page_title: Torvosaurus
section_title: Discovery
hierarchical_section_title: Torvosaurus / Discovery
caption_attribution_description: English: Fossil of Torvosaurus tanneri, an extinct theropod
context_page_description: Torvosaurus is a genus of carnivorous megalosauroid theropod dinosaur that lived approximately 153 to 148 million years ago during the Late Jurassic Period in what is now Colorado and Portugal. It contains two currently recognized species, Torvosaurus tanneri and Torvosaurus gurneyi.
  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 10 m. T. tanneri was among the largest carnivores of its time, together with Epanterias and Saurophaganax. Specimens referred to Torvosaurus gurneyi were initially claimed to be up to twelve metres long, but later shown to be smaller. Based on bone morphology Torvosaurus is thought to have had short but very powerful arms.
context_section_description: Fossilized remains of Torvosaurus have been found in North America and Portugal. 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 onwards 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 kilometres 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.
  In 1992, fossils of a large theropod found at Como Bluff in Wyoming, containing skull, shoulder girdle, pelvis and rib elements, were named by Robert T. Bakker et al. as the species Edmarka rex. Bakker et al were impressed with the size of Edmarka, noting that it "would rival T. rex in total length," and viewing this approximate size as "a natural ceiling for dinosaurian meat-eaters." This was often considered a junior synonym of Torvosaurus. The same site has rendered comparable remains for which the nomen nudum Brontoraptor has been used. Most researchers now regard both specimens as belonging to Torvosaurus tanneri.
  In 2000, material from Portugal was referred to a Torvosaurus sp. by Octávio Mateus and Miguel Telles Antunes. In 2006 fossils from the Portuguese Lourinhã Formation were referred to Torvosaurus tanneri. In 2012, however, Matthew Carrano e.a. concluded that this material could not be more precisely determined than a Torvosaurus sp. In 2013 eggs and embryos were reported from Portugal, referred to Torvosaurus. The species from Portugal was named T. gurneyi in honor of James Gurney in 2014, the creator of the Dinotopia series of books. It is the largest theropod known from Europe. It was the morphological distinctiveness of the holotype maxilla ML1100 that led to the naming of the Portuguese species.
caption: Reconstructed T. tanneri skull, Museo Capellini of Bologna
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