The Marca's marmoset (Mico marcai) is a species of marmoset that is endemic to the Amazon, in the Aripuanã-Manicoré interfluvium in Brazil.[1] Its body is light grey, with orange legs, a black tail, a pinkish face, and naked ears. It is about 9inches long, excluding the tail, and it has a 15inches long tail. It weighs about .
It was previously thought to be virtually unknown; in 2008 the IUCN noted that it had never been seen in the wild, though it has been observed since then.[2] [3] However, later studies found the Manicore marmoset (Mico manicorensis), discovered in the Campos Amazônicos National Park in 2000, to be conspecific with M. marcai, and thus both were synonymized.[1]