The back, wings, and central tail feathers of the nominate subspecies are dark with a greenish olive gloss.

[3] The nominate subspecies of Marail guan is found from eastern Venezuela through the Guianas.

P. m. jacupeba is found in northern Brazil north of the Amazon River and possibly in southeastern Venezuela, although not all authorities accept the latter.

[3] The Marail guan forages singly or in groups of up to six, mostly in the canopy and lower levels of the forest but sometimes on the ground.

It builds a cup nest high in a tree fork and lays two or three eggs.