Ocloedus, Poyato-Ariza F. J. & Wenz S., 2002

Poyato-Ariza F. J. & Wenz S., 2002, A new insight into pycnodontiform fishes, Geodiversitas 24 (1), pp. 139-248 : 221

Genus Ocloedus n. gen.

Microdon – Vidal 1902: 6. — Lacasa 1981: 70, 124, pl. 55.

Coelodus – Wenz 1968: 118. — Barale et al. 1984: table 2. — Wenz & Poyato-Ariza 1995: 50, fig. 22/1-2. Proscinetes – Wenz & Poyato-Ariza 1995: 50.

TYPE SPECIES. — Coelodus subdiscus Wenz, 1989 .

INCLUDED SPECIES. — The type species, Ocloedus costae ( Heckel, 1856) n. comb., and cf. Ocloedus “ rosadoi ” ( Silva Santos, 1963) n. comb.

ETYMOLOGY. — Anagram of Coelodus , the genus to which the Ocleodus species previously belonged to.

DIAGNOSIS. — Pycnodontid fish with the following unique combination of derived characters: mouth gape inclined; body discoid, maximum body height about 80% of standard length; caudal pedicle not differentiated; dermocranial fenestra present; preopercular of similar size to the expanded ornamented portion of the dermohyomandibula; larger prearticular teeth oval in contour; eight teeth on main prearticular tooth row; grooves on vomerine and prearticular teeth present; about 28 to 29 vertebrae; 12 or 13 hypochordal elements in caudal endoskeleton, some of them enlarged; diastema in caudal endoskeleton absent; pelvic fins at more than 55% of standard length; dorsal ridge scales in point contact with each other; three or four spines on dorsal ridge scales.

Ocloedus subdiscus (Wenz, 1989) n. comb.

( Figs 2B ; 22B, C ; 27B ; 38A ; 41B ) HOLOTYPE. — MNHN MSE-341 ( Wenz 1989b: fig. 1, pl. 1; Kriwet et al. 1999: pl. 1, fig. 4).

PARATYPES. — MNHN MSE-442, MGSB 20.659 ( Wenz 1989b: pl. 1, fig. 4; Fig. 22B ) .

REFERRED SPECIMENS. — IEI LP-084a-b; MNHN- MSE-290a-b, 291a-b, 292, 300a-b, 302a-b, 303a-b, 439a-b, 652a-b, 653a-b, 656, 965 ( Figs 2B ; 27B ; 41B ); MGB 536 , 537-1 , 29455 a-b, 30345, 30377 ; MGSB 8.997, 13.376 a-b, 20.658, 20.376 ( Figs 22C ; 38A ), 27.298, 27.299, 56.216 ; NHML 10996 a-b, 10997, 10999, 37497, 37500-1 .

TYPE HORIZON. — Berriasian-Valanginian.

TYPE LOCALITY. — “La Pedrera de Meià”, El Montsec, province of Lérida, Spain.

DIAGNOSIS. — See Kriwet et al. 1999.

Figures

FIG. 2. — Forms previously referred to the genus Coelodus Heckel, 1854; A, C. saturnus Heckel, 1854, type species, holotype, NMW.XXXIII.2. Photo Schumacher, courtesy Ortwin Schultz; B, Ocloedus subdiscus n. comb., topotype MNHN MSE 965. Photo Serrette. Scale bars: A, 5 cm; B, 1 cm.

FIG. 22. — A, Coelodus saturnus Heckel, 1854, oral region of the holotype, NMW.XXXIII.2, right side, lateral view, with left prearticular in occlusal view. Photo Schumacher, courtesy Ortwin Schultz.; B, Ocloedus subdiscus n. comb., vomer of specimen MGSB 20659. Photo Serrette (from Wenz 1989b); C, Ocloedus subdiscus n. comb., lower mandible of specimen MGSB 20376a, left side, occlusal view. Photo Serrette (from Kriwet et al. 1999); D, Coccodus armatus Pictet, 1850, vomer in occlusal view (private collection). Photo Serrette. Abbreviations: D, dentary teeth; Part, prearticular teeth; Pmx, premaxillary teeth; Vo, vomerian teeth. Scale bars: A, 2 cm; B, 1 cm; C, D, 5 mm.

FIG. 27. — A, Coelodus saturnus Heckel, 1854, caudal region as shown by the holotype, NMW 1857.XXXIII.2. Photo Schumacher, courtesy Ortwin Schultz; B, Ocloedus subdiscus n. comb., camera lucida drawing of the caudal region as shown by specimen MNHN MSE 965. Both right side. Abbreviations: aax, anal axonost; dax, dorsal axonost; di, diastema; epel, epichordal elements; ha, haemal arcocentrum; hyel, hypochordal elements; na, neural arcocentrum; sf, sagittal flange; ud, urodermals. Scale bars: A, 1 cm; B, 2 mm.

FIG. 38. — Anterodorsal region of the body in A, Ocloedus subdiscus n. comb., specimen MGSB 20376b. The incompleteness of the posterior region of the dermosupraoccipital allows observation of the shape of the first dorsal ridge scale, which is normally in a very close contact with this bone. Reverted left side, lateral view. Photo Serrette, under ultraviolet light; B, Coelodus saturnus Heckel, 1854, holotype, NMW 1857.XXXIII.2. Right side, lateral view. Photo Schumacher, courtesy Ortwin Schultz. Abbreviations: dax, dorsal axonosts; drs, dorsal ridge scales; drs1, dorsal ridge scale 1; ll, lateral line; papr, parietal process; rsc, reduced scales; sf, sagittal flanges. Scale bars: A, 5 mm; B, 1 cm.

FIG. 41. — Non-mosaic cloacae without bifid scale; A, Proscinetes elegans (Agassiz, 1833), camera lucida drawing from specimen JM 1941.12a, right side, lateral view; B, Ocloedus subdiscus n. comb., camera lucida drawing from specimen MNHN MSE 965. Modified from Kriwet et al. 1999. Ribs not depicted. Ventral keel scales under pelvic fin partially visible by transparency and in relief. Right side, lateral view; C, Stemmatodus rhombus (Agassiz, 1839), restoration mostly from camera lucida drawings of specimens NHML P9672 and 43451, reverted left side, lateral view; D, Stenamara mia Poyato-Ariza & Wenz, 2000, camera lucida drawing of silicone peel from the holotype, MCCM LH-14365. Remains of some pelvic and anal fin rays not depicted. Reverted left side, lateral view (right side on original specimen). Abbreviations: aax, anal axonosts; af, anal fin; an, anal notch; clr, cloacal rib; csc, complete scale(s); cv, cloacal vestibule; hs, haemal spine; opv, opening for pelvic fin; pcb, post-coelomic bone; pvf, pelvic fin; pvg, pelvic girdle; r, rib(s); rsc, reduced scales; vks, ventral keel scale(s); 1, 2, anterior modified cloacal scales; 1’, 2’, 3’, posterior modified cloacal scales. Scale bars: A-C, 2 mm; D, 5 mm.