Brighstoneus simmondsi

Early Cretaceous (125 million years ago)

Brighstoneus simmondsi is an iguanodontian dinosaur described in 2021 from a specimen originally collected near Brighstone on the south-west coast of the Isle of Wight in 1978. The long gap between collection and formal description is not unusual in palaeontology, where specimens may sit in museum collections for decades before researchers have the time and resources to study them in detail. The description was led by Jeremy Lockwood, a PhD student at the Natural History Museum and University of Portsmouth, who recognised the specimen as distinct from previously known species.

The genus name references Brighstone, the village near the discovery site, while the species name honours Keith Simmonds, the collector who found the specimen. Brighstoneus was a large herbivore, estimated at roughly eight metres in length, making it one of the bigger iguanodontians known from the Wessex Formation. It was a solidly built animal with a heavy skull and powerful jaw musculature.

The key distinguishing feature of Brighstoneus is its dental anatomy. The animal possessed a bulbous nose region and an unusually shaped snout, with proportions markedly different from those of Mantellisaurus and other Wessex Formation iguanodontians. The teeth were arranged in dental batteries, multiple rows of replacement teeth stacked behind the functional teeth, that allowed continuous replacement as teeth wore down from grinding tough plant material. The specific proportions and arrangement of these tooth batteries differ from other known species.

The description of Brighstoneus was part of a broader effort to re-examine the iguanodontian material from the Isle of Wight's Wessex Formation. For decades, most large herbivore material from the formation was assigned to either Iguanodon or Mantellisaurus without detailed comparative study. Lockwood's work demonstrated that the formation contains at least three or four distinct iguanodontian genera, a level of diversity comparable to modern large herbivore communities in African savannahs.

This finding has significant implications for understanding Cretaceous ecology. If multiple large herbivore species coexisted in the same environment, they must have been partitioning resources in some way, perhaps by feeding at different heights, eating different plant types, or occupying slightly different habitats within the floodplain landscape. Such ecological partitioning is well documented in modern ecosystems but had been less clearly demonstrated for Cretaceous dinosaur faunas.

The specimen is held in the collections of the Dinosaur Isle museum on the Isle of Wight. Its description demonstrates the continuing scientific value of the island's fossil collections and the importance of revisiting historical specimens with modern analytical techniques. The Wessex Formation continues to produce new material, and further taxonomic revisions are likely as additional specimens come to light.