Bonnethead began with a taxon that had a highly pronounced cephalofoil (most likely that similar to the winghead shark, "Eusphyra blochii"), and was later modified through selective pressures. Thus, judging by their smaller cephalofoils, bonnethead sharks are the more recent developments of a 25-million-year evolutionary process. This species occurs off the American coast, in regions where the water is usually warmer than . It ranges from New England, where it is rare, to the Gulf of Mexico and Brazil, and from southern California to Ecuador. During the summer, it is common in the inshore waters of the Carolinas and Georgia; in
Creature Catalogue of the player characters, originally printed in the Master Set, is reproduced in the introduction. Each creature is listed with appropriate "D&D" statistics and a short description of the creature, its abilities and tactics. A variety of authors and artists combined to the listings including Zeb Cook and Gary Gygax. AC9 "Creature Catalogue" was compiled by Graeme Morris, Phil Gallagher, and Jim Bambra, and was published by TSR in 1986. The "Creature Catalogue" is in the format of a 96-page perfect-bound book, which TSR had been adopting more frequently at the time. Cover art is by Keith Parkinson. An updated