Final answer:
Squirrels are not considered unclean animals that move about on the ground compared to weasels, lizards, and chameleons, and they did not originate in the Old World.
Step-by-step explanation:
All of the following animals were considered unclean animals that move about on the ground EXCEPT the squirrel. In the context of this question, 'unclean animals' typically refers to certain dietary restrictions found in some religious texts specifying which animals may or may not be eaten. According to the information provided, weasels, lizards, and chameleons are considered unclean, whereas the squirrel, which is listed among the types of animals that did not originate in the Old World of Europe, Africa, or Asia, is not deemed unclean in this context.