Chinchaysuyoa Marceniuk et al. 2019

(Figs 1–3, 12A – 13)

Type species: Arius labiatus Boulenger, 1898 .

Diagnosis

Mesethmoid posterior horn tubular, narrow, and elongate (5, 0> 1); bony bridge formed by lateral ethmoid and frontal cylindrical and thin (16, 0> 1); vomer anterior margin very pronounced and acute (50, 0> 1); accessory tooth plates small, transversely elongate, and narrow (60, 2> 0); optic foramen very reduced (67, 1> 2); anterior opening of aortic canal at base of subvertebral process and anteroventrally oriented (77, 0> 1); posterior process of exoccipital connected to Müllerian ramus by suture (93, 0> 1); one-half or less of interopercle posterior part contacting ventral margin of opercle (131, 1> 0); anterior portion of interopercle compressed and bifurcate (132, 0> 1); interopercle anterior portion conspicuously narrow (133, 0> 1); metapterygoid one and a one-half times longer than deep in perpendicular section (135, 1> 2); uncinate process of third epibranchial much longer and wider than mesial portion of third epibranchial delimited by uncinate process (182, 0> 1); posterior process of cleithrum very long (224, 1> 2); gas bladder with three chambers (238, 0> 2).

Included species

Chinchaysuyoa ortegai Marceniuk, Marchena, Oliveira & Betancur-R., 2019

Chinchaysuyoa labiata (Boulenger, 1898) *.

442 • Marceniuk et al.

Habitat and distribution: Freshwater, western South America in Ecuador and Peru (Fig. 12).

Remarks

The total-evidence analysis corroborates the monophyly, relationships, and species composition of Chinchaysuyoa, as proposed by Marceniuk et al. (2019b).