Standardising curved carapace length measurements for leatherback turtles, Dermochelys coriacea, to investigate global patterns in body size

There are two commonly utilised, but distinct, methods for measuring carapace length of leatherback turtles (Dermochelys coriacea). Either the carapace is measured along the central ridge or to the side of the central ridge. Here, we demonstrate that these two measurements produce differing results. Moreover, we formulate a globally-applicable correction factor to standardise between these two measurements. Standardised curved carapace length measurements from leatherback turtles at nesting sites worldwide generally fit into 3 size categories: small (<150 cm; Atlantic: Southeast and Pacific: East), mid-sized (150-157.5 cm; Atlantic: Northwest), and large (>157.5 cm; Indian: Southwest, Indian: Northeast, and Pacific: West).