|©Jaime A. Headden (cropped for today)|
The legs of Achillobator, despite the overall size of the animal, are quite small. Tibia and tarsus both are extremely short compared to the femur, though, admittedly, the heads of the tibia and tarsus both appear to be either missing or broken and chipped (though I have to admit I am going off of 2nd hand illustrations still). Shorter legs generally require higher energy consumption than longer legs to cover equal distances. The Achilles' tendon of Achillobator, obviously lending itself to the name, was reported as having to have been rather large, however, even on the shorter leg. The large tendon and the short leg most likely packed a rather large punch, causing great damage through the arc of the swinging motion of the leg. Not possessing as much speed but, rather, being more like the muscle laden Utahraptor, Achillobator was probably much more likely to wrestle and bring down prey with power than tiring it out in pursuit. This, then, would also make it much more likely to be an ambush predator like a lion rather than a pursuit predator like a cheetah. Of course, this is not necessarily the view put forth by the paper, but I cannot state the author's viewpoint as I still do not have a copy of the paper.