Alley Oop (not pictured here) doesn't name the dinosaur in the background this month, but it's very clearly a triceratops. For such a well-known dinosaur, I'm frankly surprised there have been so few triceratops in comic books so far. Triceratops was, of course, statted in Supplement I: National for Hideouts & Hoodlums.
The missing links have a special kind of invisibility that makes you unable to hear them as well as see them. It's more like the psionic disicpline of invisibility that just makes people unable to notice you. Psionics were introduced in Supplement III: Better Quality and will probably not go in the 2nd ed. basic rulebook.
(Scans courtesy of Digital Comic Museum)