The original post: /r/todayilearned by /u/magikcassy on 2024-12-06 21:37:46.

Original Title: TIL platypuses only recently (geologically speaking) lost their teeth, with this change coinciding with the arrival of the rakali (water rat). These rodents outcompeted platypuses for hard-bodied prey, forcing platypuses to evolve dental pads and specialize in soft-bodied food instead.