is angled downward, so that the leg is positioned beneath the body and acts as a weight-bearing pillar. Nevertheless, there was likely significant variation in the hip structure of aetosaurs, and the forelimbs may have had a semi-sprawling 'hybrid' stance. While the hindlimb posture is similar to rauisuchians, other traits are more plesiomorphic (typical to ancestral pseudosuchians), such as the stout pelvis and broad, five-toed feet. The forelimbs were smaller than the hind limbs, and the radius in particular was much shorter than the humerus. Nevertheless, their low and heavy body shape requires that all aetosaurs were quadrupeds. They had multiple adaptations to strengthen the body in response to their heavy armor: the iliofibularis muscle attached to a lower position on the fibula, the fourth trochanter of the femur was enlarged, the transverse processes (rib attachments) developed into long massive pedestals, and the largest species even acquired hyposphene-hypantrum reinforcements between their vertebrae. Although aetosaurs were generally wide-bodied reptiles, there is some variation in the degree of this trend. The typothoracines, exemplified by Typothorax and Paratypothorax, had a very broad, disc-shaped carapace, edged by small spines or keels and transitioning to a narrow tail. The largest species of typothoracines may have been around 3 meters (9.8 feet) in length and 110 kg (243 lbs) in weight. The desmatosuchines (Desmatosuchinae sensu stricto), such as Desmatosuchus and Longosuchus, had moderately narrower bodies and no belly armor. However, they also acquired spinier back armor, especially in the cervical (neck) region. Desmatosuchus was likely one of the largest known aetosaurs, at in length and in weight. Aetosaurs which do not fit into these two categories, such as Stagonolepis and Neoaetosauroides, generally had narrow forms, slender limbs, and a restriction in the carapace above the hip. This body type is plesiomorphic (ancestral) to the other two shapes, with some narrow-bodied aetosaurs more closely related to typothoracines and others closer to desmatosuchines. Some plesiomorphic genera, like the widespread Norian genus Aetosaurus and the Carnian Coahomasuchus, tended to be small, about a metre (3.2 ft) in length. Others were larger, such as the basal-most aetosaur Aetosauroides and the early desmatosuchine Calyptosuchus. Armor Aetosaurs were very heavily armored, with rows of large, interlocking bony plates, known as osteoderms, protecting the back, sides, belly, and tail. These osteoderms generally have a quadrangular (four-sided) shape, and were most certainly used as a defense against predators. Most osteoderms are heavily pitted on