Survey of medium-sized and large mammals of Piedras Blancas National Park, Costa Rica Beal, Maxwell R. W. Matzinger, Parker J. Saborío-R., Guido Noguera Bristan, Jonathan Olson, Erik R. Check List 2020 2020-07-31 16 4 939 950 C5QJ (Gray, 1849) Gray 1849 [813,1148,1208,1232] Mammalia Atelidae Alouatta Animalia Primates 8 947 Chordata species palliata   Material examined. COSTA RICA• PuntarenasPro- vince, Piedras Blancas National Park; J. Noguera opportunistic observation.  Identification.The Mantled Howler Monkey is a medium-sized primate with dark fur and a reddish colored mantle on its sides. Males have white testicles, and both males and females have beards ( Wainwright and Arias 2007).