Page 49 - Dinosaur (DK Eyewitness Books)

Radius
(forearm bone) Radius

Ulna
Ulna
(forearm
bone)

Compact
Fine, downy wrist joint
feathers may have
covered the skin
Wrist Phalanx

Phalanx
(finger bone)

Elephant forelimb Camarasaurus forelimb
SUPPORTING WEIGHT
Camarasaurus’s forelimb bones were like those of an elephant—
made for bearing weight. They were thick and strong, and the
phalanges (finger bones) were short and stubby. Each hand had
five fingers, as with this sauropod’s bipedal ancestors, but the
finger bones had become fewer and shorter. Camarasaurus’s hands
worked like fleshy, semicircular forefeet, and it walked on its
Long forearm fingertips, leaving horseshoe-shaped handprints in soft ground.
bones

Clawed
finger
RAPTOR HANDS
Bambiraptor had long arms and three-fingered
grasping hands for seizing animals before
eating them. A cat-sized theropod like this could
probably grip a victim in both hands to bring the
animal closer to its mouth. When chasing prey, this Late
Cretaceous maniraptoran would tuck its hands and arms
in tightly to protect them and to make the body
Wrist compact for balance and maneuverability. The
flexible forelimbs of some maniraptorans were Bambiraptor skeleton
also useful in brooding eggs and climbing trees.
Maniraptorans evolved into birds. Over time, their
forelimbs became longer and feathered, evolving
into wings that were used for flapping flight.
Claw

PUNY PROPS
For its great size, Tyrannosaurus (“tyrant lizard”)
had astonishingly tiny arms and hands. They
seem too puny to have been useful, and yet
they were very muscular. One scientist has
suggested that the hands served as props. For a
Tyrannosaurus lying down to rest, pushing its
hands down against the ground might have helped
raise its head and chest so that it could stand up again. Two-fingered hand

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