refugium for animals that had gone extinct elsewhere. This identification was challenged by Samuel Welles, who thought it more resembled that of an ornithomimid, but the original authors defended their identification. With fifteen years of new specimens and research to look at, Daniel Chure reexamined the bone and found that it was not Allosaurus, but could represent an allosauroid. Similarly, Yoichi Azuma and Phil Currie, in their description of Fukuiraptor, noted that the bone closely resembled that of their new genus. This specimen is sometimes referred to as "Allosaurus robustus", an informal museum name. It may have belonged to something similar to, or the same as, Australovenator, or it may represent an abelisaur. Description Allosaurus was a typical large theropod, having a massive skull on a short neck, a long, slightly sloping tail, and reduced forelimbs. Allosaurus fragilis, the best-known species, had an average length of and mass of , with the largest definitive Allosaurus specimen (AMNH 680) estimated at long, with an estimated weight of . In his 1976 monograph on Allosaurus, James H. Madsen mentioned a range of bone sizes which he interpreted to show a maximum length of . As with dinosaurs in general, weight estimates are debatable, and since 1980 have ranged between , , and approximately for modal adult weight (not maximum). John Foster, a specialist on the Morrison Formation, suggests that is reasonable for large adults of A. fragilis, but that is a closer estimate for individuals represented by the average-sized thigh bones he has measured. Using the subadult specimen nicknamed "Big Al", since assigned to the species Allosaurus jimmadseni, researchers using computer modelling arrived at a best estimate of for the individual, but by varying parameters they found a range from approximately to approximately . A. europaeus has been measured up to in length and in body mass. Several gigantic specimens have been attributed to Allosaurus, but may in fact belong to other genera. The closely related genus Saurophaganax (OMNH 1708) reached perhaps in length, and its single species has sometimes been included in the genus Allosaurus as Allosaurus maximus, though recent studies support it as a separate genus. Another potential specimen of Allosaurus, once assigned to the genus Epanterias (AMNH 5767), may have measured in length. A more recent discovery is a partial skeleton from the Peterson Quarry in Morrison rocks of New Mexico; this large allosaurid may be another individual of