Synonyms for alectrosaurus or Related words with alectrosaurus
Examples of "alectrosaurus"
Some paleontologists have considered "
olseni" to be a species of "Albertosaurus".
Below is a cladogram showing the phylogenetic position of "
" according to Loewen "et al." (2013).
According to Carr (2005), "
" can be distinguished based on the following characteristics:
" and "Gigantoraptor" were the top predators of their paleoenvironment and preyed on ornithischians like "Bactrosaurus" and "Gilmoreosaurus".
" was originally characterized as a long-armed theropod, but Mader and Bradley (1989) observed that the forelimbs (AMNH 6368) did not belong to this individual and assigned them to the segnosauridae. The remaining material, AMNH 6554 represents the hind limb of a true tyrannosauroid, and were assigned as the lectotype for "
olseni". Mader and Bradley also described and assigned caudal vertebrae AMNH 21784 to this genus. These researchers concluded that "
" was closely related to "Maleevosaurus novojilov" based on hind limb proportions.
Rey has finally received the 2008 Society of Vertebrate Paleontology Lanzendorf PaleoArt Prize for two dimensional art for his piece "Gigantoraptor vs
" was a medium-sized, moderately built carnivorous dinosaur. The length of its tibia and femur are very close, in contrast to the majority of other
In a 2001 study conducted by Bruce Rothschild and other paleontologists, 23 foot bones referred to "
" were examined for signs of stress fracture, but none were found.
The paleofauna of the Bayan Shireh Formation included, the therizinosaurid "Segnosaurus", the deinocheirid "Garudimimus", and the ankylosaurid "Talarurus", as well as a genus of sauropod, a tyrannosauroid formerly referred to "
", and an azhdarchid pterosaur.
The describers concluded that "Xiongguanlong" split off from the main branch of the Tyrannosauroidea before "Appalachiosaurus", being the sister taxon of a clade consisting of "Appalachiosaurus" and the Tyrannosauridae. It has been found to be closely related to "
A 2003 attempt by Christopher Brochu included "Albertosaurus", "
", "Alioramus", "Daspletosaurus", "Gorgosaurus", "Tarbosaurus" and "Tyrannosaurus" in the definition. Holtz redefined the clade in 2004 to use all of the above as specifiers except for "Alioramus" and "
", which his analysis could not place with certainty. However, in the same paper, Holtz also provided a completely different definition, including all theropods more closely related to "Tyrannosaurus" than to "Eotyrannus". The most recent definition is that of Sereno in 2005, which defined Tyrannosauridae as the least inclusive clade containing "Albertosaurus", "Gorgosaurus" and "Tyrannosaurus".
The generic name "
" can be translated as "alone lizard", and is derived from the Greek words "alektros" and "sauros" ("lizard"). There is one named species ("A. olseni"), which is named in honor of George Olsen, who discovered the first specimens. Both genus and species were described and named by American paleontologist Charles Gilmore in 1933.
More material, including comparable hind limb material as well as skull and shoulder elements, has been referred to "
". These fossils were found in the Bayan Shireh Formation of Outer Mongolia, a formation which is also of uncertain age. It may possibly extend into the early Campanian, but recent estimates suggest it was deposited from Cenomanian through Santonian times. Iren Dabasu and Bayan Shireh dinosaur faunas are similar, but van Itterbeecka "et al." claimed that the Iren Dabasu is probably Campanian-Maastrichtian in age and possibly correlated with the Nemegt Formation, so it is not surprising that a species of "
" would be found there. Furthermore, several more partial skeletons may have been found in both Inner and Outer Mongolia.
Charles Whitney Gilmore (March 11, 1874 – September 27, 1945) was an American paleontologist who gained renown in the early 20th century for his work on vertebrate fossils during his career at the United States National Museum (now the National Museum of Natural History). Gilmore named many dinosaurs in North America and Mongolia, including the Cretaceous sauropod "Alamosaurus", "
", "Archaeornithomimus", "Bactrosaurus", "Brachyceratops", "Chirostenotes", "Mongolosaurus", "Parrosaurus", "Pinacosaurus", "Styracosaurus" and "Thescelosaurus".
(; meaning "alone lizard") is an extinct genus of tyrannosaurid theropod dinosaur that lived approximately 83 to 74 million years ago during the latter part of the Cretaceous Period in what is now Inner Mongolia. It was a medium-sized, moderately-built, ground-dwelling, bipedal carnivore, with a body shape similar to its much larger relative, "Tyrannosaurus rex", and could grow up to an estimated long.
With the advent of phylogenetic taxonomy in vertebrate paleontology, Tyrannosauridae has been given several explicit definitions. The original was produced by Paul Sereno in 1998, and included all tyrannosauroids closer to Tyrannosaurus than to either "
", "Aublysodon" or "Nanotyrannus". However, "Nanotyrannus" is often considered to be a juvenile "Tyrannosaurus rex", while "Aublysodon" is usually regarded as a "nomen dubium" unsuitable for use in the definition of a clade. Definitions since then have been based on more well-established genera.
In 1933 Charles Gilmore examined the available material and concluded that AMNH 6554 and AMNH 6368 were syntypes belonging to the same genus. He based this on his observation that the manual unguals from both specimens were morphologically similar. Observing similarities with the hindlimbs of specimen AMNH 5664 "Gorgosaurus sternbergi", he classified this new genus as a "Deinodont", a term that is now considered equivalent to tyrannosaurid. Due to its fragmentary nature, there is presently very little confidence in restoring its relationships with other tyrannosauroids and many recent cladistic analyses have omitted it altogether. One study recovered "
" at no less than eight equally parsimonious positions in a tyrannosauroid cladogram.
Later in the same paper he proposed that Tyrannosauridae be defined as "all descendants of the most recent common ancestor of "Tyrannosaurus" and "Aublysodon"." He also criticized definitions previously proposed by other workers, like one proposed by Paul Sereno, that the Tyrannosauridae was "all taxa closer to "Tyrannosaurus" than to "
", "Aublysodon", and "Nanotyrannus"." Holtz observed that since "Nanotyrannus" was probably a misidentified "T. rex" juvenile, Sereno's proposed definition would have the family Tyrannosauridae as a subtaxon of the genus "Tyrannosaurus". Further, his proposed definition of the subfamily Tyrannosaurinae would also be limited to "Tyrannosaurus".
The only known specimen "Appalachiosaurus" was complete enough to be included in phylogenetic analyses using cladistics. The first was performed before the animal had even been named, and found "Appalachiosaurus" to be a member of the albertosaurine subfamily of Tyrannosauridae, which also includes "Albertosaurus" and "Gorgosaurus". The original description also included a cladistic analysis, finding "A. montgomeriensis" to be a basal tyrannosauroid outside of Tyrannosauridae. However, Asian tyrannosaurs like "Alioramus", and "
" were excluded, as was "Eotyrannus" from England. Earlier tyrannosaurs such as "Dilong" and "Guanlong" had not been described at the time this analysis was performed. These exclusions may have a significant effect on the phylogeny.
The most basal tyrannosauroid known from complete skeletal remains is "Guanlong". Other early taxa include "Stokesosaurus" and "Aviatyrannis", known from far less complete material. The better-known "Dilong" is considered slightly more derived than "Guanlong" and "Stokesosaurus". "Dryptosaurus", long a difficult genus to classify, has turned up in several recent analyses as a basal tyrannosauroid as well, slightly more distantly related to Tyrannosauridae than "Eotyrannus" and "Appalachiosaurus". "
", a poorly known genus from Mongolia, is definitely a tyrannosauroid but its exact relationships are unclear. Other taxa have been considered possible tyrannosauroids by various authors, including "Bagaraatan" and "Labocania". "Siamotyrannus" from the Early Cretaceous of Thailand was originally described as an early tyrannosaurid, but is usually considered a carnosaur today. "Iliosuchus" has a vertical ridge on the ilium reminiscent of tyrannosauroids and may in fact be the earliest known member of the superfamily, but not enough material is known to be sure.
Copyright © 2017