Allosaurus fragilis

Marsh, 1877 
Original : AMNH FARB 680. MNHN.F.AMN148
Reptilia, Dinosauria, Saurischia, Theropoda
Upper Jurassic, 152 million years
Morrison Formation, Cleveland-Lloyd, Utah, USA

Allosaurus is a carnivorous dinosaur. Its name comes from the Greek for “different lizard”. It lived in North America and Europe during the Upper Jurassic.

Allosaurus measured almost 9 m in length and weighed 2.3 tonnes. Its skull had long, pointed, serrated teeth and small horn-like protuberances just above the eyes. Its fore limbs were much larger than those of Tyrannosaurus and Carnotaurus. The hands had three fingers with long sharp claws. The hind limbs were powerfully muscled, making Allosaurus an efficient predator, one of the largest of its time. A contemporary of Diplodocus, it mainly ate herbivorous dinosaurs.

The specimen displayed here comes from the Cleveland-Lloyd dinosaur quarry where, between 1960 and 1965, palaeontologists uncovered the remains of at least 46 individuals of all ages. Allosaurus has thus been studied in detail and is one of the best understood theropods.

The first Allosaurus remains were discovered in 1869 within the Morrison geological formation in Middle Park (Colorado) and were among the very first theropods uncovered. Today, we know that the posture of the specimen displayed here is incorrect, and that it should be more like the statuette displayed on the same podium.