''Atlasaurus'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

sauropod Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', ' lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

s from

Middle Jurassic The Middle Jurassic is the second Epoch (geology), epoch of the Jurassic Period (geology), Period. It lasted from about 174.1 to 163.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively ...

(

Bathonian In the geologic timescale the Bathonian is an age and stage of the Middle Jurassic. It lasted from approximately 168.3 Ma to around 166.1 Ma (million years ago). The Bathonian Age succeeds the Bajocian Age and precedes the Callovian Age. ...

Callovian In the geologic timescale, the Callovian is an age and stage in the Middle Jurassic, lasting between 166.1 ± 4.0 Ma (million years ago) and 163.5 ± 4.0 Ma. It is the last stage of the Middle Jurassic, following the Bathonian and preceding the ...

stages) beds in

North Africa North Africa, or Northern Africa is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region, and it is sometimes defined as stretching from the Atlantic shores of Mauritania in ...

.M. Monbaron, D. A. Russell, and P. Taquet. (1999). ''Atlasaurus imelakei'' n.g., n.sp., a brachiosaurid-like sauropod from the Middle Jurassic of Morocco. ''Comptes Rendus de l'Académie des Sciences à Paris, Sciences de la Terre et des Planètes'' 329:519-526.

Description

''Atlasaurus'' differs from ''

Brachiosaurus ''Brachiosaurus'' () is a genus of sauropod dinosaur that lived in North America during the Late Jurassic, about 154to 150million years ago. It was first Species description, described by American paleontologist Elmer S. Riggs in 1903 in pal ...

'' relative to the estimated length of the dorsal vertebral column (assuming 12

vertebra The spinal column, a defining synapomorphy shared by nearly all vertebrates, Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristi ...

e, ), in having a proportionately larger

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, th ...

, a shorter

neck The neck is the part of the body on many vertebrates that connects the head with the torso. The neck supports the weight of the head and protects the nerves that carry sensory and motor information from the brain down to the rest of the body. In ...

(with at least 13 cervical vertebrae, shorter and more uniform in length than ''Brachiosaurus''), a longer tail and more elongated limbs (

humerus The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a r ...

femur The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates ...

ratio: 0.99;

ulna The ulna (''pl''. ulnae or ulnas) is a long bone found in the forearm that stretches from the elbow to the smallest finger, and when in anatomical position, is found on the medial side of the forearm. That is, the ulna is on the same side of t ...

tibia The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it conn ...

ratio: 1.15). The teeth are spoon-shaped and have denticles. The lower jaw of ''Atlasaurus'' is about long, the neck was about long, the humerus long, and the femur about long. It has been estimated at in length, and in weight.

Discovery and naming

The ''Atlasaurus'' holotype was discovered in 1981 described by Monbaron, Russell & Taquet in 1999. It was named after the location of discovery in the

High Atlas High Atlas, also called the Grand Atlas ( ar, الأطلس الكبير, Al-Aṭlas al-Kabīr; french: Haut Atlas; shi, ⴰⴷⵔⴰⵔ ⵏ ⴷⵔⵏ ''Adrar n Dern''), is a mountain range in central Morocco, North Africa, the highest part of t ...

range of the

Atlas Mountains The Atlas Mountains are a mountain range in the Maghreb in North Africa. It separates the Sahara Desert from the Mediterranean Sea and the Atlantic Ocean; the name "Atlantic" is derived from the mountain range. It stretches around through ...

Morocco Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to A ...

(where the

Titan Titan most often refers to: * Titan (moon), the largest moon of Saturn * Titans, a race of deities in Greek mythology Titan or Titans may also refer to: Arts and entertainment Fictional entities Fictional locations * Titan in fiction, fictiona ...

Atlas An atlas is a collection of maps; it is typically a bundle of maps of Earth or of a region of Earth. Atlases have traditionally been bound into book form, but today many atlases are in multimedia formats. In addition to presenting geogra ...

was said to hold up the heavens), and for the animal's size (about long). It is known from a nearly complete skeleton with a skull found at Wawmda, in the Middle Jurassic (Bathonian-Callovian) Guettioua Formation in Morocco's

Azilal Province Azilal (in berber : ⴰⵣⵉⵍⴰⵍ) is a province in the Moroccan region of Béni Mellal-Khénifra. Its population in 2004 is 504,501. The major cities and towns are: * Afourar * Azilal * Ait Attab * Bzou Bzou (بزو) is a town in th ...

. The

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specim ...

is ''Atlasaurus imelakei'', the specific name coming from Arabic ''عملاق'' ("eimlaq" or "imelake"), meaning "giant". A second specimen of ''A. imelakei'', a near-complete tail, was also discovered in

and was pieced back together in

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to its ...

after 300 hours of preparation. It was eventually sent to

Mexico Mexico (Spanish language, Spanish: México), officially the United Mexican States, is a List of sovereign states, country in the southern portion of North America. It is borders of Mexico, bordered to the north by the United States; to the so ...

and was put on display in the lobby of the BBVA Bancomer tower in

Mexico City Mexico City ( es, link=no, Ciudad de México, ; abbr.: CDMX; Nahuatl: ''Altepetl Mexico'') is the capital and largest city of Mexico, and the most populous city in North America. One of the world's alpha cities, it is located in the Valley o ...

until it was auctioned off to an anonymous businessman in January 2018 to pay for the rebuilding of schools destroyed during the

2017 Puebla earthquake The 2017 Puebla earthquake struck at 13:14 CDT (18:14 UTC) on 19 September 2017 with an estimated magnitude of and strong shaking for about 20 seconds. Its epicenter was about south of the city of Puebla, Mexico. The earthquake caused d ...

Classification

It was classified as a relatively primitive sauropod identified as a "

cetiosaur Cetiosauridae is a family of sauropod dinosaurs which was first proposed by Richard Lydekker in 1888. While traditionally a wastebasket taxon containing various unrelated species, some recent studies have found that it may represent a natural ...

" when first discovered, although upon further study, ''Atlasaurus'' appears to be closer to ''

'' than to any other known sauropod based on detailed similarities between the vertebral column and limbs. However, more recent analyses have considered it to be a putative member of the

Turiasauria Turiasauria is an unranked clade of basal sauropod dinosaurs known from Middle Jurassic to Early Cretaceous deposits in Europe, North America, and Africa. Description Turiasauria was originally erected by Royo-Torres et al. (2006) to include '' ...

. The most recent analysis of turiasaurs recovers ''Atlasaurus'' as a brachiosaurid.

References

{{Taxonbar, from=Q2456661 Sauropods Middle Jurassic dinosaurs of Africa Jurassic Morocco Fossils of Morocco Fossil taxa described in 1999 Taxa named by Dale Russell Taxa named by Philippe Taquet