Page 85 - DINOSOUR ATLAS

After the Dinosaurs

If the Impact theory of dInosaur extInctIon is correct, life on Earth must have
suffered a catastrophic blow at the end of the Cretaceous Period. Yet although
all the big dinosaurs, flying pterosaurs, and marine reptiles died out, many other
types of animal lived on into the Tertiary Period. The reason for their survival is
still uncertain. They may have been protected by their biology or their habitats, or
the extinction may have been a much more
gradual, selective process. Either way, the survivors
were the ancestors of the animals that live on Earth today.

, mammal survivors
Mammals had existed throughout the dinosaur era, but
they were small, probably secretive creatures. Many forms
were eliminated in the mass extinction, but some survived
and started evolving into a much wider variety
of species, including early primates
like this Plesiadapis.

killer marsupial .
Many of the mammals that
lived alongside the dinosaurs short wings
were marsupials, or pouched were far too small for
mammals. Relatively few flight, but were armed
survived the catastrophe, with sharp claws
but those that did gave rise
to spectacular species like , Feathered dinosaur
Thylacosmilus, a fearsome There is evidence that the ancestors of birds
hunter that lived about were carnivorous dinosaurs like Velociraptor. If
6 million years ago. so, then these “feathered dinosaurs”
Powerful legs lived on after the extinction. Some
enabled Titanis to evolved into giant, flightless hunters
run at high speed,
like a modern ostrich such as this Titanis, which stood
8 ft (2.5 m) high. It lived 2 million
long saber teeth years ago, and probably hunted by
were used to stab and kill running down its prey and killing it
big, thick-skinned mammals with its huge hooked beak.

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