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DinoFan83 · 12-27-2020, 06:47 PM

Allosaurus is a genus of carnivorous theropod dinosaur that lived 155 to 150 million years ago during the late Jurassic period (Kimmeridgian to early Tithonian), with fossils known from both North America and Europe to date. Allosaurus was fairly typical as large theropods go, having a massive skull on a powerful neck, a counterbalancing tail and strong clawed forelimbs to aid in prey capture. Its hunting and feeding strategy is notable, in which it would have used its strong skull and powerful neck to hack its prey to bits.
A number of species are known and not all of which are formally named, with much variance in size between them. Some species (such as A. jimmadseni, which includes the famous specimen Big Al or MOR 693) would have been large by theropod standards but not immensely so, being in the region of 7.1-7.6 meters and 1.2-1.4 tonnes based on known specimens of adult size. Other species (namely the very well known A. fragilis and also the type) seem to have been 8.5-9.5 meters long and 2-3 tonnes as adults, although this species may have been larger than this. And other species still (eg: A. "amplexus" and A. "maximus", which may or may not belong to already existing species) appear to have reached sizes in the region of 13-14.3 meters and 7.5-10 tonnes as adults, with one such specimen for the former being almost certainly immature despite its size.
Allosaurus is known from a very large number of specimens from hatchlings to adults, and is thus very completely known given the large sample. One of the best quarries for it is the Cleveland-Lloyd quarry in the United States, which preserves a minimum of 46 individuals of every ontogenetic stage. It is hypothesized for the animals to have ended up there during a drought.

DinoFan83 · 12-27-2020, 06:53 PM

Allosaurus mounted skeleton by Creoqueteamo.