Is it the hard outer shell of the bulb?
What Is the Foliage of a Sago Palm Pup?
Certified GKH Gardening Expert
The new heads or offshoots located on the trunk are pups. This article will tell you how to remove them and repot them (bottom of article):
This article may help as well: https://www.gardeningknowhow.com/ornamental/trees/palms-trees/propagate-palm-pups.htm