From the Early Cretaceous, far fewer finds are known and it seems that the group had declined in diversity. Some fragmentary fossils have been described, such as "Craterosaurus" from England and "Paranthodon" from South Africa. The only more substantial discoveries are those of "Wuerhosaurus", the exact age of which is highly uncertain. In the autumn of 2016, the teeth and tail spikes of stegosaurs were found in a Russian ravine that was once part of an Early Cretaceous river. The remains of these stegosaurs and other dinosaurs in the area were all miniature, implying that either large amounts of baby dinosaurs spent the first stage in their lives here, or that the area was home to dwarf dinosaurs. Several Russian scientists also theorize that the remains of these stegosaurs, as well as the remains of allosaurids in the same area, could imply that the area could have once been a "refugium", where these Jurassic dinosaurs managed to survive into the Cretaceous period.