When Was That, Again?
PALEOZOIC: 545-245 million years ago
Pennsylvanian (320-290 million years ago):
oldest ěstem diapsidsî
Permian (290-245 million years ago):
division into archosaur and
lepidosaur
lineages
early ěthecodontî archosaurs
Previous slide
Next slide
Back to first slide
View graphic version