Gracilisuchus stipanicicorum

Middle Triassic of Argentina. Discovered in the early 1970s and described in 1972.

Very small pseudosuchian (30cm long) yet it was previously described as a dinosaur (since rejected). Its skeleton suggests that it probably was quadrupedal, and the sharp teeth indicate that it was carnivorous. Although its remains are fragmentary, Gracilisuchus is an important animal to study because it is generally agreed to lie in the middle of the pseudosuchian lineage, and thus it can provide information on how early forms changed into more crocodile-like forms.

Gracilisuchus
Artistic interpretation of Gracilisuchus by John Conway