Lourinhanosaurus

Type Species: Lourinhanosaurus antunesi

Classification: Dinosauria - Saurischia - Theropoda - Carnosauria - Megalosauroidea

Time Period: Late Jurassic 

Location: Europe (Portugal)

Diet: Carnivore   

The theropod Lourinhanosaurus prowled the wooded islands of southwest Europe during the Late Jurassic. Contemporary dinosaurs in this environment included the theropods Lusovenator (a carcharodontosaur), Torvosaurus, and Allosaurus; the sauropods Oceanotitan, Supersaurus, and Zby; the stegosaurs Dacentrurus and Miragaia; and the ornithopods Draconyx and Dryosaurus. Lourinhanosaurus’ classification is murky: was it an allosaur? a megalosaur? something in between? The current consensus has swung towards it being a megalosaur. The holotype specimen, discovered in Portugal, belonged to a juvenile around fifteen years old and stretched fourteen feet snout-to-tail. Adults may have grown up to twenty-six feet in length. Dinosaur eggs and embryos, believed to belong to Lourinhanosaurus on the grounds that they were found near the Lourinhanosaurus type specimen, have been discovered; these eggs were around thirteen centimeters long, and the nest contained over a hundred of them!

The juvenile specimen had gastroliths in its abdominal cavity. While gastroliths are common in herbivorous dinosaurs, they’re rare in theropods. One explanation is that the Lourinhanosaurus accidentally swallowed them when feasting on the stomach of dismembered prey; another theory is that Lourinhanosaurus used gastroliths to tenderize meat that had been swallowed (since predatory dinosaurs weren’t great at chewing and thus would’ve swallowed large chunks of meat, tendons and gristle and all whole); or, perhaps, Lourinhanosaurus was a specialized predator that fed on crustaceans and shellfish. The latter would’ve been abundant among the island ecosystem, and other megalosaurs appear to be specialized towards this end. Gastroliths would’ve been helpful in demolishing tough shells in the dinosaur’s gut. Perhaps a juvenile Lourinhanosaurus employed such a diet until they became older and were unable to subsist off what could be dredged from the tidal shallows; some scientists speculate that adults shed this ‘marine’ diet and began hunting other dinosaurs. In this manner, the two generations – the juveniles and the adults – wouldn’t be competing against each other for the same resources. In an island community, resources were scarcer, and such niche partitioning would ensure the survival and flourishing of the species.