A 99-million year old beetle in amber was a myrmecophile—a social impostor of the earliest-known ant colonies—revealing the most ancient behavioral symbiosis yet discovered in the Metazoa.
Daniel J Paluh, Karina Riddell ... David C Blackburn
Teeth are maintained in two amphibian groups (caecilians and salamanders) but were lost in frogs over 20 times independently, a higher incidence of edentulism than any other major vertebrate group.
