Interestingly – the carlsbad ankylosaur is not only encrusted by serpulid worms and oysters, but also has hollowed-out limb bones, which the original authors (Coombs and Demere 1996) argued was taphonomic rather than natural, as no other ankylosaurs are known to possess hollow limb bones.

Although one can certainly view this as a case of information loss – it is a far more interesting case, taphonomically speaking. We know that after skeletonization, the bones were colonized – and that the preserved portion of the skeleton was not substantially disarticulated during this period of time, which is surprising given that it was exposed on the seafloor long enough to host relatively large encrusting bivalves. This subject is of keen interest for me, as I just submitted a manuscript over the weekend documenting barnacle colonization of fossil sea lion bones.

Lastly – a friend of mine who was a former SDSU student affectionately referred to this specimen as the “ankylosaur ass”.