Page 34 - Dinosaur (DK Eyewitness Books)

Meat-eaters Serrated edge
Cracks due
to fossilization
New tooth
MȢȯȺ ȭȢȳȨȦ ȮȦȢȵ ȦȢȵȪȯȨ ȥȪȯȰȴȢȶȳȴ had jaws
used as weapons for killing and tearing up big game.
KILLING TEETH
The head was large, with strong muscles powering jaws With serrated edges like a steak knife,
that were rimmed with knifelike teeth. These were the curved teeth of Megalosaurus sliced
easily through flesh. They were even
used to cut through the skin and flesh of bulky strong enough to crunch through bone.
plant-eating dinosaurs with ease. Allosaurus would Such hard use made them wear out
fairly fast, and some even snapped
use its powerful jaws to seize and kill its victim, then off. But new teeth always grew to
tear off massive chunks of meat. But not all theropods replace those worn out or lost.
had heads for tackling such heavy tasks. The heads
of spinosaurids were shaped for seizing fish. Small,
sharp-toothed coelurosaurs swallowed lizards whole. Large, curved tooth
Beaked ornithomimids (“ostrich mimics”) were toothless of Megalosaurus
and snapped up insects, but also fed on leaves and fruit.

Sliding jaw joint Opening for attachment and
helped to grip expansion of jaw muscles
wriggling prey

Maxilla
(upper jaw)
Tarbosaurus

Curved,
serrated tooth

Mandible
(lower jaw)
TOP CHOPPER
The sturdiest bones in an Allosaurus’s skull
supported jaw muscles and bladelike teeth.
Allosaurus would snap its jaws shut on a victim,
then slice off flesh with its sharp teeth. The skull
was specialized for rapid chopping rather than Barsboldia
forceful biting, and this theropod probably could
not crush bones in the same way as Tyrannosaurus.

Upper jaw
opens far
apart

TYRANNOSAUR ATTACK
Lower jaw This Tarbosaurus (“terrible lizard”) has clamped its
moves
powerful jaws on the neck of a young Barsboldia—a
downward
hadrosaur named after Mongolian paleontologist
and outward
Rinchen Barsbold. Both dinosaurs lived in the eastern
part of central Asia, late in the Cretaceous Period.
Tarbosaurus grew nearly as huge as its American
OPEN WIDE cousin Tyrannosaurus, and, like its relative, probably
Allosaurus’s skull was loosely constructed and preyed on hadrosaur herds. Too slow to catch
there were movable joints between some of the big or fit animals, Tarbosaurus preyed on the
bones. This meant that the jaws could not only sick, old, and young. It attacked by tearing off
gape wide apart, but could also expand outward mouthfuls of flesh and bone with great lunging
to engulf huge chunks of meat. bites. It also scavenged on dead animals.
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