Open Paleo

Chindesaurus

Long & Murry, 1995 CHIN-diss-OR-uhs /ˌtʃɪndɪˈsɔːrəs/

Named for the Chinde Point area of Petrified Forest National Park in Arizona, where the fossils were found, combined with Greek 'sauros' meaning 'lizard'.

227.3–205.7 million years ago Norian, Late Triassic
Late Triassic stages

Chindesaurus is an extinct genus of basal saurischian dinosaur from the Late Triassic (213-210 million years ago) of the southwestern United States. It is known from a single species, C. bryansmalli, based on a partial skeleton recovered from Petrified Forest National Park in Arizona. The original specimen was nicknamed "Gertie", and generated much publicity for the park upon its discovery in 1984 and airlift out of the park in 1985. Other fragmentary referred specimens have been found in Late Triassic sediments throughout Arizona, New Mexico, and Texas, but these may not belong to the genus. Chindesaurus was a bipedal carnivore, approximately as large as a wolf.

Under dispute

Chindesaurus bryansmalli is recovered as a non-herrerasaurid herrerasaurian outside Theropoda, in the clade later named Morphoraptora, by recent analyses (Novas and colleagues, 2021; Ezcurra and colleagues, 2025; Srivastava and colleagues, 2026), but as the sister taxon of Tawa at the base of Theropoda by Marsh and colleagues (2019), a position Ezcurra and colleagues (2025) also recover under strong implied weighting on one of their matrices.

Diagnosis

  1. Diagnosed by a unique combination of character states rather than discrete autapomorphies; the 'glutealiform' astragalus formerly used to diagnose the genus is now referred to the Chindesaurus + Tawa hallae clade.
  2. Proximal surface of the femoral head smooth, lacking a groove.
  3. Dorsolateral ('greater') trochanter of the femur forming a rounded ridge.
  4. Dorsal centra anteroposteriorly short, with centrum length less than 1.33 times the height of the anterior articular surface.
  5. Prezygapophyses of the distal caudal vertebrae reduced, not extending farther anteriorly than 24% of centrum length.

Species

Chindesaurus bryansmalli Long & Murry, 1995

Type species

Named for Bryan Small, who discovered the holotype skeleton in 1984 at Petrified Forest National Park in Arizona.

Holotype
PEFO 10395 , Petrified Forest National Park
Material
Partial skeleton: cervical and dorsal centra, sacral and caudal vertebrae, hemal arches, both iliac pubic peduncles with a partial iliac blade and the left postacetabular process, partial pubes, the proximal left and complete right femora, a partial right tibia, and a partial right astragalus.
Horizon
Petrified Forest Member, Chinle Formation, Norian, Late Triassic , 227.3–205.7 million years ago
Locality
Dinosaur Hollow, Arizona, United States

References

  1. Long, R. A.; Murry, P. A. (1995). Late Triassic (Carnian and Norian) Tetrapods from the Southwestern United States. New Mexico Museum of Natural History and Science Bulletin 4: 1-254. New Mexico Museum of Natural History and Science. long1995a
  2. Marsh, A. D.; Parker, W. G.; Langer, M. C.; Nesbitt, S. J. (2019). Redescription of the holotype specimen of Chindesaurus bryansmalli Long and Murry, 1995 (Dinosauria, Theropoda), from Petrified Forest National Park, Arizona. Journal of Vertebrate Paleontology 39(3): e1645682. doi:10.1080/02724634.2019.1645682

    Redescribes and re-inventories the holotype PEFO 10395, revises the diagnosis, removes most referred specimens, and recovers Chindesaurus as the sister taxon to Tawa hallae outside Neotheropoda.

    marsh2019a
  3. Ezcurra, M. D.; Garcia, M. S.; Novas, F. E.; Müller, R. T.; Agnolín, F. L.; Chatterjee, S. (2025). A new herrerasaurian dinosaur from the Upper Triassic Upper Maleri Formation of south-central India. Royal Society Open Science 12(5): 250081. The Royal Society. doi:10.1098/rsos.250081

    New herrerasaurian description recovered Chindesaurus outside Theropoda in Morphoraptora.

    ezcurra2025a
  4. Novas, F. E.; Agnolín, F. L.; Ezcurra, M. D.; Müller, R. T.; Martinelli, A. G.; Langer, M. C. (2021). Review of the fossil record of early dinosaurs from South America, and its phylogenetic implications. Journal of South American Earth Sciences 110: 103341. doi:10.1016/j.jsames.2021.103341

    Recovered Chindesaurus as a non-herrerasaurid herrerasaurian outside Theropoda, within Morphoraptora

    novas2021a
  5. Srivastava, S.; Nesbitt, S. J. (2026). A new taxon of saurischian dinosaur from the Coelophysis Quarry of New Mexico, USA (Triassic: latest Norian or Rhaetian) highlights herrerasaurian diversity in the latest Triassic. Papers in Palaeontology 12(2). doi:10.1002/spp2.70069

    Recovered Chindesaurus as non-herrerasaurian herrerasaurian outside Theropoda in Morphoraptora

    srivastava2026a
  6. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

    Treats Chindesaurus as the sister of Tawa at the base of Theropoda.

    jones2026c