| Summary: | Yoldiella spitsbergensis Amano sp. nov. Fig. 7E–K. 1925 Nuculana sp. 1; Hägg 1925: pl. 3: 6a, 7. 1925 Nuculana sp. 2; Hägg 1925: pl. 3: 8a, b. 1927 Portlandia sp.; Gripp 1927: 31. 1970 Nuculana ( Jupiteria ) haeggi n. sp.; Anderson 1970: pl. 9: 2a–c (not pl. 9: 1a–c). ZooBank LSID : urn:lsid:zoobank.org:act: 994EA500-2375-482E-AC28- 450F0DD0DA11 Etymology : Named after the type locality. Type material : Holotype: ZPAL V.48/17, internal mold (Fig. 7E). Paratypes: NRM-PZ Mo 186241–186242, silicified shells, ZPAL V.48/18– 21, internal molds (Fig. 7F–K). Type locality : Fossildalen, Spitsbergen, Svalbard. Type horizon : Cold seep carbonates from the Basilika Formation, upper Paleocene. Material .— 27 specimens, shells, internal molds and silicified shells, including seven figured (ZPAL V.48/14–18; NRM-PZ Mo 186241–186242) from the upper Paleocene of Fossildalen, Spitsbergen, Svalbard. Measurements .—The holotype (ZPAL V.48/17): L, 4.9 mm; H, 3.6 mm; W, 3.2 mm. Dimensions range: L, 3.3–6.3 mm; H, 2.8–5.0 mm; W, 1.8–3.8 mm; W/L, 0.41–0.65; H/L, 0.59– 0.85; n = 14. See Table 1 for full list of measured specimens. Diagnosis .—Small Yoldiella with concave postero-dorsal margin, prominent, centrally located beak, taxodont teeth interrupted by rather wide resilifer, ten teeth anteriorly and nine teeth posteriorly, and narrow and very shallow pallial sinus in front of posterior muscle scar. Description. —Shell small, moderately inflated, elongate-ovate, equivalve, inequilateral. Surface partly preserved, smooth apart from fine growth lines. Antero-dorsal margin nearly straight, passing into narrowly rounded anterior margin; postero-dorsal margin slightly concave, passing into acutely rounded posterior end; ventral margin broadly arcuate. Two fine, weak internal ridges extending from beak to posterior corner, forming shallow depressed area on internal mold between ridges. Beak prominent, swollen, prosogyrate, situated centrally. Hinge with two series of small teeth, interrupted by rather wide resilifer; anterior series ...
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