Complex sentence: When the "Pteranodons" escape the aviary and attack park visitors, Zara locates the boys, but is grabbed by a "Pteranodon" and falls into the "Mosasaurus" lagoon.
Split into simpler sentences: When the "Pteranodons" escape the aviary and attack park visitors, Zara locates the boys. However, a "Pteranodon" picks her up and drops her into the "Mosasaurus" lagoon.