Shantungosaurus

*Shantungosaurus giganteus*

***Shantungosaurus***(meaning "Shandong Lizard") is a genus of very large saurolophine hadrosaurid dinosaur found in the Late Cretaceous Wangshi Group of the Shandong Peninsula in China, containing a single species, *Shantungosaurus giganteus*. The stratigraphic interval of *Shantungosaurus* ranges from the top of the Xingezhuang Formation to the middle of the Hongtuya Formation, middle to late Campanian in age. *Shantungosaurus* is so far the largest hadrosauroid taxon in the world: the greatest length of its femur is about 1.7 metres (5.6 ft), and the greatest length of its humerus is about 0.97 metres (3.2 ft). It is one of the longest and largest known hadrosaurids; the composite skeleton of a medium-sized individual mounted at the Geological Institute of China in Beijing measures 14.72 metres (48.3 feet) in length, and the type skull is 1.63 metres (5.3 feet) long. The weight of this genus is estimated at up to 16 tonnes (18 short tons). With a composite mounted skeleton 16.6 meters long (54.5 feet) it is currently the largest known ornithischian and therefore the largest non-sauropod herbivore. It had an unusually long tail, presumably to counterbalance the great weight of the body at the animal's hips.

## Description

   *Shantungosaurus giganteus* is one of the largest known ornithischians. The type skull is 1.63 metres (5.3 ft) long, and the composite skeleton mounted at the Geological Institute of China in Beijing measures 14.7 metres (48 ft) in length. Another mounted skeleton, originally referred to as *Zhuchengosaurus maximus*, measures 16.6 metres (54 ft) in length. The largest individuals may have weighed as much as 16 tonnes (18 short tons). Like all hadrosaurs its beak was toothless, but its jaws were packed with around 1,500 tiny chewing teeth. A large hole near its nostrils may have been covered by a loose flap of skin, which could be inflated to make sounds.

## Discovery and species

First described in 1973, *Shantungosaurus* is known from over five incomplete skeletons. Chinese scientist Xing Xu and his colleagues indicate that *Shantungosaurus* is very similar to and shares many unique characters with *Edmontosaurus*, forming an Asian node of an *Edmontosaurus*–*Shantungosaurus* clade, based on the new materials recovered in Shandong. Remains of several individuals, including skull bones, limb bones, and vertebrae, were found in Shandong, China. These specimens were classified in the new genus and species *Zhuchengosaurus maximus* in 2007. However, further study showed that the supposedly distinct features of *Zhuchengosaurus* were simply a result of different growth stages.

## Classification

Recent maximum parsimony-based phylogenetic analyses of Hadrosauroidea from Xing and colleagues recovered a stable sister group relationship between *Edmontosaurus* and *Shantungosaurus*. *Shantungosaurus* is the single hadrosaurid from the Zhucheng area that is considered valid. *Zhuchengosaurus* and *Huaxiaosaurus*, both of which are known from the same region, have been interpreted by the analyses as junior synonyms of *Shantungosaurus*. All unequivocal morphological discrepancies among these three taxa could be attributed to intraspecific variation (ontogenetic and polymorphic variation) and post-depositional distortion.

The following cladogram is the result of Prieto-Márquez et al. in 2016. It shows the position of *Shantungosaurus* as sister group of *Edmontosaurus* in the Edmontosaurini clade:

## JPInstitute.com Description

This was the largest of the plant-eating, duck-billed dinosaurs - bigger even than T. rex! It was longer and taller than a house! Imagine a herd of these huge creatures crossing the Cretaceous plains in search of food; it would have been an impressive sight. Like the other duck-billed dinosaurs, it had hundreds of teeth packed closely together to form what is called a dental battery. These were used to grind tough plant fiber into mushy pulp.

There is still some debate that Shantungosaurus is a large Edmontosaurus. It is the largest hadrosaurid yet found, discovered fairly recently in 1964. More than 30 tons of material was collected, representing five individual specimens, which lent support to the theory that these animals lived in herds. The mounted specimen on display utilized bones from all five individuals. Currently, scientists are in the process re-describing this specimen.

## Links

https://web.archive.org/web/20030803072958/http://www.jpinstitute.com/dinopedia/dinocards/dc\_shant.html