Lecho Formation

Lecho Formation
Stratigraphic range: Early Maastrichtian ~70–68  Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Geological formation
Unit of	Salta Group
Underlies	Yacoraite Formation
Overlies	Los Blanquitos Formation
Lithology
Primary	Sandstone
Location
Coordinates	26°06′S65°24′W / 26.1°S 65.4°W / -26.1; -65.4
Approximate paleocoordinates	28°36′S52°00′W / 28.6°S 52.0°W / -28.6; -52.0
Region	Jujuy, Salta
Country	Argentina
Extent	Salta Basin
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. ^[1]

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
Genus	Species	Location	Material	Notes	Images
Abelisauridae [2]	Indeterminate	El Brete	Isolated teeth.	May represent more than one species of abelisaurid
Elbretornis [3]	E. bonapartei	El Brete	Scapula, partial coracoid, humerus, partial radius, partial ulna	An enantiornithine bird
Enantiornis [3] [4]	E. leali	El Brete	Postcranial elements	An enantiornithine bird
Euenantiornithes indet. [3]	Indeterminate	El Brete	Partial right lower jaw	An enantiornithine bird
Lectavis [5]	L. bretincola	El Brete	Tarsometatarsus and tibiotarsus	An enantiornithine bird
Martinavis [3]	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 [2]	N. leali	El Brete	Isolated elements from the head and foot, as well as a verebral arch.	A Noasaurid abelisaur
Saltasaurus [6]	S. loricatus	El Brete	"Partial skeletons of at least [six] individuals, including jaws and armor." [7]	A saltasaurid titanosaur
Soroavisaurus [5]	S. australis	El Brete	Tarsometatarsus and phalanges.	An enantiornithine bird
Yungavolucris [5]	Y. brevipedalis	El Brete	Tarsometatarsi	An enantiornithine bird

See also

• List of dinosaur-bearing rock formations
• Marília Formation

References

1. Weishampel et al., 2004, "Dinosaur distribution (Late Cretaceous, South America)." pp. 600-604
2. 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.
3. 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. Chiappe, Luis (1993). "Enantiornithine (Aves) tarsometatarsi from the Cretaceous Lecho Formation of northwestern Argentina". American Museum Novitates (3083): 1–27. S2CID   39613970.
6. 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. ISSN   0195-6671.
7. "Table 13.1," in Weishampel et al., 2004, p.270

Bibliography

• Walker; Dyke (2009), "Euenantiornithine birds from the Late Cretaceous of El Brete (Argentina)", Irish Journal of Earth Sciences , 27: 15–62, doi:10.3318/IJES.2010.27.15
• Agnolin, F.L.; Martinelli, A.G. (2007), "Did oviraptorosaurs (Dinosauria; Theropoda) inhabit Argentina?" (PDF), Cretaceous Research , 28 (5): 785–790, Bibcode:2007CrRes..28..785A, doi:10.1016/j.cretres.2006.10.006
• Weishampel, David B.; Dodson, Peter; Osmólska, Halszka (2004), The Dinosauria, 2nd edition, Berkeley: University of California Press, pp. 1–880, ISBN   0-520-24209-2 , retrieved 2019-02-21
• Frankfurt, N.G.; Chiappe, L.M. (1999), "A Possible Oviraptorosaur From The Late Cretaceous of Northwestern Argentina", Journal of Vertebrate Paleontology , 19 (1): 101–105, Bibcode:1999JVPal..19..101F, doi:10.1080/02724634.1999.10011126