Postosuchus was one of the largest carnivorous reptiles of the Triassic, reaching 5-7 meters (16-23 ft) long 2 to 3.5 meters tall and weighed 250–300 kg (550-660 lbs). It had a massively built skull, bearing powerful jaws and dagger like teeth that can easily kill its quarry. Rows of protective plates covering its back formed a defensive shield, protecting it from other predators.
Postosuchus's forelimbs were over half the size of its hind legs, this characteristic of short forelimbs can usually be seen in bipedal reptiles. Chatterjee suggested that Postosuchus could walk in an erect stance, since the short forelimbs were used probably only during slow moving locomotion. However, in 1995, Robert Long and Phillip A. Murry claimed that Postosuchus was a stocky quadruped. There is a debate over whether Postosuchus was either a biped or a quadruped as scientists aren't sure yet. However, some paleontologists suggested that Postosuchus was probably a facultative biped, meaning that it altered between bipedally and quadrupedally.
In the media
Postosuchus makes an appearance on the well known documentary Walking With Dinosaurs, first shown preying opon and killing a Placerias. Later, it had a tusk wound on its thigh, perhaps a later attack on a Placerias, then it is driven away from its home by another Postosuchus. And then, due to its weakened back legs, it has died and became prey to a large team of Coelophysis.
In the 2008 video game Turok, creatures called Lurkers, resemble
Postosuchus. Lurkers also share traits to jungle cats, capable of climbing up trees and observing its prey there.