 The brain was slightly <unk> ( S @-@ shaped ) , without much expansion of the cerebral hemispheres , more like a crocodile than a bird . This is in keeping with the overall conservatism of non @-@ coelurosaurian theropod brains . Acrocanthosaurus had large and bulbous olfactory bulbs , indicating a good sense of smell . Reconstructing the semicircular canals of the ear , which control balance , shows that the head was held at a 25 ° angle below horizontal . This was determined by orienting the endocast so that the lateral semicircular canal was parallel to the ground , as it usually is when an animal is in an alert posture . 
