In which of these extant classes did jaws occur earliest?
A)lampreys
B)chondrichthyans
C)ray-finned fishes
D)lungfishes
E)placoderms

Name: In which of these extant classes did jaws occur earliest? A)lampreys B)chondrichthyans C)ray-finned fishes D)lungfishes E)placoderms
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Question

Quizplus · Accepted Answer

Chondrichthyans, which include sharks and rays, are the only extant class on this list that have jaws. They evolved during the Silurian period, around 420 million years ago, making them the earliest known group with jaws.

In Which of These Extant Classes Did Jaws Occur Earliest