How Dinosaurs Evolved to Become So Huge

This page is the CodyCross answer for the clue below from Casino, Group 279, Puzzle 4 (Hand Mucking).

Question is: How Dinosaurs Evolved to Become So Huge

and the answer is: GIGANTISM

Word Meaning:

GIGANTISM — The quality or state of being gigantic; being of abnormally large size.

Definitions from Wiktionary.