 Mammals
come in all shapes and sizes, and can be found all over the
earth. There are around 5500 species of mammals in all. All
mammals are warm-blooded and have either hair or fur on their
bodies. The majority of all mammals give birth to live
young, but there are a few species of mammals that lay eggs.
The Triassic period, 220 million years ago, was the age that
the first mammals can be found. Humans are mammals,
but are not included on this site.
| Platypus |
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| The Platypus is native to Australia and
Tazmania, and is a semi-aquatic mammal. They are
one of five different mammals that give birth to
eggs, instead of live animals. |
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| Learn
About the Platypus |
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During the Triassic period, about 220 million years ago,
the first Mammal species were roaming the
Earth. These mammal ancestors were preceded by a group called
the 'synapsids'. There were three distinct groups of creatures
prior to the Triassic period, of which 'synapsid' is one.
The others are 'diapsids' and 'anapsids'. The terminology
makes reference to the holes on their skulls where the jaw
muscles attach. 'Synapsids' (mammals) have
one hole on either side, 'diapsids' (dinosaurs, reptiles,
birds) have two holes on either side, and 'anapsids' (turtles)
have none. |
