Kayentavenator elysiae was named by Gay (2010) [Kayentavenator elysiae differs from other contemporaneous theropods as follows: From Coelophysis bauri; straighter femoral shaft; prominent mediodistal crest that extends 50% of the length of the femur (unlike C. bauri); acetabular rim more prominent; reduced antitrochanter; ellipsoid acetabulum; accessory condyle on medial femoral condyle; spike on lateral surface of tibia; and highly compressed caudal centra. From Coelophysis rhodesiensis (Downs, 2001; Bristowe and Raath, 2004): femoral head more elongate; lesser trochanter more pronounced; prominent mediodistal crest that extends 50% of the length of the femur (unlike C. rhodesiensis); pronounced accessory condyle on medial femoral condyle; spike on lateral surface of tibia; ellipsoid acetabulum; and highly compressed caudal centra. From Dilophosaurus wetherilli: femoral head has a more pronounced downturned tip of the proximal articular surface; lesser trochanter placed more medially; prominent mediodistal crest that extends 50% of the length of the femur; prominent accessory condyle on the medial femoral condyle; ellipsoid acetabulum; presence of a pubic fenestra; highly compressed caudal centra; and a spike on lateral surface of tibia. From Megapnosaurus kayentakatae: ellipsoid acetabulum; prominent mediodistal crest that extends 50% of the length of the femur (unlike M. kayentakatae); lesser trochanter placed more medial; groove in ventral surface of femoral head; prominent accessory condyle on medial femoral condyle; spike on medial surface of tibia; and highly compressed caudal centra, lacking ventral grooves.]. Its type specimen is UCMP 128659, a set of postcrania, and it is a 3D body fossil. Its type locality is Willow Springs 2 (UCMP V82309), which is in a Sinemurian/Pliensbachian channel sandstone in the Kayenta Formation of Arizona. It is the type species of Kayentavenator.