The Dolores Formation is a geologic

formation Formation may refer to: Linguistics * Back-formation, the process of creating a new lexeme by removing or affixes * Word formation, the creation of a new word by adding affixes Mathematics and science * Cave formation or speleothem, a secondary ...

Uruguay Uruguay, officially the Oriental Republic of Uruguay, is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast, while bordering the Río de la Plata to the south and the A ...

. The formation is dated to the

Late Pleistocene The Late Pleistocene is an unofficial Age (geology), age in the international geologic timescale in chronostratigraphy, also known as the Upper Pleistocene from a Stratigraphy, stratigraphic perspective. It is intended to be the fourth division ...

Early Holocene In the geologic time scale, the Greenlandian is the earliest age or lowest stage of the Holocene Epoch or Series, part of the Quaternary. Beginning in 11,650 BP (9701 BCE or 300 HE) and ending with the 8.2-kiloyear event (c. 8200–8300 B ...

. Performing

optically stimulated luminescence In physics, optically stimulated luminescence (OSL) is a method for measuring doses from ionizing radiation. It is used in at least two applications: * Luminescence dating of ancient materials: mainly geological sediments and sometimes fired pot ...

and

thermoluminescence Thermoluminescence is a form of luminescence that is exhibited by certain crystalline materials, such as some minerals, when previously absorbed energy from electromagnetic radiation or other ionizing radiation is re-emitted as light upon hea ...

methods on sand samples from different locations within the formation produced ages between 32,230 ± 2,640 and 10,570 ± 990 years ago, while a set of

calibrated In measurement technology and metrology, calibration is the comparison of measurement values delivered by a device under test with those of a calibration standard of known accuracy. Such a standard could be another measurement device of known ...

radiocarbon dating Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for Chronological dating, determining the age of an object containing organic material by using the properties of carbon-14, radiocarbon, a radioactive Isotop ...

based on organic soil, wood, and mammal teeth resulted in ages between 27,436 and 11,857 years ago.

Fossil content

The following fossils have been reported from the formation: * ''

Catonyx cuvieri ''Catonyx'' is an extinct genus of ground sloth of the family Scelidotheriidae, endemic to South America during the Pliocene and Pleistocene epochs. It lived from 2.5 Ma to about 10,000 years ago, existing for approximately . The most recent date ...

'' * ''

Hippidion ''Hippidion'' (meaning ''little horse'') is an extinct genus of equine that lived in South America from the Late Pliocene to the end of the Late Pleistocene (Lujanian), between 2.5 million and 11,000 years ago. They were one of two lineages of eq ...

'' * '' Lestodon armatus'' * ''

Macrauchenia ''Macrauchenia'' ("long llama", based on the now-invalid llama genus, ''Auchenia'', from Greek "big neck") is an extinct genus of large ungulate native to South America from the Pliocene or Middle Pleistocene to the end of the Late Pleistocene. I ...

'' * '' Panochthus tuberculatus'' * ''

Smilodon fatalis ''Smilodon'' is an extinct genus of felids. It is one of the best known saber-toothed predators and prehistoric mammals. Although commonly known as the saber-toothed tiger, it was not closely related to the tiger or other modern cats, belon ...

'' * '' Smilodon populator'' * ''

Notiomastodon platensis ''Notiomastodon'' is an extinct genus of gomphothere proboscidean (related to modern elephants), endemic to South America from the Pleistocene to the early Holocene. ''Notiomastodon'' specimens reached a size similar to that of the modern Asian e ...

'' * ''

Toxodon ''Toxodon'' (meaning "bow tooth" in reference to the curvature of the teeth) is an extinct genus of large ungulate native to South America from the Pliocene to the end of the Late Pleistocene. ''Toxodon'' is a member of Notoungulata, an order of ...

References

Bibliography

* Geologic formations of Uruguay Fossiliferous stratigraphic units of South America Paleontology in Uruguay Paraná Basin Lujanian {{SouthAm-geologic-formation-stub

Fossil content

See also

References

Bibliography