POLAND / SAN MARINO, 1965

Poland 1965 San Marino 1965
The first pictorial stamps depicting prehistoric animals were issued in 1965, the Polish issue just predating the one from San Marino. Both issues had only one purpose: to be collected.
The illustrations on the Polish stamps are after the famous Czech painter Z. Burian; the first time his works appear on stamps, but definetely not the last.
Note the misprint (colour shift) in the Polish stamp.
 
TvE