DID YOU KNOW? Monotremes are mammals that lay eggs, such as the platypus and echidnas
Triassic, around 230 million
years ago
These creatures were also
technically mammal-like
lizards. They had many
features in common with
mammals, such as hair and
possibly even warm bloodCynognathus
Late-Jurassic to early-Oligocene,
160 to 35 million years ago
This group of little mammals was
around for roughly 120 million years.
It’s the longest-surviving mammal
group on recordMultituberculata
“Mammals were
able to successfully
occupy empty
niches once the
dinosaurs died out”