Dinosaurs in Corsets!
In the previous post “Asia’s Heaviest Dinosaur”, a comment was made about the body armour found on many Titanosaurs. Scientists now know that many Titanosaurs excavated from places as far apart as Argentina, Malawi and France were covered in bony plates, separated by groups of bony tubercles. Some of the larger specimens had bony plates or scutes the size of CDs, perhaps in life these were covered in horn and formed a spike.
The first recorded evidence of armour in a Sauropod was in 1896 when the eminent scientist Charles Deperet described Titanosaurus from the Late Cretaceous of Madagascar. At the time his paper on an armoured Sauropod was treated with derision. It was not until the likes of Saltasaurus were described in the 1980s that Deperet’s paper was remembered and treated with more respect.
Scientist’s still ponder why such large creatures had armour on their backs. These animals were huge (even the medium sized ones were 12-15 metres long and would have easily weighed far more than any known carnivores around at the time).
The skin of a Titanosaur has been estimated to be over 7 cms thick, even the most determined Tyrannosaur would have had a job to bite into this to cause any damage.
These observations have led scientists to put forward a different theory for the body armour. The armour may have had nothing to do with defence.
Close study of the backbones of Titanosaurs show that these bones were very different from the backbones of other Sauropods such as the Camarasaurids and Brachiosaurids. The backbones of Titanosaurs seem to lack the large hollows that are found in other types of long-necked dinosaur. They lack the struts and bony projections that anchored the back muscles seen in other Sauropod families. In fact the vertebrae are quite unsophisticated in their structure and quite small for such large animals.
Perhaps the armour on the back and flanks was more of a stiffening system to provide added strength to the back and hind quarters to aid locomotion. From fossil trackways, it does seem like Titanosaurs had a very wide stance, the wide body was required to house the massive digestive tract that these animals possessed. Like the carapace on a lobster to provide support or like wearing a set of corsets to help keep their tummies in.