Open Paleo

Chucarosaurus

Agnolín et al., 2023 SHOO-kah-ro-SOR-us

From Mapudungun or Quechua chucaro ('indomitable' or 'wild, untamed') + Greek sauros ('lizard'), meaning 'indomitable reptile'.

100.5–89.8 million years ago Cenomanian–Turonian, Late Cretaceous
Late Cretaceous stages

Chucarosaurus is an extinct genus of titanosaurian dinosaur from the Late Cretaceous (middle Cenomanian-lower Turonian) Huincul Formation of Argentina. The genus contains a single species, C. diripienda, known from various limb and pelvic bones.

Diagnosis

  1. Ischium with very short and robust iliac peduncle with a poorly developed neck (autapomorphy)
  2. Tibia with articular surface for ascending process of astragalus strongly extended anteriorly, separated from rest of bone by a notch (autapomorphy)
  3. Humerus with proximally convex humeral head separated from major tubercle by a well-defined concavity
  4. Femur with epicondyle extremely developed laterally, close to the lateral condyle
  5. Femur with fourth trochanter located in the proximal third of the femur
  6. Tibia with cnemial crest prominent and medially curved but dorsoventrally short

Species

Chucarosaurus diripienda Agnolín et al., 2023

Type species

From Latin 'diripienda' meaning 'scrambled', likely referring to the disarticulated nature of the fossil remains.

Holotype
MPCA-PV 820 , Museo provincial de Cipolletti "Carlos Ameghino"
Material
Complete left humerus, left radius lacking proximal end, left complete metacarpal II, left ischium, left femur with eroded proximal end, left fibular shaft, incomplete proximal end of right tibia, and distal end of indeterminate metapodial.
Horizon
Huincul Formation, Cenomanian–Turonian, Late Cretaceous , 100.5–89.8 million years ago
Locality
Pueblo Blanco Natural Reserve, Río Negro, Argentina

References

  1. Agnolín, F. L.; González Riga, B. J.; Aranciaga Rolando, A. M.; Rozadilla, S.; Motta, M. J.; Chimento, N. R.; Novas, F. E. (2023). A new giant titanosaur (Dinosauria, Sauropoda) from the Upper Cretaceous of Northwestern Patagonia, Argentina. Cretaceous Research 146. Elsevier BV. doi:10.1016/j.cretres.2023.105487 agnolín2023a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Sauropods. Princeton University Press.

    Source of the body length estimate.

    jones2026b