They were far better at their job and far more adaptable to the drying climate than the temospondyii, and almost all of them went extinct. That is, until actual crocodiles evolved about 210 MYA. They survived as salamander-like animals, acting like crocodiles. They used to be very diverse in the Carboniberous and Permian period, but the Permian/Triassic mass extinction event (aka the Great Dying) wiped out most of them.
But it was actually the last living representative of the temospondyii, a ancient group of amphibians that roamed the earth from 360-110 MYA. Koolasuchus was first thought to be a crocodile when first discovered, hence the suffix -suchus. For those of you saying that there are no crocodiles in this clip, you are correct.
