Striatolamia macrota
Striatolamia macrota
Summary
Striatolamia macrota was a widespread sand-tiger-type shark and one of the characteristic lamniform predators of Eocene seas. It possessed a mouthful of tall grasping teeth suited to catching fast-moving, soft-bodied prey.
Fishes were probably a major part of its diet, with cephalopods and other marine animals also plausible. The teeth varied considerably around the jaw, with different positions contributing to prey capture and retention rather than forming a single uniform cutting blade.
The species was geographically widespread and lived across a substantial part of the Eocene, showing that this feeding strategy was highly successful. In the London Clay sea it formed part of a rich predatory community ranging from small benthic sharks to much heavier otodontids and cow sharks.
Quick Identification
Look for: a slender tooth with a long sharp central point, a smaller pointed projection on each side and a root that divides into two branches. Turn the tooth over: one face often has fine vertical lines near the bottom of the crown, while the opposite face is much smoother.
Diagnostic Features
- Main cusp is tall and slender in anterior and lateral teeth, while posterior teeth become markedly lower and broader.
- Lateral teeth typically carry a pair of broad, shovel-shaped lateral cusplets beside the principal cusp.
- Lingual crown face carries parallel vertical striations, usually strongest near the base, while the labial surface is much smoother.
- Cutting edges are complete, blade-like and unserrated.
- Root is two-lobed and labially notched, with a swollen lingual surface divided by a deep central furrow and a shallow V-shaped interlobe.
Fossil Details
Similar Species
Recorded Fossil Sites
Lessness Shell Bed
London Clay Formation
Walton Member
References
- Casier, E. (1966). Faune ichthyologique du London Clay. 496 pp.. Trustees of the British Museum (Natural History), London View reference
- Rayner, D.; Mitchell, T.; Rayner, M. (2009). London Clay Fossils of Kent and Essex. 228 pp.. Medway Fossil and Mineral Society, Rochester, Kent View reference
- Ward, D.J. (1980). The distribution of sharks, rays and chimaeroids in the English Palaeogene. Tertiary Research, 3(1), 13–19 View reference