''Abydosaurus'' (meaning " Abydos lizard") is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

brachiosaurid The Brachiosauridae ("arm lizards", from Greek ''brachion'' (βραχίων) = "arm" and ''sauros'' = "lizard") are a family or clade of herbivorous, quadrupedal sauropod dinosaurs. Brachiosaurids had long necks that enabled them to access the l ...

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 b ...

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

known from skull and

postcrania The postcranium ("behind the cranium"; plural: postcrania) or postcranial skeleton in zoology and vertebrate paleontology is the skeleton apart from the skull. The postcranium encompasses the axial skeleton, which includes the entirety of the verte ...

l material found in upper

Lower Cretaceous Lower may refer to: * ''Lower'' (album), 2025 album by Benjamin Booker * Lower (surname) * Lower Township, New Jersey *Lower Receiver (firearms) * Lower Wick Gloucestershire, England See also * Nizhny {{Disambiguation ...

rocks of northeastern

Utah Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

Discovery

''Abydosaurus'' is one of the few sauropods known from skull material, with the first described complete skull for a Cretaceous sauropod from the Americas. It is also notable for its narrow teeth, as earlier brachiosaurids had broader teeth. ''Abydosaurus'' is based on the

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

DINO Dino may refer to: Prefix * dino-, a common prefix in taxonomy, meaning "terrible", "formidable" **Dinosaur ** Dinosaurus People * Dino (given name), a masculine given name and a nickname * Dino (surname), a surname found in Albania and Turkey ...

16488, a nearly complete skull and lower jaws with the first four neck

vertebra Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spina ...

e. Abundant skull and postcranial bones were found at the same site, including partial skulls from three additional individuals, a partial

hip In vertebrate anatomy, the hip, or coxaLatin ''coxa'' was used by Celsus in the sense "hip", but by Pliny the Elder in the sense "hip bone" (Diab, p 77) (: ''coxae'') in medical terminology, refers to either an anatomical region or a joint on t ...

and associated tail vertebrae, a

shoulder blade The scapula (: scapulae or scapulas), also known as the shoulder blade, is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone). Like their connected bones, the scapulae are paired, with each scapula on either side ...

, an upper arm bone, and hand bones. These fossils were found in a

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

bed at the base of the Mussentuchit Member of the

Cedar Mountain Formation The Cedar Mountain Formation is the name given to a distinctive sedimentary geologic formation in eastern Utah, spanning most of the early and mid-Cretaceous. The formation was named for Cedar Mountain (Utah), Cedar Mountain in northern Emery Cou ...

, near the old visitor center of

Dinosaur National Monument Dinosaur National Monument is an American national monument located on the southeast flank of the Uinta Mountains on the border between Colorado and Utah at the confluence of the Green River (Colorado River tributary), Green and Yampa River, Y ...

Zircon Zircon () is a mineral belonging to the group of nesosilicates and is a source of the metal zirconium. Its chemical name is zirconium(IV) silicate, and its corresponding chemical formula is Zr SiO4. An empirical formula showing some of th ...

s from mudstones beneath the bone-bearing sandstone indicate the age of the sandstone and its contained bones is less than 104.46 ± 0.95 million years, in the

Albian The Albian is both an age (geology), age of the geologic timescale and a stage (stratigraphy), stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early Cretaceous, Early/Lower Cretaceous epoch (geology), Epoch/s ...

stage of the

Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...

. ''Abydosaurus'' was named in 2010 by Daniel Chure and colleagues. The genus name is a reference to

Egyptian mythology Egyptian mythology is the collection of myths from ancient Egypt, which describe the actions of the Egyptian pantheon, Egyptian gods as a means of understanding the world around them. The beliefs that these myths express are an important part ...

: Abydos is the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

name for a city on the

Nile The Nile (also known as the Nile River or River Nile) is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa. It has historically been considered the List of river sy ...

where the head and neck of

Osiris Osiris (, from Egyptian ''wikt:wsjr, wsjr'') was the ancient Egyptian deities, god of fertility, agriculture, the Ancient Egyptian religion#Afterlife, afterlife, the dead, resurrection, life, and vegetation in ancient Egyptian religion. He was ...

were buried, while the holotype of ''Abydosaurus'' consists of a head and neck found in rocks overlooking the Green River. The

type species In International_Code_of_Zoological_Nomenclature, 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 spe ...

is ''A. mcintoshi'' in honor of John S. ("Jack") McIntosh, Professor of Physics, Emeritus,

Wesleyan University Wesleyan University ( ) is a Private university, private liberal arts college, liberal arts university in Middletown, Connecticut, United States. It was founded in 1831 as a Men's colleges in the United States, men's college under the Methodi ...

, and his contributions to Dinosaur National Monument and the study of sauropod dinosaurs.

Description

Although ''Abydosaurus'' lived some 50 million years after ''

Giraffatitan ''Giraffatitan'' (name meaning "titanic giraffe") is a genus of sauropod dinosaur that lived during the late Jurassic Period (geology), Period (Kimmeridgian–Tithonian stages) in what is now Lindi Region, Tanzania. Only one species is known, ...

'', the skulls of these two genera are similar except for the narrower, sharper teeth and smaller nose of ''Abydosaurus''. ''Abydosaurus'' can be differentiated from all other sauropods, including ''Giraffatitan'', by subtle features of the

nasal Nasal is an adjective referring to the nose, part of human or animal anatomy. It may also be shorthand for the following uses in combination: * With reference to the human nose: ** Nasal administration, a method of pharmaceutical drug delivery * ...

and

maxilla In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxil ...

ry bones, its relatively small external nares (nostrils), and some features of the teeth. In 2012 Thomas Holtz gave a length of .

References

External links

* {{Taxonbar, from1=Q18511044, from2=Q131241 Brachiosauridae Dinosaur genera Albian dinosaurs Cedar Mountain Formation Dinosaurs of the United States Fossil taxa described in 2010