Using the supplementary CD "Complete Showa Plastic Model List" from "50 Years of Japanese Plastic Models" as a reference, I've compiled a list of domestic dinosaur plastic models released by the 70s.

1963: Imai Kagaku "Walking Stegosaurus" → Treasure House Vol.1
1966: Imai Kagaku "Walking Dinosaur" → Treasure House Vol.31 and Photo 1 (reprinted from Yahoo! Auctions)

1969: Nitto Kagaku Kyozai "Dinosaur Stegosaurus," "Tyrannosaurus" ● Wind-up walking. Box size around 25cm.
*Re-released in 1978 with the addition of "Brontosaurus" → Treasure House Vol.31 and Photos 2, 3 (images from enclosed catalog)

1970: Nitto Kagaku Kyozai "Dinosaur Gorgon" (description says herbivore, so presumed to be Edaphosaurus) ● Wind-up walking → Photos 4, 5

1970: Nitto Kagaku Kyozai "Dinosaur Mini Gorgon" → Photo 6 (reprinted from Yahoo! Auctions)

1971: Fujimi Mokei, Jump Kaiju Series "Tyrannosaurus" and 4 other types. Details unknown.
1972: Bandai "Brontosaurus," "Iguanodon," "Tyrannosaurus," "Triceratops," "Dimetrodon," "Ankylosaurus," "Stegosaurus" ● Wind-up walking. Around 25cm. → Treasure House Vol.31 and Photo 7 (still haven't collected them all... T_T)

1978: Nitto Kagaku Kyozai "Dinosaur 4-Piece Pack" → Photos 8, 9)
*Miniature size, about 10cm. Re-released in the 90s by Kawai Shokai under the name "Jurassic Series" with updated packaging → Photo 10

1978: Eikai "Tyrannosaurus," "Brontosaurus," "Stegosaurus," "Pteranodon" → Photos 11, 12
*Miniature size. With gimmicks such as jaw opening/closing. It's listed as "saurus" for the first time, but "Brontosaurus" is quite disappointing! Later re-released by Arii Seisakusho and Mark (date unknown), and also as a toy with confectionery by Kobito Gum → Photo 13. Only Eikai and Kobito included diorama bases.

Looking at this, 1978 seems to have been a banner year for dinosaur plastic models. Furthermore, Gakken would release the masterpiece "Skeleton Series," but I'll talk about that in detail next time.
Next time, I'll also introduce Tamiya's 1/35 Dinosaur Series, which left dinosaur fans feeling completely deflated in 1981.

By the way, do you know what Photo 14 is? It's the foot of Tamiya's Tyrannosaurus... It just has to be modified, right?