Given the task definition and input, reply with output. You are given a sentence and your task is to generate another sentence that supports the given input.

Arandaspids represent the oldest known craniates, a proposed group of chordates that contain all chordates with a cartilage-derived skull (i.e., lampreys, armored agnathans, and gnathostomes), and hagfish.
Hagfishes have a skull made of cartilage.