Ekrixinatosaurus novasi was discovered in 2004 by the Gasoducto del Pacífico Company when they were constructing a section of pipeline. Ekrixinatosaurus was described by Karen Moreno, Jorge Calvos, and David Rubilar-Rogers in 2004.
The holotype was discovered in the Easten part of the province of Neuquén in Argentina, along the Baja del Añelo formation that runs through the province. Only one specimen has been found.
Ekrixinatosaurus is a theropod from the abelisauridae family. Abelisaurids are large carnivorous theropods similar to tyrannosaurs, just from South America in a later time period.
The holotype consists of parts of the upper and lower jaws, teeth, vertebrae, ribs, pelvis, ischia, left femur, left tibia, left fibula, right tibia, metatarsals, and phalanges. The original size esitmation was 7-8 metres; in 2011, the size was re-evaluated in comparison to other abelisaurids and estimated to be between 10 and 11 metres; in 2016, another review of abelisaurid sizes was conducted, and the length of Ekrixinatosaurus was re-evaluated again to be 7.4 metres, give or take 0.8 metres.
Ekrixinatosaurus is thought to be a stockier abelisaurid, like Carnotaurus, as evidenced by its relatively thick femur.
As with the other abelisaurids, Ekrixinatosaurus was a carnivore, as evidenced by its serrated teeth and skull/jaw structure.
Ekrixinatosaurus, meaning "explosion-born lizard", refers to the fact that the specimen was discovered as the result of an explosion used to prepare the area for pipeline construction. "Novasi" is to honour Fernando E. Novas, and his important work in abelisaurid research.