Septarian nodules washed out from cliff of Palaeocene clays, Moeraki Boulders, Dunedin, South Island, New Zealand, Pacific

Septarian nodules washed out from cliff of Palaeocene clays, Moeraki Boulders, Dunedin, South Island, New Zealand, Pacific

Spiral Wrack (Fucus spiralis), clear view of inflated nodules at the ends of this algae view on the shore, St Abbs, Scotland, UK North Sea

Adult humpback whale (Megaptera novaeangliae) surfacing (head/rostrum/splashguard details) in the AuAu Channel, Maui, Hawaii, USA. Pacific Ocean.

Knotted Wrack (Ascophyllum nodosum), one of the largest wrack species with distinctive nodules, St Abbs, Scotland, UK NORTH SEA

Thyroid Nodule, Scan

27-year-old female researcher working on nitrogen exchange between bacteria and the roots of legumes showing an example of a nodule of bacteria attached to the roots in the rainforest of the "La Selva" research station in Puerto Viejo de Sarapiqui, Costa Rica