Heres another Ron Smith classic..
Back to Zero 405-435 (1960)
Thanks to Kashgar for the infomation.
Gerald "Ron Smith- Back from Zero Topper 1961":
This reminds me of a 1968 Topper serial featuring a lost land where dinosaurs still live. It recounts the adventures of a father and son who go there and must brave tropical poisons, volcanoes and other hazards, as well as the dinosaurs, as they try to get back to civilisation. Another of Ron Smith's, perhaps?...