The generic name, derived from Latin similis, "resembling", refers to its similarity to the closely related Caudipteryx.

The holotype specimen, IVPP V 12556, was recovered from the Jiufotang Formation of northeastern China, dating to the early Cretaceous Period middle Aptian stage, about 120 million years ago or perhaps early Albian stage, about 112 million years old.

It consists of a nearly complete skeleton of an adult individual compressed on a plate, that however lacks the skull, the front neck and the hands.

Both were reported as found in the Yixian Formation, dating to the early Aptian stage, about 124 million years ago.

The only other oviraptorosaur reported to have a pygostyle is Nomingia, though the feature is widespread in more advanced birds and appears to have evolved at least twice.