to salt water, which is the main habitat type for bivalves. The majority of species of bivalve molluscs live in the sea, but in addition, a number of different families live in fresh water (and in some cases, also in brackish water). These families belong to two different evolutionary lineages (freshwater mussels and freshwater clams), and the two groups are not closely related. Freshwater bivalves have a simple morphology that varies among taxa, and are distributed around most regions of the world. Species in the two groups vary greatly in size. Some pea clams ('' Pisidium'' species) have an adult size of only 3 mm. In contrast, one of the largest species of freshwater bivalves is the swan mussel, in the family Unionidae; it can grow to a length of 20 cm, and usually lives in lakes or slow rivers. Freshwater pearl mussels are eco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
