Living members of the lineage ____ are jawless vertebrates called lampreys, which are mostly parasitic as adults. They have shards of cartilage that partially cover the nerve cord, which may represent an early stage of the evolution of vertebrae.
a. Petromyzontoidea
b. Placodermi
c. Cephalochordata
d. Urochordata
e. Myxinoidea
A
Biology & Microbiology
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a. lemurs b. tarsiers c. New World monkeys d. orangutans e. Old World monkeys
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