("great wonder") is a name given to the remains of a large ceratopsid
that lived in Wyoming
during the Late Cretaceous
, around 65-70 million years ago). The name comes from Greek
- 'much' and θαυμα
- 'wonder'. It is important because it was the first ceratopsian whose remains were found and described by a paleontologist
. Relatively little is known about the species because the only fossils found were of the back half of the dinosaur. It is considered a nomen dubium
and debate exists to what Agathaumas
is, most arguing that Agathaumas
is simply a mislabeled Triceratops
Agathaumas was found in 1872 in southwestern Wyoming by F. B. Meek, who notified Edward Drinker Cope of the find. Cope himself participated in the dig, eventually recovering most of the back half of the animal, excluding the legs. Since these were the first ceratopsian remains found, Cope was uncertain as to precisely what sort of dinosaur Agathaumas was (although he recognized it as being something new) until O. C. Marsh described Triceratops in 1889.
In a 1889 paper, Cope suggested that Marsh's Ceratopsidae be renamed Agathaumidae, because of the paucity of Ceratops remains.
- Agathaumas (Triceratops) sylvestris Cope, 1872; 16 vertebrae from the tail, sacrum and back, a partial pelvis and several ribs
- A. flabellatus (Marsh, 1889/Scott, 1900); included with Triceratops horridus.
- A. milo (Cope, 1874); included with Thespesius occidentalis.
- A. monoclonius (Breihaupt, 1994); nomen dubium included with Monoclonius sphenocerus.
- A. mortuarius (Cope, 1874/Hay, 1902); nomen dubium included with Triceratops horridus.
- A. prorsus (Marsh, 1890/Lydekker, 1893); included with Triceratops prorsus.
- A. sphenocerus (Cope, 1890); nomen dubium included with Monoclonius sphenocerus.
Unfortunately, the bones of the rear half of the animal found are not particularly diagnostic in ceratopsians and Agathaumas remains a nomen dubium. No other remains have been found in the area, but based on its size and age of the rocks, it probably was a Triceratops or Torosaurus.
In 1897, artist Charles R. Knight painted Agathaumas for Cope, creating an imposing beast which blended the long facial horns of Triceratops with the spiked frill of the Styracosaurus. The artwork was seen years later by stop-motion animator Willis O'Brien, who used the Agathaumas in the 1925 film The Lost World. The Agathaumas has appeared in various forms since then.
- Peter Dodson; The Horned Dinosaurs (1996)
- Don Glut; The Dinosaur Scrapbook