Dalzell was a popular fan artist in the 1970s and 1980s at conventions in the Northeast, and this is one of her drawings from 1973.  Bonnie studied Studied Paleontotology, Anatomy and Evolutionary Biology at University of California, Berkeley so it's no wonder that she was inspired to apply that knowledge when depicting fantasy and science fiction creatures!  Hand-drawn in inks on parchment drawing paper, 8.5" x 14" and is signed and dated 1973 bottom right