Description
- Hypselosaurus
- Cretaceous Age
- Provence Region
- France
- See picture for measurements
Hypselosaurus (meaning ‘highest lizard’, from Greek ὑψηλός meaning ‘high’ or ‘lofty’ and σαυρος meaning ‘lizard’) was a titanosaurian sauropod that lived in southern France during the Late Cretaceous, approximately 70 million years ago in the early Maastrichtian. Hypselosaurus was first described in 1846, but was not formally named until 1869, when Phillip Matheron named it under the binomial Hypselosaurus priscus.
Eggs attributed to Hypselosaurus by Matheron and Paul Gervais have been found in France since 1846, and were the earliest dinosaur eggs actually discovered, although they were not recognized as being dinosaurian for several decades. The eggs are unusually large; measuring at around 1-foot (0.30 m) in length. Age determination studies performed on the fossilized remains have been inconclusive, with results ranging from a few decades to several hundred years.
Eggs with abnormally thin shells have been attributed to Hypselosaurus priscus. Some experts have speculated that this was the cause of the species’ extinction, with vegetation changes, climatic change and overcrowding being the original impetus for the shell thinning. However, there are alternative explanations for the thin eggshell not dependent on pathology. Later researchers found evidence that the eggs in question successfully hatched. Some researchers postulated that the thinner “Hypselosaurus priscus” eggshells came from different taxa than the thicker eggshells, and subsequent researchers have come to support this idea. Another potential explanation for variation in eggshell thickness is that the thinner eggs were laid by younger individuals than the thicker shell eggs laid by older individuals or that it was a consequence of natural variations of eggshell thickness within a single species.
