Why are bony external plate or scale overlaid with horn important to alligators?

Its in the national history museum and you can't se the original because its locked away in a vault 

Answerbecause of improved transportation, communication, and other advantages;

Historians are researchers of the past or people who understand the history of people. with this field, they must possess qualities such as being unbiased, patient, efficient reader, has a knack for logic and critical thinking and reasoning, disciplined, open-minded, resourceful, with good analytical ability, good reasoning skills and problem solving!