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Guildayichthyiformes
Guildayichthyidae is a prehistoric family of marine fish from the Mississippian Bear Gulch Limestone of Montana. It is the only family in the order Guildayichthyiformes. Guildayichthyids possess an uncommon mixture of primitive and modern characteristics in their skull bones. Taxonomy This family consists of the following genera and species: * Genus '' Guildayichthys'' Lund, 2000 ** Species '' Guildayichthys carnegiei'' Lund, 2000 * Genus ''Discoserra'' Lund, 2000 ** Species ''Discoserra pectinodon ''Discoserra'' is a prehistoric Actinopterygii, ray-finned fish from the Mississippian (geology), Mississippian of Montana, a member of the Guildayichthyiformes, with a round body and a skull possessing primitive and modern traits. ''Discoserra' ...'' Lund, 2000 References Prehistoric fish of North America Prehistoric ray-finned fish families {{Paleo-rayfinned-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discoserra
''Discoserra'' is a prehistoric Actinopterygii, ray-finned fish from the Mississippian (geology), Mississippian of Montana, a member of the Guildayichthyiformes, with a round body and a skull possessing primitive and modern traits. ''Discoserra'' is about 60 mm long. In 2006, ''Discoserra'' was hypothesized to be a Crown group#Stem groups, stem Neopterygii, neopterygian, although it has alternatively been placed in Cladistia along with other Guildayichthyiformes. References [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discoserra Pectinodon
''Discoserra'' is a prehistoric ray-finned fish from the Mississippian of Montana, a member of the Guildayichthyiformes, with a round body and a skull possessing primitive and modern traits. ''Discoserra'' is about 60 mm long. In 2006, ''Discoserra'' was hypothesized to be a stem neopterygian, although it has alternatively been placed in Cladistia Cladistia is a clade of bony fishes whose only living members are the bichirs. Their major synapomorphies are a heterocercal tail in which the dorsal fin has independent rays, and a posteriorly elongated parasphenoid. Cladistia are the earlie ... along with other Guildayichthyiformes. References Mississippian fish of North America Guildayichthyiformes {{paleo-rayfinned-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guildayichthyiformes
Guildayichthyidae is a prehistoric family of marine fish from the Mississippian Bear Gulch Limestone of Montana. It is the only family in the order Guildayichthyiformes. Guildayichthyids possess an uncommon mixture of primitive and modern characteristics in their skull bones. Taxonomy This family consists of the following genera and species: * Genus '' Guildayichthys'' Lund, 2000 ** Species '' Guildayichthys carnegiei'' Lund, 2000 * Genus ''Discoserra'' Lund, 2000 ** Species ''Discoserra pectinodon ''Discoserra'' is a prehistoric Actinopterygii, ray-finned fish from the Mississippian (geology), Mississippian of Montana, a member of the Guildayichthyiformes, with a round body and a skull possessing primitive and modern traits. ''Discoserra' ...'' Lund, 2000 References Prehistoric fish of North America Prehistoric ray-finned fish families {{Paleo-rayfinned-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bear Gulch Limestone
The Bear Gulch Limestone is a limestone-rich geological lens in central Montana, renowned for the quality of its late Mississippian-aged fossils. It is exposed over a number of outcrops northeast of the Big Snowy Mountains, and is often considered a component of the more widespread Heath Formation. The Bear Gulch Limestone reconstructs a diverse, though isolated, marine ecosystem which developed near the end of the Serpukhovian age. It is a lagerstätte, a particular type of rock unit with exceptional fossil preservation of both articulated skeletons and soft tissues. Bear Gulch fossils include a variety of fish, invertebrates, and algae occupying a number of different habitats within a preserved shallow bay. Fish include a high diversity of unusual Chondrichthyes, chondrichthyans (cartilaginous fish) and one of the oldest known lampreys, along with other vertebrates. Invertebrates include numerous fossils of crustaceans, worms, cephalopods, and Sponge, sea sponges, which are con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mississippian (geology)
The Mississippian ( , also known as Lower Carboniferous or Early Carboniferous) is a subperiod in the geologic timescale or a subsystem of the geologic record. It is the earlier of two subperiods of the Carboniferous period lasting from roughly 358.9 to 323.2 million years ago. As with most other geochronologic units, the rock beds that define the Mississippian are well identified, but the exact start and end dates are uncertain by a few million years. The Mississippian is so named because rocks with this age are exposed in the Mississippi Valley. The Mississippian was a period of marine transgression in the Northern Hemisphere: the sea level was so high that only the Fennoscandian Shield and the Laurentian Shield were dry land. The cratons were surrounded by extensive delta systems and lagoons, and carbonate sedimentation on the surrounding continental platforms, covered by shallow seas. In North America, where the interval consists primarily of marine limestones, it is treate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Montana
Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbia, and Saskatchewan to the north. It is the fourth-largest state by area, the eighth-least populous state, and the third-least densely populated state. Its state capital is Helena. The western half of Montana contains numerous mountain ranges, while the eastern half is characterized by western prairie terrain and badlands, with smaller mountain ranges found throughout the state. Montana has no official nickname but several unofficial ones, most notably "Big Sky Country", "The Treasure State", "Land of the Shining Mountains", and " The Last Best Place". The economy is primarily based on agriculture, including ranching and cereal grain farming. Other significant economic resources include oil, gas, coal, mining, and lumber. The health ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Fish Of North America
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iron Age. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
