Yoldiella oblata
Yoldiella oblata
Summary
Yoldiella oblata was a tiny clam that probably lived buried just beneath the muddy London Clay seabed. Like living yoldiid protobranchs, it was most likely a deposit feeder, using a mobile foot to move through soft sediment while collecting organic-rich particles for food.
Related clams use long palp proboscides to gather and sort material from the surrounding mud. Soft parts are not preserved in Y. oblata, so that feeding method is inferred, but it would have made the species one of the small sediment-processing animals of the London Clay sea floor.
Quick Identification
Look for: a tiny, strongly convex subelliptical valve with rounded ends, an umbo close to the middle of the dorsal margin, a nearly smooth exterior, and two unequal rows of large angular taxodont teeth—about 17 anterior and 11 posterior.
Diagnostic Features
- The hinge has about 17 large angulate teeth in the convex anterior row and about 11 in the slightly concave posterior row.
- Valve outline is subelliptical and slightly inequilateral, with a rounded anterior end and almost rounded posterior end.
- The umbo is slightly opisthogyrate and lies close to the middle of the dorsal margin.
- Valve convexity is strong, especially anteriorly and immediately below the umbo.
- The exterior bears very fine commarginal ribs or growth lines.
Fossil Details
Similar Species
Recorded Fossil Sites
No fossil-site occurrences have yet been recorded for this species.
References
- Jeffery, P.; Tracey, S. (1997). The Early Eocene London Clay Formation mollusc fauna of the former Bursledon Brickworks, Lower Swanwick, Hampshire. Tertiary Research, 17(3–4), 75–137 View reference
- Schnetler, K. I.; Heilmann-Clausen, C. (2011). The molluscan fauna of the Eocene Lillebælt Clay, Denmark. Cainozoic Research, 8(1–2), 41–99 View reference