The earliest vertebrates resembled hagfish and lived more than 500 million years ago. As other classes of fish appeared, they evolved traits such as a complete vertebral column, jaws, and a bony endoskeleton.
CK-12 (High School)
How did vertebrates evolve from fish?
RST.1 - Analysis & Evidence, RST.4 - Key Terms
DEPTH OF KNOWLEDGE (DOK) LEVELS:
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