Barilium

Phylogeny: Dinosauria > Ornithischia > Genasauria > Neornithischia > Cerapoda > Ornithopoda > Iguanodontia > Ankylopollexia > Styracosterna > Hadrosauriformes (?) > Iguanodontidae (?)

Overview: Barilium was an iguanodontian ornithopod that closely resembled Iguanodon itself. In a few modern studies, Barilium has been classified within the family Iguanodontidae, making the two potentially close relatives on top of their superficial similarities. This isn’t accepted by all scientists, however, as Barilium may’ve been more basal than Iguanodon, more properly classified within the larger clade Styracosterna, outside the Iguanodontidae. Iguanodon famously had a spike-like bone in place of a normal thumb, covered in life by a pointed, keratinous sheathe. Even if it didn’t belong to the Iguanodontidae specifically, Barilium also likely had such a spike, as this trait was apparently widespread among iguanodonts (though they varied in size between different species). This spike is thought to have been used for both defense and foraging. Barilium, like other iguanodonts, walked both bipedally and quadrupedally, depending on the situation and its need.

Fossilized remains of Barilium were first described in the 1880’s by the renowned British naturalist Richard Lydekker, who interpreted them as having come from a new species of Iguanodon, called Iguanodon dawsoni. Lydekker named the species in honor of Charles Dawson, who first collected the remains from a quarry in East Sussex, England. Dawson was an amateur fossil hunter, but also a fraudster who forged many of his discoveries. Fortunately, some of his finds were legitimate – Barilium among them. Later studies would prove that Barilium and Iguanodon were distinct taxa, leading to this genus being officially named in 2010. The creature’s name means “heavy ilium”, in reference to the animal’s rather robust bone of the same name, which makes up the upper part of the pelvis. Other notable traits include the short neural spines on its vertebrae and its fairly robust and strong forelimbs. Fossils of the animal come from England’s Wadhurst Clay.