Mesadactylus | |
---|---|
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Order: | † Pterosauria |
Family: | † Anurognathidae |
Genus: | † Mesadactylus Jensen & Padian, 1989 |
Species: | †M. ornithosphyos |
Binomial name | |
†Mesadactylus ornithosphyos Jensen & Padian, 1989 | |
Mesadactylus ('mesa finger') is an extinct genus of pterosaur from the Kimmeridgian-Tithonian-age Upper Jurassic Morrison Formation of Colorado, United States. The genus was named in 1989 by James Jensen and Kevin Padian. The type species is Mesadactylus ornithosphyos.
The holotype is BYU 2024, a synsacrum of seven sacral vertebrae, featuring a unique—for a pterosaur—complete fusion of the spinae into a supraneural blade, a character, as the specific name indicates more typical for birds, at first leading Jensen to assign the fossil to a bird, Palaeopteryx .
Further referred associated remains include arms bones, pectoral girdle bones, vertebrae (including cervix and sacral), and femora. [1] Additional material was described in 2004 (including a partial braincase) [2] and 2006; in the latter publication, the authors suggested that its larger contemporary Kepodactylus could be the same animal, although there are minor differences. [3] [4]
Jensen and Padian classified Mesadactylus as a pterodactyloid. In 2007 S. Christopher Bennett claimed that the holotype and the referred material came from different forms and that, while the last was indeed of a pterodactyloid nature, the synsacrum belonged to a member of the Anurognathidae. [5]
Supersaurus is a genus of diplodocid sauropod dinosaur that lived in North America during the Late Jurassic period. The type species, S. vivianae, was first discovered by Vivian Jones of Delta, Colorado, in the middle Morrison Formation of Colorado in 1972. The fossil remains came from the Brushy Basin Member of the formation, dating to about 153 million years ago. A potential second species, S. lourinhanensis, is known from Portugal and has been dated to a similar time.
Camarasaurus was a genus of quadrupedal, herbivorous dinosaurs. It was the most common of the giant sauropods to be found in North America. Its fossil remains have been found in the Morrison Formation of Colorado and Utah, dating to the Late Jurassic epoch, between 155 and 145 million years ago.
Ceratosaurus was a carnivorous theropod dinosaur in the Late Jurassic period. This genus was first described in 1884 by American paleontologist Othniel Charles Marsh based on a nearly complete skeleton discovered in Garden Park, Colorado, in rocks belonging to the Morrison Formation. The type species is Ceratosaurus nasicornis.
Torvosaurus is a genus of carnivorous megalosaurid theropod dinosaur that lived approximately 165 to 148 million years ago during the late Middle and Late Jurassic period in what is now Colorado, Portugal, Germany, and possibly England, Tanzania, and Uruguay. It contains two currently recognized species, Torvosaurus tanneri and Torvosaurus gurneyi, plus a third species from Germany that is currently unnamed.
Dryosaurus is a genus of an ornithopod dinosaur that lived in the Late Jurassic period. It was an iguanodont. Fossils have been found in the western United States and were first discovered in the late 19th century. Valdosaurus canaliculatus and Dysalotosaurus lettowvorbecki were both formerly considered to represent species of Dryosaurus.
Saurophaganax is a genus of large allosaurid dinosaur from the Morrison Formation of Late Jurassic Oklahoma, United States. Some paleontologists consider it to be a junior synonym and species of Allosaurus. Saurophaganax represents a very large Morrison allosaurid characterized by horizontal laminae at the bases of the dorsal neural spines above the transverse processes, and "meat-chopper" chevrons. The maximum size of S. maximus has been estimated at anywhere from 10.5 meters (34 ft) to 13 meters (43 ft) in length, and 3 metric tons to 4.5 metric tons in weight.
Stokesosaurus is a genus of small, carnivorous early tyrannosauroid theropod dinosaurs from the late Jurassic period of Utah, United States.
Herbstosaurus is the name given to a genus of pterosaurs that lived during the Late Jurassic period, in what is now Argentina. In 1969 Argentine paleobotanist Rafael Herbst in the province Neuquén at Picun Leufú dug up a piece of sandstone holding a number of disarticulated bones of a small reptile. At the time it was assumed the rock dated to the Middle Jurassic (Callovian), about 163 million years ago.
Marshosaurus is a genus of medium-sized carnivorous theropod dinosaur, belonging to the Megalosauroidea, from the Late Jurassic Morrison Formation of Utah and possibly Colorado.
Palaeopteryx is a genus of theropod dinosaur now considered a nomen dubium. It was named and misidentified by J. A. Jensen in 1981, then redescribed by Jensen and K. Padian in 1989. At that time the binomial Palaeopteryx thomsoni was deemed invalid by Jensen. The only referred specimen is a single bone fragment.
Anurognathidae is a family of small pterosaurs, with short or absent tails, that lived in Europe, Asia, and possibly North America during the Jurassic and Cretaceous periods. Five genera are known: Anurognathus, from the Late Jurassic of Germany; Jeholopterus, from the Middle to Late Jurassic of China; Dendrorhynchoides, from the Middle Jurassic of China; Batrachognathus, from the Late Jurassic of Kazakhstan; and Vesperopterylus, from the Early Cretaceous of China. Bennett (2007) claimed that the holotype of Mesadactylus, BYU 2024, a synsacrum, belonged to an anurognathid. Mesadactylus is from the Late Jurassic Morrison Formation of the United States. Indeterminate anurognathid remains have also been reported from the Middle Jurassic Bakhar Svita of Mongolia and the Early Cretaceous of North Korea.
Campylognathoides is a genus of pterosaur discovered in the Württemberg Lias deposits of Germany; this first specimen however, consisted only of wing fragments. Further better preserved specimens were found in the Holzmaden shale; based on these specimens, Felix Plieninger erected a new genus.
Dermodactylus was a genus of pterodactyloid pterosaur from the Kimmeridgian-Tithonian-age Upper Jurassic Morrison Formation of Wyoming, United States. It is based on a single partial bone, from the hand.
Diopecephalus is a genus of pterodactyloid pterosaur from the Lower Tithonian of the Lithographic Limestone, Bavaria, Germany. The type and only species is D. kochi, although the name has been applied to Pterodactylus longicollum, with longicollum erroneously listed as the type species.
Kepodactylus is an extinct genus of ctenochasmatid pterodactyloid pterosaur from the Kimmeridgian-Tithonian-age Upper Jurassic Morrison Formation of Colorado, United States.
Utahdactylus was a genus of extinct reptile from the Kimmeridgian-Tithonian-age Upper Jurassic Morrison Formation of Utah, United States. Based on DM 002/CEUM 32588, Czerkas and Mickelson (2002) identified it as a "rhamphorhynchoid" pterosaur. Bennett (2007) however, concluded that it has no diagnostic features of the Pterosauria, and cannot be positively identified beyond being an indeterminate diapsid.
Amphicoelias is a genus of herbivorous sauropod dinosaur that lived approximately 150 million years ago during the Tithonian of what is now Colorado, United States. An herbivore, Amphicoelias was moderately sized at about 25 m (82 ft) long–roughly the same length as Diplodocus, to which it was related. Its hindlimbs were very long and thin, and its forelimbs were proportionally longer than in relatives.
Brachiosaurus is a genus of sauropod dinosaur that lived in North America during the Late Jurassic, about 154–153 million years ago. It was first described by American paleontologist Elmer S. Riggs in 1903 from fossils found in the Colorado River valley in western Colorado, United States. Riggs named the dinosaur Brachiosaurus altithorax; the generic name is Greek for "arm lizard", in reference to its proportionately long arms, and the specific name means "deep chest". Brachiosaurus is estimated to have been between 18 and 21 meters long; weight estimates range from 28.3 to 58 metric tons. It had a disproportionately long neck, small skull, and large overall size, all of which are typical for sauropods. Atypically, Brachiosaurus had longer forelimbs than hindlimbs, which resulted in a steeply inclined trunk, and a proportionally shorter tail.
The Morrison Formation is a distinctive sequence of Late Jurassic sedimentary rock that is found in the western United States, which has a wide assortment of taxa represented in its fossil record, including dinosaur fossils in North America. It is composed of mudstone, sandstone, siltstone and limestone and is light grey, greenish gray, or red. Most of the fossils occur in the green siltstone beds and lower sandstones, relics of the rivers and floodplains of the Jurassic period.
Sarahsaurus is a genus of basal sauropodomorph dinosaur which lived during the lower Jurassic period in what is now northeastern Arizona, United States.