Sonic 2 Artist posts dumps of Development sprites, Should we archive here?

[Paraemon]

A lot of this stuff looks proto-Sonic 1 (or fan-made) in design, most notably the Pterodactyl thing, if by the way it was drawn.

I've just glanced through the Sonic Retro discussion on it, and it seems legit. Though, my main question would be how to quantify them ought they end up site-side. We know a few bits about one or two of them, but nothing about the rest.