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Squalicorax Pristodontus
''Squalicorax'', commonly known as the crow shark, is a genus of extinct lamniform shark known to have lived during the Cretaceous period. The genus had a global distribution in the Late Cretaceous epoch. Multiple species within this genus are considered to be wastebasket taxon due to morphological similarities in the teeth. Etymology The name ''Squalicorax'' is derived from the Latin ''squalus'' for shark and the Greek κόραξ, "''korax''" for raven. Description ''Squalicorax'' was a medium-sized shark, typically measuring about long. The largest specimen of ''S. pristodontus'', SDSM 47683, was significantly larger, measuring up to long. Their bodies were similar to the modern gray reef sharks, but the shape of the teeth is strikingly similar to that of a tiger shark. The teeth are numerous, relatively small, with a curved crown and serrated, up to 2.5 – 3 cm in height. Large numbers of fossil teeth have been found in Europe, North Africa, and North America. Squa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albian
The Albian is both an age (geology), age of the geologic timescale and a stage (stratigraphy), stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early Cretaceous, Early/Lower Cretaceous epoch (geology), Epoch/series (stratigraphy), Series. Its approximate time range is 113.0 ± 1.0 annum, Ma to 100.5 ± 0.9 Ma (million years ago). The Albian is preceded by the Aptian and followed by the Cenomanian. Stratigraphic definitions The Albian Stage was first proposed in 1842 by Alcide d'Orbigny. It was named after Alba, the Latin name for Aube (river), River Aube in France. A Global Boundary Stratotype Section and Point (GSSP), ratified by the IUGS in 2016, defines the base of the Albian as the first occurrence of the planktonic foraminiferan ''Hedbergellidae, Microhedbergella renilaevis'' at the Col de Pré-Guittard section, Arnayon, Drôme, France. The top of the Albian Stage (the base of the Cenomanian Stage and Upper Cretaceous Series) is defined ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tooth
A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tearing food, for defensive purposes, to intimidate other animals often including their own, or to carry prey or their young. The roots of teeth are covered by gums. Teeth are not made of bone, but rather of multiple tissues of varying density and hardness that originate from the outermost embryonic germ layer, the ectoderm. The general structure of teeth is similar across the vertebrates, although there is considerable variation in their form and position. The teeth of mammals have deep roots, and this pattern is also found in some fish, and in crocodilians. In most teleost fish, however, the teeth are attached to the outer surface of the bone, while in lizards they are attached to the inner surface of the jaw by one side. In cartila ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kansas Sea2DB
Kansas ( ) is a landlocked state in the Midwestern region of the United States. It borders Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the west. Kansas is named after the Kansas River, in turn named after the Kansa people. Its capital is Topeka, and its most populous city is Wichita; however, the largest urban area is the bi-state Kansas City metropolitan area split between Kansas and Missouri. For thousands of years, what is now Kansas was home to numerous and diverse Indigenous tribes. The first settlement of non-indigenous people in Kansas occurred in 1827 at Fort Leavenworth. The pace of settlement accelerated in the 1850s, in the midst of political wars over the slavery debate. When it was officially opened to settlement by the U.S. government in 1854 with the Kansas–Nebraska Act, conflict between abolitionist Free-Staters from New England and pro-slavery settlers from neighboring Missouri broke out over the question of whe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pteranodon
''Pteranodon'' (; from and ) is a genus of pterosaur that included some of the largest known flying reptiles, with ''P. longiceps'' having a wingspan of over . They lived during the late Cretaceous geological period of North America in present-day Kansas, Nebraska, Wyoming, South Dakota and Alabama. More fossil specimens of ''Pteranodon'' have been found than any other pterosaur, with about 1,200 specimens known to science, many of them well preserved with nearly complete skulls and articulated skeletons. It was an important part of the animal community in the Western Interior Seaway. When the first fossils of ''Pteranodon'' were found, they were assigned to toothed pterosaur genera, ''Ornithocheirus'' and ''Pterodactylus''. In 1876, Othniel Charles Marsh recognised it as a genus of its own, making particular note of its complete lack of teeth, which at the time was unique among pterosaurs. Over the decades, multiple species would be assigned to ''Pteranodon'', though today, o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyodectiformes
Ichthyodectiformes is an Extinction, extinct order of marine stem-teleost ray-finned fish. The order is named after the genus ''Ichthyodectes'', established by Edward Drinker Cope in 1870. Ichthyodectiforms are usually considered to be some of the closest relatives of the teleost crown group. They were most diverse throughout the Cretaceous period, though basal forms like ''Thrissops, Occithrissops'' and ''Allothrissops'' are known from the Middle-Late Jurassic of Europe and North America. They were almost entirely wiped out by the Cretaceous–Paleogene extinction event, Cretaceous-Paleogene extinction event, but a single species, ''Saurocephalus, Saurocephalus lanciformis'', appears to have survived into the earliest Paleocene (Danian). Most ichthyodectiforms ranged between in length. Most of known taxa were predators, feeding on smaller fish; in several cases, larger ichthyodectiforms preyed on smaller members of the order. Some species had remarkably large teeth, though othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mosasaur
Mosasaurs (from Latin ''Mosa'' meaning the 'Meuse', and Ancient Greek, Greek ' meaning 'lizard') are an extinct group of large aquatic reptiles within the family Mosasauridae that lived during the Late Cretaceous. Their first fossil remains were discovered in a limestone quarry at Maastricht on the Meuse in 1764. They belong to the order Squamata, which includes lizards and snakes. During the last 20 million years of the Cretaceous period (Turonian–Maastrichtian ages), with the extinction of the ichthyosaurs and Pliosauridae, pliosaurs, mosasaurids became the dominant marine predators. They themselves became extinct as a result of the Cretaceous–Paleogene extinction event, K-Pg event at the end of the Cretaceous period, about 66 million years ago. Description Mosasaurs breathed air, were powerful swimmers, and were well-adapted to living in the warm, shallow Inland sea (geology), inland seas prevalent during the Late Cretaceous period. Mosasaurs were so well adapted to thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turtle
Turtles are reptiles of the order (biology), order Testudines, characterized by a special turtle shell, shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked turtles), which differ in the way the head retracts. There are 360 living and recently extinct species of turtles, including land-dwelling tortoises and freshwater terrapins. They are found on most continents, some islands and, in the case of sea turtles, much of the ocean. Like other Amniote, amniotes (reptiles, birds, and mammals) they breathe air and do not lay eggs underwater, although many species live in or around water. Turtle shells are made mostly of bone; the upper part is the domed Turtle shell#Carapace, carapace, while the underside is the flatter plastron or belly-plate. Its outer surface is covered in scale (anatomy), scales made of keratin, the material of hair, horns, and claws. The carapace bones deve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinosaur
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutionary history, evolution of dinosaurs is a subject of active research. They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 mya and their dominance continued throughout the Jurassic and Cretaceous periods. The fossil record shows that birds are feathered dinosaurs, Evolution of birds, having evolved from earlier Theropoda, theropods during the Late Jurassic epoch, and are the only dinosaur lineage known to have survived the Cretaceous–Paleogene extinction event approximately 66 mya. Dinosaurs can therefore be divided into avian dinosaurs—birds—and the extinct non-avian dinosaurs, which are all dinosaurs other than birds. Dinosaurs are varied from taxonomy (biology), taxonomic, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hadrosaurid
Hadrosaurids (), also hadrosaurs or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod family, which includes genera such as ''Edmontosaurus'' and ''Parasaurolophus'', was a common group of herbivores during the Late Cretaceous Period (geology), Period. Hadrosaurids are descendants of the Late Jurassic/Early Cretaceous iguanodontian dinosaurs and had a similar body layout. Hadrosaurs were among the most dominant herbivores during the Late Cretaceous in Asia and North America, and during the close of the Cretaceous several lineages dispersed into Europe, Africa, and South America. Like other ornithischians, hadrosaurids had a Glossary of dinosaur anatomy#predentary, predentary bone and a pubic bone which was positioned backwards in the pelvis. Unlike more primitive iguanodonts, the teeth of hadrosaurids are stacked into complex s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metatarsal
The metatarsal bones or metatarsus (: metatarsi) are a group of five long bones in the midfoot, located between the tarsal bones (which form the heel and the ankle) and the phalanges ( toes). Lacking individual names, the metatarsal bones are numbered from the medial side (the side of the great toe): the first, second, third, fourth, and fifth metatarsal (often depicted with Roman numerals). The metatarsals are analogous to the metacarpal bones of the hand. The lengths of the metatarsal bones in humans are, in descending order, second, third, fourth, fifth, and first. A bovine hind leg has two metatarsals. Structure The five metatarsals are dorsal convex long bones consisting of a shaft or body, a base ( proximally), and a head ( distally).Platzer 2004, p. 220 The body is prismoid in form, tapers gradually from the tarsal to the phalangeal extremity, and is curved longitudinally, so as to be concave below, slightly convex above. The base or posterior extremity is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scavenger
Scavengers are animals that consume Corpse decomposition, dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feeding behavior. Scavengers play an important role in the ecosystem by consuming dead animal and plant material. Decomposer, ''Decomposers'' and detritivores complete this process, by consuming the remains left by scavengers. Scavengers aid in overcoming fluctuations of food resources in the environment. The process and rate of scavenging is affected by both Biotic component, biotic and Abiotic component, abiotic factors, such as carcass size, habitat, temperature, and seasons. Etymology Scavenger is an alteration of ''scavager,'' from Middle English ''skawager'' meaning "customs collector", from ''skawage'' meaning "customs", from Old North French ''escauwage'' meaning "inspection", from ''schauwer'' meaning "to inspect", of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Predator
Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation (which usually do not kill the Host (biology), host) and parasitoidism (which always does, eventually). It is distinct from Scavenger, scavenging on dead prey, though many predators also scavenge; it overlaps with Herbivore, herbivory, as Seed predation, seed predators and destructive frugivores are predators. Predation behavior varies significantly depending on the organism. Many predators, especially carnivores, have evolved distinct hunting strategy, hunting strategies. Pursuit predation involves the active search for and pursuit of prey, whilst ambush predation, ambush predators instead wait for prey to present an opportunity for capture, and often use stealth or aggressive mimicry. Other predators are opportunism, opportunistic or om ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
