''Hadrosaurus'' (; ) is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
hadrosaurid
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 inclu ...
ornithopod
Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (), that started out as small, bipedal running grazers and grew in size and numbers until they became one of the most successful groups of herbivores in the Cretaceous world ...
dinosaurs
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 ...
that lived in
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
during the
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...
Period
Period may refer to:
Common uses
* Era, a length or span of time
* Full stop (or period), a punctuation mark
Arts, entertainment, and media
* Period (music), a concept in musical composition
* Periodic sentence (or rhetorical period), a concept ...
in what is now the
Woodbury Formation
The Woodbury Formation is a Mesozoic geologic formation in New Jersey, United States. It primarily consists of massive dark gray clays and silts with carbonized wood fragments and pyrite, deposited in a marine setting.
The remains of the dinosaur ...
about 80 million to 78 million years ago. The
holotype
A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...
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 and . 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 biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
in this
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
, 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
The Woodbury Formation is a Mesozoic geologic formation in New Jersey, United States. It primarily consists of massive dark gray clays and silts with carbonized wood fragments and pyrite, deposited in a marine setting.
The remains of the dinosaur ...
in
New Jersey
New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware ...
,
US, representing the first dinosaur species known from more than isolated teeth to be identified in North America. Using
radiometric dating
Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares t ...
of
bivalve
Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...
shells from the same formation, the sedimentary rocks where the ''Hadrosaurus'' fossil was found have been
dated
Date or dates may refer to:
*Date (fruit), the fruit of the date palm (''Phoenix dactylifera'')
Social activity
*Dating, a form of courtship involving social activity, with the aim of assessing a potential partner
**Group dating
*Play date, an ...
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
State may refer to:
Arts, entertainment, and media Literature
* '' State Magazine'', a monthly magazine published by the U.S. Department of State
* ''The State'' (newspaper), a daily newspaper in Columbia, South Carolina, United States
* ''Our ...
of
New Jersey
New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware ...
.
History of discovery
![NHL Marl Pit 2](https://upload.wikimedia.org/wikipedia/commons/3/39/NHL_Marl_Pit_2.JPG)
In 1838, John Estaugh Hopkins was digging in a
marl
Marl is an earthy material rich in carbonate minerals, clays, and silt. When hardened into rock, this becomes marlstone. It is formed in marine or freshwater environments, often through the activities of algae.
Marl makes up the lower part o ...
pit (on a small tributary of the
Cooper River in
Haddonfield, New Jersey
:''Not the fictional Illinois town from the Halloween film series.''
Haddonfield is a borough located in Camden County, New Jersey, United States. As of the 2010 United States Census, the borough had a total population of 11,593, , and part of the
Campanian
The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian s ...
-age
Woodbury Formation
The Woodbury Formation is a Mesozoic geologic formation in New Jersey, United States. It primarily consists of massive dark gray clays and silts with carbonized wood fragments and pyrite, deposited in a marine setting.
The remains of the dinosaur ...
) 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
William Parker Foulke (1816–1865) discovered the first full dinosaur skeleton in North America (''Hadrosaurus foulkii'', which means "Foulke's big lizard") in Haddonfield, New Jersey in 1858.
Born in Philadelphia, and a descendant of Welsh ...
, who dug out the full skeleton from the marl pit in the same year. The excavation site, known as the
''Hadrosaurus foulkii'' Leidy site, is now a
National Historic Landmark
A National Historic Landmark (NHL) is a building, district, object, site, or structure that is officially recognized by the United States government for its outstanding historical significance. Only some 2,500 (~3%) of over 90,000 places listed ...
.
Foulke contacted
paleontologist
Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...
Joseph Leidy
Joseph Mellick Leidy (September 9, 1823 – April 30, 1891) was an American paleontologist, parasitologist and anatomist.
Leidy was professor of anatomy at the University of Pennsylvania, later was a professor of natural history at Swarthmore ...
, and together they recovered eight
teeth
A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...
from the
maxilla
The maxilla (plural: ''maxillae'' ) in vertebrates 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 t ...
r and
dentary
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...
areas,
dental battery fragments, left maxilla fragments, three partial
dorsal vertebrae
In vertebrates, thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. In humans, there are twelve thoracic vertebrae and they are intermediate in size between the cervical ...
, 13 caudal
centra
Centra is a convenience shop chain that operates throughout Ireland. The chain operates as a symbol group owned by Musgrave Group, the food wholesaler, meaning the stores are all owned by individual franchisees.
The chain has three different ...
, including an almost complete middle
caudal 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 characteristic ...
. Other fragments included a partial right
coracoid
A coracoid (from Greek κόραξ, ''koraks'', raven) is a paired bone which is part of the shoulder assembly in all vertebrates except therian mammals (marsupials and placentals). In therian mammals (including humans), a coracoid process is prese ...
, left
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 roun ...
, left
radius
In classical geometry, a radius ( : radii) of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length. The name comes from the latin ''radius'', meaning ray but also the ...
, left
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 ...
, left
ilium, right
, right partial
pubis, the left hindlimb composed by the
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 with ...
,
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 connects ...
,
fibula
The fibula or calf bone is a leg bone on the lateral side of the tibia, to which it is connected above and below. It is the smaller of the two bones and, in proportion to its length, the most slender of all the long bones. Its upper extremity is ...
with
metatarsals
The metatarsal bones, or metatarsus, are a group of five long bones in the foot, located between the tarsal bones of the hind- and mid-foot and the phalanges of the toes. Lacking individual names, the metatarsal bones are numbered from the medi ...
II and IV and the first pedal
phalanx
The phalanx ( grc, φάλαγξ; plural phalanxes or phalanges, , ) was a rectangular mass military formation, usually composed entirely of heavy infantry armed with spears, pikes, sarissas, or similar pole weapons. The term is particularly use ...
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
Greek may refer to:
Greece
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 ...
, , meaning "bulky" or "large", and , , 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
''Iguanodon'' ( ; meaning 'iguana-tooth'), named in 1825, is a genus of iguanodontian dinosaur. While many species have been classified in the genus ''Iguanodon'', dating from the late Jurassic Period to the early Cretaceous Period of Asia, Eu ...
'', 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
The American Civil War (April 12, 1861 – May 26, 1865; also known by other names) was a civil war in the United States. It was fought between the Union ("the North") and the Confederacy ("the South"), the latter formed by states th ...
delayed its publication until 1865.
Leidy reconstructed ''Hadrosaurus'' as a biped, in contrast to the view at the time that such dinosaurs were
quadruped
Quadrupedalism is a form of locomotion where four limbs are used to bear weight and move around. An animal or machine that usually maintains a four-legged posture and moves using all four limbs is said to be a quadruped (from Latin ''quattuor' ...
al. The entire skeleton was completely assembled in 1868 by a team including English
sculptor
Sculpture is the branch of the visual arts that operates in three dimensions. Sculpture is the three-dimensional art work which is physically presented in the dimensions of height, width and depth. It is one of the plastic arts. Durable sc ...
and
naturalist Benjamin Waterhouse Hawkins
Benjamin Waterhouse Hawkins (8 February 1807 – 27 January 1894) was an English sculptor and natural history artist renowned for his work on the life-size models of dinosaurs in the Crystal Palace Park in south London. The models, accurately ...
and was put on display at
Philadelphia Academy of Natural Sciences
The Academy of Natural Sciences of Drexel University, formerly the Academy of Natural Sciences of Philadelphia, is the oldest natural science research institution and museum in the Americas. It was founded in 1812, by many of the leading natura ...
. 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
''Gryposaurus'' (meaning "hooked-nosed (Ancient Greek, Greek ''grypos'') lizard"; sometimes incorrectly translated as "griffin (Latin ''gryphus'') lizard") was a genus of hadrosaur, duckbilled dinosaur that lived about 80 to 75 million years ...
'' and ''
Brachylophosaurus
''Brachylophosaurus'' ( or ; meaning "short-crested lizard", Greek ''brachys'' = short + ''lophos'' = crest + ''sauros'' = lizard, referring to its small crest) was a mid-sized member of the hadrosaurid family of dinosaurs. It is known from sev ...
''. 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, NJ the ''Hadrosaurus'' was named the state dinosaur of
New Jersey
New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware ...
in 1991. It is one of the most celebrated dinosaurs ever and is of great historic importance.
[ 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.
]
Description
''Hadrosaurus'' were large sized animals growing up to and weighing as much as .[Genus List for Holtz 2012]
/ref> According to Prieto-Márquez, ''Hadrosaurus'' can be distinguished in having a shortened pectoral crest that is slightly over 40% of the total humeral
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 round ...
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.
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.[ The holotype specimen was a relatively large animal at the time of death with a long ]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 with ...
and long 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 connects ...
. Most of the preserved elements feature a marked robust composition with the fibula
The fibula or calf bone is a leg bone on the lateral side of the tibia, to which it is connected above and below. It is the smaller of the two bones and, in proportion to its length, the most slender of all the long bones. Its upper extremity is ...
being one of the most robust among hadrosaurs.[
]
Classification
Despite the fact that the family Hadrosauridae
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 includ ...
has ''Hadrosaurus'' as its type genus
In biological taxonomy, the type genus is the genus which defines a biological family and the root of the family name.
Zoological nomenclature
According to the International Code of Zoological Nomenclature, "The name-bearing type of a nominal f ...
, 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.[ 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
In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...
.[
''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
Lambeosaurinae is a group of crested hadrosaurid dinosaurs.
Classification
Lambeosaurines have been traditionally split into the tribes or clades Parasaurolophini (''Parasaurolophus'', ''Charonosaurus'', others (?).) and Lambeosaurini (''Coryt ...
. 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
''Edmontosaurus'' ( ) (meaning "lizard from Edmonton") is a genus of hadrosaurid (duck-billed) dinosaur. It contains two known species: ''Edmontosaurus regalis'' and ''Edmontosaurus annectens''. Fossils of ''E. regalis'' have been found in rocks ...
'' and ''Saurolophus
''Saurolophus'' (; meaning "lizard crest") 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 68 million ...
''. As a result of this, the name Hadrosaurinae was restricted to ''Hadrosaurus'' alone, and the subfamily comprising the traditional "hadrosaurines" was renamed the Saurolophinae
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 Hadro ...
.
Below is a simplified cladogram
A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...
recovered by Ramírez-Velasco ''et al.'' in 2012 in their description of '' Huehuecanauhtlus''. This topology was recovered using an extensive sampling of 60 hadrosauroid
Hadrosauroidea is a clade or superfamily of ornithischian dinosaurs that includes the "duck-billed" dinosaurs, or hadrosaurids, and all dinosaurs more closely related to them than to ''Iguanodon''. Their remains have been recovered in Asia, Eu ...
species, and two outgroup taxa, which were scored based on 287 morphological traits, and included data from two recent redescriptions of ''Hadrosaurus'' by Prieto-Márquez ''et al.'' (2006)[ and Prieto-Márquez (2011).][
]
Paleobiology
In 2003, Rothschild and colleagues performed a study looking for epidemiology of tumors in dinosaurs. Evidence of tumors
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
, including hemangiomas
A hemangioma or haemangioma is a usually benign vascular tumor derived from blood vessel cell types. The most common form, seen in infants, is an infantile hemangioma, known colloquially as a "strawberry mark", most commonly presenting on the ski ...
, desmoplastic fibroma
In medicine, a desmoplastic fibroma is a benign, but locally aggressive, fibrous and rare tumor of the bone, affecting children and young adults, potentially resulting in cortical bone destruction. It usually affects craniofacial bones, mandible mo ...
, metastatic cancer
Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, then, ...
, and osteoblastoma
Osteoblastoma is an uncommon osteoid tissue-forming primary neoplasm of the bone.
It has clinical and histologic manifestations similar to those of osteoid osteoma; therefore, some consider the two tumors to be variants of the same disease, wit ...
were discovered in specimens of ''Hadrosaurus'' by analyzing dinosaur vertebrae using computerized tomography and fluoroscope
Fluoroscopy () is an imaging technique that uses X-rays to obtain real-time moving images of the interior of an object. In its primary application of medical imaging, a fluoroscope () allows a physician to see the internal structure and function ...
screening. Several other hadrosaurids, including ''Brachylophosaurus
''Brachylophosaurus'' ( or ; meaning "short-crested lizard", Greek ''brachys'' = short + ''lophos'' = crest + ''sauros'' = lizard, referring to its small crest) was a mid-sized member of the hadrosaurid family of dinosaurs. It is known from sev ...
'', ''Edmontosaurus
''Edmontosaurus'' ( ) (meaning "lizard from Edmonton") is a genus of hadrosaurid (duck-billed) dinosaur. It contains two known species: ''Edmontosaurus regalis'' and ''Edmontosaurus annectens''. Fossils of ''E. regalis'' have been found in rocks ...
'', and ''Gilmoreosaurus
''Gilmoreosaurus'' (meaning "Charles Whitney Gilmore's lizard") is the name given to a genus of dinosaur from the Cretaceous of Asia. The type species is ''Gilmoreosaurus mongoliensis''. It is believed to be a hadrosaur or iguanodont from the Ire ...
'', also tested positive. Although more than 10000 fossils
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in ...
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.
Paleoecology
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
The Woodbury Formation is a Mesozoic geologic formation in New Jersey, United States. It primarily consists of massive dark gray clays and silts with carbonized wood fragments and pyrite, deposited in a marine setting.
The remains of the dinosaur ...
.[ Through the ]radiometric dating
Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares t ...
of bivalve
Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...
shells known from the formation, the sedimentary rocks where the holotype specimen of ''Hadrosaurus'' was found have been dated
Date or dates may refer to:
*Date (fruit), the fruit of the date palm (''Phoenix dactylifera'')
Social activity
*Dating, a form of courtship involving social activity, with the aim of assessing a potential partner
**Group dating
*Play date, an ...
from 80.5 million to 78.5 million years ago.[Gallagher, W.B. (2005).]
Recent mosasaur discoveries from New Jersey and Delaware, USA: stratigraphy, taphonomy and implications for mosasaur extinction.
" ''Netherlands Journal of Geosciences'', 84(3): 241.
References
External links
The discovery of ''H. foulkii''
Hadrosaurus skeletal diagram
website
Joseph Leidy and ''Hadrodaurus foulkii'' at The Academy of Natural Sciences
''Hadrosaurus foulkii'' exhibit at The Academy of Natural Sciences
{{Taxonbar, from=Q14511
Late Cretaceous dinosaurs of North America
Hadrosaurs
Haddonfield, New Jersey
Natural history of New Jersey
Fossil taxa described in 1858
Taxa named by Joseph Leidy
Paleontology in New Jersey
Campanian genus first appearances
Campanian genus extinctions
Symbols of New Jersey
Ornithischian genera