Open Paleo

Aardonyx

Yates et al., 2010 ar-don-ix

From Afrikaans 'aard' meaning 'earth' and Greek 'onux' meaning 'nail' or 'claw'.

201.4–192.9 million years ago Hettangian–Sinemurian, Early Jurassic
Early Jurassic stages

Aardonyx is a genus of basal sauropodomorph dinosaur. It is known from the type species Aardonyx celestae found from the Early Jurassic Elliot Formation of South Africa. A. celestae was named after Celeste Yates, who prepared much of the first known fossil material of the species. It has arm features that are intermediate between basal sauropodomorphs and more derived sauropods.

Diagnosis

  1. Five premaxillary teeth (convergent in Plateosaurus)
  2. Band of dense, fine pits and small foramina along the lower half of the lateral surface of the maxilla
  3. Reduced lateral maxillary neurovascular foramina rostral to the large caudally facing foramen (middle foramina <6% of maxilla depth caudal to antorbital fossa)
  4. Reduced cervical diapophyses remaining as low tubercles with absent diapophyseal laminae along the full cervical series
  5. Large, rugose biceps scar (maximum diameter 13% of radius length) on the craniomedial surface of the radius shaft
  6. Exceptionally broad and flat proximal end of metatarsal IV (transverse width 2.9× the extensor-flexor depth) with strongly laterally flared caudolateral corner distally

Species

Aardonyx celestae Yates et al., 2010

Type species

Named for Celeste Yates, who prepared much of the first described fossil material of the species.

Holotype
BP/1/6254 , Evolutionary Studies Institute (formerly Bernard Price Institute for Palaeontological Research), University of the Witwatersrand
Material
Rostral half of the left maxilla. A non-overlapping, weathered, caudal portion of a left maxilla was found about a meter from the holotype, and may represent the same bone.
Horizon
upper Elliot Formation, Hettangian–Sinemurian, Early Jurassic , 201.4–192.9 million years ago
Locality
Marc's Quarry, farm Spion Kop 932, Free State, South Africa

References

  1. Yates, A. M.; Bonnan, M. F.; Neveling, J.; Chinsamy, A.; Blackbeard, M. G. (2010). A new transitional sauropodomorph dinosaur from the Early Jurassic of South Africa and the evolution of sauropod feeding and quadrupedalism. Proceedings of the Royal Society B: Biological Sciences 277(1682): 787-794. The Royal Society. doi:10.1098/rspb.2009.1440 yates2010b
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Sauropods. Princeton University Press.

    Source of the hip height estimate.

    jones2026b