What is Flagellicaudata?

Diplodocus longus, Dicraeosaurus hansemanni, their most recent common ancestor and all descendants. The diplodocoids (relatives of Diplodocus) with long, "whip tails". Some palaeontologists speculate that their extremely long, tapering tails were literally used as whips: not necessarily to whip would-be predators but to create loud "sonic booms" as a deterrant. However, later research concluded that, due to friction of the musculature and articulations, as well as aerodynamic drag, their tailtips could achieve velocities of no more than 100 km/h, which is far slower than the speed of sound. Furthermore, skin, ligaments and tendons would not be able to withstand super-sonic speeds, even with the presence of a conjectural, soft tissue version of the "popper", found at the tip of real bullwhips.

Funnily enough, Flagellicaudata was erected to house all non diplodocid/non dicraeosaurid diplodocoids which, at the time, was just Suuwassea. As many experts expected, Suuwassea was later identified as a member of Dicraeosauridae, which renders Flagellicaudata a bit unnecessary, as it doesn't include anthing that isn't also a diplodocid or a dicraeosaurid. Still, it neaty segregates all diplodocoids with "whip tails" from those who don't.

Click here to search Dinochecker's database for Flagellicaudata. Flagellicaudata is derived from the Latin "flagellum" (whip) and "cauda" (tail), because of their long, tapering tails.