Open Paleo

Sefapanosaurus

Otero et al., 2015 SEF-uh-PAR-no-SOR-us

From Sesotho 'sefapano' (cross) + Greek 'sauros' (lizard), meaning 'cross lizard', referring to the distinctive cross-shaped astragalus (ankle bone).

227.3–199.5 million years ago Norian–Hettangian, Late Triassic–Early Jurassic
Late Triassic and Early Jurassic stages

Sefapanosaurus was an early, herbivorous sauropodomorph dinosaur occurring in the southern regions of Gondwana some 200 million years ago in the Late Triassic or Early Jurassic. The sauropodomorphs were the dominant terrestrial herbivores throughout much of the Mesozoic Era, from their origins in the mid-Triassic (approximately 230 Ma) until their decline and fall at the end of the Cretaceous (approximately 66 Ma). A distinctive feature of this dinosaur is the cross-shaped astragalus or talus bone in its ankle. The generic name is derived from the Sesotho word sefapano, meaning 'cross' and the Greek word saurus, meaning 'lizard'. The specific name refers to Zastron, the type locality, where the specimen was discovered.

Diagnosis

  1. Tall ascending process of astragalus, 35% of mediolateral length of astragalar body
  2. T-shaped, triradiate cross-section of ascending process of astragalus
  3. Ascending process of astragalus framed by well-developed, straight, thick ridges with subcircular cross-sections
  4. Slit-shaped posterior dorsal neural canal
  5. Length of proximal neural spine base greater than half the neural arch length
  6. Square-shaped cross-section of distal caudal centra
  7. Long ridge from craniodorsal coracoid margin to coracoid foramen
  8. Craniomedial ulnar process twice as long as craniolateral process and distally tapered

Species

Sefapanosaurus zastronensis Otero et al., 2015

Type species

Named for Zastron, the type locality in South Africa where the specimen was discovered.

Holotype
BP/1/386 , Evolutionary Studies Institute (formerly Bernard Price Institute for Palaeontological Research), University of the Witwatersrand
Material
Incomplete articulated left pes including astragalus, calcaneum, distal tarsal IV, metatarsals III, IV, and V
Horizon
Elliot Formation, Norian–Hettangian, Late Triassic–Early Jurassic , 227.3–199.5 million years ago
Locality
near the town of Zastron, Free State, South Africa

References

  1. Otero, A.; Krupandan, E.; Pol, D.; Chinsamy, A.; Choiniere, J. (2015). A new basal sauropodiform from South Africa and the phylogenetic relationships of basal sauropodomorphs. Zoological Journal of the Linnean Society 174(3): 589-634. Oxford University Press (OUP). doi:10.1111/zoj.12247 otero2015a
  2. Paul, G. S. (2024). The Princeton Field Guide to Dinosaurs (3rd ed.). Princeton University Press.

    Source of the body length and mass estimates.

    paul2024a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Sauropods. Princeton University Press.

    Source of the hip height estimate.

    jones2026b