Some articles on herrerasaurids:

... Herrerasaurids are among the oldest known dinosaurs, appearing in the fossil record 231.4 million years ago (Late Triassic) ... Herrerasaurids were small-sized (not more than 4 metres (13 ft) long) carnivorous theropods or basal saurischians ... Less complete herrerasaurids have been found in North America, and they may have inhabited other continents as well ...