Abydosaurus
Encyclopedia
| name = Abydosaurus
| fossil_range = Early Cretaceous
,
| image = Abydosaurus.jpg
| image_width = 250px
| image_caption =
| genus = Abydosaurus
| parent_authority = Chure et al., 2010
| species = mcintoshi
| authority = Chure et al., 2010
}}
Abydosaurus (meaning "Abydos
lizard") is a genus
of brachiosaurid
sauropod
dinosaur
known from skull and postcrania
l material found in upper Lower Cretaceous rocks of northeastern Utah
, United States
.
Abydosaurus is based on
DINO
16488, a nearly complete skull and lower jaws with the first four neck vertebrae. Abundant skull and postcranial bones were found at the same site, including partial skulls from three additional individuals, a partial hip
and associated tail vertebrae, a shoulder blade
, an upper arm bone
, and hand bones. These fossils were found in a sandstone
bed at the base of the Mussentuchit Member of the Cedar Mountain Formation
, near the old visitor center of Dinosaur National Monument
. Zircon
s in the sandstone and underlying mudstone
indicate an age of 104.46 ± 0.95 million years, in the Albian
stage of the Early Cretaceous
.
Although Abydosaurus lived some 45 million years after Giraffatitan
, 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
and maxilla
ry bones, its relatively small external nares (nostrils), and some features of the teeth.
Abydosaurus was named in 2010 by Daniel Chure and colleagues. The genus name is a reference to Egyptian mythology
: Abydos
is the Greek
name for a city on the Nile
where the head and neck of Osiris
were buried, while the holotype of Abydosaurus consists of a head and neck found in rocks overlooking the Green River
. The type species
is A. mcintoshi in honor of John S. ("Jack") McIntosh, Professor of Physics, Emeritus, Wesleyan University
, and his contributions to Dinosaur National Monument and the study of sauropod dinosaurs.
| fossil_range = Early Cretaceous
Early Cretaceous
The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous...
,
| image = Abydosaurus.jpg
| image_width = 250px
| image_caption =
| genus = Abydosaurus
| parent_authority = Chure et al., 2010
2010 in paleontology
-Anomalocaridids:-Newly named crustaceans:-Newly named insects:* A new family, Cascopleciidae, is published by Poinar Jr.* A new family of ceraphronoid Hymenopters, Radiophronidae, is published by Ortega-Blanco, Rasnitsyn, and Delclòs....
| species = mcintoshi
| authority = Chure et al., 2010
}}
Abydosaurus (meaning "Abydos
Abydos, Egypt
Abydos is one of the most ancient cities of Upper Egypt, and also of the eight Upper Nome, of which it was the capital city. It is located about 11 kilometres west of the Nile at latitude 26° 10' N, near the modern Egyptian towns of el-'Araba el Madfuna and al-Balyana...
lizard") is a genus
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 brachiosaurid
Brachiosauridae
Brachiosauridae are a family of dinosaurs, whose members are known as brachiosaurids. They were herbivorous quadrupeds with longer forelegs than hind legs - the name derives from the Greek for arm lizard - and long necks...
sauropod
Sauropoda
Sauropoda , or the sauropods , are an infraorder of saurischian dinosaurs. They had long necks, long tails, small heads , and thick, pillar-like legs. They are notable for the enormous sizes attained by some species, and the group includes the largest animals to have ever lived on land...
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...
known from skull and postcrania
Postcrania
Postcrania[p] in zoology and vertebrate paleontology refers to all or part of the skeleton apart from the skull. Frequently, fossil remains, e.g...
l material found in upper Lower Cretaceous rocks of northeastern Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
, United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
.
Discovery and description
It is of interest because it 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
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...
DINO
Dinosaur National Monument
Dinosaur National Monument is a National Monument located on the southeast flank of the Uinta Mountains on the border between Colorado and Utah at the confluence of the Green and Yampa Rivers. Although most of the monument area is in Moffat County, Colorado, the Dinosaur Quarry is located in Utah...
16488, a nearly complete skull and lower jaws with the first four neck vertebrae. Abundant skull and postcranial bones were found at the same site, including partial skulls from three additional individuals, a partial hip
Pelvis
In human anatomy, the pelvis is the lower part of the trunk, between the abdomen and the lower limbs .The pelvis includes several structures:...
and associated tail vertebrae, a shoulder blade
Scapula
In anatomy, the scapula , omo, or shoulder blade, is the bone that connects the humerus with the clavicle ....
, an upper arm bone
Humerus
The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....
, and hand bones. These fossils were found in a sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
bed at the base of the Mussentuchit Member of the Cedar Mountain Formation
Cedar Mountain Formation
The Cedar Mountain Formation is the name given to distinctive sedimentary rocks in eastern Utah that occur between the underlying Morrison Formation and overlying Naturita Formation . It is composed of non-marine sediments, that is, sediments deposited in rivers, lakes and on flood plains...
, near the old visitor center of Dinosaur National Monument
Dinosaur National Monument
Dinosaur National Monument is a National Monument located on the southeast flank of the Uinta Mountains on the border between Colorado and Utah at the confluence of the Green and Yampa Rivers. Although most of the monument area is in Moffat County, Colorado, the Dinosaur Quarry is located in Utah...
. Zircon
Zircon
Zircon is a mineral belonging to the group of nesosilicates. Its chemical name is zirconium silicate and its corresponding chemical formula is ZrSiO4. A common empirical formula showing some of the range of substitution in zircon is 1–x4x–y...
s in the sandstone and underlying mudstone
Mudstone
Mudstone is a fine grained sedimentary rock whose original constituents were clays or muds. Grain size is up to 0.0625 mm with individual grains too small to be distinguished without a microscope. With increased pressure over time the platey clay minerals may become aligned, with the...
indicate an age of 104.46 ± 0.95 million years, in the Albian
Albian
The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous epoch/series. Its approximate time range is 112.0 ± 1.0 Ma to 99.6 ± 0.9 Ma...
stage of the Early Cretaceous
Early Cretaceous
The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous...
.
Although Abydosaurus lived some 45 million years after Giraffatitan
Giraffatitan
Giraffatitan, meaning "giraffe titan", is a genus of sauropod dinosaur that lived during the late Jurassic Period . It was originally named as an African species of Brachiosaurus...
, 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 bone
The nasal bones are two small oblong bones, varying in size and form in different individuals; they are placed side by side at the middle and upper part of the face, and form, by their junction, "the bridge" of the nose.Each has two surfaces and four borders....
and maxilla
Maxilla
The maxilla is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible , which is also a fusion of two halves at the mental symphysis. Sometimes The maxilla (plural: maxillae) is a fusion of two bones along the palatal fissure that form the upper...
ry bones, its relatively small external nares (nostrils), and some features of the teeth.
Abydosaurus was named in 2010 by Daniel Chure and colleagues. The genus name is a reference to Egyptian mythology
Ancient Egypt
Ancient Egypt was an ancient civilization of Northeastern Africa, concentrated along the lower reaches of the Nile River in what is now the modern country of Egypt. Egyptian civilization coalesced around 3150 BC with the political unification of Upper and Lower Egypt under the first pharaoh...
: Abydos
Abydos, Egypt
Abydos is one of the most ancient cities of Upper Egypt, and also of the eight Upper Nome, of which it was the capital city. It is located about 11 kilometres west of the Nile at latitude 26° 10' N, near the modern Egyptian towns of el-'Araba el Madfuna and al-Balyana...
is 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...
name for a city on the Nile
Nile
The Nile is a major north-flowing river in North Africa, generally regarded as the longest river in the world. It is long. It runs through the ten countries of Sudan, South Sudan, Burundi, Rwanda, Democratic Republic of the Congo, Tanzania, Kenya, Ethiopia, Uganda and Egypt.The Nile has two major...
where the head and neck of Osiris
Osiris
Osiris is an Egyptian god, usually identified as the god of the afterlife, the underworld and the dead. He is classically depicted as a green-skinned man with a pharaoh's beard, partially mummy-wrapped at the legs, wearing a distinctive crown with two large ostrich feathers at either side, and...
were buried, while the holotype of Abydosaurus consists of a head and neck found in rocks overlooking the Green River
Green River (Utah)
The Green River, located in the western United States, is the chief tributary of the Colorado River. The watershed of the river, known as the Green River Basin, covers parts of Wyoming, Utah, and Colorado. The Green River is long, beginning in the Wind River Mountains of Wyoming and flowing...
. The type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
is A. mcintoshi in honor of John S. ("Jack") McIntosh, Professor of Physics, Emeritus, Wesleyan University
Wesleyan University
Wesleyan University is a private liberal arts college founded in 1831 and located in Middletown, Connecticut. According to the Carnegie Foundation for the Advancement of Teaching, Wesleyan is the only Baccalaureate College in the nation that emphasizes undergraduate instruction in the arts and...
, and his contributions to Dinosaur National Monument and the study of sauropod dinosaurs.