T.rex’s smaller yet no less well-known cousin, Allosaurus dominated the Jurassic food chain.


Meaning of name: Different lizard

Species: Allosaurus tendagurensis, Allosaurus fragilis, Allosaurus amplexus, Allosaurus trihedrodon and Allosaurus whitei. Saurophaganax maximus is now considered a larger subspecies of Allosaurus.

Size: 12 meters (39 feet) long

Classifiations: Theropoda, Tetanurae, Carnosauria, Allosauridae.

Time: Kimmeridgian to Tithonian stages (late Jurassic).

Location: USA (Utah; most are found at the Cleveland-Lloyd quarry of the Morrison Formation), possibly Portugal and Tanzania.

Named by: Othniel Charles Marsh, in 1877.


With it’s three-clawed hands and eyebrow ridges, this carnivore is instantly recognisable. The largest terres.trial carnivore of it’s time and locale, this beast is often compared to the great Tyrannosaurus.

It is thought that Allosaurs lived in small family groups (amother and her young or a group of siblings), and this is prettyeasy to believe, seeing as they hunted animals that were usually well over double their size.

Allosaurus was light and agile for it’s size, which would have made for an excellent predatry animal, but it probably also scavenged and stole kills from the considerably smaller Marshosaurus.

This has been Allosaurus, this has been me; and you’ve been reading Paleontology Made Easy.

Picture courtesy of Walking with Dinosaurs Wiki.