FIGURE 1. Partial map of the United States showing the northern limit of the range of D. novemcinctus and the study area in Lafayette County, MS.
FIGURE 2. Skeletal anatomy of the distal right forelimb of D. novemcinctus (Modified from Vaughan, 1972); approximate scale based on adult forelimb measurements from Costa and Vizcaíno (2010).
FIGURE 3. Overview of armadillo foraging traces. 1) Paired, linear trails in grass (arrows) associated with soil pits. 2) Pits in grass-covered soil surface. 3) Type 2 burrow and associated sediment wedge. 4) Close-up of Type 2 burrow in part 3. Note rounded triangular cross-section of apex (inset).
FIGURE 4. Animations (see online) showing rotation of textured 3D models of plaster casts of armadillo pits. Animations were created in Blender (Stichting Blender Foundation, 2013); light source is a hemispherical lamp aligned to camera view. Pit numbers correspond to numbers in Table 1. 1) Pit 1 (animation). 2) Pit 2 (animation). 3) Pit 3 (animation). 4) Pit 4 (animation). 5) Pit 5 (animation). 6) Pit 6 (animation).
FIGURE 5. Animations (see online) showing rotation of textured 3D models of plaster casts of armadillo pits. Animations were created in Blender (Stichting Blender Foundation, 2013); light source is a hemispherical lamp aligned to camera view. Pit numbers correspond to numbers in Table 1. 1) Pit 7 (animation). 2) Pit 8 (animation). 3) Pit 9 (animation). 4) Pit 10 (animation).
FIGURE 6. Qualitative observations of pit casts. Note that all pits are displayed upside down for stability. 1) Three plaster casts of pits (from left to right: pits 5, 3, and 2); view parallel to long axes. Note asymmetry. 2) Contour map (contour interval = 1.2 cm) of a pit cast (pit 2) with superimposed ellipse. Note how the pit is asymmetrical about the x and y axes of the ellipse and the apex of the pit falls into a quadrant of the ellipse. 3) Three plaster casts of pits from part 1 (from left to right: pits 5, 3, and 2) oriented perpendicular to long axes. Note asymmetry. 4) Plaster cast of pit (pit 9) with tiered wall (arrows). See Figure 7.4-5 for more detail.
FIGURE 7. Surficial morphology of plaster casts of soil pits. All are shown upside down relative to original orientation. 1) Three parallel groove casts oriented roughly parallel to vertical axis of pit. 2) Plaster cast of soil pit (pit 8) with isolated, curved groove casts and paired groove casts. 3) Line drawing of pit cast in part 2. 4) Pit cast from Figure 6.4 (pit 9) oriented to show paired groove casts associated with each wall tier. 5) Line drawing of pit cast from part 4.
FIGURE 8. Graphs of armadillo pit data. 1) Scatterplot of height vs. diameter for armadillo pits. Data for conical trace fossils from Pemberton et al. (1988) provided for comparison. 2) Scatterplot of volume vs. surface area of armadillo pit casts. Data from other modern traces and trace fossils from Platt et al. (2010) provided for comparison. 3) Rose diagram showing orientations of foraging pit long axes.
FIGURE 9. Possible examples of fossil vertebrate foraging pits from the Upper Jurassic Morrison Formation. 1) Composite image showing three conical features associated with a paleosol in an outcrop of the Salt Wash Member in Garfield County, Utah. Note that all three originate from the upper bedding plane. 2) Close-up of left-most conical trace fossil in part 1. 3) Close-up of center conical trace fossil in part 1. 4) Close-up of conical trace fossil in part 3. Note broken apex and sets of parallel groove casts on base. 5) Close-up of right-most trace fossil in part 1. Jacob staff is marked in decimeters.
