Pteranoman: Crossover or Spinoff?

[Ninjinister]

I got my copy of Shell Shock today (great stuff, by the way), and I noticed that there's a 1989 copyright for Pteranoman and the Cave Babes by Donald Simpson in the story "Teen Techno Turtle Trio Plus One!". I figured, since the Triple T +1 and Splicer weren't mentioned, that they must have some other use in comics.

So I check Google, and find Pteranoman #1 was published in April 1990. So, I figured maybe he was part of another series before getting his own comic. However, according to TripAtlas.com, he was part of another comic series, Megaton Man, but only after having his own comic.

Originally Posted by http://tripatlas.com/Megaton_Man#Pteranoman

An anthropomorhic Pterosaur, Pteranoman is basically a human dinosaur, but had his own comic series prior to being amalgamated into Megaton Mans' fiascoverse.

The International Catalogue of Superheroes indicates that Pteranoman's first appearance is Pteranoman #1 ( http://www.internationalhero.co.uk/p/pterano.htm ). How can this be if he appeared in Shell Shock before that? Then again, this same site says Casey Jones' first appearance was Teenage Mutant Ninja Turtles #1.

So my question is, which of the information is correct, and would he be considered crossed over or spun off with/from TMNT?