Hadrosaurus ‭(‬Sturdy lizard‭)‬

Short Info

Hadrosaurus ‭(‬Sturdy lizard‭)‬

Phonetic : Had-roe-sore-us.

Named By : Joseph Leidy‭ ‬-‭ ‬1858

Diet : Herbivore

Size : Estimated 9 meters long

Type of Dinosaur : Euornithopod

Type Species : H.‭ ‬foulkii‭ (‬type‭)

Found in : USA,‭ ‬New Jersey‭ ‬-‭ ‬Woodbury Formation

When it Lived : Late Cretaceous, 78-74 million years ago

Hadrosaurus (/.haedr@’so:r@s/) is a genus that contains hadrosaurid and ornithopod dinosaurs. It lived in North America in the Late Cretaceous Period, which is now the Woodbury Formation. It was about 80 million to 1978 million years ago. Fluvial marine sedimentation was the location where the holotype specimen was found. This means that the corpse was transported by a river to the sea.

Hadrosaurus reconstructionJim, the Photographer from Springfield PA, United States of America, CC BY 2.0, via Wikimedia Commons

These large animals were between 7 and 8 m (23-26 ft) in height, with 2 to 4 tons (2,000 to 4,000 kilograms). The majority of the elements preserved are strong and unusual characteristics in hadrosaurs. Hadrosaurus was a large-bodied animal with complex teeth and keratinous beaks that could crop leaves.

Hadrosaurus foulkii is the only known species of this genus. It was found in a single specimen that included much of the skull and skeleton. This specimen was found in the Woodbury Formation, New Jersey, USA in 1858. It is the first known dinosaur species from more than just isolated teeth in North America. Radiometric dating of bivalve shells from a similar formation has been used to date the sedimentary rocks that contained the Hadrosaurus fossil. It was dated between 80.5 million and 78.5 millions years ago. The first dinosaur skeleton was mounted in 1858 with the only known specimen. H. foulkii was made the official state dinosaur for New Jersey in 1991.

John Estaugh Hopkins discovered large bones while digging in a marlpit in Haddonfield in New Jersey in 1838. They were displayed at his Haddonfield home. The bones attracted William Parker Foulke in 1858 to the bones. He also excavated the entire skeleton from the Marl Pit that year. This excavation site is now a National Historic Landmark.

Foulke reached out to Joseph Leidy, a paleontologist, and they together recovered eight teeth from the maxillar, dentary, and dental areas. They also found three partial dorsal and 13 caudal centrus as well as three fragments of dental batteries, left maxillas, and three partial dorsal and middle vertebrae. Other fragments include a partial right coracoid and left radius, left right humerus and left ulna. They also found left ischium, right partial pubis and three partial dorsal vertebrae. Foulke and Leidy worked together to study the fossils. In 1858, Leidy officially described Hadrosaurus foulkii and gave it the name. Haddonfield was the original name. The location of Hadrosaurus’ discovery was named Hadrosaurus foulkii. Scientifically, Hadrosaurus is derived from the Greek adros (hadros) and sauros (sauros), which are both Greek words meaning “bulky” or large. Leidy added a play on words to give the name, which translates from Greek as Foulke’s big Lizard.

Because the bones resembled those of Iguanodon in England, Leidy knew they were dinosaur bones. However, Hadrosaurus’ skeleton was the best dinosaur skeleton at that time. Leidy’s monograph Cretaceous Reptiles of the United States which describes Hadrosaurus better and includes illustrations was published in 1860. However, the American Civil War delayed publication to 1865.

Leidy rebuilt Hadrosaurus as an animal biped. This was contrary to the belief that these dinosaurs were quadrupedal. The complete skeleton was assembled by an English team, which included naturalist Benjamin Waterhouse Hawkins. It was then displayed at the Philadelphia Academy of Natural Sciences. It was the first ever mounted dinosaur skeleton. The skeleton was initially assembled with a Hawkins-sculpted plaster skull. Other artists have also recreated Hadrosaurus using skulls from related species like Brachylophosaurus and Gryposaurus. John Giannotti, a Haddonfield resident, created a statue of Hadrosaurus to commemorate its discovery. In 1994, Hadrosaurus was designated the state fossil for New Jersey. It is a famous dinosaur and has great historical importance. The Academy does not usually keep the skeleton in its collections. From November 22, 2008 to April 19, 2009, the Academy’s collections housed a complete cast of the skeleton and an exhibit on the science and culture that led to the discovery.

Hadrosaurus was a large-sized animal that grew to approximately 7-8m (23-26 feet) in height and weighed between 2 and 4 t (2,000 – 4,000 kg). According to PrietoMarquez, Hadrosaurus has a shortened pectoral crest of slightly more than 40% of its total humeral length. This is a deltopectoral crest which is formed from the humeral stem. It is located at the lowermost point of the supraacetabular crest, from the rear to bottom on the posterior tuberosity. The breadth of this supraacetabular crest is half the length of a middle iliac plates.

The forelimbs of most hadrosaurs were shorter than the hindlimbs but they were strong enough to be used for standing and movement. The holotype specimen measured 1.05m (105 cm) in length and had a 93.3 cm (933mm) long leg. The preserved elements have a strong composition, with the fibula being the strongest among all hadrosaurs.

Source: Wikipedia