Lurdusaurus

Chapter • Meet the dinosaur

Overview

Lurdusaurus was one of the strangest plant-eaters in the entire ornithopod family tree. Its body was barrel-shaped and extraordinarily heavy for its length, carried on short, stout limbs, while a surprisingly long and flexible neck ended in a small head with a toothless beak. The hand bore a large conical thumb spike of the same kind seen in its better-known relative Iguanodon. At roughly nine to ten metres long but with the most frequently cited mass estimates approaching five tonnes, the animal had an unusually low centre of gravity – a build closer to a hippopotamus than to the slender, running ornithopods most people picture. When Taquet and Russell described the animal in 1999 they suggested that Lurdusaurus may have led a partly aquatic life in shallow river water, much like a hippo. That reading rests on body proportions and remains hypothetical; other researchers have argued it may simply have been a slow, ground-bound browser whose four sturdy limbs carried its bulk. What is better supported is that Lurdusaurus walked on all fours, moved slowly, and could hardly have outrun a predator. Instead, sheer body mass and the thumb spike may have served as its defence. Its diet was entirely vegetarian. Tightly packed tooth batteries in the upper and lower jaws ground up soft plant material, and the long neck let it sweep across a wide feeding area without shifting its heavy body. Ferns, horsetails, cycads and conifers dominated the river margins of what is now the Sahara, and Lurdusaurus appears to have been built for cropping low vegetation close to the water rather than reaching into treetops. The holotype, a nearly complete skeleton, was found as early as 1965 by the French palaeontologist Philippe Taquet at Gadoufaoua in Niger, in beds of the Elrhaz Formation. The specimen waited more than thirty years for a formal description, which finally came in 1999 when Taquet and Dale Russell published the name Lurdusaurus arenatus. The name means roughly "heavy lizard of the sand", referring both to its compact body and to the sandy desert where the fossil was excavated.

Chapter • Where it lived

Habitat

Lurdusaurus lived during the Aptian stage of the Early Cretaceous, roughly 121–112 million years ago, in what is now the Ténéré desert of Niger. All known material comes from the Elrhaz Formation at Gadoufaoua. At that time the region was not desert at all but a lush floodplain crossed by broad meandering rivers, with wetlands, lakes and stands of ferns, horsetails, cycads and conifers. Its neighbours included the sail-backed ornithopod Ouranosaurus, the sauropod Nigersaurus, the spinosaurid Suchomimus and the enormous crocodyliform Sarcosuchus.

Chapter • Wild behavior

Behavior & Ecology

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Chapter • Scientific place

Taxonomy