Diaphus Eigenmann & Eigenmann 1890

• Main Authors: Schwarzhans, Werner, Mors, Thomas, Engelbrecht, Andrea, Reguero, Marcelo, Kriwet, Jurgen
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2016
• Subjects: Biodiversity; Taxonomy; Animalia; Chordata; Myctophiformes; Myctophidae; Diaphus; Antarc*; Antarctica; Seymour Island
• Online Access: https://doi.org/10.5281/zenodo.10903180; http://treatment.plazi.org/id/041B87CAFFA3FFF8D67AF8E2E2B8D935

Diaphus ? marambionis sp. nov. (Figs 3D—I, 6B, C) Material. Holotype: NRM-PZ P.15966 (Figs 3D—F, 6B, C). Paratypes: two specimens NRM-PZ P.15967 (Fig. 3G—I). Other material: two fragmentary specimens NRM-PZ P.15968. Occurrence. Telm 5 unit; ‘ Natica horizon’, Cucullea I member, La Meseta Formation, late Ypresian, early Eocene. Site IAA 2/95, Seymour Island, Antarctica. Etymology. Named after Marambio, the Argentinian research station on Seymour Island. Diagnosis. OL:OH about 1.3. Ventral rim shallow. Dorsal rim regularly rounded, slightly depressed postdorsally. Rostrum about 10% of OL. OCL: CCL = 1.5. Inner face convex. Dorsal margin of ostium curved. Caudal pseudocolliculum well developed. Description. One well-preserved and four incompletely preserved or partly encrusted otoliths; moderately thick and up to nearly 6 mm in length (holotype 5.2 mm long). OH:OT = 3.5—4.0. Dorsal rim rather regularly curved, slightly undulating, somewhat depressed postdorsally and regularly inclined predorsally, sometimes with slight postdorsal angle. Ventral rim shallow, slightly undulating, with (eroded) denticles or protuberances indicated by up to eight grooves seen in ventral view (Fig. 3E, G). Rostrum slightly projecting, blunt, about 10% of OL. Posterior rim rounded, with its tip above caudal tip. Inner face markedly convex, with moderately wide, median, shallow sulcus. Ostium about 1.5 times the length of cauda and equally wide, its dorsal margin slightly curved; cauda slightly bent upwards, terminating at moderate distance from posterior rim of otolith, its colliculum narrower than ostial colliculum; caudal pseudocolliculum well developed. Dorsal depression wide; ventral field with distinct ventral furrow moderately close to ventral rim of otolith and few faint radial furrows underpinning the marginal crenulation or inter-denticle incisions. Outer face flat to slightly concave, rather smooth, with faint postcentral umbo. Remarks. The degree of variability appears to be relatively low in this species and confined to minor ...