Lecho Formation

Lecho Formation
Stratigraphic range: Early Maastrichtian
~70–68 Ma
TypeGeological formation
Unit ofSalta Group
UnderliesYacoraite Formation
OverliesLos Blanquitos Formation
Lithology
PrimarySandstone
Location
Coordinates26°06′S 65°24′W / 26.1°S 65.4°W / -26.1; -65.4
Approximate paleocoordinates28°36′S 52°00′W / 28.6°S 52.0°W / -28.6; -52.0
RegionJujuy, Salta
CountryArgentina
ExtentSalta Basin
Lecho Formation is located in Argentina
Lecho Formation
Lecho Formation (Argentina)

The Lecho Formation is a geological formation in the Salta Basin of the provinces Jujuy and Salta of northwestern Argentina. Its strata date back to the Early Maastrichtian, and is a unit of the Salta Group. The fine-grained bioturbated sandstones of the formation were deposited in a fluvial to lacustrine coastal plain environment.

Dinosaur remains are among the fossils that have been recovered from the formation.

According to Frankfurt and Chiappe (1999), the Lecho Formation is composed of reddish sandstones. The Lecho is part of the Upper/Late Cretaceous Balbuena Subgroup (Salta Group), which is a near-border stratigraphic unit of the Andean sedimentary basin. Fossils from this formation include the titanosaur Saltasaurus along with a variety of avian and non-avian theropods.

Fossil content

Dinosaurs

Dinosaurs from the Lecho Formation
GenusSpeciesLocationMaterialNotesImages
Abelisauridae Indeterminate El Brete Isolated teeth. May represent more than one species of abelisaurid
Elbretornis E. bonapartei El Brete Scapula, partial coracoid, humerus, partial radius, partial ulna An enantiornithine bird
Enantiornis E. leali El Brete Postcranial elements An enantiornithine bird
Euenantiornithes indet. Indeterminate El Brete Partial right lower jaw An enantiornithine bird
Lectavis L. bretincola El Brete Tarsometatarsus and tibiotarsus An enantiornithine bird
Martinavis M. minor El Brete Partial humerus An enantiornithine bird
M. saltariensis El Brete Humerus
M. vincei El Brete Humeri
M. whetstonei El Brete Partial humerus
Noasaurus N. leali El Brete Isolated elements from the head (maxilla, quadrate), vertebral column (cervical and dorsal? vertebrae, ribs), manus (phalanx, unguals) and foot (metatarsal II). A Noasaurid abelisaur
Saltasaurus S. loricatus El Brete "Partial skeletons of at least [six] individuals, including jaws and armor." A saltasaurid titanosaur
Soroavisaurus S. australis El Brete Tarsometatarsus and phalanges. An enantiornithine bird
Yungavolucris Y. brevipedalis El Brete Tarsometatarsi An enantiornithine bird

See also

References

  1. ↑ Weishampel et al., 2004, "Dinosaur distribution (Late Cretaceous, South America)." pp. 600-604
  2. ↑ Hendrickx, C.; Soto Núñez, M.; Araújo, R.; Meso, J. G.; Maganuco, S.; Ben-Salahuddin, A. (2025). "Isolated abelisaurid teeth from Gondwana and dental evolution in Abelisauridae". Ameghiniana. 62 (6): 407–451. Bibcode:2025Amegh..62.3654H. doi:10.5710/AMGH.17.09.2025.3654.
  3. 1 2 3 4 Cyril A. Walker; Gareth J. Dyke (2009). "Euenantiornithine birds from the Late Cretaceous of El Brete (Argentina)" (PDF). Irish Journal of Earth Sciences. 27: 15–62. doi:10.3318/IJES.2010.27.15. S2CID 129573066. Archived from the original (PDF) on 2012-03-20.
  4. ↑ Walker, C. A. (1981). "New subclass of birds from the Cretaceous of South America". Nature. 292 (5818): 51–53. doi:10.1038/292051a0. ISSN 0028-0836.
  5. 1 2 3 Chiappe, Luis (1993). "Enantiornithine (Aves) tarsometatarsi from the Cretaceous Lecho Formation of northwestern Argentina". American Museum Novitates (3083): 1–27. S2CID 39613970.
  6. ↑ Hendrickx, Christophe; Cerroni, Mauricio A; Agnolín, Federico L; Catalano, Santiago; Ribeiro, Cátia F; Delcourt, Rafael (2024-12-01). "Osteology, relationship, and feeding ecology of the theropod dinosaur Noasaurus leali, from the Late Cretaceous of North-Western Argentina". Zoological Journal of the Linnean Society. 202 (4). doi:10.1093/zoolinnean/zlae150. ISSN 0024-4082.
  7. ↑ Zurriaguz, Virginia; Powell, Jaime (2015-05-01). "New contributions to the presacral osteology of Saltasaurus loricatus (Sauropoda, Titanosauria) from the Upper Cretaceous of northern Argentina". Cretaceous Research. 54: 283–300. doi:10.1016/j.cretres.2014.12.012. hdl:11336/32746. ISSN 0195-6671.
  8. ↑ "Table 13.1," in Weishampel et al., 2004, p.270

Bibliography