(Dubois, WY) – Just outside of Dubois, a team of scientists has uncovered a 230-million-year-old mass grave of giant amphibians. Known as the Nobby Knob bonebed, this fossil site is now the oldest known gathering of Buettnererpeton bakeri – a crocodile-sized, swamp-dwelling amphibian that roamed Wyoming during the Late Triassic period.
Wyoming has long been a hotspot for paleontologists and amateur fossil hunters alike, but this discovery within the Popo Agie Formation is more than just a collection of scattered bones.
Unlike other fossil sites where bones were washed away and buried elsewhere, the sediment and bone patterns at Nobby Knob show little evidence of movement. Scientists say this likely means the animals died and were buried where they lived.
The remains were found close together, with some bones still partially connected, suggesting the creatures died together in the same spot. The researchers believe this was a mass death event – possibly caused by drought, disease, or a sudden environmental change – that happened around a shallow lake near present-day Dubois.
This is the first mass death site of its kind found in the Popo Agie Formation and it more than doubles the number of Buettnererpeton fossils ever found.