Neacomys musseri

Karyotype: 2n = 34 and FN = 60. Chromosomal complement: 15 pairs of biarmed elements large to small decreasing in size, and two small acrocentric pairs. The sex chromosomes were unknown as only a female was examined, but presumably the X would represent one of the medium-sized biarmed elements characteristic of others known karyotypes in the genus (Patton et al. 2000, pp. 110, Fig. 75A).

There was a misunderstanding about the fundamental number described by Patton et al. (2000): the authors mentioned the fundamental number as being 64 or 68, however if the X chromosome represent one of the mediumsized biarmed elements, the fundamental number of this karyotype was actually 60.