 The pygmy three @-@ toed sloth ( Bradypus pygmaeus ) , also known as the monk sloth or dwarf sloth , is a sloth endemic to Isla Escudo de Veraguas , a small island off the coast of Panama . The species was first described by Robert P. Anderson of the University of Kansas and Charles O. Handley Jr . , of the Smithsonian Institution in 2001 . The pygmy three @-@ toed sloth is significantly smaller than the other three members of its genus , but otherwise resembles the brown @-@ throated three @-@ toed sloth . According to Anderson and Handley Jr . , the head @-@ and @-@ body length is between 48 and 53 centimetres ( 19 and 21 in ) , and the body mass ranges from 2 @.@ 5 to 3 @.@ 5 kg ( 5 @.@ 5 to 7 @.@ 7 lb ) . 
