Language Matters | Turtle, tortoise, terrapin - history of the words and which came first ahead of World Turtle Day

Turtles, tortoises and terrapins all belong to the taxonomic order Testudines, distinguished from all other vertebrates by their body being encased in a bony shell extending from their rib cage, comprising carapace on top and plastron on the bottom.

The name Testudines is based on the Latin word testudo, for “tortoise”, originating in the Latin testa, “shell”. Modern usage tends to have turtle as the term for all in the order, with tortoise referring to the slow-moving terrestrial species.

The tortoise, in fact – as in the fable – came first, with origins in the late popular Latin tortūca, commonly believed to be a derivative of the Latin tortus, “twisted”, in reference to the crooked feet of the south European species.

The name Tortuga, documented in 15th century writings, then became tortuce/tortuse, based on the French tortue, and eventually settled on one of the many variant spellings circulating in the late-16th century, tortoise.

This word encompassed all species: land-, marsh-, river- and marine tortoises. The latter, with feet compressed into flippers or paddles, are now commonly distinguished as turtles.

The origin of the word turtle requires a taxonomic leap to the class Aves, specifically the turtle dove – a dove of the genus Turtur, noted for its graceful form, and affection for its mate.