Knife point in grey shale; slit, twist, prise, old strata
opened on shoreline, splayed like mackerel gutting;
cross-section of a fossil fish slabbed to light.

Broken in curve of a plunge, scooped gesture,
jutted bone chin-strap stretched to gulp at ocean,
sheened scales, spread armour's silver overlap,
skeleton fan finnage poised to change ...