Author Question: Which of these might have been observed in the common ancestor of chondrichthyan (Read 742 times)

federox

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Which of these might have been observed in the common ancestor of chondrichthyans and osteichthyans?
A) a mineralized, bony skeleton
B) opercula
C) bony fin rays
D) a spiral valve intestine
E) a swim bladder



theo

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