By Stacey Venzel
Lacking teeth, turtles do not have to worry about losing a set of dentures when they bite into something hard. Their skulls lack lips, too, providing a bony substrate for crushing and grinding thick shells into broken pieces that are more readily digestible.
Just like the mouth structure determines the diet of a turtle, so does it allow certain species to eat hard-shelled creatures. The solid mouths and big heads of some turtles make them well-known food crushing powerhouses.
FAMOUS HARD-SHELLED EATERS
Diamondback terrapins are known to enjoy periwinkle snails that they can crush with their strong, sharp jaws, though they may have their limitations, avoiding the bulkier mud snails. Named for its massive head, the loggerhead turtle is outfitted with muscular jaws and a wide surface for cracking crustaceans and mollusks, even horseshoe crabs and heavy conch shells.
BIG HEAD, HARD FOOD
A phenomenon known as macrocephaly—literally, “big head”—helps some species with small bodies manage to chomp on hard-shelled creatures, their heads increasing exponentially in size into adulthood. It is noted in four species of Australian turtles including the Australian snake-necked turtle, whose head is so big and heavy the turtle can be seen struggling to raise it above the surface for a breath of air! Mussel-eating North American map turtles are another smaller species exhibiting this trait.
Karen Eckert, David Gulko, Sea Turtles: An Ecological Guide (Honolulu, Mutual Publishing, 2004), 38-39.
Carl J Franklin, Turtles: An Extraordinary Natural History 245 Million Years in the Making (St. Paul, Voyageur Press, 2007), 28.
Whit Gibbons, Judy Greene, Turtle: The Animal Answer Guide (Baltimore, The John Hopkins University Press, 2009), 79-80.
#turtles #terrapins #tortoises #TSF