Pulvinites

Saether, Kristian P., Jingeng, Sha, Little, Crispin T. S. & Campbell, Kathleen A., 2016, New records and a new species of bivalve (Mollusca: Bivalvia) from Miocene hydrocarbon seep deposits, North Island, New Zealand, Zootaxa 4154 (1), pp. 1-26 : 8

cf. Pulvinites sp.

( Fig. 5 A, B)

Material. Five specimens from Moonlight North (Y16/f0694), large shell fragments, two numbered, L4650 ( Fig. 5 A), L4651 ( Fig. 5 B), UOA.

Description. Shell large (up to ca. 70 mm at widest diameter), composed of very thin plates, outline irregular; dimpled texture observed on many of the plates, some plates more or less smooth without dimpled texture, some with calcitic lamellae.

Remarks. Specimens are numerous at only one site, found in dense and diverse assemblages with caryophylliid corals, mytilids and thyasirids. It cannot be confirmed that the specimens belong to Pulvinites Blainville, 1824 , with such internal features common to all species of this genus [e.g. posterior adductor muscle scar, anterior pedobyssal retractor muscle scar, byssal foramen, posterior pedal retractor muscle scar and suture ( Palmer 1984; Tëmkin 2006)] not evident on any of the specimens, nor do any have the distinctive ligamental area preserved. However, the general morphology of the shelly plates closely resembles the nature of those of P. exempla ( Fig. 5 C: cf. Marshall 1998; Tëmkin 2006).

Figures

FIGURE 5 Non-seep-typical bivalves found at Miocene New Zealand hydrocarbon seeps. A – B. cf. Pulvinites sp. from Moonlight North. Scale bar is 10 mm. A. Specimen L 4650. A 1. External view of shell. A 2. Internal view of shell. B. Specimen L 4651. B 1. Internal view of shell. B 2. Lateral view, showing thin laminae. C. Image of modern Pulvinites exempla (Hedley, 1914) for comparison. Specimen M. 281853, NMNZ (photography by K. P. S.). C 1. External view of shell. C 2. Lateral view, showing thin laminae. C 3. Internal view of shell. D. Acesta cf. saginata Marshall, 2001. Specimen L 4652 from Rocky Knob. Scale bar is 10 mm. D 1. Lateral view of right valve. D 2. Anterior view. D 3. Dorsal view. E. Parvamussium cf. maorium Dell, 1956. Scale bar is 2 mm. E 1. Specimen TM 9421 from Moonlight North, anteroventral portion absent. Lateral view of right valve. E 2. Image of modern Parvamussium maorium Dell, 1956 for comparison. Specimen M. 138360, NMNZ (photography by K. P. S.).