Daspletosaurus

Daspletosaurus
Temporal range: Late Cretaceous (Campanian), 78–74.4 Ma
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Cast skeleton mount of D. torosus on display at Milwaukee Public Museum
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Family: †Tyrannosauridae
Clade: †Daspletosaurini
Genus: †Daspletosaurus
Russell, 1970
Type species
†Daspletosaurus torosus
Russell, 1970
Other species
  • †D. horneri
    Carr et al., 2017
  • †D. degrootorum?
    Voris et al., 2020[1]
  • †D. wilsoni?
    Warshaw & Fowler, 2022
Synonyms

Daspletosaurus (/dæsˌpliːtəˈsɔːrəs/ das-PLEET-ə-SOR-əs; meaning "frightful lizard") is a genus of tyrannosaurid dinosaur that lived in Laramidia between about 78 and 74.4 million years ago, during the Late Cretaceous Period. The genus Daspletosaurus contains three named species. Fossils of the earlier type species, D. torosus, have been found in Alberta, while fossils of a later species, D. horneri, have been found only in Montana. D. wilsoni has been suggested as an intermediate species between D. torosus and D. horneri that evolved through anagenesis, but this theory has been disputed by other researchers.

There are also multiple specimens which may represent new species of Daspletosaurus from Alberta and Montana, but these have not been formally described. The taxon Thanatotheristes has been suggested to represent a species of Daspletosaurus, D. degrootorum, but this has not been widely supported. Daspletosaurus is closely related to the much larger and more recent tyrannosaurid Tyrannosaurus rex. Like most tyrannosaurids, Daspletosaurus was a large bipedal predator, with the average adult measuring 8.5–9 m (28–30 ft) and weighing 3 metric tons (3.3 short tons). However, the largest potential specimen measures around 11 metres (36 ft) long and weighs up to 5 metric tons (5.5 short tons). Daspletosaurus had the small forelimbs typical of tyrannosaurids, although they were proportionately longer than in other genera.

As an apex predator equipped with dozens of large, sharp teeth, Daspletosaurus was at the top of the food chain, probably preying on large dinosaurs like the ceratopsid Centrosaurus and the hadrosaur Hypacrosaurus. In some areas, Daspletosaurus coexisted with another tyrannosaurid, Gorgosaurus, though there is some evidence of niche differentiation between the two.[2] While Daspletosaurus fossils are not as common as other tyrannosaurid fossils, the available specimens allow some analysis of the biology of these animals, including social behavior, diet, and life history.[3]

  1. ^ Chan-gyu Yun (2020). "A Subadult Frontal of Daspletosaurus torosus (Theropoda: Tyrannosauridae) from the Late Cretaceous of Alberta, Canada with Implications for Tyrannosaurid Ontogeny and Taxonomy". PalArch's Journal of Vertebrate Palaeontology. 17: 1–13. Archived from the original on September 27, 2020. Retrieved January 15, 2021.
  2. ^ Yun, Changyu (2021). Tyrannosaurid theropod specimens in the San Diego Natural History Museum from the Dinosaur Park Formation (Campanian) of Alberta, Canada. New Mexico Museum of Natural History and Science. pp. 569–578.
  3. ^ Trexler, David; Currie, Phillip; Koppelhus, Eva; Wicks, Kelly; Murphy, Nate (June 2005). Carpenter, Kenneth (ed.). The Carnivorous Dinosaurs. Bloomington, Ind: Indiana University Press. pp. 313–324. ISBN 9780253345394. Retrieved January 12, 2022.