American paleontologist Joseph Leidy describes the new genus and species Laelaps aquilunguis, demonstrating that theropoddinosaurs walked on their hind limbs rather than on all fours as in earlier reconstructions.[12]
Down, J. Langdon H. (1866). "Observations on the Ethnic Classification of Idiots". Clinical Lectures and Reports by the Medical and Surgical Staff of the London Hospital. 3: 259–62.
Holtz, Thomas R. (2004). "Tyrannosauroidea". In Weishampel, David B.; Dodson, Peter; Osmólska, Halszka (eds.). The Dinosauria (2nded.). Berkeley: University of California Press. pp.111–136. ISBN0-520-24209-2.