22 August 2012
Skorpiovenator's Fast Legs
There have been studies recently, such as Persons and Currie 2011, which have analyzed abelisaur speed characteristics. The specific animal they studied was Carnotaurus and they looked specifically at muscle attachment sites along the beginning of the tail (caudal vertebrae) and the related attachment sites along the femur. What they found in Carnotaurus indicated a large predatory dinosaur that was capable of short fast sprints, a powerful land-striding gait, and an inability, due to the rigidity of the caudal vertebrae anchoring muscles, to make tight turns at speed. Why is this important for Skorpiovenator, a cousin of Carnotaurus? As a South American ableisaur Skorpiovenator shares more with Carnotaurus than do Indian and African abelisaurs. It is well documented that the South American abelisaurs evolved traits, as a whole, that did not develop on the other continents after the Gondwanan split into more recognizable continents that we have today (see page 5 of Canale et al's original paper linked yesterday). It is not, therefore, too odd to find that the caudal ribs of Skorpiovenator are similar to those of Carnotaurus, indicating that Skorpiovenator too was a fairly quick predator. It may have had different bumps and horns on its skull, but it was a good short distance runner as well. Persons and Currie make no statement to the effect that Skorpiovenator would have had trouble turning, but given that its ribs and muscle attachments are similar to Carnotaurus, it may very well be the case that it as well did not make very good tight turns at speed. Considering that both animals likely hunted large sauropods in numbers, along with smaller animals when they had to including young sauropods, a high rate of turn would not likely have been a factor (I have no paper to cite sauropod turning radii at the present, though I am sorting through some papers by Carrano, Christensen and Bonnan on sauropod locomotion).