Hippodraco Temporal range: Early Cretaceous, | |
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Diagram showing known elements of the holotype specimen | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Order: | † Ornithischia |
Clade: | † Ornithopoda |
Clade: | † Styracosterna |
Genus: | † Hippodraco McDonald et al., 2010 |
Type species | |
†Hippodraco scutodens McDonald et al., 2010 |
Hippodraco is a genus of iguanodontian ornithopod dinosaur from the Early Cretaceous Cedar Mountain Formation of Utah, United States. The genus contains a single species, H. scutodens, known from a partial skeleton belonging to an immature individual. [1]
The holotype of Hippodraco, UMNH VP 20208, was discovered in 2004 by Andrew R. C. Milner. It is a fragmentary specimen including a fragmented skull and dentary teeth, vertebrae (dorsal, caudal and cervical), a right humerus, a right scapula, a left ischium, a right tibia, a right femur, and left metatarsals. [1] [2] [3] [4]
It was later named in 2010 by Andrew T. McDonald, James I. Kirkland, Andrew R. C. Milner, Scott K. Madsen, Donald D. DeBlieux, Jennifer Cavin and Lukas Panzarin. The generic name Hippodraco is a combination of the Greek word hippos ("horse") and the Latin word draco ("dragon"). It refers to the elongated shape of the skull, which resembles a horse skull. The specific name scutodens is a combination of the Latin words scutum (meaning shield) and dens (meaning tooth), and it references the shield-shaped dentary tooth crowns. UMNH VP 20208 was unearthed from the Yellow Cat Member of the Cedar Mountain Formation, Utah, at a site known as Andrew's Site, dating from the Valanginian stage in the Early Cretaceous period. [1]
Hippodraco is a relatively small iguanodontid, with the holotype reaching 4.5 m (15 ft) in length. Holtz estimated its weight between 227 to 454 kg (500.4 to 1,000.9 lb). [5] However, a large orbital in the skull indicates that the specimen is immature. The left side of the skull is well preserved, although the right side is very fragmented. The left dentary is preserved on the skull along with teeth, which, have shield-shaped crowns. The lacrimal bone closely resembles those of Dakotadon and Theiophytalia . [1]
Vertebrae indicates a characteristic iguanodont body shape. Most of the body remains are gracile, such as the right humerus and scapula, the right tibia and femur are fragmented, having irregular surfaces. The nearly-complete metatarsus is very similar to those of Camptosaurus and Iguanodon . [1]
In 2010 and 2011 cladistic analyses of McDonald and colleagues, Hippodraco has been recovered as a basal member of the Styracosterna and its closest relative was Theiophytalia . [1] [6] [7] [8]
Ankylopollexia |
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The holotype of Hippodraco was unearthed from the Upper Yellow Cat Member of the Cedar Mountain Formation. [1] Contemporaneous fauna from the Upper Yellow Cat include the fellow ornithopod Cedrorestes , sauropods ( Cedarosaurus and Moabosaurus ), theropods ( Martharaptor and Nedcolbertia ), the nodosaurid Gastonia , and the giant dromaeosaurid Utahraptor . [9] [10] [11] Other dromaeosaurids with fragmentary remains are also known from the formation: an indeterminate eudromaeosaur (UMNH VP 20209) and an indeterminate velociraptorine (UMNH VP 21752). [12]
Utahraptor is a genus of large dromaeosaurid dinosaur that lived in North America during the Early Cretaceous period. It was a heavy-built, ground-dwelling, bipedal carnivore. It contains a single species, Utahraptor ostrommaysi, which is one of the largest-known member of the family Dromaeosauridae, measuring 4.9–5.5 m (16–18 ft) long and weighing 280–300 kg (620–660 lb).
Muttaburrasaurus was a genus of herbivorous iguanodontian ornithopod dinosaur, which lived in what is now northeastern Australia sometime between 110 and 103 million years ago during the early Cretaceous period. It has been recovered in some analyses as a member of the iguanodontian clade Rhabdodontomorpha. After Kunbarrasaurus, it is Australia's most completely known dinosaur from skeletal remains. It was named after Muttaburra, the site in Queensland, Australia, where it was found.
Camptosaurus is a genus of plant-eating, beaked ornithischian dinosaurs of the Late Jurassic period of western North America and possibly also Europe. The name means 'flexible lizard'.
Iguanodontia is a clade of herbivorous dinosaurs that lived from the Middle Jurassic to Late Cretaceous. Some members include Camptosaurus, Dryosaurus, Iguanodon, Tenontosaurus, and the hadrosaurids or "duck-billed dinosaurs". Iguanodontians were one of the first groups of dinosaurs to be found. They are among the best known of the dinosaurs, and were among the most diverse and widespread herbivorous dinosaur groups of the Cretaceous period.
Eolambia is a genus of herbivorous hadrosauroid dinosaur from the early Late Cretaceous of the United States. It contains a single species, E. caroljonesa, named by paleontologist James Kirkland in 1998. The type specimen of Eolambia was discovered by Carole and Ramal Jones in 1993; the species name honors Carole. Since then, hundreds of bones have been discovered from both adults and juveniles, representing nearly every element of the skeleton. All of the specimens have thus far been found in Emery County, Utah, in a layer of rock known as the Mussentuchit Member of the Cedar Mountain Formation.
Iguanodontidae is a family of iguanodontians belonging to Styracosterna, a derived clade within Ankylopollexia.
Cumnoria is a genus of herbivorous iguanodontian dinosaur. It was a basal iguanodontian that lived during the Late Jurassic period in what is now Oxfordshire, United Kingdom.
Dysalotosaurus is a genus of herbivorous iguanodontian dinosaur. It was a dryosaurid iguanodontian, and its fossils have been found in late Kimmeridgian-age rocks of the Tendaguru Formation of Lindi Region in Tanzania. The type and only species of the genus is D. lettowvorbecki. This species was named by Hans Virchow in 1919 in honor of the Imperial German Army Officer, Paul von Lettow-Vorbeck. For much of the 20th century the species was referred to the related and approximately contemporary genus Dryosaurus, but newer studies reject this synonymy.
Zalmoxes is an extinct genus of rhabdodontid ornithopod dinosaur from the Maastrichtian of Romania. The genus is known from specimens first named as the species Mochlodon robustum in 1899 by Franz Nopcsa before being reclassified as Rhabdodon robustum by him in 1915. In 1990 this name was corrected to Rhabdodon robustus by George Olshevsky, and in 2003 the species was once more reclassified, this time as the type species Zalmoxes robustus. Zalmoxes refers to the Dacian deity Zalmoxis, and robustus to the robustness of the remains. In 2003 another species was named, Zalmoxes shqiperorum, named for the Albanian name for Albanians.
James Ian Kirkland is an American paleontologist and geologist. He has worked with dinosaur remains from the south west United States of America and Mexico and has been responsible for discovering new and important genera. He named Animantarx, Cedarpelta, Eohadrosaurus, Jeyawati, Gastonia, Mymoorapelta, Nedcolbertia, Utahraptor, Zuniceratops, Europelta and Diabloceratops. At the same site where he found Gastonia and Utahraptor, Kirkland has also excavated fossils of the therizinosaur Falcarius.
Theiophytalia is a genus of herbivorous iguanodontian dinosaur from the lower Cretaceous period of Colorado, USA. It contains a single species, T. kerri.
Dryosaurids were primitive iguanodonts. They are known from Middle Jurassic to Early Cretaceous rocks of Africa, Europe, and North America.
Eudromaeosauria is a subgroup of terrestrial dromaeosaurid theropod dinosaurs. They were relatively small to medium-sized, feathered hypercarnivores that flourished in the Cretaceous Period.
Iguanacolossus is a genus of iguanodontian ornithopod dinosaur that lived in North America during the Early Cretaceous period. It is known from UMNH VP 20205, the associated holotype with a large partial skeleton of a single individual.
Geminiraptor is a genus of troodontid theropod dinosaur that lived in North America during the Early Cretaceous period. Geminiraptor was a small, ground-dwelling bipedal carnivorous paravian. The type species of Geminiraptor is G. suarezarum.
Ankylopollexia is an extinct clade of ornithischian dinosaurs that lived from the Late Jurassic to the Late Cretaceous. It is a derived clade of iguanodontian ornithopods and contains the subgroup Styracosterna. The name stems from the Greek word, “ankylos”, mistakenly taken to mean stiff, fused, and the Latin word, “pollex”, meaning thumb. Originally described in 1986 by Sereno, a most likely synapomorphic feature of a conical thumb spine defines the clade.
Xiaotingia is a genus of anchiornithid theropod dinosaur from Middle Jurassic or early Late Jurassic deposits of western Liaoning, China, containing a single species, Xiaotingia zhengi.
Yurgovuchia is a genus of dromaeosaurid theropod dinosaurs that lived in North America during the Early Cretaceous period in what is now the Cedar Mountain Formation. It contains a single species, Yurgovuchia doellingi. The remains were discovered in Utah, United States.
Lythronax is a genus of tyrannosaurid dinosaur that lived in North America around 81.9-81.5 million years ago during the Late Cretaceous period. The only known specimen was discovered in Utah in the Wahweap Formation of the Grand Staircase–Escalante National Monument in 2009, and it consists of a partial skull and skeleton. In 2013, it became the basis of the new genus and species Lythronax argestes; the generic name Lythronax means "gore king", and the specific name argestes originates from the Greek poet Homer's name for the wind from the southwest, in reference to the specimen's geographic provenance in North America.
Mierasaurus is an extinct genus of sauropod dinosaur from the Early Cretaceous of Utah, United States. The taxon was first described and named in 2017 by Rafael Royo-Torres and colleagues, from a mostly complete skeleton including a disarticulated partial skull and mandible, teeth, multiple vertebrae from along the length of the body, both scapulae, radius and ulna bones, a left manus, a complete pelvis, both femora and the entire left hindlimb. Additionally, they referred a lower jaw and femur from juvenile individuals, which were found nearby, to the genus. Collectively, Mierasaurus is among the most completely known North American sauropods. The genus name honours Bernardo de Miera y Pacheco, the first European scientist to enter what is now Utah. The type species for Mierasaurus is Mierasaurus bobyoungi, named after Robert Glen Young, a paleontologist who researched the Early Cretaceous of Utah.