Open Paleo

Pampadromaeus

Cabreira et al., 2011 PAM-puh-DROH-me-us

From Quechua 'pampa' meaning 'plain', referring to the landscape of the discovery site in southern Brazil, and Greek 'dromeus' meaning 'runner', referring to its cursorial habits.

237.0–227.3 million years ago Carnian, Late Triassic
Late Triassic stages

Pampadromaeus is an extinct genus of basal sauropodomorph dinosaurs known from the Late Triassic (Carnian) Santa Maria Formation of the Paraná Basin in Rio Grande do Sul, southern Brazil.

Under dispute

Pampadromaeus barberenai is an early sauropodomorph from the Late Triassic of Brazil whose finer position is unsettled. Langer and colleagues (2019) recovered it within Saturnaliidae, grouped with Saturnalia and Chromogisaurus in every most-parsimonious tree, though they describe the clade as weakly supported. Cabreira and colleagues (2011), describing the genus, instead placed it on the sauropodomorph stem outside any such clade, with its sister taxon varying between analyses.

Diagnosis

  1. Head longer than two-thirds of femoral length
  2. Premaxilla with short subnarial process not reaching nasal
  3. Sacral vertebrae with dorsoventrally expanded ribs
  4. Femur with reduced medial tuberosity in head and well-developed trochanteric shelf
  5. Epipodium significantly longer than femur (nearly 20% longer)

Species

Pampadromaeus barberenai Cabreira et al., 2011

Type species

Named for Mário Costa Barberena, the Brazilian paleontologist honored by the describers.

Holotype
ULBRA-PVT016 , Museu de Ciências Naturais, Universidade Luterana do Brasil
Material
Disarticulated partial skeleton in mudstone block, most skull bones, mandibular parts, incomplete vertebral column, appendicular skeleton.
Horizon
upper Alemoa Member, Santa Maria Formation, Carnian, Late Triassic , 237.0–227.3 million years ago
Locality
Várzea do Agudo, Rio Grande do Sul, Brazil Cabreira and colleagues (2011) give the "Reddish mudstones of the Alemoa Member, Santa Maria Formation" at the Janner or Várzea do Agudo site, in "the upper portions of the Hyperodapedon Assemblage Zone". Langer and colleagues (2018) date the bone bed near the top of the formation at no older than 233.23 ± 0.73 Ma, "consistent with a late Carnian (Tuvalian) age", and correlate the zone with the Scaphonyx-Exaeretodon-Herrerasaurus biozone of the Ischigualasto Formation; the Norian beds of the supersequence are in the overlying Caturrita Formation.

References

  1. Cabreira, S. F.; Schultz, C. L.; Bittencourt, J. S.; Soares, M. B.; Fortier, D. C.; Silva, L. R.; Langer, M. C. (2011). New stem-sauropodomorph (Dinosauria, Saurischia) from the Triassic of Brazil. Naturwissenschaften 98(12): 1035-1040. Springer Science and Business Media LLC. doi:10.1007/s00114-011-0858-0

    Erected Pampadromaeus and placed it on the sauropodomorph stem, with its recovered sister taxon varying across four re-run matrices.

    cabreira2011a
  2. Langer, M. C.; McPhee, B. W.; Marsola, J. C. de A.; Roberto-da-Silva, L.; Cabreira, S. F. (2019). Anatomy of the dinosaur Pampadromaeus barberenai (Saurischia—Sauropodomorpha) from the Late Triassic Santa Maria Formation of southern Brazil. PLoS ONE 14(2): e0212543. doi:10.1371/journal.pone.0212543

    Recovered Pampadromaeus within Saturnaliidae, grouped with Saturnalia and Chromogisaurus in all most-parsimonious trees, on weak support.

    langer2019b
  3. Paul, G. S. (2024). The Princeton Field Guide to Dinosaurs (3rd ed.). Princeton University Press.

    Source of the body length and mass estimates.

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

    Treats the placement of Pampadromaeus within Sauropodomorpha as uncertain.

    jones2026b
  5. Langer, M. C.; Ramezani, J.; Da Rosa, Á. A. S. (2018). U-Pb age constraints on dinosaur rise from south Brazil. Gondwana Research 57: 133-140. doi:10.1016/j.gr.2018.01.005

    Dates the Alemoa bone bed near the top of the Santa Maria Formation at no older than 233.23 Ma, late Carnian.

    langer2018a