Elaphrosaurus

''Elaphrosaurus (pron.:ell-AH-fro-SAWR-us) is a genus of ceratosaurian theropod dinosaur that lived approximately 154 to 150 million years ago during the later part of the Jurassic Period in what is now Tanzania in Africa. Elaphrosaurus was a medium-sized, but lightly built, bipedal, carnivore, that could grow up to 6.2 m (20 ft) long. Morphologically, this dinosaur is significant in two ways. First, it has a relatively long trunk but is very shallow-chested for a theropod of its size. Second, its has very short hindlimbs when compared to its relatively long trunk. Phylogenetic analysis indicates that this genus is likely a ceratosaur, and earlier suggestions that it is a late surviving coelophysoid have been examined but generally dismissed.

Etymology
The genus name Elaphrosaurus is derived from the Greek words elaphro (ελαφρός) meaning "light" as in "light-weight", a reference to its slender frame and "sauros" (σαυρος) meaning "lizard";[1] thus, "lightweight lizard". Elaphrosaurus was described and named by Werner Janensch in 1920 and the type species is Elaphrosaurus bambergi.

Description
Elaphrosaurus was long and slender, with a long neck. What is known about Elaphrosaurus mostly comes from a single nearly complete skeleton and no skull has been found. It was distinctive among theropods for being short-legged for its length. Paul (1988) noted that this was the longest-trunked and shallowest-chested theropod that he has examined.[2] Elaphrosaurus was about 6.2 m (20 ft) long, 1.46 m (5 ft) tall at the hip, and weighed about 210 kilograms (463 pounds).[2] The tibia (shin bone) of Elaphrosaurus, measured 608 mm was considerably longer than its femur (thigh bone) that measured 520 mm, which indicates that it could probably run very fast.[3] Its long tail ended with a rare downward bend which may be unrelated to taphonomy.