Los Blanquitos Formation

The Los Blanquitos Formation is a geological formation in Salta Province, Argentina whose strata date back to the late Campanian to early Maastichtian age of the Late Cretaceous Period. Dinosaur remains are among the fossils that have been recovered from the formation.^[2] The formation consists of friable, micaceous, grayish-red sandstones with quartz pebbles containing small carbonate veins. In the base of this layer the remains of a titanosaurid dinosaur were discovered. Above the layer with bones appears a lens of thick, greenish-gray, calcareous, very hard sandstone with pebbles and gravel. The bones were covered by a "halo" of the same rock but of greenish or grayish color, especially visible because the normal sediment is red. The bed thickness is 1.5 metres (4.9 ft).^[3]

Los Blanquitos Formation
Stratigraphic range: Late Campanian - Early Maastrichtian ~72 Ma[1] PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Geological formation
Unit of	Salta Group
Underlies	Lecho Formation
Overlies	Las Curtiembres Formation
Lithology
Primary	Sandstone
Location
Coordinates	24.3°S 65.3°W / -24.3; -65.3
Approximate paleocoordinates	27.6°S 47.5°W / -27.6; -47.5
Region	Salta Province
Country	Argentina
Extent	Salta Basin
Los Blanquitos Formation (Argentina)

Vertebrate paleofauna

• Guemesia ochoai - an abelisaurid theropod dinosaur, known from a nearly complete braincase^[4]
• Unquillosaurus ceiballi - a theropod dinosaur (possibly carcharodontosaurian or Maniraptoran), known from a pubis^[3][5][6]
• ?Titanosaurus sp. - a sauropod dinosaur^[3]

See also

• List of dinosaur-bearing rock formations

References

1. Novas, F.E.; Agnolín (2004 (2004). "Unquillosaurus ceibalii Powell, a giant maniraptoran (Dinosauria, Theropoda) from the Late Cretaceous of Argentina". Revista del Museo Argentino de Ciencias Naturales. 6 (1): 61–66. doi:10.22179/REVMACN.6.73.{{cite journal}}: CS1 maint: numeric names: authors list (link)
2. Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, South America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 600-604. ISBN 0-520-24209-2.
3. Arroyo El Morterito at Fossilworks.org
4. Agnolín FL, Cerroni MA, Scanferla A, Goswami A, Paulina-Carabajal A, Halliday T, Cuff AR, Reuil S (2022). "First definitive abelisaurid theropod from the Late Cretaceous of Northwestern Argentina". Journal of Vertebrate Paleontology. 41 (4): e2002348. doi:10.1080/02724634.2021.2002348. S2CID 246766133.
5. "Table 10.1," in Weishampel, et al. (2004). Page 199.
6. Carrano, Matthew T.; Benson, Roger B. J.; Sampson, Scott D. (2012-06-01). "The phylogeny of Tetanurae (Dinosauria: Theropoda)". Journal of Systematic Palaeontology. 10 (2): 211–300. Bibcode:2012JSPal..10..211C. doi:10.1080/14772019.2011.630927. ISSN 1477-2019. S2CID 85354215.

Further reading

• J.F. Bonaparte and G. Bossi. 1967. Sobre la presencia de dinosaurios en la Formación Pirgua del Grupo Salta y su significado cronologico [On the presence of dinosaurs in the Pirgua Formation of the Salta Group and its chronologic significance]. Acta Geologica Lilloana 9:25-44
• Powell, J.E. 2003. Revision of South American titanosaurid dinosaurs: palaeobiological, palaeobiogeographical and phylogenetic aspects. Records of the Queen Victoria Museum Launceston 111:1-173
• Powell, J.E. 1979. Sobre una asociacion de dinosaurios y otras evidencias de vertebrados del Cretacico superior de la region de La Candelaria, Prov. de Salta, Argentina. Ameghiniana 16: pp. 191–204