Pyrgopolon sp. A

Vinn, Olev, Hryniewicz, Krzysztof, Little, Crispin T. S. & Nakrem, Hans A., 2014, A Boreal serpulid fauna from Volgian-Ryazanian (latest Jurassic-earliest Cretaceous) shelf sediments and hydrocarbon seeps from Svalbard, Geodiversitas 36 (4), pp. 527-540 : 532

? Pyrgopolon sp. A

( Fig. 4 A-E)

MATERIAL AND LOCALITY. — See Table 1.

DESCRIPTION

Maximum tube diameter 4.8 mm. Free tube part smooth, circular in cross section, without any ornamentation, slightly meandering.Tube wall rather thick, 0.7 to 1.0 mm at 4.8 mm tube diameter, twolayered, inner layer microgranular, occupying about half of the tube thickness, outer layer prismatic.

DISCUSSION ffle specimen is tentatively assigned to Pyrgopolon because of its relatively thick walls.

Figures

FIG. 4. — Serpulids from seep carbonate bodies, Spitsbergen, Svalbard: A-E,?Pyrgopolon sp. A: A, large specimen showing the shape and external surface of the tube (PMO 217.365), seep 8; B, details of the outer surface of?Pyrgopolon sp. A, showing the smooth outer surface (PMO 217.365), seep 8; C, cross-section of the tube showing the thickness relation of inner and outer layers (PMO 217.365), seep 8; D, details of the outer prismatic layer (PMO 217.365), seep 8; E, details of the inner microgranular layer (PMO 217.365), seep 8. F, Propomatoceros sp. A, apertural view (PMO 217.354), seep 3. G, H, Nogrobs aff. quadricarinata Münster in Goldfuss, 1831: G, specimen showing shape and external ornament of the tube (PMO 217.356), Myklegardfjellet seep; H, details of the outer surface showing ornament composed of incomplete rings and concave surface of the tube (PMO 217.356), Myklegardfjellet seep. Scale bars: A, 5 mm; B, C, H, 1 mm; D, 200 µm; E, 100 µm; F, G, 2 mm.