Definitely Dinosaurs were a series of "dinosaur" toys first produced by Playskool in the 1980s. Each dinosaur had a distinctive Apatosaurus stamp on its underbelly or leg to indicate authenticity. They also included cavemen and cavewomen, with different faces and racial features. However, no other mammals were produced. Smaller versions were included in the Wendy's kid's meal and on blister cards.

The animals included:

• Anatosaurus (both large and small)
• Ankylosaurus (both large and small)
• Apatosaurus (both large and small)
• Brachiosaurus (small only)
• Ceratosaurus (small only)
• Deinonychus
• Dimetrodon (not a dinosaur)
• Leptoceratops (small only)
• Moschops (not a dinosaur)
• Pachycephalosaurus
• Parasaurolophus (both large and small)
• Polacanthus
• Protoceratops
• Psittacosaurus
• Spinosaurus
• Stegosaurus (both large and small)
• Struthiomimus
• Triceratops (both large and small)
• Tyrannosaurus (both large and small)
• Ultrasaurus