Hadrosaurus | |
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Reconstructed skeleton, Academy of Natural Sciences | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | † Ornithischia |
Clade: | † Ornithopoda |
Family: | † Hadrosauridae |
Subfamily: | † Hadrosaurinae |
Genus: | † Hadrosaurus Leidy, 1858 |
Type species | |
†Hadrosaurus foulkii Leidy, 1858 | |
Synonyms | |
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Hadrosaurus ( /ˌhædrəˈsɔːrəs/ ; lit. 'bulky lizard') is a genus of hadrosaurid ornithopod dinosaurs that lived in North America during the Late Cretaceous Period in what is now the Woodbury Formation about 78-80 Ma. The holotype specimen was found in fluvial marine sedimentation, meaning that the corpse of the animal was transported by a river and washed out to sea.
They were large animals ranging from 7 to 8 m (23 to 26 ft) and 2 to 4 t (2.2 to 4.4 short tons). Most of the preserved elements are very robust, unusual traits in hadrosaurs. Hadrosaurus were ponderously-built animals equipped with keratinous beaks for cropping foliage and a specialized and complex dentition for food processing.
Hadrosaurus foulkii, the only species in this genus, is known from a single specimen consisting of much of the skeleton and parts of the skull. The specimen was collected in 1858 from the Woodbury Formation in New Jersey, US, representing the first dinosaur species known from more than isolated teeth to be identified in North America. Using radiometric dating of bivalve shells from the same formation, the sedimentary rocks where the Hadrosaurus fossil was found have been dated at some time between 80.5 and 78.5 million years ago. In 1858, the only known specimen became the first-ever dinosaur skeleton to be mounted. In 1991, H. foulkii became the official state dinosaur of New Jersey. [2]
In 1838, John Estaugh Hopkins was digging in a marl pit (on a small tributary of the Cooper River in Haddonfield, New Jersey, and part of the Campanian-age Woodbury Formation) when he uncovered large bones. He put them on display at his home, also in Haddonfield. In 1858, the bones sparked the interest of a visitor, William Parker Foulke, who dug out the rest of the bones from the marl pit in the same year. The excavation site, known as the Hadrosaurus foulkii Leidy site, is now a National Historic Landmark.
Foulke contacted paleontologist Joseph Leidy, and together they recovered eight teeth from the maxillar and dentary areas, dental battery fragments, left maxilla fragments, three partial dorsal vertebrae, 13 caudal centra, including an almost complete middle caudal vertebra. Other fragments included a partial right coracoid, left humerus, left radius, left ulna, left ilium, right ischium, right partial pubis, the left hindlimb composed by the femur, tibia, fibula with metatarsals II and IV and the first pedal phalanx from the third digit. Foulke and Leidy studied the fossils together and, in 1858, Leidy formally described and named Hadrosaurus foulkii in honor of his collaborator. While originally a portmanteau of Haddonfield, the location of its discovery with the accepted suffix for dinosaurs -saurus, the name Hadrosaurus was scientifically justified as deriving from the Greek ἁδρός, hadros, meaning "bulky" or "large", and σαῦρος, sauros, meaning "lizard". The name was an additional play on words by Leidy since it translates from Greek as Foulke’s big lizard.
Leidy recognized that the bones were from a dinosaur because of their similarity to those of Iguanodon , discovered in England some decades before but, at the time, the skeleton of Hadrosaurus was one of the most complete dinosaur skeletons known. Leidy's monograph Cretaceous Reptiles of the United States, describing Hadrosaurus more completely, and with illustrations, was written in 1860, but the American Civil War delayed its publication until 1865. [3]
Leidy reconstructed Hadrosaurus as a biped, in contrast to the view at the time that such dinosaurs were quadrupedal. The entire skeleton was completely assembled in 1868 by a team including English sculptor and naturalist Benjamin Waterhouse Hawkins and was put on display at Philadelphia Academy of Natural Sciences. It was the first-ever mounted dinosaur skeleton. When the skeleton was first put together, it was displayed with a plaster skull sculpted by Hawkins. Many other artists have recreated Hadrosaurus with skulls from other, related species such as Gryposaurus and Brachylophosaurus . A statue of Hadrosaurus, sculpted by Haddonfield resident John Giannotti, now stands in the center of the town of Haddonfield, commemorating its discovery there. Thanks to Joyce Berry and her 4th grade classes (1988–1991) at Strawbridge Elementary School in Haddon Twp, New Jersey, the Hadrosaurus was named the state dinosaur [4] of New Jersey in 1991. It is one of the most celebrated dinosaurs ever and is of great historic importance. [3] The skeleton is usually kept out of sight in the Academy's collections. However, from November 22, 2008, to April 19, 2009, a fully assembled cast of the skeleton, and an exhibit about the science and culture surrounding the dinosaur's discovery, was open to the public.[ citation needed ]
Hadrosaurus were large sized animals growing up to 7–8 m (23–26 ft) and weighing as much as 2 to 4 t (2.2 to 4.4 short tons). [5] [6] According to Prieto-Márquez, Hadrosaurus can be distinguished in having a shortened pectoral crest that is slightly over 40% of the total humeral length, a deltopectoral crest that is developed from the humeral shaft causing the laterodistal border to display a broad lateral facet, a lower greatest point of the supraacetabular crest located above lateral edge from the rear to the bottom on the posterior tuberosity of the ischial peduncle of the ilium, a shortened supraacetabular crest from the front to the rear with its breadth being half the length of the middle iliac plate. [7]
As in most hadrosaurs, the forelimbs were not as heavily built as the hindlimbs, but were long enough to be used in standing or movement. [3] [8] [6] The holotype specimen was a relatively large animal at the time of death with a 1.05 m (105 cm) long femur and 93.3 cm (933 mm) long tibia. Most of the preserved elements feature a marked robust composition with the fibula being one of the most robust among hadrosaurs. [3]
Despite the fact that the family Hadrosauridae has Hadrosaurus as its type genus, the skeleton lacks a skull and was long viewed as too incomplete to compare to other hadrosaurs for classification purposes, leading most scientists to consider it a nomen dubium, or dubious name. [7] However, a re-evaluation of the fossil material in 2011 noted several distinct characteristics of the skeleton that could allow the genus Hadrosaurus and species H. foulkii to remain in use as valid taxa. [7]
Hadrosaurus has also traditionally served as the basis for a large subfamily called Hadrosaurinae, which was seen as a group of largely crestless hadrosaurs related to the crested subfamily Lambeosaurinae. However, the changing view of Hadrosaurus classification in relation to other hadrosaurs has led some scientists to rename these subfamilies. In a 2008 study, Hadrosaurus was found to be more primitive than either lambeosaurines or other "hadrosaurines", and not a particularly close relative of classic "hadrosaurines" such as Edmontosaurus and Saurolophus . As a result of this, the name Hadrosaurinae was restricted to Hadrosaurus alone, and the subfamily comprising the traditional "hadrosaurines" was renamed the Saurolophinae. [9]
Below is a simplified cladogram recovered by Ramírez-Velasco et al. in 2012 in their description of Huehuecanauhtlus . This topology was recovered using an extensive sampling of 60 hadrosauroid species, and two outgroup taxa, which were scored based on 287 morphological traits, [10] and included data from two recent redescriptions of Hadrosaurus by Prieto-Márquez et al. (2006) [3] and Prieto-Márquez (2011). [7]
Hadrosauroidea |
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In 2003, Rothschild and colleagues performed a study looking for epidemiology of tumors in dinosaurs. Evidence of tumors, including hemangiomas, desmoplastic fibroma, metastatic cancer, and osteoblastoma were discovered in specimens of Hadrosaurus by analyzing dinosaur vertebrae using computerized tomography and fluoroscope screening. Several other hadrosaurids, including Brachylophosaurus , Edmontosaurus , and Gilmoreosaurus , also tested positive. Although more than 10000 fossils were examined in this manner, the tumors were limited to Hadrosaurus and other hadrosaurs. The tumors were only found on caudal vertebrae and they may have been caused by environmental factors or genetic inheritance. [11]
The holotype of Hadrosaurus was found in marine sediments, which suggests the skeleton was transported by a river and then deposited in the Cretaceous sea. The Hadrosaurus remains all persist to the Woodbury Formation. [3] Through the radiometric dating of bivalve shells known from the formation, the sedimentary rocks where the holotype specimen of Hadrosaurus was found have been dated from 80.5 million to 78.5 million years ago. [12]
Trachodon is a dubious genus of hadrosaurid dinosaur based on teeth from the Campanian-age Upper Cretaceous Judith River Formation of Montana, U.S. It is a historically important genus with a convoluted taxonomy that has been all but abandoned by modern dinosaur paleontologists.
Hadrosaurids, or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod family, which includes genera such as Edmontosaurus and Parasaurolophus, was a common group of herbivores during the Late Cretaceous Period. Hadrosaurids are descendants of the Late Jurassic/Early Cretaceous iguanodontian dinosaurs and had a similar body layout. Hadrosaurs were among the most dominant herbivores during the Late Cretaceous in Asia and North America, and during the close of the Cretaceous several lineages dispersed into Europe, Africa, and South America.
Claosaurus is a genus of hadrosauroid dinosaur that lived during the Late Cretaceous Period (Santonian-Campanian).
Brachylophosaurus was a mid-sized member of the hadrosaurid family of dinosaurs. It is known from several skeletons and bonebed material from the Judith River Formation of Montana, the Wahweap Formation of Utah and the Oldman Formation of Alberta, living about 81-76.7 million years ago.
Saurolophus is a genus of large hadrosaurid dinosaur from the Late Cretaceous period of Asia and North America, that lived in what is now the Horseshoe Canyon and Nemegt formations about 70 million to 66 million years ago. It is one of the few genera of dinosaurs known from multiple continents. The type species, S. osborni, was described by Barnum Brown in 1912 from Canadian fossils. A second valid species, S. angustirostris, is represented by numerous specimens from Mongolia, and was described by Anatoly Konstantinovich Rozhdestvensky.
Gryposaurus was a genus of duckbilled dinosaur that lived about 80 to 75 million years ago, in the Late Cretaceous of North America. Named species of Gryposaurus are known from the Dinosaur Park Formation in Alberta, Canada, and two formations in the United States: the Lower Two Medicine Formation in Montana and the Kaiparowits Formation of Utah. A possible additional species from the Javelina Formation in Texas may extend the temporal range of the genus to 66 million years ago.
Kritosaurus is an incompletely known genus of hadrosaurid (duck-billed) dinosaur. It lived about 74.5-66 million years ago, in the Late Cretaceous of North America. The name means "separated lizard", but is often mistranslated as "noble lizard" in reference to the presumed "Roman nose".
Olorotitan was a monotypic genus of lambeosaurine duck-billed dinosaur, containing a single species, Olorotitan arharensis. It was among the last surviving non-avian dinosaurs to go extinct during the Cretaceous–Paleogene extinction event, having lived from the middle to late Maastrichtian-age of the Late Cretaceous era. The remains were found in the Udurchukan Formation beds of Kundur, Arkharinsky District, Amur Oblast, Eastern Russia, in the vicinity of the Amur River.
Lophorhothon is a genus of hadrosauroid dinosaur from the Late Cretaceous of Alabama and North Carolina. It was the first genus of dinosaur discovered in Alabama, in the United States.
Barsboldia is a genus of large hadrosaurid dinosaur from the early Maastrichtian Nemegt Formation of Ömnogöv', Mongolia. It is known from a partial vertebral column, partial pelvis, and some ribs.
Ornithotarsus is a genus of hadrosaurid ornithopod dinosaurs that lived in North America during the Late Cretaceous Period in what is now the Merchantville Formation about 84 million to 78 million years ago.
Pararhabdodon is a genus of tsintaosaurin hadrosaurid dinosaur, from the Maastrichtian-age Upper Cretaceous Tremp Group of Spain. The first remains were discovered from the Sant Romà d’Abella fossil locality and assigned to the genus Rhabdodon, and later named as the distinct species Pararhabdodon isonensis in 1993. Known material includes assorted postcranial remains, mostly vertebrae, as well as maxillae from the skull. Specimens from other sites, including remains from France, a maxilla previously considered the distinct taxon Koutalisaurus kohlerorum, an additional maxilla from another locality, the material assigned to the genera Blasisaurus and Arenysaurus, and the extensive Basturs Poble bonebed have been considered at different times to belong to the species, but all of these assignments have more recently been questioned. It was one of the last non-avian dinosaurs known from the fossil record that went extinct during the Cretaceous-Paleogene extinction event.
Naashoibitosaurus is a genus of hadrosaurid dinosaur that lived about 73 million years ago, in the Late Cretaceous, and was found in the Kirtland Formation of the San Juan Basin in New Mexico, United States. Only a partial skeleton has been found to date. It was first described as a specimen of Kritosaurus by Jack Horner, and has been intertwined with Kritosaurus since its description.
Saurolophinae is a subfamily of hadrosaurid dinosaurs. It has since the mid-20th century generally been called the Hadrosaurinae, a group of largely non-crested hadrosaurs related to the crested sub-family Lambeosaurinae. However, the name Hadrosaurinae is based on the genus Hadrosaurus which was found in more recent studies to be more primitive than either lambeosaurines or other traditional "hadrosaurines", like Edmontosaurus and Saurolophus. As a result of this, the name Hadrosaurinae was dropped or restricted to Hadrosaurus alone, and the subfamily comprising the traditional "hadrosaurines" was renamed the Saurolophinae. Recent phylogenetic work by Hai Xing indicates that Hadrosaurus is placed within the monophyletic group containing all non-lambeosaurine hadrosaurids. Under this view, the traditional Hadrosaurinae is resurrected, with the Hadrosauridae being divided into two clades: Hadrosaurinae and Lambeosaurinae.
The Hadrosaurus foulkii Leidy Site is a historic paleontological site in Haddonfield, Camden County, New Jersey. Now set in state-owned parkland, it is where the first relatively complete set of dinosaur bones were discovered in 1838, and then fully excavated by William Parker Foulke in 1858. The dinosaur was later named Hadrosaurus foulkii by Joseph Leidy. The site, designated a National Historic Landmark in 1994, is now a small park known as "Hadrosaurus Park" and is accessed at the eastern end of Maple Avenue in northern Haddonfield.
Latirhinus is an extinct genus of lambeosaurine hadrosaurid dinosaur from the Late Cretaceous of Mexico. The type species, Latirhinus uitstlani, was named in 2012 on the basis of a partial skeleton from the Campanian-age Cerro del Pueblo Formation. The specific name uitstlani means "southern" in the Náhuatl language of Mexico, a reference to the species' southern occurrence in the Cretaceous landmass Laramidia.
Paleontology in New Jersey refers to paleontological research in the U.S. state of New Jersey. The state is especially rich in marine deposits.
This timeline of hadrosaur research is a chronological listing of events in the history of paleontology focused on the hadrosauroids, a group of herbivorous ornithopod dinosaurs popularly known as the duck-billed dinosaurs. Scientific research on hadrosaurs began in the 1850s, when Joseph Leidy described the genera Thespesius and Trachodon based on scrappy fossils discovered in the western United States. Just two years later he published a description of the much better-preserved remains of an animal from New Jersey that he named Hadrosaurus.
Eotrachodon orientalis is a species of hadrosaurid that was described in 2016. The holotype was found in the Mooreville Chalk Formation in Alabama in 2007 and includes a well-preserved skull and partial skeleton, making it a rare find among dinosaurs of Appalachia. Another primitive hadrosaur, Lophorhothon, is also known from the same formation, although Eotrachodon lived a few million years prior. A phylogenetic study has found Eotrachodon to be the sister taxon to the hadrosaurid subfamilies Lambeosaurinae and Saurolophinae. This, along with the other Appalachian hadrosaur Hadrosaurus and possibly Lophorhothon, Claosaurus and both species of Hypsibema, suggests that Appalachia was the ancestral area of Hadrosauridae.
Bonapartesaurus is an extinct genus of herbivorous ornithopod dinosaur belonging to Hadrosauridae, which lived in the area of modern Argentina during the Campanian and Maastrichtian stages of the Late Cretaceous.