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Squatinidae
Squatiniformes is an order of sharks belonging to Squalomorphi. It contains only a single living genus ''Squatina'', commonly known as angelsharks. The oldest genus of the order, ''Pseudorhina'' is known from the Late Jurassic of Europe. Three other genera, ''Cretasquatina'', ''Cretascyllium'' and ''Parasquatina'' are known from Cretaceous fossils from North America and Europe, though the placement of ''Parasquatina'' in the order has been questioned. All living and extinct members of the order share a similar body morphology with a highly flattened body with enlarged pectoral and pelvic fins suggestive of a bottom-dwelling ambush predator ecology. Teeth have been assigned to the modern genus from the Late Jurassic onwards, but the actual genus assignment of many of these species is unclear. The earliest records that can be assigned with confidence to the modern genus are known from the Early Cretaceous (Aptian) of England. References {{Taxonbar, from=Q15207720 Cartilaginou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squatina Dumeril
The sand devil or Atlantic angel shark (''Squatina dumeril'') is a species of angelshark, family (biology), family Squatinidae, native to the northwestern Atlantic Ocean. It occurs off the eastern United States, in the northern Gulf of Mexico, and possibly in parts of the Caribbean Sea. This benthic fish, bottom-dwelling shark is found in shallow inshore waters in summer and fall, and deep offshore waters in winter and spring. The sand devil's flattened body and enlarged pectoral fin, pectoral and pelvic fins give it a Batoidea, ray-like appearance. There is a band of enlarged thorns running along the middle of its back. It is gray or brown in color, with scattered small dark spots. This species reaches in length. The diet of the sand devil consists mainly of small teleost fishes and squid, which are captured via ambush predator, ambush attack. This species is viviparous, with the unborn young nourished by their yolk sacs. Females have a multi-year reproductive cycle and give bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squatiniformes
Squatiniformes is an order of sharks belonging to Squalomorphi. It contains only a single living genus '' Squatina'', commonly known as angelsharks. The oldest genus of the order, '' Pseudorhina'' is known from the Late Jurassic of Europe. Three other genera, '' Cretasquatina'', '' Cretascyllium'' and '' Parasquatina'' are known from Cretaceous fossils from North America and Europe, though the placement of ''Parasquatina'' in the order has been questioned. All living and extinct members of the order share a similar body morphology with a highly flattened body with enlarged pectoral and pelvic fins suggestive of a bottom-dwelling ambush predator ecology. Teeth have been assigned to the modern genus from the Late Jurassic onwards, but the actual genus assignment of many of these species is unclear. The earliest records that can be assigned with confidence to the modern genus are known from the Early Cretaceous (Aptian The Aptian is an age (geology), age in the geologic timescale ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudorhina
''Pseudorhina'' is an extinct genus of squatiniform shark closely related to modern angelsharks. Fossils are known from the Late Jurassic and Early Cretaceous of Europe. Taxonomy and relationships ''Pseudorhina'' is currently the oldest known angel shark genus. It is thought to represent the earliest diverging group in the Squatiniformes and has been placed in a monotypic family called Pseudorhinidae. While most fossil genera and species of angel shark are represented solely by isolated teeth, ''Pseudorhina'' is relatively well known from articulated individuals. This allows for detailed comparisons with other genera known from articulated remains including the extant ''Squatina''. Description Like all other members of Squatiniformes, ''Pseudorhina'' has a flattened body with large pectoral and pelvic fins. ''Pseudorhina'' differs from living ''Squatina'' in numerous morphological characters, including "antero-posterior length of the first basiventral is equal to that of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squalomorphi
Squalomorphi is a superorder of sharks, generally characterized by lacking traits such as an anal fin, nictitating membrane, or suborbital shelves in the cranium. Squalomorphs are also called squalea, or squaleans. There are about 163 living species in 11 families. Squalean sharks are divided into six orders: Echinorhiniformes, Hexanchiformes, Squaliformes, Squatiniformes, Pristiophoriformes and the extinct Protospinaciformes. Extant orders Order Hexanchiformes The order Hexanchiformes is a very small and primitive order consisting of cow sharks and frilled sharks. These sharks have only 1 dorsal fin, 6-7 gill slits, and no nictitating membrane on the eyes. Cow sharks are fairly large and stocky, while frilled sharks are smaller and have eel-like bodies. The oldest fossils from this order can be dated back to the mid-Jurassic. There are six living species in 4 genera, and 2 families. * Family Hexanchidae (Cow sharks) * Family Chlamydoselachidae (Frilled sharks) Order Sq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Jurassic
The Late Jurassic is the third Epoch (geology), epoch of the Jurassic Period, and it spans the geologic time scale, geologic time from 161.5 ± 1.0 to 143.1 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic stratum, strata.Owen 1987. In European lithostratigraphy, the name "Malm" indicates rocks of Late Jurassic age. In the past, ''Malm'' was also used to indicate the unit of geological time, but this usage is now discouraged to make a clear distinction between lithostratigraphic and geochronologic/chronostratigraphic units. Subdivisions The Late Jurassic is divided into three ages, which correspond with the three (faunal) stages of Upper Jurassic rock: Paleogeography During the Late Jurassic Epoch, Pangaea broke up into two supercontinents, Laurasia to the north, and Gondwana to the south. The result of this break-up was the emergence of the Atlantic Ocean, which initially was relatively narrow. Life forms This epoch is well known for many famous types of d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ninth and longest geological period of the entire Phanerozoic. The name is derived from the Latin , 'chalk', which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation . The Cretaceous was a period with a relatively warm climate, resulting in high Sea level#Local and eustatic, eustatic sea levels that created numerous shallow Inland sea (geology), inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was largely ice-free, although there is some evidence of brief periods of glaciation during the cooler first half, and forests extended to the poles. Many of the dominant taxonomic gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bottom-dwelling
The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". Organisms living in this zone are called benthos and include microorganisms (e.g., bacteria and fungi) as well as larger invertebrates, such as crustaceans and polychaetes. Organisms here, known as bottom dwellers, generally live in close relationship with the substrate and many are permanently attached to the bottom. The benthic boundary layer, which includes the bottom layer of water and the uppermost layer of sediment directly influenced by the overlying water, is an integral part of the benthic zone, as it greatly influences the biological activity that takes place there. Examples of contact soil layers include sand bottoms, rocky outcrops, coral, and bay mud. Description Oceans The benthic region of the ocean begins at the shore ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ambush Predator
Ambush predators or sit-and-wait predators are carnivorous animals that capture their prey via stealth, luring or by (typically instinctive) strategies utilizing an element of surprise. Unlike pursuit predators, who chase to capture prey using sheer speed or endurance, ambush predators avoid fatigue by staying in concealment, waiting patiently for the prey to get near, before launching a sudden overwhelming attack that quickly incapacitates and captures the prey. The ambush is often opportunistic, and may be set by hiding in a burrow, by camouflage, by aggressive mimicry, or by the use of a trap (e.g. a web). The predator then uses a combination of senses to detect and assess the prey, and to time the strike. Nocturnal ambush predators such as cats and snakes have vertical slit pupils helping them to judge the distance to prey in dim light. Different ambush predators use a variety of means to capture their prey, from the long sticky tongues of chameleons to the expand ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
