Torvosaurus

***Torvosaurus*** (/ˌtɔːrvoʊˈsɔːrəs/) 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 (Callovian to Tithonian stages) 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.

In 1979 the type species *Torvosaurus tanneri* was named: it was a large, heavily built, bipedal carnivore, that could grow to a length of about 11 meters (36 ft). *T. tanneri* was among the largest carnivores of its time, together with *Epanterias* and *Saurophaganax* (which could both be synonyms for *Allosaurus*). Specimens referred to *Torvosaurus gurneyi* were initially claimed to be up to 12 meters (39 ft) long, but later shown to be smaller. Based on bone morphology *Torvosaurus* is thought to have had short but very powerful arms.

Fossilized remains of *Torvosaurus* have been found in North America, Portugal, Germany, and possibly also England, Tanzania, and Uruguay.

The first discovered remains referable to *Torvosaurus* were discovered in 1899 by Elmer Riggs in the "Freeze-out Hills" of southeastern Wyoming, 18 kilometers (11 mi) northwest of the town of Medicine Bow. The material consisted of part of the left foot and right hand and they were taken to the Field Museum of Natural History in Chicago, Illinois where they were stored until being re-discovered around 2010. The specimen was assigned to *Torvosaurus tanneri* after being described in 2014.

More remains of a large theropod that is now believed to have been *Torvosaurus* were discovered in the Tendaguru Formation of Tanzania and was named "*Megalosaurus*" *ingens* by Werner Janensch in 1920, based on the specimen MB R 1050, a 12-centimeter (4.7 in) long tooth from German East Africa (now Tanzania). It was eventually reclassified as a probable member of the Carcharodontosauridae before being reclassified as a probable member of the *Torvosaurus* genus in 2020, thus potentially creating the new species *Torvosaurus ingens* as Soto *et al.* recognized the Tendaguru and Tacuarembó material as a new species of *Torvosaurus*, although however, more specimens would need to be collected before this can become officially recognized as a new species. This species of *Torvosaurus* was probably the same species of *Torvosaurus* as the species from the Tacuarembó Formation of Uruguay. However, Rauhut *et al.* consider the teeth to be undiagnostic, being coherent in size and shape with a variety of other theropods (including carcharodontosaurids), and thus they consider their attribution to the genus to be problematic.

In 1971, Vivian Jones, of Delta, Colorado (USA), in the Calico Gulch Quarry in Moffat County, discovered a single gigantic thumb claw of a theropod. This was shown to James Alvin Jensen, a collector working for Brigham Young University. In an effort to discover comparable fossils, Vivian's husband Daniel Eddie Jones directed Jensen to the Dry Mesa Quarry, where abundant gigantic theropod bones, together with *Supersaurus* remains, proved present in rocks of the Morrison Formation. From 1972 onward the site was excavated by Jensen and Kenneth Stadtman. The type species *Torvosaurus tanneri* was named and described in 1979 by Peter Malcolm Galton and Jensen. The genus name *Torvosaurus* derives from the Latin word *torvus*, meaning "savage", and the Greek word *sauros* (σαυρος), meaning "lizard". The specific name *tanneri*, is named after first counselor in the First Presidency of The Church of Jesus Christ of Latter-day Saints Nathan Eldon Tanner.

In 1985, Jensen could report a considerable amount of additional material, among it the first skull elements. The fossils from Colorado were further described by Brooks Britt in 1991. The holotype BYU 2002 originally consisted of upper arm bones (humeri) and lower arm bones (radii and ulnae). The paratypes included some back bones, hip bones, and hand bones. When the material described in 1985 is added, the main missing elements are the shoulder girdle and the thighbone. The original thumb claw, specimen BYUVP 2020, was only provisionally referred as it had been found in a site 195 kilometers (121 mi) away from the Dry Mesa Quarry. The holotype and paratypes represented at least three individuals: two adults and a juvenile. In 1991, Britt concluded that there was no proof that the front limbs of the holotype were associated and chose the left humerus as the lectotype. Several single bones and teeth found in other American sites have been referred to *Torvosaurus*.