Procompsognathus may have been about 1 meter long (3.3 ft). A biped, it had long hind legs, short arms, large clawed hands, a long slender snout with many small teeth, and a stiff tail. It lived in a relatively dry, inland environment and may have eaten insects, lizards, other small prey.
The only known fossil of this animal is extremely poorly preserved, so it is hard to tell what it was. Today it is thought to be a dinosaur in family Coelophysidae.