FIGURE 3 in Neoichnology of the burrowing spiders Gorgyrella inermis (Mygalomorphae: Idiopidae) and Hogna lenta(Araneomorphae: Lycosidae)

FIGURE 3. Quantitative properties of burrows. 1, Measurements of burrows included maximum depth (D), slope (OA), total length (L), branching angle (BA), and tunnel and shaft width (w), height (h), and circumference (c). Width is defined as parallel to the hinge-line of the burrow trapdoor; height is defined as perpendicular to the hinge-line of the burrow trapdoor. 2, Complexity (C) is the sum of the number of segments (s), chambers (h), and surface openings (e) of a single burrow system. 3, Tortuosity is a measure of the average sinuosity of all of the segments of a burrow system. The tortuosity of a single segment is found by dividing the total length (u) by the straight-line distance (v). Modified from Hembree et al., 2012.