Waco Mammoth National Monument (WMNM) in central Texas is a significant Pleistocene
paleontological site, containing at least 16 Columbian mammoths and specimens of 12
other vertebrate taxa. Interpreting this site, however, is contingent on understanding
the environment Pleistocene animals lived in and how they interacted with that environment
behaviorally. Actualistic studies of modern analogs can be used to better understand
the behavior and geographic range of a Pleistocene animal and thus increase their
usefulness as paleoclimate and paleoenvironmental indicators. Mass and thermal modeling
studies done on modern tortoises have been used to determine the temperature tolerance
of the giant tortoise species of central Texas, constraining the climate present at
WMNM during its formation. Understanding the long-term movements of a fossil organism
can reflect the environment it lives in. Strontium isotope ratio analysis of megafaunal
teeth from WMNM have shown that not all of the mammoths at the site shared a geographic
origin. The behavior revealed–mammoths congregated at WMNM from a wide area–necessitated
a reconsideration of the long-standing mechanism of death for the megafauna there.
Serial analysis of carbon and oxygen isotopes from the same teeth revealed that while
the animals at WMNM shared a diet, some may have had distinct sources of drinking
water. They also reveal that the WMNM megafauna lived in a drier, more drought-prone
world that previously thought. Taking a multi-proxy approach to better understand
interactions between Pleistocene megafauna and the environmental changes they experienced
should inform our attempts to conserve our remaining megafauna.
