 The hooked rear edge of the coracoid region is also offset from the glenoid (shoulder socket) by a large U-shaped notch.The humerus (upper arm bone) was thin and straight, with a low and somewhat rounded humeral head (the portion which attached to the shoulder).In contrast, abelisaurids had a large and bulbous humeral head (although similarly rounded) while that of other theropods was flattened from front to back.