Anchisaurus (ANG-kee-sawr-us) meaning "near lizard", because it resembled its reptilian ancestors and was an early dinosaur (Greek anchi = near + sauros = lizard) is a genus of dinosaurs. In biology, a genus (plural genera) is a grouping in the classification of living organisms having one or more related and morphologically similar species. ... Orders Saurischia Sauropodomorpha Theropoda Ornithischia Dinosaurs are vertebrates (that range from crocodile-like to birds) that dominated the terrestrial ecosystem for over 160 million years from around 230 million years ago until 65 million years ago, at the end of the Cretaceous period, when all non-avian dinosaurs became extinct...

Discovery

The first discovery of Anchisaurus remains was made before anything was known about the dinosaurs, and it was probably the first dinosaur discovery in North America. When, in 1818, some large bones were discovered in Connecticut, USA, it was assumed that they were of human origin. Gradually, as a result of further finds in Massachusetts, the number of these bones began to accumulate and by 1855 they were at least recognised as reptilian. Hitchcock collected these bones under the name "Megadactylus" in 1865. The great paleontologist Othniel Charles Marsh named Anchisaurus in 1885, and Megadactylus became part of the genus Anchisaurus. More bones belonging to the genus were found in South Africa, suggesting that those two land masses were at the time joined in one super-continent (Pangaea). A recovery from Nova Scotia may also be Anchisaurus but this is unconfirmed. Orders Saurischia Sauropodomorpha Theropoda Ornithischia Dinosaurs are vertebrates (that range from crocodile-like to birds) that dominated the terrestrial ecosystem for over 160 million years from around 230 million years ago until 65 million years ago, at the end of the Cretaceous period, when all non-avian dinosaurs became extinct... World map showing North America A satellite composite image of North America North America is a continent in the northern hemisphere bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the south by the Caribbean Sea, and on the west by the... 1818 is a common year starting on Thursday. ... State nickname: The Constitution State Official languages English Capital Hartford Largest city Bridgeport Governor M. Jodi Rell (R) Senators Chris Dodd (D) Joe Lieberman (D) Area  - Total  - % water Ranked 48th 14,371 km² 12. ... Human evolution is a multidisciplinary scientific inquiry which seeks to understand and describe the origin and development of humanity. ... State nickname: Bay State Official languages English Capital Boston Largest city Boston Governor Mitt Romney (R) Senators Edward Kennedy (D) John Kerry (D) Area  - Total  - % water Ranked 44th 27,360 km² 25. ... 1855 was a common year starting on Monday (see link for calendar). ... Orders  Crocodilia - Crocodilians  Rhynchocephalia - Tuataras  Squamata   Suborder Sauria- Lizards   Suborder Serpentes - Snakes   Suborder Amphisbaenia - Worm lizards Testudines - Turtles Superorder Dinosauria  Saurischia  Ornithischia Reptiles are tetrapods, and also are amniotes, animals whose embryos are surrounded by an amniotic membrane. ... 1865 is a common year starting on Sunday. ... A paleontologist carefully chips rock from a column of dinosaur vertebrae. ... Othniel Charles Marsh (October 29, 1831 - March 18, 1899) was one of the pre-eminent paleontologists of the 19th century, who discovered and named many fossils found in the American West. ... 1885 is a common year starting on Thursday. ... Map of Pangaea Pangaea or Pangea (derived from Παγγαία, Greek for all earth) is the name given to the supercontinent that existed during the Paleozoic and Mesozoic eras, before the process of plate tectonics separated the component continents into their current configuration. ... Motto: Munit Haec et Altera Vincit (Latin: One defends and the other conquers) Official languages English Capital Halifax Largest city Halifax Lieutenant-Governor of Nova Scotia Myra Freeman Premier John Hamm (PC) Parliamentary representation  - House seat  - Senate seats 11 10 Area  - Total  - % water Ranked 12th 55,283 km² 3. ...

Today, parts of Anchisaurus' skeleton are still missing. Reconstructions usually assume that the tail and neck are like that of other dinosaurs of the same family, prosauropods. Anchisaurus was quite typical of this group and so this assumption is probably justified.

Description

In order to have been mistaken for human bones, one would expect Anchisaurus to be a rather small dinosaur - and, with a length of just over 2 metres, indeed it was. It probably weighed around 27 kg. However, Marsh's species A. major was larger, from 2.5 m up to 4 m, and some estimates give it a weight of up to 70 kg. All species lived during the late Jurassic era; more specifically, the Pliensbachian to Toarcian periods, 200 to 188 million years ago. The Jurassic period is a major unit of the geologic timescale that extends from about 200 Ma (million years ago) at the end of the Triassic to 146 Ma at the beginning of the Cretaceous. ... The Pliensbachian (also known as Charmouthian) is a stage of the Early Jurassic Epoch. ... The Toarcian Stage was the last faunal stage of the Early Jurassic period. ...

Digesting plant matter is a much more intensive biochemical process than digesting meat, and so herbivorous dinosaurs needed a huge gut. Since this had to be positioned in front of the pelvis, balancing on two legs became increasingly tricky, and they gradually evolved into the quadripedal position that characterises the later sauropods such as Diplodocus. Prosauropods, then, represented a middle phase between the earliest bipedal herbivores, and the later giant sauropods. Anchisaurus was typical of this group that flourished briefly during the late Triassic and Jurassic. It would have spent most of its time on four legs, but could have raised up on its hind legs to reach higher plants. Digestion is the process whereby a biological entity processes a substance, in order to chemically convert the substance into nutrients. ... Biochemistry the chemistry of life, a bridge between biology and chemistry that studies how complex chemical reactions give rise to life. ... Meat is animal tissue (mainly muscle) used as food. ... For the Physics term GUT, please refer to Grand unification theory The gastrointestinal or digestive tract, also referred to as the GI tract or the alimentary canal or the gut, is the system of organs within multicellular animals which takes in food, digests it to extract energy and nutrients, and... Human male pelvis, viewed from front Human female pelvis, viewed from front The pelvis is the bony structure located at the base of the spine (properly known as the caudal end). ... Families Brachiosauridae Camarasauridae Cetiosauridae Diplodocidae Euhelopodidae Nemegtosauridae Titanosauridae Vulcanodontidae Sauropoda, the sauropods, are a suborder or infraorder of the saurischian (lizard-hipped) dinosaurs. ... Species (Hatcher, 1901) (Holland, 1924) (Marsh, 1878; holotype) Diplodocus ( Latin: double-beam) is a type of dinosaur of subgroup Sauropoda. ... The Triassic is a geologic period that extends from about 245 to 202 Ma (million years ago). ...

On the other hand, paleontologists believe Anchisaurus may also have eaten meat, as it was in the transition between these two ultimately distinct groups. The teeth were blunt but with file-like edges, suggesting mostly plant matter was eaten, and the jaw hinge was arranged in a way not entirely suited for tearing meat. Nevertheless, there is still some debate. The thumb had a large claw, and the large eyes were not entirely on the side (as would be expected in an animal used to being prey).

As a quadropedal/bipedal crossover, Anchisaurus had to have multi-purpose front legs. As hands, they could be turned inwards and be used for grasping. It had a simple reversible first finger, similar to a thumb. As feet, the five toes could be placed flat against the floor and were strong at the ankle. This unspecialised design is typical of the early dinosaurs. The bones in the foot In anatomy, the ankle, or ancle (a word common, in various forms, to Teutonic languages, probably connected in origin with the Latin angulus, or Greek αγκυλος, bent), is the part of the lower limb that is located between the foot and the leg, and is actually...

Classification

• Order: Saurischia
• Suborder: Sauropodomorpha
• Infraorder: Prosauropoda
• Family: Anchisauridae
• Genus: Anchisaurus

Anchisaurus is sometimes known as Yaleosaurus, due to Huene (1932). Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. ... Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. ... 1932 (MCMXXXII) is a leap year starting on a Friday. ...

Marsh was originally happy with Hitchcock's name Megadactylus, but this name was already taken. Therefore, he renamed it Amphisaurus in 1882. However, this name was also preoccupied! Therefore, it became Anchisaurus in 1885.

The type species is Hitchcock's A. polyzelus. Marsh's A. major ("greater near lizard") is still considered among the Anchisaurs. However, his A. colurus of 1891 is now generally accepted as a female A. polyzelus, and his A. solus of 1892 is now reclassified as Ammosaurus major. However, Ammosaurus itself may well be a synonym of A. polyzelus. Broom named "Gyposaurus" in 1911, from the bones discovered in South Africa, but Peter Galton officially named it A. capensis in 1971. This species has since been reclassified again, and is now Massospondylus carinatus. Other specimens are still awaiting reclassification. This confusion is typical of the first dinosaurs to be discovered, when classification was not considered such an important process. Type specimens When a new species is discovered, more important than creating a new and unique name for the species is developing a reasonably detailed description. ... 1891 was a common year starting on Thursday (see link for calendar). ... Binomial name Ammosaurus solus Marsh, 1891 Ammosaurus (AM-o-sawr-us) meaning lizard of the sand, because it was found in sandstone (Greek ammos = sand + sauros = lizard) has been identified by four incomplete skeletons found in United States and Canada regions. ... Look up Synonym on Wiktionary, the free dictionary Synonyms (in ancient Greek syn συν = plus and onoma όνομα = name) are different words with similar or identical meanings and are interchangable. ...

External links

• "Anchisaurus". DinoData.