Although not strictly speaking part of the series, the title The Doctor Who Dinosaur Book, published in 1976 established the format. Each book featured the Fourth Doctor relating historical and scientific information to the reader as he explored the subject in the TARDIS. Each of the books included a pull-out poster stapled to the centre, depicting the cover artwork by Jeff Cummins. Priced at 75p, the books each had a print run of 40,000 copies, apart from the final instalment Doctor Who Discovers: Strange and Mysterious Creatures which had a reduced print run of 10,140 copies.