Claudio Contreras / Colony of Monarch butterflies (Danaus plexippus) hibernating on Oyamel fir trees (Abies religiosa) El Zacatal Colony, Monarch Butterfly Sanctuary, Mexico, December 1996

Jack Dykinga / Roots of Fig trees (Ficus sp) growing in the collapsed Cenote Oxpeejool (sink hole), near Tekax, Yucatan, Mexico. Afternoon light illuminates the elongated cavern on the right. October 2009

Jack Dykinga / Stalagmites and stalactites in underground cavern with tourquise waters of Cenote Papakal (sink hole), near Merida, Yucatan, Mexico October 2009

Jack Dykinga / Cenote Samula (sink hole) with elongated roots of a Fig tree (Ficus sp) from ground level descending to the subterranian tourquoise coloured water below. Rays of sulight pass through the hole to illum...

Marie Read / Comb-crested Jacana / Lotusbird (Irediparra gallinacea), adult walking over lilypad, showing its elongated toes. Yellow Water, Kakadu National Park, Northern Territory, Australia, September.

Luciano Candisani / Black River Stingray (Potamotrygon motoro) venomous spine located in the base of the elongated caudal tail, Rio Negro, Pantanal, Brazil

Chris Newbert / Elongated Egg Cowry (Volva volva) mantle, Papua New Guinea

Chris Newbert / Elongated Egg Cowry (Volva volva) pair feeding on soft coral, Papua New Guinea

Albert Lleal / Eyelash Gecko (Rhacodactylus ciliatus) with elongated scales over eyes was thought extinct but rediscovered in 1994, New Caledonia

Mark Moffett / Kerengga Ant-like Jumper (Myrmarachne plataleoides) males fight showing elongated jaws ending in fangs which are usually sheathed, Sri Lanka

Mark Moffett / Kerengga Ant-like Jumper (Myrmarachne plataleoides) male in fighting posture showing elongated jaws ending in fangs which are usually sheathed, Sri Lanka

Mark Moffett / Kerengga Ant-like Jumper (Myrmarachne plataleoides) males fight showing elongated jaws ending in fangs which are usually sheathed, Sri Lanka

Tim MacMillan /John Downer Pro / Blandford's flying lizard {Draco blanfordii} with outstretched wings in flight - elongated ribs act as struts. Captive, (Resolution restriction due to Image digitised from film for 'Weird Nature' BBC...