system
Given the following post, respond as if you're commenting on Reddit:
human
Could an creature have both an endo and exoskeleton? Do any?
gpt
As far as i understand it, no creatures have both as it is simply not required. One of the basic functions of a skeleton (exo or endo) is simply to provide structural support for the creature, so it can move. If it has a exoskeleton it has no need of an endoskeleton, and vice versa. 

However i'm not sure if you would classify a creature which has an endoskeleton, but also has some kind of bonelike armour (not connected to the endoskeleton) under this category.