I'm not ashamed to say that I've caught them all. Seriously, I spent six months playing Pokemon Pearl, catching them all. Before that, I'd blown chunks of my childhood mowing through Pokemon Red and Pokemon Gold. For reasons I'm unsure of, I skipped Pokemon Ruby/Sapphire. Anyway, there are more than 490 Pokemon in the series, and I caught them all through in-game catching, trading with friends, or pulling them off my brother's cheat-enabled Sapphire cart. Out of those 490+ Pokemon, there are several prehistoric forms. Many are derived from dinosaurs and other vertebrates, and I thought I'd share those critters here. In part 2, we'll look at arthropod and crinoid Pokemon, but for now, let's look at reptiles and mammals.
Meganium is the adult form of the Chikorita-Bayleef line. It is clearly based on sauropods, but has its own unique features, such as the flower petals growing around the base of the neck, and the small antennae above the eyes. Supposedly, the pollen given off by the petals has great healing abilities, and can even help bring dying plants back to life.
The clearly-related Tropius is a strange sauropod Pokemon with giant palm leaves growing its back. Supposedly these leaves allow the beast to fly, although I somehow doubt that hypothesis. Its leafy helmet somehow grows bannanas. Strangely, Tropius has reduced the number of phalanges in its forefeet to one each, and has lost its tail.
Sceptile is a strange theropod which is the adult form of the Treeko-Grovyle line. The spines on its lower arms are reinforced with bone, and large spines grow in a cross-shape along the tail. Despite its heavy spines, Sceptile is a very fast Pokemon.
The size of a tyrannosaurine tyrannosaur, Groudon looks like something out of a Godzilla movie. It's wide shape and powerful forelimbs have evolved to sustain a burrowing lifestyle. Groudon is a desert-dweller, burying itself in the dunes during the day and hunting at night. The huge claw-like structures on its tail are useful in the pursuit of prey, as are its large manual claws.
Rampardos is a heavyset pachycephalosaur which is the adult form of Cranidos. Its dorsal neural spines are higher toward the shoulders, forming a distinct "hump" along the back. The large head is bordered by four long spines, and the knees are capped with small bony spikes. Rampardos is not a particularly large Pokemon, but it is very spirited and can be dangerous!
Bastiodon is a bizarre ceratopsian Pokemon, although it looks like something that would guard Aztec ruins! Although functionally toothless, Bastiodon has four lower teeth which grow upwards and give the face a cagey look. The orbital horns stick out laterally and act more as eyeshades than anything elese. The creature's back is armored, as are its lower legs. Although it looks menacing, Bastiodon is a gentle giant that lives in small groups and cares for its young, called Shieldons.
Aerodactyl is a large, dangerous pterosaur Pokemon! It is fairly heavy for a pterosaur, and instead of a tail "rudder," like other rhamphorhynchoids, Aerodactyl has a devil tail. It retains large mandibular teeth, and its lower jaw fits snuggly around the upper jaw, giving this strange pterosaur a prominant underbite.
Lapras, an armored-backed plesiosaur Pokemon, is easily tamed and often used as a mount by human trainers. It uses its unique unicorn horn to scrounge the seabed for invertebrate prey, and its coiled ears give it unnaturally good hearing. Unlike other plesiosaurs, Lapras' foreflippers are much larger than its hind flippers, which may somehow relate to the weight of its strange dorsal armor.
Mamoswine is an ice-age Pokemon that is more related to pigs than elephants. Its tusks are proportionately longer than any mammoth's. Rather than a trunk, Mamoswine has a ridiculously long tongue, which it uses to snatch up food uncovered by the tusks. Mamoswines may have evolved from Piloswine, which itself is the adult form of Swinub.
Relicanth is a "living fossil" fish. While most of the other Pokemon you see here must be cloned from extracted DNA, Relicanth can be caught in ancient caverns and deep beneath the sea. It lies nearly motionless on the seabed, waiting for a meal to come swimming by. The red dot on its side is bioluminescent, and seems to be used for interspecies communication.