Sometimes you work on a fossil and just think "oooh, that had to hurt". This tail from a pretty large Clidastes
from the upper Niobrara chalk is fairly boring when viewed from afar. Up close though something just doesn't look right.
|Yep, pretty boring|
Of the 45 bones, 23 are pathological, with 17 of them fused at the centrum in 5 separate masses. All of these bones lack transverse processes, so they come from the lower lobe of Clidastes'
bifurcated tail fin: a bit of dangling flesh that might make for a tasty morsel for a predator.
|I think this mass used to be 8 separate vertebrae, based on the number of chevrons|
The bones, though mostly healed, show bone growth consistent with a long infection. As the tail was the primary means of locomotion/propulsion for mosasaurs, this injury must have been very painful for a very long time for this mosasaur.
|3 verts become one|
|Fused verts, and centra with vertical scars|