| Diet | Carnivore |
| Height | 0.6m |
| Length | 2m |
| Weight | 20 kg |
| Environment | Land |
| Era | Cretaceous |
| Period | Late Cretaceous |
| Type | Theropod |
| Location | North America |
Polyodontosaurus is one of palaeontology's more mysterious theropod dinosaurs, known only from a single fragment of fossilised jaw bone discovered in the famous Dinosaur Park Formation of Alberta, Canada. Named by Charles W. Gilmore in 1932, this creature lived during the Late Cretaceous period, approximately 76 to 74 million years ago, in what was then a lush, subtropical environment teeming with diverse dinosaur species.
As a theropod, Polyodontosaurus was a bipedal carnivore, likely resembling other small predatory dinosaurs of its time. The fossil evidence suggests it was a relatively small dinosaur, probably measuring around 2 metres in length and standing about 0.6 metres tall at the hip. Its name, meaning 'many-toothed lizard', refers to the multiple teeth preserved in the jaw fragment, which would have been used for catching and processing prey.
For decades, scientists debated whether Polyodontosaurus was truly a distinct species or simply another example of better-known dinosaurs like Stenonychosaurus or Troodon. The fragmentary nature of the fossil made it extremely difficult to identify unique characteristics that would distinguish it from its relatives. This uncertainty has led modern palaeontologists to classify Polyodontosaurus as a nomen dubium, meaning the original fossil material is insufficient to definitively establish it as a separate species.
Despite its dubious status, Polyodontosaurus remains an important reminder of how challenging it can be to identify prehistoric species from limited fossil evidence, and highlights the incredible diversity of small theropod dinosaurs that lived alongside giants like Albertosaurus in Late Cretaceous North America.
The only distinguishing feature that can be determined from the fossil evidence is the arrangement of multiple teeth in the preserved left dentary (lower jaw bone). However, these features are not unique enough to definitively separate Polyodontosaurus from other similar theropods.
Based on its classification as a small theropod, Polyodontosaurus likely hunted small prey such as insects, small mammals, and possibly fish. It would have been an active, bipedal predator, though specific behavioural details cannot be determined from the limited fossil evidence.
Polyodontosaurus was first described by Charles W. Gilmore in 1932. The original fossils were discovered at Dinosaur Park Formation, Alberta, Canada.
