A cartilaginous fish from off the southwest coast of the ancient supercontinent Gondwana (and later Pangaea), Helicoprion first appeared in the late Carboniferous (310 million years ago) and survived up until just past the massive Permian-Triassic extinction (250mya). […]
I think evolution must work like Ikea, because occasionally nature completely misread the directions and puts a piece on backwards.
Just want to say really quick, I’m pretty sure Gondwana/Gondwanaland came after Pangea. Gondwana was the southern break-up of Pangea which continued into the modern day drifting of continents on tectonic plates. The northern part was Laurasia.
Gondwana actually existed long before Pangaea, forming at roughly the same time as the Cambrian explosion, 550-500 million years ago — and was probably created during the breakup of a proposed older supercontinent known as Pannotia.
It became part of the forming Pangaea in the late Carboniferous period, about 300 mya, then started breaking off again during the mid Jurassic, around 175 mya. Post-Pangaea Gondwana wasn’t exactly the same as it had been before, leaving a few chunks of itself attached to Laurasia, but it was similar enough that the same name is used for both its earlier and later forms.