Plicofollis Kailola, 2004

MP 92, BI 1, ML 100

(Figs 1–3, 20C, 23)

Type species: Arius argyropleuron Valenciennes, 1840 .

Diagnosis

Posterior branch of lateral ethmoid depressed (13, 0> 1); parasphenoid very wide in ventral view (66, 0> 1); maxilla with mesial and lateral margins parallel for proximal two-thirds, converging in distal one-third, distal margin truncate (102, 2> 0); posterior margin of interopercle straight and inclined (130, 0> 1); metapterygoid one and one-half times longer than deep in perpendicular section (135, 1> 2); metapterygoid anterior process truncate (138, 0> 1); anterior portion of anterior ceratohyal very thick (152, 0> 1); posterolateral processes of urohyal more than one-half as long as distal portion of bone (162, 2> 3); gas bladder lateral diverticula present (243, 0> 1).

Ambiguous optimization: Mesethmoid median portion moderately wide (2, 0> 1); extension of diagonal crest associated with posterior branch of parapophysis of complex vertebra short, reaching transverse crest (199, 1> 0); opening delimited by epioccipital posterior process and crests of sustentaculum of Weberian apparatus moderate (203, 2> 1).

Included species

Plicofollis argyropleuron Valenciennes, 1840

Plicofollis aff. argyropleuron sp 1

Plicofollis aff. argyropleuron sp 2

Plicofollis crossocheilos (Bleeker, 1846) * sedis mutabilis Plicofollis dussumieri Valenciennes, 1840

Plicofollis layardi Günther, 1866

Plicofollis aff. layardi

Plicofollis magatensis Herre, 1926 *

Plicofollis nella Valenciennes, 1840

Plicofollis platystomus Day, 1877

Plicofollis polystaphylodon Bleeker, 1846

Plicofollis aff. polystaphylodon

Plicofollis tenuispinis Day, 1877

Plicofollis tonggol Bleeker, 1846 .

Habitat and distribution: Brackish and marine waters, eastern Africa, South and Southeast Asia, southern New Guinea, and northern Australia (Fig. 20).

Remarks

Plicofollis was established by Kailola (2004) based on the examination of Plicofollis argyropleuron, Plicofollis polystaphylodon, and Plicofollis nella . Monophyly of the genus was ratified, and its species composition revised, based on morphological and molecular data (Marceniuk and Menezes 2007, Betancur-R. 2009, Marceniuk et al. 2012, 2017c). The results of the total-evidence analysis corroborate the monophyly of the genus, with the addition of four currently unnamed species, but without consensus on its relationships within the Ariinae (Betancur-R. 2009).

In addition to the diagnostic character states listed above, all species of Plicofollis except Plicofollis platystomus share the following morphological states. On the basis of this suite of characters, we interpret Plicofollis platystomus as the sister to all other species of Plicofollis . Posterior cranial fontanel reduced to a small opening (27, 1> 0); epioccipital dorsally visible (41, 0> 1); general shape of vomer arrow shaped (49, 1> 2); vomer lateral processes short (52, 0> 1); anterior portion of posterior process of vomer as narrow as distal portion (54, 0> 1); accessory tooth plates large, longitudinally elongate (60,?> 4); orbitosphenoid and pterosphenoid lateral expansions slight projections with straight lateral faces (65, 0> 3); lachrymal-antorbital narrow (100, 0> 1); premaxilla narrow and very long, its length two to three times in width (120, 1> 2); anteroventral margin of opercle concave or almost straight (128, 0> 1); anterior portion of interopercle compressed and bifurcate (132, 0> 1); interopercle subrectangular (134, 0> 2); posterolateral processes of urohyal short (160, 1> 0); second basibranchial short and narrow (167, 2> 4); contact face between first epibranchial and first pharyngobranchial very conspicuous (177, 0> 1); posterior margin of first epibranchial straight (181, 0> 1); margin of lateral uncinate process of third epibranchial notched (185, 0> 1); first pharyngobranchial large and depressed (190, 0> 1). The following additional morphological character states are shared by species of Plicofollis except Plicofollis platystomus, but are of ambiguous optimization. Tooth plates associated with vomer present (55, 0> 1); contact face for articulation of transcapular process with basioccipital small and columnar (85, 1> 0); exoccipital posterior process not supporting Müllerian ramus (94, 1> 0); dorsal crest of hyomandibula long and low (141, 1> 0); posterior end of urohyal truncated (158, 0> 2); 15 or more ribs (213, 0> 1); adipose-fin base very short (222, 2> 3); adipose-fin origin vertically above posterior one-half of anal fin (223, 1> 2).