A Kryptonian throwback lands on Earth in the Finger, Sprang and Paris story in World’s Finest 102 (June 1959).
The caveman lands and goes on a rampage. Superman is amazed when the creature uses x-ray vision, and after examining the rock he landed buried within, realizes that he is from Krypton. It’s an outrageous coincidence, but commonplace in the Superman mythos.
The situation becomes complicated when hoods go around with a fake caveman to scare people off. They get ahold of Batman and Robin, and keep Superman at bay with kryptonite, but the caveman is the one to capture the bad guys, tossing their car off a cliff. Superman saves their lives, and is about to tackle the caveman when he simply keels over, dead. Superman has a sort of explanation, about cosmic rays and kryptonite.
Tommy Tomorrow moves over to World’s Finest from Action Comics, having lost his spot to Supergirl.
Arnold Drake and Jim Mooney start his run here with a story that is completely along the lines of most of his tales. With his pal Brent Wood, Tommy Tomorrow is on the case of space raiders who seem to have taken control of a giant space-bird that spits tar. We see a number of odd alien creatures before Tommy figures out that the space-bird is really a ship in disguise. They use the other alien creatures to capture the raiders.