Resources.LoadAll with automatic GameObjects?

I'm using Resources.LoadAll with a folder that only contains an FBX file. If I use the LoadAll that doesn't take a type, I get back 2 objects, one mesh and one GameObject. Is there some documentation somewhere that explains the circumstances by w$$anonymous$$ch a GameObject is automatically created for a mesh for the resource system? T$$anonymous$$s unexpected GameObject throws extra noise in my desire to be able to assume that all GameObjects are prefabs. Anyone know why t$$anonymous$$s happens? The debugger shows prefabs as a UnityEngine.Prefab type, but I'm guessing that is an internal class, because I can't seem to use it as a type filter for LoadAll to get the results I expect, and must rely on grabbing the game objects as prefabs.

My expectation is that when I do Resources.LoadAll on a folder that only has an fbx in it, that I will only get that single mesh object back, and not some GameObject that appears to be automatically created as well.