The tadpole lived simultaneously with the dinosaurs about 161 million years ago and is described in a new study, published in the journal Nature.
The fossil was found well-preserved with both skeleton and soft tissues in fine sediment. Per Ahlberg, professor at the Department of Organismal Biology at Uppsala University, describes the study as "a very good piece of work".
It looks like a tadpole in general, but it's very large. The tip of the tail is missing, but it should have been 16 centimeters, he says to SR.
The discovery provides a first glimpse of the origin of tadpoles, he emphasizes.
This is a very ancient frog. It lies in the evolutionary tree far down in the common stem that gives rise to all other frogs.