_Dinosaurs in Your Backyard_ page 51 by Babbletrish
From Dinosaurs in Your Backyard, written and illustrated by William Mannetti in 1982, published by Atheneum. The illustrations are kind of odd, but some of the ideas he presents were well ahead of their time. He comes right out the gate saying birds are dinosaurs, for example.
This book has also proved to be a gold mine of Weird Old Theories I Am Glad I Didn’t Hallucinate. More information about this particularly odd theory can be found at good old Tetrapod Zoology.