Mamenchisaurus vs. Prosaurolophus
Time Period & Environment: Late Jurassic Shaximiao Formation of Sichuan Province, China. Large lake surrounded by lush forests
Written By: Emily Bamforth
The Prosaurolophus munches the soft conifer fronds dispassionately. The plant material is far too soft and supple for his highly specialized dentation, which is adapted for grinding up tough, woody vegetation. The landscape of lush, damp, dense forest around him is vaguely familiar, reminiscent of his Late Cretaceous home in Alberta. But many parts of this Late Jurassic world are foreign to him. At 8m long and standing two metres high at the hip, he is used to being one of the largest animals around. But here there are herds of the towering, 20m-long Omeisaurus, which terrify him. There are no long-necked sauropods like this where he comes from.
Despondently, he gives up trying to chew the soft vegetation. His teeth are just not designed for it, and he decides to try and find seething better to eat. He begins to pick his way carefully through the dense underbrush of ferns and moss, careful where he places his delicate hoofed front feet. He’s so intent on finding something delicious that he walks straight into a tree trunk. At least he thinks it’s a tree truck until it moves.
The Mamenchisaurus had been using his long, long neck (more than half the length of its 35m-long body) to browse from the highest branches of the towering conifers. Startled at the impact, he peers down and sees the Prosaurolophus. This is not a creature the Mamenchisaurus is familiar with. He shares the ecosystems with other sauropods and stegosaurs like Tuojiangosaurus and Chungkingosaurus. He sees this unfamiliar duck-billed dinosaur is a threat and a danger to his family, who are browsing nearby. The Mamenchisaurus gives a low bellow and stamps his enormous feet, making the ground vibrate around them. Three small Hexinlusaurs, herbivorous dinosaurs not larger than beagles, explode from the fern fronds and sprint away in terror.
Sensing the danger, the Prosaurolophus tries to flee as well, but he is too big to turn around quickly in the dense foliage. The Mamenchisaurus bellows again and moves forward in a terrible, slow-motion charge that splitters trees in the understorey like toothpicks. Although the Prosaurolophus is a large animal, he is no match for this angry 80-ton colossus. He falls, bellowing his panic, beneath the pounding feet. Nearby, the large theropod Yangchuanosaurushears the distress call and senses an easy meal. Waste not.