Doug Wechsler / Showy bur marigold (Bidens laevis) in the riparian zone of the Manumuskin River, New Jersey, USA, September

Toby Roxburgh / Scientists from the Welsh Marine Environmental Monitoring team and ranger from Kenfig Nature Reserve looking at the carcass of Sowerby's Beaked Whale (Mesoplodon bidens), washed up on the coast near P...

Toby Roxburgh / Scientist from the Welsh Marine Environmental Monitoring team dissecting the carcass of Sowerby's Beaked Whale (Mesoplodon bidens) washed up on beach near Porthcawl to try to determine the cause of de...

Toby Roxburgh / Scientists from the Welsh Marine Environmental Monitoring team photographing the carcass of Sowerby's Beaked Whale (Mesoplodon bidens) washed up on beach near Porthcawl to try to determine the cause o...

Toby Roxburgh / Scientist from the Welsh Marine Environmental Monitoring team dissecting the carcass of a Sowerby's Beaked Whale (Mesoplodon bidens) washed up on a beach in order to try to help determine the cause of...

Toby Roxburgh / Scientists from the Welsh Marine Environmental Monitoring team dissecting the carcass of a Sowerby's Beaked Whale (Mesoplodon bidens) washed up on a beach in order to try to help determine the cause o...

Toby Roxburgh / Scientist from the Welsh Marine Environmental Monitoring team and ranger from Kenfig Nature Reserve looking at the carcass of a Sowerby's Beaked Whale (Mesoplodon bidens), washed up on the coast near...

Juan Manuel Borrero / Two-Toothed Brassia orchid (Brassia bidens) close up in flower, Bosque de Protección Alto Mayo. Amazonas Department. Peru

Dietmar Nill / Shieldbug (Picromerus bidens) catching caterpillar prey amongst red currant berries, Germany

Mark Bowler / Red clawed / claw crab {Perisesarma bidens} front and rear view

Mark Bowler / Red clawed / claw crab {Perisesarma bidens}

Fred Bavendam / Pistol Shrimp (Alpheus bidens), Edithburgh, Australia

Dietmar Nill / Spix's round eared bat {Tonatia bidens} Panama

Dietmar Nill / Spix's round eared bat {Tonatia bidens} close up of penis, captive, Panama

Luiz Claudio Marigo / Pirapitinga fish {Colossoma bidens} Amazonas, Brazil

Luiz Claudio Marigo / Boy with caught Pirapitinga fish {Colossoma bidens} Panaua, Amazonas, Brazil

Dietmar Nill / Spix's round eared bat (Tonatia bidens) close-up of head. Panama, Central America

Martin Camm / Carwardine / Illustration of Sowerby's Beaked Whale (Mesoplodon bidens) female, Ziphidae (Wildlife Art Company).

Martin Camm / Carwardine / Illustration of Sowerby's / North Sea / North Atlantic beaked whale (Mesoplodon bidens) dive sequence. Surface profile, (Wildlife Art Company).

Toby Roxburgh / Scientists from the Welsh Marine Environmental Monitoring team dissecting the carcass of a Sowerby's Beaked Whale (Mesoplodon bidens) washed up on beach in order to determine cause of death. Near Port...

Toby Roxburgh / Scientists from the Welsh Marine Environmental Monitoring team dissecting the carcass of Sowerby's Beaked Whale (Mesoplodon bidens) washed up on a beach near Porthcawl to try to determine cause of dea...

Toby Roxburgh / Close-up of the carcass of Sowerby's Beaked Whale (Mesoplodon bidens) being disected by the Welsh Marine Environmental Monitoring team in order to determine cause of death. Near Porthcawl, South Wales...

Toby Roxburgh / Scientists from the Welsh Marine Environmental Monitoring team measure the carcass of a Sowerby's Beaked Whale (Mesoplodon bidens), washed up on the coast near Porthcawl, South Wales, Model released.

Premaphotos / Tortoise beetle (Batanota bidens) mimicking a fallen seed in rainforest, Brazil

Premaphotos / Tortoise beetle (Batanota bidens) larva carrying a protective shield of its own faeces in rainforest, Costa Rica