Shantungosaurus

Chapter • Meet the dinosaur

Overview

Shantungosaurus was the largest hadrosaurid ever discovered and one of the heaviest animals ever to walk on two legs at least part of the time. It reached roughly 15 to 16.6 metres in length and weighed an estimated 13 to 16 tonnes. The skull alone measured about 1.6 metres and was long, low and completely crestless, ending in a broad, duck-like beak of horn. Behind the beak sat dental batteries — tightly packed columns of small teeth totalling around 1,500, which were worn down and replaced continuously throughout life. Powerful hind limbs carried most of the body weight, while the more slender forelimbs supported the animal when it walked on all fours. The tail was held out horizontally as a counterweight, stiffened by ossified tendons running along the backbone. Like other hadrosaurids, Shantungosaurus was facultatively bipedal. It probably grazed and browsed on all fours, rising onto its hind legs to move quickly or to reach higher foliage. Speed estimates for large hadrosaurids fall around 20–25 km/h, but a fifteen-tonne animal was no sprinter over long distances. Skin impressions from close relatives show small, non-overlapping scales; there is no evidence of feathers in hadrosaurids. The broad snout and jaw region of hadrosaurids is often linked to vocal communication, and large eye sockets and well-developed olfactory regions of the brain suggest that sight and smell were important senses. The diet was entirely plant-based. The beak cropped twigs, conifer needles, ferns and leaves, which were then ground between the dental batteries in a chewing stroke where the upper jaws rotated outward — a mechanism known as pleurokinesis. Microwear on the teeth of related hadrosaurids shows they could process fairly tough, silica-rich plant material. An animal this size must have consumed hundreds of kilograms of vegetation daily, and herds of them would have shaped the vegetation of the Chinese lowlands much as elephants shape savannahs today. The first bones were found in 1964 by geologists working near Zhucheng in Shandong Province, eastern China, and the species was named in 1973 by the Chinese palaeontologist Hu Chengzhi. The name means roughly "Shandong lizard", using an older romanisation of the province name. Since 2008, large-scale excavations at Longgujian — the "Dinosaur Valley" — have exposed some of the richest bone beds in the world, containing thousands of bones dominated by Shantungosaurus. Two later-named giants, Zhuchengosaurus maximus and Huaxiaosaurus aigahtens, are now regarded by most researchers as growth stages of Shantungosaurus itself.

Chapter • Where it lived

Habitat

Shantungosaurus lived in the Late Cretaceous, during the Campanian stage roughly 77–72 million years ago, in what is now Shandong Province in eastern China. Its fossils come from the Xingezhuang Formation of the Wangshi Group, sediments laid down on floodplains and alluvial fans crossed by seasonal rivers. The landscape was a warm, semi-humid lowland of rivers, open plains and patches of woodland with conifers, ferns and early flowering plants. The key localities lie around the city of Zhucheng, above all the Longgujian bone bed, where mass mortality — probably caused by flooding or drought — buried large numbers of individuals together.

Chapter • Wild behavior

Behavior & Ecology

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Chapter • Scientific place

Taxonomy