Irritator

Irritator was a medium-sized spinosaurid theropod that prowled the coastal lagoons and rivers of what is now northeastern Brazil approximately 110-113 million years ago. Like its more famous relative Spinosaurus, it possessed an elongated, crocodile-like snout filled with conical teeth perfectly adapted for snatching fish from the water. Its narrow skull and interlocking teeth suggest it was primarily a fish-eater, though it likely opportunistically preyed on other small animals.

The discovery story of Irritator is as memorable as the dinosaur itself. The nearly complete skull was acquired by fossil dealers in Brazil before being sold to the State Museum of Natural History in Stuttgart, Germany. When paleontologists David Martill, Arthur Cruickshank, Eberhard Frey, and others began studying it in 1996, they discovered that the dealers had heavily modified the skull with plaster and automobile body filler to make it appear more complete and impressive—a deceptive practice that required months of careful work to undo.

The genus name directly reflects the researchers' frustration with this tampering, derived from 'irritation.' The species name honors Professor George Edward Challenger, the fictional scientist and explorer from Arthur Conan Doyle's adventure novel 'The Lost World,' which itself was set in a Brazilian plateau where dinosaurs had supposedly survived.

Despite the challenges presented by its altered holotype, Irritator has proven scientifically valuable, providing important information about spinosaurid skull anatomy and the diversity of these unusual fish-eating theropods in Early Cretaceous South America.