T-Rex: There are folks who don't know how to swim!
T-Rex: Feels like an oversight to me, folks!
T-Rex: Suppose you find yourself in a body of water: you're screwed! Swimming's really just a SURVIVAL thing at this point!
Dromiceiomimus: T-Rex, how is your long distance running?
T-Rex: Huh?
Dromiceiomimus: When was the last time you ran a 5k?
T-Rex: I... haven't?
Utahraptor: Seems to me like you're much more likely to face threats on LAND than at sea, bud!
T-Rex: Oh!
T-Rex: I see your point: swimming saves you while in the WATER, but as a land-dweller, MY threats are likely here. Thus, running a 5k isn't so much an exercise thing, but rather, a SURVIVAL thing, as it'll let me outrun any and all land-based threats!
Utahraptor: Exactly! I'll demo it. Try to catch me!
Narrator: LATER:
T-Rex: *huff* Arrgh *huff* slow *huff* down *huff* Utahraptor
Narrator: IT'S ONLY THREE SECONDS LATER THOUGH
Narrator: WOW, THIS IS REALLY BAD