Open Paleo

Laplatasaurus

Huene, 1929 lah-PLAHT-a-SAWR-us

Named for La Plata, Argentina, combined with Greek 'sauros' meaning 'lizard', hence 'La Plata lizard'. The species name refers to the Araucanos (Mapuche) people.

83.6–72.2 million years ago Campanian, Late Cretaceous
Late Cretaceous stages

Laplatasaurus is a genus of titanosaurian sauropod dinosaur that lived during the Late Cretaceous in what is now Argentina. Huene erected it in 1929 for material from several Patagonian localities together with fossils from Uruguay, Madagascar and India, but never designated a type specimen; Bonaparte and Gasparini supplied a lectotype fifty years later. A 2015 reassessment found none of the remaining material diagnostically referable and restricted the genus to that lectotype alone, reassigning the rest to indeterminate titanosaurs and the Rancho de Ávila sample to a form comparable to Bonitasaura.

Diagnosis

  1. Slender tibia with a deep cnemial fossa extending more than one-third the length of the shaft
  2. Fibula with an extremely developed anterior fossa on the proximal end, laterally delimited by a thick margin
  3. Fibula with a well-developed lateral tuberosity

Species

Laplatasaurus araukanicus Huene, 1929

Type species

Named for the Araucanos (Mapuche), the indigenous people of Patagonia and central Chile, in whose traditional territory the type material was found.

Lectotype
MLP-CS 1128, MLP-CS 1127 , Museo de La Plata
Material
A complete right tibia and a right fibula, found in articulation and belonging to one individual
Notes
Bonaparte and Gasparini (1979) cataloged the pair as MLP 26-306, giving the Cinco Saltos numbers 1128 for the tibia and 1127 for the fibula.
Horizon
Anacleto Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
Locality
Cinco Saltos, Río Negro, Argentina Which unit the lectotype came from is unresolved. Bonaparte and Gasparini (1979), who designated it, and Powell (2003) place it in the Allen Formation. Gallina and Otero (2015) put it at the top of the Anacleto Formation and mark that reading as contrary to both, but reach it by correlating Huene's unspecific 'bed d' to a section measured for Neuquensaurus rather than by new work on the lectotype.

Synonyms

  • Titanosaurus araukanicus reassigned

    Huene erected the species in Laplatasaurus in 1929. Powell (2003) sank the genus into Titanosaurus and used this combination, which Wilson and Upchurch (2003) reversed in restoring Laplatasaurus for the lectotype.

References

  1. Huene, F. V. (1927). Sichtung der Grundlagen der jetzigen Kenntnis der Sauropoden [Sorting through the basis of the current knowledge of sauropods]. Eclogae Geologicae Helvetiae 20: 444-470.

    In German. First paper in which the genus name Laplatasaurus appears.

    huene1927c
  2. Huene, F. V. (1929). Los saurisquios y ornitisquios del Cretáceo Argentino [The Saurischians and Ornithischians of the Argentine Cretaceous]. Anales del Museo de La Plata, series 2 3: 1-196.

    In Spanish. First formal description of Laplatasaurus.

    huene1929a
  3. Bonaparte, J. F.; Gasparini, Z. (1979). Los saurópodos de los grupos Neuquén y Chubut, y sus relaciones cronológicas [The Sauropods of the Neuquén and Chubut Groups and their Chronological Relations]. Actas del VII Congreso Geológico Argentino 2: 393-406.

    In Spanish. Designated MLP 26-306 (a right tibia and right fibula) as the lectotype of Laplatasaurus araukanicus; source of the type material.

    bonaparte1979c
  4. Powell, J. E. (1986). Revisión de los titanosáuridos de América del Sur. Doctoral thesis, Universidad Nacional de Tucumán, Tucumán, Argentina.

    Unpublished doctoral thesis, 493 pp., as cited in Powell's own 2003 revision of it. The two are separate works: this thesis is in Spanish, while the revision published on it, Powell (2003), is in English. The thesis is retained here because the literature cites it as the first mention of several names, which as a thesis it did not make available.

    powell1986a
  5. Wilson, J. A.; Upchurch, P. (2003). A revision of Titanosaurus Lydekker (Dinosauria - Sauropoda), the first dinosaur genus with a 'Gondwanan' distribution. Journal of Systematic Palaeontology 1(3): 125-160. Informa UK Limited. doi:10.1017/S1477201903001044

    Revision of Titanosaurus. Removed araukanicus from that genus and restored Laplatasaurus for the lectotype tibia and fibula.

    wilson2003b
  6. Gallina, P. A.; Otero, A. (2015). Reassessment of Laplatasaurus araukanicus (Sauropoda: Titanosauria) from the Upper Cretaceous of Patagonia, Argentina. Ameghiniana 52(5): 487-501. Asociacion Paleontologica Argentina. doi:10.5710/AMGH.08.06.2015.2911

    Restricts the species to the lectotype and reassigns all other referred material. Places the lectotype at the top of the Anacleto Formation, at the INDUPA quarry about 3 km west of Cinco Saltos.

    gallina2015a
  7. Paul, G. S. (2024). The Princeton Field Guide to Dinosaurs (3rd ed.). Princeton University Press.

    Gives 18 m and 11 tonnes, but describes neck anatomy and a minority of several skeletons, so its figures rest on material the 2015 reassessment removed from the species.

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

    Source of the size estimates, which are drawn on the restricted hypodigm of a tibia and fibula.

    jones2026b
  9. Powell, J. E. (2003). Revision of South American Titanosaurid dinosaurs: palaeobiological, palaeobiogeographical and phylogenetic aspects. Records of the Queen Victoria Museum 111: 1-173.

    Places the lectotype in the Allen Formation, and sinks the genus into Titanosaurus as Titanosaurus araukanicus.

    powell2003a