TUNNEL THROUGH TIME

In my quest to find dinosaur-related children's and young adult fiction, I was pleased to come across this one by Lester Del Rey, who founded the Del Rey imprint at Ballantine Books, many of which I read throughout the 80s:

TUNNEL THROUGH TIME, by Lester Del Rey (Westminster 1966)(ages 10+). Bob Miller’s father has invented a “time tunnel” but when he sends paleontologist "Doc" Tom through, he vanishes.  So Bob and Tom’s son Pete try to find him.  

At first, they’re sent to the Cretaceous, where they encounter T.rex, Triceratops, Allosaurus, Brontosaurus, and “sea serpents.”  (The existence of Allosaurus and "Brontosaurus" at the same time as T.rex is explained away as "our knowing less than we think," which may be the definition of "hand wave." :-)).  

As they incrementally jump forward through time, they encounter woolly mammoths, the saber-toothed Smilodon, Megatherium, and primitive humans.

TUNNEL THROUGH TIME is a sort of fun romp.  It feels a bit old-fashioned, in large part because of the terrific old-school cover, reminiscent of Charles Knight's paintings.  Also, the teen protagonists (17 and 18) could have used a bit more autonomy at times.  Still, they're likeable and develop a good rapport with each other and with Doc.