The plains coqui or (Spanish: coquí llanero), Eleutherodactylus juanariveroi, is an endangered species of coqui, a frog species, endemic to Puerto Rico. It was discovered in 2005 by Neftalí Rios, and was named after Puerto Rican herpetologist Juan A. Rivero, in honor of his contributions to Puerto Rican herpetology. It is only found in the old Naval Base of Sábana Seca in Toa Baja, Puerto Rico. It is characterized by a high-frequency, chip-like sound, a light-brown skin color, and a strip between the eyes. It is the smallest species of coqui.