For the same reason as [MENTION=41954]blalien[/MENTION] gives - its the contrast between "living", "use" names and abstract, merely scientific names.Do you use different names for rhinoceros, or hippopotamus, or octopus, or even for the mythological hippocampus?
There's a lot of words/animal names which are derived from Latin or Greek, so I'm genuinely curious as to why dinosaurs need to be renamed to maintain fantasy world verisimilitude, but not all the others.
Count me out on this idea! I really don't want my MM to be full of fantasy names like this. A handful is tolerable, especially for creatures that are radically fantastic or alien (eg illithid or aboleth), but when the creature is meant to be recognisable as, or in relation to, a real-world creature, I prefer a name that reflects and communicates that.if they'd include a Lost Plateau location with "Tyrants" along with, say, a population of native barbarians, that's some useful context! Then they can give the creatures names that reflect the Barbarians of the Lost Plateau that have nothing to do with our world or language whatsoever and just sound cool.
And then they can put the actual dinosaur names in parentheses so that someone looking for T-rex stats doesn't need to remember that they're called Ip'Bil-din.
For this reason, I'm not the biggest fan of the creature naming conventions in Dark Sun.