Bulgaria
| Country: | Bulgaria |
| Type: | Postage stamps |
| Series: | Prehistoric Animals |
| Nominal: | 20 ст |
| Year: | 1971 |
| Perforation: | line 12½ |
| Mintage: | 250,000 |
Prehistoric Animals
 Plesiosaurus 0.11$ |  Iguanodon 0.1$ |  Archaeopteryx 0.1$ |  Edmontonia 0.16$ |
 Styracosaurus 0.15$ |  Tyrannosaurus 1.4$ |  Brontosaurus 0.06$ |  Stegosaurus 0.09$ |
 Edaphosaurus 0.16$ |  Rhamphorhynchus 0.07$ |  Protoceratops 0.1$ |  Triceratops 0.48$ |