In ice age 3, we are introduced to the crazy weasel Buck. One of the most defining things about him (other than his eyepatch) is his knife (he got both at the same time). Here is a still of him with it:
Later, in Ice age 4, we see Gupta, one of Gutt's crew give Weiner his knife:
Later on we see buck still having his knife in ice age 5.
To me, these seem to be the same knife, and I'm not alone: someone has already asked this question. However, the answer they got was not very helpful.
Is there a better explanation as to how a seafaring pirate got a dino-tooth (and not just any Dino! This is the tooth of Rudy himself!) knife, or is it just animator laziness?