brachiosaur
noun
brach·i·o·saur ˈbra-kē-ō-ˌsȯr 
: any of a genus (Brachiosaurus) of very large sauropod dinosaurs of the Late Jurassic period having a massive body, a very long neck, and forelegs longer than hind legs
Example Sentences
Recent Examples on the Web From there, though, brachiosaurs started to shrink back. 
Brian Switek, Scientific American Blog Network, 5 May 2017
Brian Switek, Scientific American Blog Network, 5 May 2017 Word History
Etymology
New Latin Brachiosaurs, from brachi- + Greek sauros lizard
First Known Use
1912, in the meaning defined above