Board Thread:Jurassic Park News/@comment-67.241.51.221-20151215203210/@comment-50.128.214.154-20160314173403

If you remember the bit with the shark, the Mosasaur let the shark go after the initial bite, and then took it down under water. Also there were two other Pteranodons already in the water that we never see again. It's conceivable that were eaten before the Pteranodon with Zara. Therefore the Mosasaur would have been satiated/more interested in a third helping of Pteranodon than in a tiny morsel like poor Zara who could have escaped, or more likely because of her injuries been rescued. It's not the most likely scenario, but it is plausible.