What's the name of these parts when importing animated models?

Unity Engine
1

When you import an animated model, it appears with an arrow icon which allows to expand and see all parts of the imported model. I can distinguish the meshes, the avatar, the animation clips, but there’s another element which has a Transform component on it and I don’t know the name of it. It is the selected element in the following capture:

There seems to be at least one per mesh in the model, and its purpose appears to be to define the relative transform of the mesh on the GameObject, but I couldn’t find information on the Animation documention. What’s the name of this element?

Thank you in advance.

2

Could be a null object from the originating 3D app. Like a spline curve rig controller. Open the file up in your 3d tool to confirm.