

This is the head of a plesiosaur from Kansas, back in the day when Kansas was an inland sea.
Or a picture from back in the day when the U.S. was still in World War II, and The University of Kansas Science Bulletin was digging up skulls of prehistoric marine creatures and giving them new names. The researcher here was E.S. Riggs, who was enlightened enough to give credit to artist Dorothea Franzen even before getting into the story of how this skull was found and what it means for our understanding of the primordial seas.
Trinocromerum willistoni is better known today as Trinacromerum, and is one of the “best represented polycotylid plesiosaurs in the fossil record.” At the time, this was the first member of this species of Trinacromerum to be identified.
I found the May 15, 1944, issue of The University of Kansas Science Bulletin here, in the Biodiversity Heritage Library.