 It is unclear how many species of Allosaurus there were . Eight species have been considered potentially valid since 1988 ( A. amplexus , A. atrox , A. europaeus , the type species A. fragilis , the as @-@ yet not formally described " A. jimmadseni " , A. lucasi , A. maximus , and A. tendagurensis ) , although only about half are usually considered valid at any given time . There are also at least ten dubious or undescribed species that have been assigned to Allosaurus over the years , along with the species belonging to genera now sunk into Allosaurus . In the most recent review of basal tetanuran theropods , only A. fragilis ( including A. amplexus and A. atrox ) , " A. jimmadseni " ( as an unnamed species ) , and A. tendagurensis were accepted as potentially valid species , with A. europaeus not yet proposed and A. maximus assigned to Saurophaganax . 
 It is unclear how many species of Allosaurus <a href='dey_it' title='1'><mark>there</mark></a> <a href='uninflect' title='2'><mark>were</mark></a> . Eight species <a href='been_done' title='3'><mark>have</mark></a> been considered potentially valid since 1988 ( A. amplexus , A. atrox , A. europaeus , the type species A. fragilis , the as @-@ yet not formally described " A. <a href='negative_concord' title='4'><mark>jimmadseni</mark></a> " , A. lucasi , A. maximus , and A. tendagurensis ) , although only about half are usually considered valid at any given time . <a href='dey_it' title='5'><mark>There</mark></a> are also at least ten dubious or undescribed species <a href='null_relcl' title='6'><mark>that</mark></a><a href='been_done' title='7'><mark>have</mark></a> been assigned to Allosaurus over the years , along with the species belonging to genera now sunk into Allosaurus . In the most recent review of basal tetanuran theropods , only A. fragilis ( including A. amplexus and A. atrox ) , " A. jimmadseni " ( as an unnamed species ) , and A. tendagurensis <a href='uninflect' title='8'><mark>were</mark></a> accepted as potentially valid species , with A. <a href='negative_concord' title='9'><mark>europaeus</mark></a> not yet proposed and A. maximus assigned to Saurophaganax . 
It is unclear how many species of Allosaurus it was . Eight species done been considered potentially valid since 1988 ( A. amplexus , A. atrox , A. europaeus , the type species A. fragilis , the as @-@ yet not formally described " A. no jimmadseni " , A. lucasi , A. maximus , and A. tendagurensis ) , although only about half r usually considered valid at any given time . It is also at least ten dubious or undescribed species done been assigned to Allosaurus over the years , along with da species belonging to genera now sunk into Allosaurus . In the most recent review of basal tetanuran theropods , only A. fragilis ( including A. amplexus and A. atrox ) , " A. jimmadseni " ( as an unnamed species ) , and A. tendagurensis was accepted as potentially valid species , w A. no europaeus not yet proposed and A. maximus assigned to Saurophaganax .