Open Paleo

Kayentavenator

Gay, 2010 KAI-en-tuh-VEN-uh-tuh Disputed

Named after the Kayenta Formation of northeastern Arizona combined with Latin venator (hunter); meaning "Kayenta hunter"

199.5–184.2 million years ago Sinemurian–Pliensbachian, Early Jurassic
Early Jurassic stages

Kayentavenator is a genus of small carnivorous theropod dinosaur that lived during the Early Jurassic Period. Fossils were recovered from the Kayenta Formation of northeastern Arizona, and were described in 2010. Its affinities are contested, with interpretations ranging from a basal tetanuran to a coelophysoid.

Under dispute

Kayentavenator elysiae, based on an immature partial skeleton, was described as a basal tetanuran closer to Allosaurus than to coelophysoids (Gay, 2010), but subsequent work treats the holotype as a specimen of the coelophysoid "Syntarsus" (Megapnosaurus) kayentakatae, making Kayentavenator a possible junior synonym (Ezcurra, 2012, 2017). Because the tetanuran and coelophysoid hypotheses span Neotheropoda, it is placed conservatively at Neotheropoda incertae sedis.

Diagnosis

  1. Ellipsoid acetabulum
  2. Fusion between the greater trochanter and the head of the femur
  3. Prominent mediodistal crest extending 50% of the femur length
  4. Prominent accessory condyle on the medial femoral condyle
  5. Groove in dorsal surface of the femoral head extending laterally
  6. Highly constricted caudal centra

Species

Kayentavenator elysiae Gay, 2010 Disputed

Type species

Named in honor of Elysia Jennett, who has been exceedingly helpful and supportive to the author during this and other research.

Holotype
UCMP V128659 , University of California Museum of Paleontology
Material
Partial skeleton consisting of part of the pelvis, partial hindlimbs, and vertebrae
Horizon
Kayenta Formation, Sinemurian–Pliensbachian, Early Jurassic , 199.5–184.2 million years ago
Locality
UCMP Locality V82309, Arizona, United States

References

  1. Gay, R. (2010). Kayentavenator elysiae, a new tetanuran from the Early Jurassic of Arizona. Notes on Early Mesozoic Theropods 27-43. gay2010a
  2. Ezcurra, M. D. (2012). Phylogenetic analysis of Late Triassic–Early Jurassic neotheropod dinosaurs: implications for the early theropod radiation. Journal of Vertebrate Paleontology, 72nd Annual Meeting 91.

    Treated Kayentavenator as a junior synonym of Megapnosaurus kayentakatae, based on an unpublished phylogenetic matrix.

    ezcurra2012a
  3. Ezcurra, M. D. (2017). A New Early Coelophysoid Neotheropod from the Late Triassic of Northwestern Argentina. Ameghiniana 54(5): 506. Asociacion Paleontologica Argentina. doi:10.5710/amgh.04.08.2017.3100

    Treated the Kayentavenator holotype as a specimen of Megapnosaurus kayentakatae.

    ezcurra2017a