Steropodon was a small mammal that lived alongside the dinosaurs in the mid-Cretaceous time period.
Steropodon was a prehistoric species of monotreme, or egg-laying mammal, that lived during the middle Albian stage, in the Lower Cretaceous period. It is the second-earliest known relative of the platypus.
In The Land Before Time
A very unusual looking Steropodon appears during the birth of Littlefoot in The Land Before Time. It resembles a primitive platypus to a degree, though it sports a pair of long ears, unlike the real animal.