Schematic summary of Bermuda’s sea level and depositional history showing postulated intervals of
habitation by the tortoise and skink (green lines). Blue represents proxy sea level changes over the past 1 My
(Shackleton et al., 1990). Platform flooding is indicated where blue oscillations cross the 210 m bathymetric
contour; hence, carbonate deposition on the platform surface, symbolized by the off-white color. Carbonate
deposition may have occurred off the platform as sea level fell below 210 m. Shades of tan, orange, and red
represent increasing levels of soil development with greater age of the substrate. The most extreme example
from Bermuda is the Big Red Soil, which developed on the early Pleistocene Walsingham Formation over the
continuous period from approximately 900,000–450,000 yr ago, up the the onset of MIS 11.