Open Paleo

Giganotosaurus

Coria & Salgado, 1995 GIG-uh-NOH-tuh-SOR-uhs /ˌɡɪɡəˌnoʊtəˈsɔːrəs/

From Greek gigas/gigantos, 'giant', + Greek notos, 'south/southern', + Greek sauros, 'lizard'; means 'giant southern lizard', referring to its enormous size and South American origin

100.5–93.9 million years ago Cenomanian, Late Cretaceous
Late Cretaceous stages

Giganotosaurus is a genus of large theropod dinosaur that lived in what is now Argentina, during the early Cenomanian age of the Late Cretaceous period, approximately 99.6 to 95 million years ago. The holotype specimen was discovered in the Candeleros Formation of Patagonia in 1993 and is almost 70% complete. The animal was named Giganotosaurus carolinii in 1995; the genus name translates to "giant southern lizard", and the specific name honors the discoverer, Ruben Carolini. A dentary bone, a tooth, and some tracks, discovered before the holotype, were later assigned to this animal. The genus attracted much interest and became part of a scientific debate about the maximum sizes of theropod dinosaurs.

Diagnosis

  1. Dorsoventrally wide main body of the maxilla, with subparallel dorsal and ventral edges.
  2. Eave-like supraorbital lacrimal-postorbital contact.
  3. Two pneumatic foramina on the internal side of the quadrate.
  4. Symphysial end of the dentary dorsoventrally expanded, bearing a ventral process.
  5. Proximal end of the scapula forwardly projected above the coracoid; tubercle-like triceps insertion on the ventral border of the scapula.
  6. Lobule-shaped obturator process of the ischium; dorsally projected femoral head; posterior intercondylar groove in the proximal end of the tibia.

Species

Giganotosaurus carolinii Coria & Salgado, 1995

Type species

Named for Rubén Darío Carolini, the amateur fossil hunter who discovered the holotype specimen in the Neuquén province of Patagonia, Argentina.

Holotype
MUCPv-CH-1 , Universidad Nacional del Comahue
Material
Disarticulated skeleton: partial skull, most of the vertebral column, complete pectoral and pelvic girdles, both femora, left tibia and fibula.
Horizon
Candeleros Formation, Cenomanian, Late Cretaceous , 100.5–93.9 million years ago
Locality
15 km south of Villa El Chocón, Neuquén, Argentina Coria and Salgado (1995) name the horizon the Candeleros Member of the Rio Limay Formation; Leanza and colleagues (2004) treat the Rio Limay as a subgroup and raise Candeleros to formation rank.

Notable specimens

  • MUCPv-95

    Universidad Nacional del Comahue Found 1987 by Jorge O. Calvo largest individual

    Referred partial left dentary about 8% larger than the holotype's at 62 cm, from a supposedly larger individual. It has been used to extrapolate a maximum length of 13.2 meters and a 1.95-meter skull, central to the debate over the largest theropods.

    Calvo & Coria (1998)

  • MUCPv-52

    Universidad Nacional del Comahue Found 1987 by A. Delgado historic

    An incomplete tooth referred to Giganotosaurus, discovered near Lake Ezequiel Ramos Mexia in 1987, making it the first known fossil of the genus, predating the holotype.

    Calvo (1999)

References

  1. Coria, R. A.; Salgado, L. (1995). A new giant carnivorous dinosaur from the Cretaceous of Patagonia. Nature 377(6546): 224-226. Springer Science and Business Media LLC. doi:10.1038/377224a0 coria1995a
  2. Calvo, J. O.; Coria, R. A. (1998). New specimen of Giganotosaurus carolinii (Coria & Salgado, 1995), supports it as the largest theropod ever found. Gaia 15: 117-122. calvo1998a
  3. Calvo, J. O. (1999). Dinosaurs and other vertebrates of the Lake Ezequiel Ramos Mexía area, Neuquén-Patagonia, Argentina. National Science Museum Monographs 15: 13-45. calvo1999a
  4. Leanza, H. A.; Apesteguía, S.; Novas, F. E.; de la Fuente, M. S. (2004). Cretaceous terrestrial beds from the Neuquén Basin (Argentina) and their tetrapod assemblages. Cretaceous Research 25(1): 61-87. Elsevier BV.

    Raises Candeleros from a member of the Rio Limay Formation to a formation within the Neuquen Group.

    leanza2004a