Vieraella is an extinct genus of frog from the Jurassic period of Argentina and the oldest true frog known.Despite living around 200 million years ago Vieraella was anatomically very similar to modern frogs. For example its hind legs were adapted for jumping and the skull already possessed the lattice-like form found in modern species. It was however an unusually small frog measuring only 3 centimetres (1.2 in) in length. Given a list of categories: company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, what category does the paragraph belong to?
Animal