STL Science Center

STL Science Center

07 April 2012

The Skeleton of Amazement

©Andrey Atuchin
Gastonia, named for Robert Gaston the man who uncovered the bones for the first time, was definitely a biological tank of the Early Cretaceous. Unlike his later cousins Euoplocephalus and Ankylosaurus, he was nearly completely defensive with only shoulder spikes and lateral spikes to serve as offensive weapons; though one could suppose that any dinosaur that could build up a little steam could simply "bar-room brawl" its enemies to the ground like a linebacker should they appear otherwise defenseless. However, sometimes patience and spikes are fabulous defensive weapons and strong enough to frustrate as well as injure any predator trying to get a bite out of you. Oh, and let's not forget that general body stature sometimes plays a part in staying alive. Gastonia was built like a tank, and it was also barely off the ground, for a dinosaur. This general configuration gives it a fantastic center of gravity that, should it play into the mind of a predator to tip over Gastonia, they would expend a massive amount of energy before they succeeded. Being able, with this body design, to keep your attacker in your sights and to ward off thrusts with spikes and by lowering your soft belly, more often than not most likely won out the day and would have allowed Gastonia to continue its lawnmower activities.

Speaking of which, what does the dental battery of a Gastonia look like? It actually just looks like a the teeth of a file have been very carefully inserted into the mouth of Gastonia. It also appears as though there was plenty of space for a cheek, which is a wonderful adaptation for an herbivorous animal to possess. The sharp edged beak in front could sheer off plant matter and, with the help of the tongue and lips, pass that plant matter back into the grinder of teeth which could tear the plant matter further. Notice that the teeth are actually sharper than they are flat. Without the ability to mash the vegetation with flat teeth the Gastonia would have most likely possessed an active gizzard full of stones to smash the vegetation up as needed. Gastonia possessing a cheek would then allow for this mashed mixture to be passed back up, as in cows and other ruminants, to be gnashed at by the teeth again with the cheek and tongue working in conjunction with the teeth to hold and move the mixture as it is chewed up again for further digestion. No cheek means no ability to keep the plant matter in the mouth, which would make chewing cud completely futile for this animal and if that is the case then all essential digestion would occur in the stomach and/or gizzard.

Gastonia's entire skeleton is jaw dropping really. The mouth and skull are great in their very turtle-like solidness; very anapsid like of Gastonia to have a skull like that actually. That is not the only part of the anatomy which has been recovered though. The remainder of the skeleton paints a rather interesting picture as well. The pelvic or sacral armor girdle is a sheet of solid bone. I have not actually checked to see if it is many fused bones or one enormous bone, but either way it is a sod mass of strong bone protecting the hips, the base of the tail, and the middle of the torso. The tail itself has little to no protection of its own. The spikes and armored plates on the upper torso and shoulders are impressive as well though. The tallest spikes are actually near the center of the back with two slightly shorter thumbtack like spikes above the shoulders and facing out from the lateral surface of the shoulders. Along that line down the side of the animal more spikes protrude and, if flexible enough, could certainly been overlapped by Gastonia in a scissor-like gesture; more on this idea later. The solid plates of bone without spikes were obviously more for deterring teeth and claws than for use as an offensive weapon, but their use was important as well.

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