Monolophosaurus (Greek for "single-crested lizard"); pronounced MON-oh-LOAF-oh-SORE-us
Woodlands of Asia
Middle Jurassic (170 million years ago)
Size and Weight:
About 17 feet long and 1,500 pounds
Bipedal stance; single crest on head
Unlike its similarly named cousin, Dilophosaurus, Monolophosaurus hasn't quite seized the public's imagination--even though this allosaur (as it has tentatively been classified) was slightly bigger than Dilophosaurus and probably more dangerous. Like all theropods, Monolophosaurus was a meat-eating biped; judging by geological clues from where it was discovered, it likely prowled the lakebeds and riversides of middle Jurassic Asia. Why did Monolophosaurus have that single, prominent crest on top of its head? As with all such anatomical features, this was likely a sexually selected characteristic--that is, males with bigger crests were dominant in the pack and could more easily mate with females.