and probably Liliensternus, though more basal than Coelophysis. Yates (2006) found Zupaysaurus to form a group with Dilophosaurus and Dracovenator, placing it in a monophyletic Dilophosauridae. But later studies found Zupaysaurus to be a sister taxon sister to a clade containing dilophosaurids, ceratosaurs and tetanurans. Below is a cladogram based on the phylogenetic analysis conducted by Sues et al. in 2011, showing the relationships of Zupaysaurus: Paleoecology Zupaysaurus was discovered in red siliciclastic sediments at the "Quebrada de los Jachaleros" locality within the Los Colorados Formation of the La Rioja province in Argentina. This formation has been shown by magnetostratigraphy to date to the Norian stage of the Late Triassic period, approximately 228 to 208 million years ago. but has also been assigned to the slightly younger Rhaetian stage, which was approximately 208 to 201 million years ago. Both specimens assigned to this genus are housed in the collection of the National University of La Rioja in La Rioja, Argentina. The Los Colorados Formation was interpreted as an ancient floodplain and it was home to several types of early sauropodomorph dinosaurs (including Riojasaurus, Coloradisaurus , and Lessemsaurus), all of which shared the same paleoenvironment with Zupaysaurus. It is recognized as one of the earliest known faunal assemblages dominated by dinosaurs, which were 43% of the number of tetrapod species currently known. The non-dinosaurs that inhabited this locality included pseudosuchians, therapsids like Cynodontia, other early reptiles, and possible archosaurs. References External links Zupaysaurus entry in The Theropod Database. Prehistoric neotheropods Dinosaur genera Norian life Late Triassic dinosaurs of South America Triassic Argentina Fossils of Argentina Los Colorados Formation Fossil taxa described in 2003 Taxa named by Rodolfo Coria