Dinosaurs, despite their extinction, are the source of endless fascination. The young, especially, never tire of reading about them and visiting their bones in museums.

Publishers know that, and their response has always been a steady trickle of children's dinosaur books. This season, however, the trickle has become a stream, and some of the books are aimed not just at children but at adults as well.

Some of this interest has been fanned by the well-publicized debate among paleontologists about the nature of dinosaurs. Were they all really the cold-blooded, clumsy behemoths we have assumed them to be? Or were some more graceful, sprightly and warm-blooded?

Most of this season's crop of books reflects the debate. In fact, Mary Packard in Dinosaurs, (illustrated by Christopher Santoro, Simon and Schuster, $6.95, Ages 4-8), says unequivocally: "Most scientists think that the speedy coelurosaurs (among the earliest dinosaurs) were warm-blooded." Packard's light -- rather than heavy -- word descriptions are tailor-made for children: "The neck plate of the triceratops is a "frill," the duckbills' crests, "hats." Also appealing to children are her details, like a "fully-grown camptosaurus would be big enough to look into your upstairs window."

Making the connection between dinosaurs of picture books and the racks of bones strung up in museums isn't always easy for a child. To help, Aliki has written Digging Up Dinosaurs (Crowell, $8.95, Ages 4-8), in which he shows and tells how fossils were formed, how people became interested in them, how they are extracted from rocks today and assembled in museums. Aliki clearly, and often humorously, traces the entire process.

Should someone you know want to draw a stegosaurus or diplodocus himself, Syd Hoff's How to Draw Dinosaurs (Windmill/Simon and Schuster, paperback $3.95, Ages 6-10) has all the tips.

For older children this season, there are two excellent books, each with its own emphasis. Dinosaurs of North America by Helen Roney Sattler, illustrated by Anthony Rao, with an introduction by Dr. John H. Ostrom (Lothrop, $10.95, Ages 8-up), is the more conscientious but less interesting of the two, but it does offer an authoritative illustrated catalogue of the more than 80 types of dinosaurs which roamed Mesozoic North America. Its detail and order will appeal to any child who likes facts classified in an orderly fashion.

For the youngster apt to find the human stories of the first fossil-hunters as intriguing as the dinosaurs themselves, there is Dinosaurs Discovered by John Gilbert (Larousse, $8.95, Ages 12-up, available in February). Published originally in France, the book traces the European naturalist tradition which sent hundreds of 19th-century ladies and gentlemen scrambling over the countryside in search of fossils. Many of their findings form the basis for what we know today about dinosaurs. But what was for them the fruit of an afternoon's walk, became for the next generation of "professionals" the cause for keen -- sometimes cut-throat -- competition.

One final book worth mentioning for adults, although it is not about dinosaurs but about the early mammals who coexisted with them, is Synapsida: A New Look into the Origin of Mammals, by John C. McLoughlin (Viking, $14.95). McLoughlin, a zoologist and a wonderful artist, caused something of a stir with his Archosauria: A New Look at an Old Dinosaur, which made a convincing case for the warm-blooded theory several years ago. Synapsida develops some of his earlier arguments and is worth picking up for the pen-and-ink illustrations alone.

So when your 5-year-old announces that he'd like you to schlep him down to the museum yet again to look at the dinosaurs, there is an alternative -- a cozy read for both of you by the fire.