Ginaga aren't the only residence of planet Tempae that had a strange case of convergent evolution with a species from Earth.
As mentioned previously on that planet a completely different group of animals took up the flying animal niche so birds make up the majority of large terrestrial animals. Crocodilians did in fact evolve on Tempae or at least something incredibly similar BUT died out millions of years ago during an extinction event leaving the niche for semiaquatic predators to the remaining archosaurs. Also besides that turcatom took another niche too: seals. While most turcatom live inland in fresh water sources some sub species of them adapted to almost complete aquatic life and as a result has a shorter rounder body and much bigger front limbs with diminished hind legs. You can see that sub species in the little image.
Turcatom are found through the planet though especially in warmer climates. Both Ginaga and Ferron have a cultural related fear of these things because neither species are good swimmers but both are large enough to look like dinner to these creatures. Chi'Tsao remain largely unconcerned because apparently being 10 inch bug people comes occasionally with that advantage.
Behaviour wise they are more similar to crocodiles than they are to seals as they are mostly focused on basic survival stuff rather than playing around. They tend to mostly be solitary hunters that ambush anything delicious that comes too close. They do often bask together but don't have any kind of group dynamic if that makes any sense.

So enjoy