Quebrada La Totora Formation

Quebrada La Totora Formation
Stratigraphic range: Albian-Turonian,
~
TypeVolcanic, volcaniclastic, and sedimentary unit
UnderliesViñita Formation
OverliesQuebrada Marquesa Formation
Thickness~1,700 m (5,600 ft)
Lithology
PrimaryConglomerate, sandstone, limestone
OtherAndesite, dacite, rhyolite, tuff
Location
RegionCoquimbo Region
CountryChile
Type section
Named forQuebrada (creek) La Totora
Named bySalazar et al. 2026

The Quebrada La Totora Formation (previously known as Quebrada La Totora Beds or Estratos Quebrada La Totora) is a volcanic, volcaniclastic, sedimentary, and fossiliferous geological formation that outcrops near Pichasca and Condoriaco of the Coquimbo Region, northern Chile. It is dated back to the latest Early Cretaceous and Late Cretaceous, about 105 to 88 million years ago (Albian-Turonian). The main lithology of the formation includes conglomerates, sandstones, and lacustrine limestones, with intercalations of andesitic to rhyolitic lavas, dacite, and tuffs.[1][2][3] The Quebrada La Totora Formation preserves a rich fossil record of plants such as conifers,[4][1] vertebrates, including dinosaurs (titanosaurs and abelisaurids),[5][6][2][7] turtles,[8] and crocodyliforms,[1] and also freshwater molluscs including bivalves and gastropods.[9]

The Viñita Formation, which overlays the Quebrada La Totora Formation, was described in 1965 by Luis Aguirre Le-Bert and Ernesto Egert Ruiz as a geological formation composed of three members, with Member 1 including conglomerate and sandstone, and Member 2 comprising limestone.[10] Later in 1969 Rodolfo M. Casamiquela and team described vertebrate and plant fossil material from Pichasca (Natural Monument Pichasca), at Río Hurtado. They assigned the strata and fossils to the Viñita Formation, and also described units A to F from this site.[11] Teresa Torres and Monica Rallo also described petrified wood in 1981 from the Pichasca site (units A, C, D, E of Casamiquela and team).[4] Carlos Emparan and Germán Pineda in 1999 informally defined Estratos Quebrada La Totora from the type locality Quebrada La Totora of Condoriaco, at La Serena, where they reassigned the two previously described members 1 and 2 of the Viñita Formation to this new unit. However, their description of Estratos Quebrada La Totora lacked the formal status of a geological formation.[12] This reassignation was followed by other authors and meant a redefinition of the Viñita Formation, which was characterized as a primarily volcanic and volcaniclastic unit with some sedimentary intercalations.[13][1][14][15] Pineda and Emparan in 2006 reinterpreted the Pichasca site as belonging to Estratos Quebrada La Totora along with the fossil content and defined four distinct facies.[1] Despite these reinterpretations and definitions, some authors continued to attribute the fossils from Pichasca to the Viñita Formation.[16][17][8][6] In 2026 the unit was formally defined by Esteban Salazar and team, coining the term Quebrada La Totora Formation.[3] As such, the known fossils from Pichasca are confined to the fossiliferous levels of the Quebrada La Totora Formation.[1][7][3]

Paleobiota of the Quebrada La Totora Formation

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
 Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Amphibians

GenusSpeciesMaterialLocalityUnitNotesImages
Amphibia indet. Indeterminate Not specified.[18] Pichasca. An amphibian.

Crocodyliformes

GenusSpeciesMaterialLocalityUnitNotesImages
Crocodyliformes indet. Indeterminate Not specified.[1] Pichasca. Facies (a).[1] A crocodyliform.

Dinosaurs

GenusSpeciesMaterialLocalityUnitNotesImages
Dinosauria indet. Indeterminate Not specified.[1] Pichasca. Facies (a).[1] A dinosaur.

Sauropods

GenusSpeciesMaterialLocalityUnitNotesImages
Lithostrotia indet. Indeterminate Partial right humerus, scapulacorocoid, caudal vertebra, ribs, ischium, and metapod.[11][16][6] Pichasca. A titanosaurid sauropod. The humerus was initially referred to Antarctosaurus wichmannianus,[11] but this assignation is considered invalid.[16][6]
Sauropoda indet. Indeterminate Not specified.[1] Pichasca. Facies (a).[1] A sauropod dinosaur.
Titanosauria indet. Indeterminate Partial bone fragments.[2] Pichasca (La Cantera). A titanosaur sauropod.
Indeterminate Partial bone fragments.[2] Pichasca (Sección Titanosaurio). A titanosaur sauropod.
Indeterminate Partial bone fragments.[2] Pichasca (Sección Titanosaurio Auxiliar). A titanosaur sauropod.
Titanosauridae indet. Indeterminate Partial dorsal vertebra and teeth.[16] Pichasca. A titanosaurid sauropod.

Theropods

GenusSpeciesMaterialLocalityUnitNotesImages
Abelisauridae indet. Indeterminate Two teeth.[7] Pichasca. Unit F.[11][7] An abelisaurid theropod. Material initially described as Coelurosauria indet.,[19] later as Theropoda indet.,[16] then as Abelisauridae? indet.,[6] and eventually concluded to represent as abelisaurid teeth.[7]
Theropoda indet. Indeterminate Tooth.[2] Pichasca (Sección Titanosaurio). A theropod dinosaur.

Fish

GenusSpeciesMaterialLocalityUnitNotesImages
Osteoglossiformes indet. Indeterminate Not specified.[18] Pichasca. A fish.

Molluscs

Bivalves

GenusSpeciesMaterialLocalityUnitNotesImages
Bivalvia indet. Indeterminate Not specified.[9] Pichasca A bivalve.
Indeterminate Not specified.[2] Pichasca (El Alero) A bivalve.
Exogyra Indeterminate Not specified.[1] Pichasca or Samo Alto. Facies (a): from "local limestones".[1] A gryphaeid bivalve.
Ostrea Indeterminate Not specified.[1] Pichasca or Samo Alto. Facies (a): from "local limestones".[1] An ostreid bivalve.

Gastropods

GenusSpeciesMaterialLocalityUnitNotesImages
Gastropoda indet. Indeterminate Not specified.[9] Pichasca A gastropod.
Indeterminate Not specified.[2] Pichasca (El Alero) A gastropod.

Plants

GenusSpeciesMaterialLocalityUnitNotesImages
Plantae indet. Indeterminate Leaf and roots remains.[11] Pichasca. Unit B and E.[11] A plant.
Indeterminate Fossil trunks.[2] Pichasca (La Cantera). A woody plant.
Indeterminate Fossil trunks.[2] Pichasca (Sección Titanosaurio). A woody plant.
Indeterminate Fossil trunks.[2] Pichasca (Sección Titanosaurio Basal). A woody plant.

Angiosperms

GenusSpeciesMaterialLocalityUnitNotesImages
Elaeocarpoxylon E. pichasquensis Wood pieces.[4] Pichasca. An elaeocarpacean. Initially described as E. pichasquensis,[4] this species is considered invalid and lies outside the assigned family.[20]
Myrtoxylon M. pichasquensis Wood pieces.[4] Pichasca. A myrtacean. Initially described as M. pichasquensis,[4] this species is considered invalid.[20]
Nothofagoxylon N. pichasquensis Two irregular wood pieces.[4] Pichasca. A nothofagacean. Initially described as N. pichasquensis,[4] this species is now considered a synonym of N. menendezii.[20][21]

Gymnosperms

GenusSpeciesMaterialLocalityUnitNotesImages
Araucarioxylon A. pichasquensis Two irregular wood pieces.[4] Pichasca. An araucariacean. Because of generic synonymy it has been reclassified as Agathoxylon (Araucarioxylon) pichasquensis.[22]
Coniferales indet. Indeterminate Not specified.[1] Pichasca. Facies (a).[1] A conifer.
Indeterminate Not specified.[1] Near Cerro Buitre or Majada. Facies (a).[1] A conifer.

Turtles

GenusSpeciesMaterialLocalityUnitNotesImages
Chelonii indet. Indeterminate Not specified.[1] Pichasca. Facies (a).[1] A turtle.
Testudinata indet. Indeterminate Not specified.[2] Pichasca (El Alero). A turtle.
Testudines indet. Indeterminate Shell fragments.[11][8] Pichasca. A turtle.

See also

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Pineda, G. F.; Emparan, C. C. (2006). "Geología del Área Vicuña-Pichasca, Región de Coquimbo, Escala 1:100000". Carta Geológica de Chile (97). Servicio Nacional de Geología y Minería: 1−40.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 Salinas, P. A. (2019). Bioestratigrafía y sedimentología de la unidad portadora de vertebrados del área de Pichasca, Región de Coquimbo, Chile (Thesis). Universidad Andrés Bello. pp. 1−107.
  3. 1 2 3 Salazar, E.; Creixell, C.; Mpodozis, C.; Súarez, M.; Rubilar, A.; Castillo, P.; Folguera, A. (2026). "Late Cretaceous stratigraphy of northern Chile between 28.5 and 30°S: Record of a greenhouse event during early Andean orogenesis". Andean Geology. 53 (3). doi:10.5027/andgeo%x.
  4. 1 2 3 4 5 6 7 8 9 Torres, T.; Rallo, M. (1981). Anatomía de troncos fósiles del Cretácico Superior de Pichasca, en el norte de Chile (PDF). Anais II Congreso Latinoaméricano Paleontología. Porto Alegre, Brasil: Universidad Federal. pp. 385−398.
  5. ↑ Rubilar-Rogers, D.; Gutstein, C. S. (2012). "Los Titanosaurios de Chile y su Contexto Filogenético y Biográfico". Boletín del Museo Nacional de Historia Natural. 61: 55−73.
  6. 1 2 3 4 5 Soto-Acuña, S.; Otero, R. A.; Rubilar-Rogers, D.; Vargas, A. O. (2015). "Arcosaurios no avianos de Chile". In Rubilar-Rogers, D.; Otero, R.; Vargas, A.; Sallaberry, M. (eds.). Vertebrados Fósiles de Chile (PDF). Publicación Ocasional. Santiago: Museo Nacional de Historia Natural Chile. pp. 189−207.
  7. 1 2 3 4 5 Amudeo-Plaza, J.; Soto-Acuña, S.; Ugalde, R.; Martínez, P.; Rubilar-Rogers, D. (2023). "Reassessment of theropod material from Pichasca, Northern Chile: Presence of Abelisauridae (Theropoda: Ceratosauria) from the Quebrada La Totora Beds (Albian - Turonian)". Journal of South American Earth Sciences. 129. doi:10.1016/j.jsames.2023.104494.
  8. 1 2 3 Otero, R. A. (2015). "Tortugas Fósiles en Chile (Testudines): Primeras perspectivas de un registro aún escaso". In Rubilar-Rogers, D.; Otero, R.; Vargas, A.; Sallaberry, M. (eds.). Vertebrados Fósiles de Chile (PDF). Publicación Ocasional. Santiago: Museo Nacional de Historia Natural Chile. pp. 189−207.
  9. 1 2 3 Suárez, M. E.; Torres, T.; Ugalde, R.; Pineda, G. (2015). Nuevos antecedentes paleontológicos sobre los Estratos de Quebrada La Totora (Cretácico) en Pichasca, Río Hurtado, IV Región de Coquimbo. XIV Congreso Geológico Chileno. La Serena: Congreso Geológico Chileno.
  10. ↑ Aguirre, L. L.-B.; Egert, E. R. (1965). "Cuadrángulo Quebrada Marquesa, Provincia de Coquimbo, Escala 1:50000". Carta Geológica de Chile (15): 1−64.
  11. 1 2 3 4 5 6 7 Casamiquela, R. M.; Corvalán, J.; Franquesa, F. (1969). "Hallazgo de Dinosaurios en el Cretácico Superior de Chile". Instituto de Investigaciones Geológicas (25): 5−30.
  12. ↑ Emparan, C. C.; Pineda, G. F. (1999). "Área Condoriaco-Rivadavia, Región de Coquimbo, Escala 1:100000". Servicio Nacional de Geología y Minería. Mapas Geológicos (12).
  13. ↑ Pineda, G. F.; Emparan, C. C. (2006). "Geología del Área Andacollo-Puerto Aldea, Región de Coquimbo, Escala 1:100000". Carta Geológica de Chile (96). Servicio Nacional de Geología y Minería: 1−85.
  14. ↑ Pineda, G. F.; Calderón, M. N. (2008). "Geología del Área Monte Patria-El Maqui, Región de Coquimbo, Escala 1:100000". Carta Geológica de Chile (116). Servicio Nacional de Geología y Minería: 1−43.
  15. ↑ Creixell, C. T.; Labbé, M. R.; Arévalo, C. V.; Salazar, E. P. (2013). "Geología del Área Estación Chañar-Junta de Chingolines, Regiones de Atacama y Coquimbo, Escala 1:100000". Carta Geológica de Chile (150). Servicio Nacional de Geología y Minería: 1−85.
  16. 1 2 3 4 5 Rubilar-Rogers, D. (2003). "Registro de Dinosaurios en Chile" (PDF). Boletín del Museo Nacional de Historia Natural. 52: 137−150.
  17. ↑ Rubilar-Rogers, D.; Otero, R. A.; Yury-Yáñez, R. E.; Vargas, A. O.; Gutstein, C. S. (2012). "An overview of the dinosaur fossil record from Chile". Journal of South American Earth Sciences. 37 (2): 242−255. doi:10.1016/j.jsames.2012.03.003.
  18. 1 2 Salinas, P.; Marshall, L.; Sepulveda, P. (1991). Vertebrados Continentales del Paleozoico y Mesozoico de Chile. 6º Congreso Geológico Chileno. Viña del Mar: Servicio Nacional de Geología y Minería Chile. pp. 310−313.
  19. ↑ Salinas, P.; Marshall, L. (1991). "Los primeros dientes de dinosaurios en Chile". Revista Técnica de Yacimientos Petrolíferos Fiscales Bolivianos. 2: 235−236.
  20. 1 2 3 Nishida, M.; Nishida, H.; Rancusi, M. H. (1988). "Notes on the petrified plants from Chile (1)". Journal of Japanese Botany. 63: 39−48.
  21. ↑ Poole, I. (2002). "Systematics of Cretaceous and Tertiary Nothofagoxylon: implications for Southern Hemisphere biogeography and evolution of the Nothofagaceae". Australian Systematic Botany. 15 (2): 247−276. doi:10.1071/SB01014.
  22. ↑ Nishida, M.; Takeshi, O.; Nishida, H.; Rancusi, M. H. (1992). "Permineralized Coniferous Woods from the XI Region of Chile, Central Patagonia". Research Institute of Evolutionary Biolology Scientific Report. 7: 47−59.
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