Bactrosaurus

The first Bactrosaurus remains recovered from the Iren Dabasu Formation in the Gobi Desert of China were composed of partial skeletons of six individual B. johnsoni.

The fossils were described in 1933 by Charles W. Gilmore, who named the new animal Bactrosaurus, or "club lizard", in reference to the large club-shaped neural spines projecting from some of the vertebrae.

[4] The nomen nudum was created and pictured in a Chinese-language book by Zhou (2005)[5] and first surfaced on the Internet during February 2006 when it was mentioned on the Dinosaur Mailing List by Jerry D.

A 1990 popular book suggested that it had an incompletely preserved crest,[3] but recent studies place Bactrosaurus as a more basal hadrosauromorph.

In 2003, evidence of tumors, including hemangiomas, desmoplastic fibroma, metastatic cancer, and osteoblastoma was discovered in fossilized Bactrosaurus skeletons.

Restored skeleton displayed at the Hong Kong Science Museum
Partial B. johnsoni skull at the Museum of Ancient Life
Size comparison