Page 1456 - Veterinary Immunology, 10th Edition

VetBooks.ir Immunity in Vertebrates

There are seven classes of living vertebrates: jawless fish,
cartilaginous fish, bony fish, amphibians, reptiles, birds, and

mammals (Fig. 43.4).

FIG. 43.4 A simplified phylogenic tree showing the major
relationships among the vertebrates.

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