Notes
Speaking of Dinosaurs, a novel by Philip E. High.

isfdb.org records the publication date as January 2001, while the book itself only records the year of original publication, i.e. 1974.

Blurb – Lower Cover
Beyond evolution . . .

A certain gifted engineer accepted the Theory of Evolution until he wandered by chance into a museum. In that museum was the skeleton of a dinosaur, and the skeleton got him thinking and enquiring . . . with terrifying results.

Attempts are made on his life and then, in a horrifying time shift, he finds himself naked and unarmed in the distant past . . . facing one of the very creatures which had aroused his interest – a dinosaur!