fearsome curlicue in front of the eyes. What are the developmental signals that drive that? Dunno, but my students next year are going to find out!
Muntiacus reevesi has a more or less normal number of chromosomes at 2N=46, which happens to be the same number as we have but it has a sister species Muntiacus muntjak which is only distinguishable from M. reevesi through very careful scrutiny by an expert 'deerologist'. M. muntjak, in contrast to Bedford's Folly, has the distinction of having the smallest number of chromosomes of any mammal at 2N=6,7. The 6,7 indicates another bizarre trait: females have 6 chromosomes (2 pairs of 'autosomes' + XX), males in this species have 7 (2 pairs of 'autosomes' + X+Y1+Y2). Somewhere along the way, their Y chromosome has gotten split into two unequal halves. Despite this absurd difference in chromosome count, the two species are interfertile, sort of, the cross yields viable offspring but they are sterile in the same way as crosses between horses Equus caballus and donkeys Equus africanus asinus are called mules or hinnies (depending on which species is the jumper and which the jumpee).