Identify movie with caveman and dinosaur

There is a short (16mm?) color film where a stop-motion dinosaur
is attacking a caveman, when another caveman says hey dinosaurs
and hominids are not of the same time period, and the dinosaur
then blips out of existence. I think the title may have been
"anachronism" however I can't locate any information
about this and other films in this series, which is unthinkable
in a post-google world! Who wrote/directed this and why?