It’s fairly simple with dinosaurs, imo. If it flies or swims - it’s not a dinosaur. So plesiosaurs, mosasaurs, ichthyosaurs are not dinos. Se goes for pterosaurs. It’s terrestrial animals where it gets difficult
Rule of thumb, it’s not perfect. Plus AFAIK archaeopteryx was more of a glider, rather than a dedicated flyer (the way pterodactyl was). You can also tell bird-like theropods from pterosaurs by the legs - birds have long-ish legs, while pterosaurs have short-ish legs (like bats).
As for the spinosaurs, while a swimmer (it’s hard to keep track, poor sod is getting retconned every other day) it was not an open sea kind of swimmer - just compare spinosaur’s limbs to that of a mosasaur
Ok wow you learn something new every day. Taxonomy is weird
It’s fairly simple with dinosaurs, imo. If it flies or swims - it’s not a dinosaur. So plesiosaurs, mosasaurs, ichthyosaurs are not dinos. Se goes for pterosaurs. It’s terrestrial animals where it gets difficult
what about animals like archaeopteryx, that could fly, or spinosaurus that had adaptations for swimming?
Rule of thumb, it’s not perfect. Plus AFAIK archaeopteryx was more of a glider, rather than a dedicated flyer (the way pterodactyl was). You can also tell bird-like theropods from pterosaurs by the legs - birds have long-ish legs, while pterosaurs have short-ish legs (like bats).
As for the spinosaurs, while a swimmer (it’s hard to keep track, poor sod is getting retconned every other day) it was not an open sea kind of swimmer - just compare spinosaur’s limbs to that of a mosasaur