The therapsids take over
Upright-legged, active synapsids spread worldwide — the first animals recognisably heading towards mammals.
- When
- Known to
- ± 5 million years
- Era
- Permian, Paleozoic
Therapsids radiate into the space Olson's Extinction opened: dinocephalians the size of cattle, tusked dicynodonts that become the most abundant herbivores on Earth, and sabre-toothed gorgonopsians as the top predators. They stand with limbs under the body, have differentiated teeth, and show the beginnings of a secondary palate — features that let an animal chew and breathe at once.