I love dinosaurs, and i live in australia so I'm always wondering Why are aussie dinos so small? However Kronosaurus is the most famous australian prehistoric reptile.
if you were to put in aussie dinos you'd need the kronosaurus
Australia was polar at the time and attached to Antarctica, the seasonal variability in vegetation growth might have something to do with dinosaur size, there was also an inland sea for most of the time we have dinos from, which would have limited land a bit.
There are still largish dinosaurs, the largest named one is a more or less a tie between
Savannasaurus and
Rhoetosaurus, being more medium sized sauropods at about 15m long. From footprints, there's even one estimated to be about 18m long apparently, and technically
Austrosaurus has been estimated at about 20m long. The largest carnivore we have is
Rapator, estimated at 9m long, so roughly
Baryonyx sized.
With the Australian dinosaurs, it's more that they aren't found in many places, basically all the discoveries in the last ten or fifteen years have been from central Queensland and southern Victoria.
There are also Western Australian dinosaur sites known, one around Exmouth and one even close to Perth, but I'd say they probably aren't going back to them for a while, with the Gogo reef being the much more popular draw for palaeontology (
also there's likely crocodiles around Exmouth for part of the year, and a river near that site).
I'm not confident about getting anything outside of the
Mosasaurus marine animal wise (
for this game anyway, sequel might change things), same goes for Aerial creatures outside of the
Pteranodon. That said,
Koolasuchus is another pretty iconic one, being likely the last of it's kind.