Metoposaurus fossil bones are rare and scientifically important specimens from one of the largest amphibians ever to walk the Earth, dominating the rivers and lakes of the Late Triassic world before the rise of the dinosaurs.
Quick Facts
| Common Name: Metoposaurus | Scientific Name: Metoposaurus diagnosticus | Meaning: Front lizard |
| Period: Late Triassic (228-201 million years ago) | Diet: Carnivore | Size: Large |
| Length: Up to 3 meters (10 feet) | Weight: 200-400 lbs | Named by: Meyer, 1842 |
Overview
Metoposaurus was a giant temnospondyl amphibian that dominated the rivers, lakes and floodplains of the Late Triassic world across what is now Europe, North America and North Africa. Built like a flattened crocodile with a broad shovel-shaped head it was one of the apex aquatic predators of its time, ambushing fish and smaller vertebrates from shallow waters. Metoposaurus belonged to an ancient lineage of large amphibians that had been successful since the Carboniferous period but would largely be swept away by the mass extinction at the end of the Triassic. Its fossils are sometimes found in enormous bone beds suggesting large numbers died together during droughts when lakes dried up.
What to Look For
The broad flat skull with forward-positioned eyes is the most distinctive feature. Skull bones are heavily sculptured with a distinctive pitted and ridged texture on the outer surface unique to temnospondyls. Vertebrae are distinctive and primitive in structure. Fossils from European sites typically have a grey to brown mineralization while North American specimens from the Chinle Formation are often red-brown.
Fun Facts
Metoposaurus fossils are sometimes found in mass death assemblages with hundreds of individuals preserved together, likely victims of Triassic drought events when their lakes dried up. Despite being an amphibian it was one of the largest predators in its ecosystem. It went extinct in the end-Triassic mass extinction event that cleared the way for dinosaurs to dominate. A remarkable new species Metoposaurus krasiejowensis was discovered in Poland in 2015 showing the genus had a much wider range than previously known.
Museum Research Articles
Learn more about the Metoposaurus
- Britannica: Temnospondyl
- National Park Service: Triassic Reptiles — Petrified Forest
