Aeolosaurus
A Late Cretaceous titanosaur from South America.
Aeolosaurus, meaning "Aeolus' lizard," is a genus of titanosaurian sauropod dinosaur that lived in what is now South America during the Late Cretaceous. Like other sauropods, it was a large, four-legged herbivore with a long neck and tail. Although it is better known than many titanosaurs—thanks to fossils from at least two species—no skull has ever been found. The genus was named and described by Argentine paleontologist Jaime Powell in 1987. The name comes from Aeolus, the keeper of the winds in Homer's *Odyssey*, a reference to the strong winds of Patagonia where the fossils were discovered. The species name *rionegrinus* points to Argentina's Río Negro Province.
The type species, *Aeolosaurus rionegrinus*, is based on a holotype consisting of seven tail vertebrae, parts of both forelimbs, and the right hindlimb. These bones were found in the Angostura Colorada Formation in Argentina, which dates to the Campanian stage, roughly 83 to 74 million years ago. A second species, *A. colhuehuapensis*, was named in 2007, also from Patagonia. A third species, *A. maximus*, was named in 2011 but was moved to a new genus, *Arrudatitan*, in 2021.
*Aeolosaurus* fossils have been collected from several formations in Argentina—Allen, Angostura Colorada, Lago Colhué Huapí, and Los Alamitos—as well as the Serra da Galga Formation in Brazil. All date to the Campanian and Maastrichtian ages. The genus was originally named in Powell's doctoral thesis, but because names in dissertations are not valid under ICZN rules, it was not formally established until the thesis was published the following year. (Powell's thesis was eventually published in 2003, which is sometimes mistakenly cited as the naming date.) In 2004, *Aeolosaurus* and *Gondwanatitan* were recognized as forming a new group called Aeolosaurini.
In terms of size, *A. rionegrinus* was roughly 14 meters (46 feet) long and weighed about 6 tonnes according to Gregory S. Paul, though Molina-Pérez and Larramendi gave a larger estimate of 18.1 meters (60 feet) and 14.7 tonnes in 2020. It was heavily built for a titanosaur, with limb bones as robust as those of *Saltasaurus*. The tail vertebrae are very distinctive: the front tail bones have down-curved prezygapophyses, and the chevrons from the front and middle tail have concave rear surfaces with double articular facets. The front tail vertebrae also have neural spine
- field
- Paleontology
- known_for
- Titanosaurian sauropod with distinctive tail vertebrae and osteoderms
- time_period
- Late Cretaceous (Campanian to Maastrichtian, about 83 to 68 million years ago)
- location
- South America (Argentina and Brazil)
- named_by
- Jaime Powell (1987)
Lore & Background
The type species Aeolosaurus rionegrinus was originally named in Jaime Powell's doctoral thesis, but according to the ICZN, names from dissertations are not valid until published the following year. Powell's thesis was ultimately published in 2003, which is sometimes incorrectly cited as having named the genus. The genus name refers to the Greek mythological figure Aeolus, Keeper of the Winds, because of the frequent winds across Patagonia where the remains were found. The specific name rionegrinus refers to the Rio Negro Province of Argentina.
Aeolosaurus is known from several formations in Argentina and Brazil, including the Angostura Colorada, Allen, Lago Colhué Huapí, Los Alamitos, and Serra da Galga Formations. Two valid species are currently recognized: A. rionegrinus and A. colhuehuapensis. A third species, A. maximus, was moved to the genus Arrudatitan in 2021. The genus is most closely related to Gondwanatitan and Panamericansaurus, together forming the clade Aeolosaurini.
Reader's Guide
Aeolosaurus is significant as a relatively well-known titanosaur from the Late Cretaceous of South America, represented by multiple individuals and at least two species. Its distinctive caudal vertebrae—with down-curved prezygapophyses and chevrons with concave posterodorsal surfaces—help define the genus and the clade Aeolosaurini. The tail was apparently curved strongly downward, a trait likely shared with other aeolosaurins, which may have aided in hindlimb retraction. Like many lithostrotian titanosaurs, Aeolosaurus bore osteoderms, unusual in form and most closely resembling those of Mendozasaurus. The genus lived alongside hadrosaurs, other titanosaurs such as Rocasaurus muniozi, and ankylosaurs. Its fossils span the Campanian and Maastrichtian ages, providing insight into the diversity and distribution of titanosaurs in South America near the end of the Cretaceous.
Did You Know?
- Aeolosaurus is named after Aeolus, the Keeper of the Winds in Homer's Odyssey, due to the frequent winds of Patagonia.
- No skull remains of Aeolosaurus are known.
- The species A. maximus was transferred to the new genus Arrudatitan in 2021.
- Aeolosaurus had osteoderms that most closely resemble those of Mendozasaurus.
More in Dinosaur genera 1-24
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