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Panamintaspis
''Panamintaspis snowi'' is an extinct species of pteraspidid heterostracan agnathan which existed during the early Middle Devonian period of Death Valley, California.Elliott, David K., and Robert R. Ilyes. "New Early Devonian pteraspidids (Agnatha, Heterostraci) from Death Valley National Monument, southeastern California." Journal of Paleontology (1996): 152-161. Fossils are found in Late Emsian-aged marine strata of the Lost Burro Formation. ''P. snowi'' strongly resembles ''Pteraspis'', though while it was originally described as a member of the same family, Pteraspididae, a recent phylogenetic reassessment of the order Pteraspidiformes places ''P. snowi'' within the paraphyletic family "Protopeteraspidae," as the sister taxon of the suborder Pteraspidoidei (the super-taxon that contains Pteraspididae together with Protaspididae and '' Gigantaspis'').Pernegre, Vincent N., and David K. Elliott. "Phylogeny of the Pteraspidiformes (Heterostraci), Silurian–Devonian jawless v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterostraci
Heterostraci (Ancient Greek, ἕτερος+ὄστρακον "those itha different shell" i is pl. of -us is an extinct subclass of pteraspidomorph jawless vertebrate that lived primarily in marine and estuary environments. Heterostraci existed from the mid-Ordovician to the conclusion of the Devonian. Description and anatomy The Heterostracans differed from other Paleozoic agnathan taxa both in the arrangement and histology of their scales. Most heterostracans had two plates which form a large dorsal shield and a large ventral shield, and had series of scales arranged in various patterns on the sides of their bodies, the exact pattern differing from one group to another. In a few primitive forms, such as '' Lepidaspis'', the dorsal and ventral shields are composed of a mosaic of tiny scales. In most other known forms, though, these tiny scales have fused together to form the shield-plates. The scales of heterostracans are histologically distinct from other vertebrate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pteraspidiformes
Pteraspidiformes is an extinct order of heterostracan agnathan vertebrates known from extensive fossil remains primarily from Early Devonian strata of Europe and North America, and from Upper Silurian Canada. Anatomy A pteraspidiform heterostracan has the cephalothorax enclosed in armor, formed from several plates, including dorsal, ventral, rostral, pineal plates, a dorsal spine derived from a scale, and a large, scale-covered tail. Many genera were benthic, others were apparently active swimming nekton.Botella, Hector, and Richard A. Farina. "Flow pattern around the rigid cephalic shield of the Devonian agnathan Errivaspis waynensis (Pteraspidiformes: Heterostraci)." Palaeontology 51.5 (2008): 1141-1150/ref> Delicate, finger-like components of the anterior end of the ventral plate forming the edges of the mouth suggest that pteraspidiform heterostracans were filter-feeding, filter-feeders that selectively filtered specific sized plankton from the water column.Purnell, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pteraspidiformes
Pteraspidiformes is an extinct order of heterostracan agnathan vertebrates known from extensive fossil remains primarily from Early Devonian strata of Europe and North America, and from Upper Silurian Canada. Anatomy A pteraspidiform heterostracan has the cephalothorax enclosed in armor, formed from several plates, including dorsal, ventral, rostral, pineal plates, a dorsal spine derived from a scale, and a large, scale-covered tail. Many genera were benthic, others were apparently active swimming nekton.Botella, Hector, and Richard A. Farina. "Flow pattern around the rigid cephalic shield of the Devonian agnathan Errivaspis waynensis (Pteraspidiformes: Heterostraci)." Palaeontology 51.5 (2008): 1141-1150/ref> Delicate, finger-like components of the anterior end of the ventral plate forming the edges of the mouth suggest that pteraspidiform heterostracans were filter-feeding, filter-feeders that selectively filtered specific sized plankton from the water column.Purnell, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterostraci
Heterostraci (Ancient Greek, ἕτερος+ὄστρακον "those itha different shell" i is pl. of -us is an extinct subclass of pteraspidomorph jawless vertebrate that lived primarily in marine and estuary environments. Heterostraci existed from the mid-Ordovician to the conclusion of the Devonian. Description and anatomy The Heterostracans differed from other Paleozoic agnathan taxa both in the arrangement and histology of their scales. Most heterostracans had two plates which form a large dorsal shield and a large ventral shield, and had series of scales arranged in various patterns on the sides of their bodies, the exact pattern differing from one group to another. In a few primitive forms, such as '' Lepidaspis'', the dorsal and ventral shields are composed of a mosaic of tiny scales. In most other known forms, though, these tiny scales have fused together to form the shield-plates. The scales of heterostracans are histologically distinct from other vertebrate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pteraspidiformes Genera
Pteraspidiformes is an extinct order of heterostracan agnathan vertebrates known from extensive fossil remains primarily from Early Devonian strata of Europe and North America, and from Upper Silurian Canada. Anatomy A pteraspidiform heterostracan has the cephalothorax enclosed in armor, formed from several plates, including dorsal, ventral, rostral, pineal plates, a dorsal spine derived from a scale, and a large, scale-covered tail. Many genera were benthic, others were apparently active swimming nekton.Botella, Hector, and Richard A. Farina. "Flow pattern around the rigid cephalic shield of the Devonian agnathan Errivaspis waynensis (Pteraspidiformes: Heterostraci)." Palaeontology 51.5 (2008): 1141-1150/ref> Delicate, finger-like components of the anterior end of the ventral plate forming the edges of the mouth suggest that pteraspidiform heterostracans were filter-feeding, filter-feeders that selectively filtered specific sized plankton from the water column.Purnell, Mark ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pteraspidoidei
Pteraspidoidei is an extinct suborder of heterostracan vertebrates. It contains the more derived taxa within Pteraspidiformes, such as ''Pteraspis'' and '' Errivaspis'', though, some protopteraspidids, such as '' Doryaspis'' and ''Panamintaspis ''Panamintaspis snowi'' is an extinct species of pteraspidid heterostracan agnathan which existed during the early Middle Devonian period of Death Valley, California.Elliott, David K., and Robert R. Ilyes. "New Early Devonian pteraspidids (Agnat ...'', share various features with these derived pteraspidids. References * Pernègre V., 2006. - Un nouveau pteraspidiforme (Vertebrata, Heterostraci) du Dévonien inférieur du Spitsberg: nouvelles données paléo-ontogéniques. Geodiversitas, fasc. 2, t. 28 Pteraspidiformes Fish suborders Devonian jawless fish Silurian jawless fish Prehistoric animal suborders Silurian first appearances Devonian extinctions {{Pteraspidomorphi-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Emsian
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began dominating al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pteraspididae
Pteraspididae is an extinct family of heterostracan vertebrates. It is an Early Devonian-aged family that contains the stereotypical, torpedo-shaped pteraspidids, such as the type genus, ''Pteraspis'', and its close relatives ''Errivaspis'' and '' Rhinopteraspis'', that are popularly thought to have actively swam about in the water column. The elongated rostral plate is thought to help with their hydrodynamic ability. Various genera are found in various marine and estuarine strata of Early Devonian Europe and North America. Genera * †'' Althaspis'' * †''Blieckaspis'' * †'' Brachipteraspis'' * †''Errivaspis'' * †'' Escharaspis'' * †'' Grumantaspis'' * †'' Helaspis'' * †'' Larnovaspis'' * †'' Loricopteraspis'' * †'' Miltaspis'' * †'' Mitraspis'' * †'' Mylopteraspidella'' * †'' Mylopteraspis'' * †'' Podolaspis'' * †''Pteraspis ''Pteraspis'' (from el, πτερόν 'wing' or 'fin' and el, ἀσπίς 'shield') is an extinct genus of pteraspidid h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Death Valley National Park
Death Valley National Park is an American national park that straddles the California–Nevada border, east of the Sierra Nevada. The park boundaries include Death Valley, the northern section of Panamint Valley, the southern section of Eureka Valley and most of Saline Valley. The park occupies an interface zone between the arid Great Basin and Mojave deserts, protecting the northwest corner of the Mojave Desert and its diverse environment of salt-flats, sand dunes, badlands, valleys, canyons and mountains. Death Valley is the largest national park in the contiguous United States, as well as the hottest, driest and lowest of all the national parks in the United States. It contains Badwater Basin, the second-lowest point in the Western Hemisphere and lowest in North America at below sea level. More than 93% of the park is a designated wilderness area. The park is home to many species of plants and animals that have adapted to this harsh desert environment including creosote bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devonian California
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began dominating al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devonian Jawless Fish
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began dominating al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Panamint Range
The Panamint Range is a short rugged fault-block mountain range in the northern Mojave Desert, within Death Valley National Park in Inyo County, eastern California. Dr. Darwin French is credited as applying the term Panamint in 1860 during his search for the fabled Gunsight Lode. The orographic identity has been liberally applied for decades to include other ranges. The origin of the name is the Paiute or Koso word Panümünt or Pa (water) and nïwïnsti (person). Geography The range runs north–south for approximately through Inyo County, forming the western wall of Death Valley and separating it from the Panamint Valley to the west. The range is part of the Basin and Range Province, at the western end of the Great Basin. The highest peak in the range is Telescope Peak, with an elevation of . Features Both Mount Whitney above the Owens Valley and Badwater Basin in Death Valley are visible from certain vantage points in the Panamint Range, making it one of few places wher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
