Aeolosaurus
Encyclopedia
Aeolosaurus is a genus
of titanosaurian sauropod dinosaur
from the Late Cretaceous
Period of what is now South America
. Like most sauropods, it would have been a quadrupedal herbivore
with a long neck and tail. The remains of this dinosaur are incomplete, so size can only be estimated but Aeolosaurus was probably at least 45 feet (14 m) in length.
This dinosaur is named after the Greek mythological
figure Aeolus
, Keeper of the Wind
s in Homer
's Odyssey
, because of the frequent winds that blow across Patagonia
, where the remains were found. The generic name also includes the Greek
sauros ('lizard'), the traditional suffix used in dinosaur names. The specific
name (A. rionegrinus), refers to its location, in the Rio Negro Province
of Argentina
. Both genus and species were named and described by Argentine paleontologist Jaime Powell in 1987.
The holotype
of Aeolosaurus rionegrinus consists of a series of seven tail vertebrae, as well as parts of both forelimbs and the right hindlimb. It was discovered in the Angostura Colorada Formation
in Argentina, which dates from the Campanian
stage of the Late Cretaceous, about 83 to 74 million years ago.
Relationships among the many titanosaurian sauropods are hazy at best, but Aeolosaurus has been tentatively linked to a few other genera, based on features of the tail vertebrae, including Rinconsaurus
and Adamantisaurus
. Gondwanatitan
and Aeolosaurus both exhibit neural spines on the tail vertebrae that point forwards, a feature not seen in any other known titanosaurians
The vertebrae from the middle part of its tail had elongated centra
. Aeolosaurus had vertebral lateral fossae that resembled shallow depressions. Fossae that similarly resemble shallow depressions are known from Saltasaurus
, Alamosaurus
, Malawisaurus
, and Gondwanatitan
. Venenosaurus also had depression-like fossae, but its "depressions" penetrated deeper into the vertebrae, were divided into two chambers, and extend farther into the vertebral columns.
Its middle tail vertebrae's neural spines angled anteriorly when the vertebrae are aligned. These vertebrae resemble those of Cedarosaurus
, Venenosaurus
, and Gondwanatitan
.
. Since there are two right ulna
(forearm) bones, the specimen must consist of at least two individuals. These bones were also associated with two osteoderms
, or bony armor
plates, providing evidence that this dinosaur was armored. This specimen is from the Allen Formation
of Rio Negro, dating back about 70 to 68 million years ago to the middle Maastrichtian
stage. While this specimen bears features that characterize the genus Aeolosaurus, it is from a younger time period and shows enough differences that the authors recognized it as a possible second species.
Another partial skeleton, including four more tail vertebrae and material from both limbs on the left side of the body, was described in 1997. This was recovered from the Los Alamitos Formation
of Rio Negro, which falls between the other two dates. This specimen was also referred to the genus Aeolosaurus, but not to the species A. rionegrinus, and may represent a third species
However, since the genus Aeolosaurus is not well known, the authors chose not to formally name either of these possible new species. For now, they are both simply known as "Aeolosaurus sp." Future discoveries may give scientists more information on variation within the genus, and show that all of the above specimens belong to A. rionegrinus, or that they merit being formally named.
Another series of 15 tail vertebrae was assigned to Aeolosaurus in the original description, but it was later determined that the series does not belong to this genus, as it lacks several features found in the other specimens of Aeolosaurus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of titanosaurian sauropod dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
from the Late Cretaceous
Late Cretaceous
The Late Cretaceous is the younger of two epochs into which the Cretaceous period is divided in the geologic timescale. Rock strata from this epoch form the Upper Cretaceous series...
Period of what is now South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
. Like most sauropods, it would have been a quadrupedal herbivore
Herbivore
Herbivores are organisms that are anatomically and physiologically adapted to eat plant-based foods. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms that feed on autotrophs in...
with a long neck and tail. The remains of this dinosaur are incomplete, so size can only be estimated but Aeolosaurus was probably at least 45 feet (14 m) in length.
This dinosaur is named after the Greek mythological
Greek mythology
Greek mythology is the body of myths and legends belonging to the ancient Greeks, concerning their gods and heroes, the nature of the world, and the origins and significance of their own cult and ritual practices. They were a part of religion in ancient Greece...
figure Aeolus
Aeolus
Aeolus was the ruler of the winds in Greek mythology. In fact this name was shared by three mythic characters. These three personages are often difficult to tell apart, and even the ancient mythographers appear to have been perplexed about which Aeolus was which...
, Keeper of the Wind
Wind
Wind is the flow of gases on a large scale. On Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space...
s in Homer
Homer
In the Western classical tradition Homer , is the author of the Iliad and the Odyssey, and is revered as the greatest ancient Greek epic poet. These epics lie at the beginning of the Western canon of literature, and have had an enormous influence on the history of literature.When he lived is...
's Odyssey
Odyssey
The Odyssey is one of two major ancient Greek epic poems attributed to Homer. It is, in part, a sequel to the Iliad, the other work ascribed to Homer. The poem is fundamental to the modern Western canon, and is the second—the Iliad being the first—extant work of Western literature...
, because of the frequent winds that blow across Patagonia
Patagonia
Patagonia is a region located in Argentina and Chile, integrating the southernmost section of the Andes mountains to the southwest towards the Pacific ocean and from the east of the cordillera to the valleys it follows south through Colorado River towards Carmen de Patagones in the Atlantic Ocean...
, where the remains were found. The generic name also includes the Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
sauros ('lizard'), the traditional suffix used in dinosaur names. The specific
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
name (A. rionegrinus), refers to its location, in the Rio Negro Province
Río Negro Province
Río Negro is a province of Argentina, located at the northern edge of Patagonia. Neighboring provinces are from the south clockwise Chubut, Neuquén, Mendoza, La Pampa and Buenos Aires. To the east lies the Atlantic Ocean.Its capital is Viedma...
of Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
. Both genus and species were named and described by Argentine paleontologist Jaime Powell in 1987.
The holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
of Aeolosaurus rionegrinus consists of a series of seven tail vertebrae, as well as parts of both forelimbs and the right hindlimb. It was discovered in the Angostura Colorada Formation
Angostura Colorada Formation
The Angostura Colorada Formation is a Mesozoic geologic formation. Dinosaur remains diagnostic to the genus level are among the fossils that have been recovered from the formation.-See also:* List of dinosaur-bearing rock formations...
in Argentina, which dates from the Campanian
Campanian
The Campanian is, in the ICS' geologic timescale, the fifth of six ages of the Late Cretaceous epoch . The Campanian spans the time from 83.5 ± 0.7 Ma to 70.6 ± 0.6 Ma ...
stage of the Late Cretaceous, about 83 to 74 million years ago.
Relationships among the many titanosaurian sauropods are hazy at best, but Aeolosaurus has been tentatively linked to a few other genera, based on features of the tail vertebrae, including Rinconsaurus
Rinconsaurus
Rinconsaurus is a genus of dinosaur from the Late Cretaceous. It was a titanosaurid sauropod which lived in what is now Argentina. The type species, Rinconsaurus caudamirus, was described by Calvo and Riga in 2003, and is based on three partial skeletons.-Description:Like all sauropods,...
and Adamantisaurus
Adamantisaurus
Adamantisaurus is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous Period of what is now South America. It is only known from six tail vertebrae but, as a sauropod, it can be assumed that this dinosaur was a very large animal with a long neck and tail...
. Gondwanatitan
Gondwanatitan
Gondwanatitan was a titanosaurian sauropod dinosaur. Gondwanatitan was found in Brazil, at the time part of the southern supercontinent Gondwana , in the late Cretaceous Period . Like some other sauropods, Gondwanatitan was tall and ate tough shoots and leaves off of the tops of trees. G...
and Aeolosaurus both exhibit neural spines on the tail vertebrae that point forwards, a feature not seen in any other known titanosaurians
The vertebrae from the middle part of its tail had elongated centra
Centra
Centra is a convenience store chain in Ireland.The chain is run by Musgrave, the Irish food wholesaler, however the stores are all owned by individual franchisees. The chain has three different formats available to franchisees — smaller Quick Stop outlets, mid-sized Foodmarkets, and larger...
. Aeolosaurus had vertebral lateral fossae that resembled shallow depressions. Fossae that similarly resemble shallow depressions are known from Saltasaurus
Saltasaurus
Saltasaurus is a genus of titanosaurid sauropod dinosaur of the Late Cretaceous Period. Relatively small among sauropods, though still massive by the standards of modern creatures, Saltasaurus was characterized by a diplodocid-like head...
, Alamosaurus
Alamosaurus
Alamosaurus is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous Period of what is now North America. It was a large quadrupedal herbivore. Isolated vertebrae and limb bones indicate that it reached sizes comparable to Argentinosaurus and Puertasaurus, which would make it the...
, Malawisaurus
Malawisaurus
Malawisaurus was a genus of sauropod dinosaur . It lived in what is now Africa, specifically Malawi, during the Aptian age of the Early Cretaceous Period. It is one of the few titanosaurs for which skull material has been found.It was named by Louis L. Jacobs and colleagues, and was originally...
, and Gondwanatitan
Gondwanatitan
Gondwanatitan was a titanosaurian sauropod dinosaur. Gondwanatitan was found in Brazil, at the time part of the southern supercontinent Gondwana , in the late Cretaceous Period . Like some other sauropods, Gondwanatitan was tall and ate tough shoots and leaves off of the tops of trees. G...
. Venenosaurus also had depression-like fossae, but its "depressions" penetrated deeper into the vertebrae, were divided into two chambers, and extend farther into the vertebral columns.
Its middle tail vertebrae's neural spines angled anteriorly when the vertebrae are aligned. These vertebrae resemble those of Cedarosaurus
Cedarosaurus
Cedarosaurus was a nasal-crested macronarian dinosaur genus from the Early Cretaceous Period . It was a sauropod which lived in what is now Utah...
, Venenosaurus
Venenosaurus
Venenosaurus named after the Poison Strip Member of the Cedar Mountain Formation in Utah, where the fossils were discovered by a Denver Museum of Natural History volunteer Tony DiCroce in 1998. Venenosaurus dicrocei was first described as a new species in 2001 by Virginia Tidwell, Kenneth...
, and Gondwanatitan
Gondwanatitan
Gondwanatitan was a titanosaurian sauropod dinosaur. Gondwanatitan was found in Brazil, at the time part of the southern supercontinent Gondwana , in the late Cretaceous Period . Like some other sauropods, Gondwanatitan was tall and ate tough shoots and leaves off of the tops of trees. G...
.
Possible Additional Species
Another specimen, described in 1993, consists of five tail vertebrae, and some bones from the forelimb and pelvisPelvis
In human anatomy, the pelvis is the lower part of the trunk, between the abdomen and the lower limbs .The pelvis includes several structures:...
. Since there are two right ulna
Ulna
The ulna is one of the two long bones in the forearm, the other being the radius. It is prismatic in form and runs parallel to the radius, which is shorter and smaller. In anatomical position The ulna is one of the two long bones in the forearm, the other being the radius. It is prismatic in form...
(forearm) bones, the specimen must consist of at least two individuals. These bones were also associated with two osteoderms
Scute
A scute or scutum is a bony external plate or scale, as on the shell of a turtle, the skin of crocodilians, the feet of some birds or the anterior portion of the mesonotum in insects.-Properties:...
, or bony armor
Armour (zoology)
Armour in animals is external or superficial protection against attack by predators, formed as part of the body , usually through the hardening of body tissues, outgrowths or secretions. It has therefore mostly developed in 'prey' species...
plates, providing evidence that this dinosaur was armored. This specimen is from the Allen Formation
Allen Formation
The Allen Formation is a geological formation in Argentina whose strata date back to the Late Cretaceous The Allen Formation is a geological formation in Argentina whose strata date back to the Late Cretaceous The Allen Formation is a geological formation in Argentina whose strata date back to the...
of Rio Negro, dating back about 70 to 68 million years ago to the middle Maastrichtian
Maastrichtian
The Maastrichtian is, in the ICS' geologic timescale, the latest age or upper stage of the Late Cretaceous epoch or Upper Cretaceous series, the Cretaceous period or system, and of the Mesozoic era or erathem. It spanned from 70.6 ± 0.6 Ma to 65.5 ± 0.3 Ma...
stage. While this specimen bears features that characterize the genus Aeolosaurus, it is from a younger time period and shows enough differences that the authors recognized it as a possible second species.
Another partial skeleton, including four more tail vertebrae and material from both limbs on the left side of the body, was described in 1997. This was recovered from the Los Alamitos Formation
Los Alamitos Formation
The Los Alamitos Formation is a geological formation in Rio Negro, Argentina whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.-Dinosaurs:-Mammaliaforms:-References:...
of Rio Negro, which falls between the other two dates. This specimen was also referred to the genus Aeolosaurus, but not to the species A. rionegrinus, and may represent a third species
However, since the genus Aeolosaurus is not well known, the authors chose not to formally name either of these possible new species. For now, they are both simply known as "Aeolosaurus sp." Future discoveries may give scientists more information on variation within the genus, and show that all of the above specimens belong to A. rionegrinus, or that they merit being formally named.
Another series of 15 tail vertebrae was assigned to Aeolosaurus in the original description, but it was later determined that the series does not belong to this genus, as it lacks several features found in the other specimens of Aeolosaurus