Causes and Consequences of Pleistocene Megafaunal Extinctions as Revealed from Rancho La Brea Mammals

Larisa R G DeSantis; Jonathan M Crites; Robert S Feranec; Kena Fox-Dobbs; Aisling B Farrell; John M Harris; Gary T Takeuchi; Thure E Cerling

doi:10.1016/j.cub.2019.06.059

Causes and Consequences of Pleistocene Megafaunal Extinctions as Revealed from Rancho La Brea Mammals

Curr Biol. 2019 Aug 5;29(15):2488-2495.e2. doi: 10.1016/j.cub.2019.06.059.

Authors

Larisa R G DeSantis¹, Jonathan M Crites², Robert S Feranec³, Kena Fox-Dobbs⁴, Aisling B Farrell⁵, John M Harris⁵, Gary T Takeuchi⁵, Thure E Cerling⁶

Affiliations

¹ Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA; Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN 37235, USA; Department of Rancho La Brea, La Brea Tar Pits and Museum, Los Angeles, CA 90036, USA. Electronic address: larisa.desantis@vanderbilt.edu.
² Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA; Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN 37235, USA.
³ Research and Collections, New York State Museum, Albany, NY 12230, USA.
⁴ Department of Geology, University of Puget Sound, Tacoma, WA 98416, USA.
⁵ Department of Rancho La Brea, La Brea Tar Pits and Museum, Los Angeles, CA 90036, USA.
⁶ Department of Geology and Geophysics, University of Utah, Salt Lake City, UT 84112, USA.

PMID: 31386836
DOI: 10.1016/j.cub.2019.06.059

Abstract

The fossils preserved in the Rancho La Brea "tar" seeps in southern California span the past ∼50,000 years and provide a rare opportunity to assess the ecology of predators (e.g., the American lion, sabertooth cats, cougars, dire wolves, gray wolves, and coyotes), including clarifying the causes and consequences of the terminal Pleistocene extinction event. Here, a multi-proxy approach elucidates dietary responses of carnivorans to changing climates and megafaunal extinctions. Using sample sizes that are unavailable anywhere else in the world, including hundreds of carnivoran and herbivore specimens, we clarify the paleobiology of the extinct sabertooth cats and dire wolves-overturning the idea that they heavily competed for similar prey. Canids (especially the dire wolf) consumed prey from more open environments than felids, demonstrating minimal competition for prey throughout the latest Pleistocene and largely irrespective of changing climates, including just prior to their extinction. Coyotes experienced a dramatic shift in dietary behavior toward increased carcass utilization and the consumption of forest resources (prey and/or plant resources) after the terminal Pleistocene megafaunal extinction. Extant predators' ability to effectively hunt smaller prey and/or utilize carcasses may have been a key to their survival, especially after a significant reduction in megafaunal prey resources. Collectively, these data suggest that dietary niches of carnivorans are not always static and can instead be substantially affected by the removal of top predators and abundant prey resources.

Keywords: Canis; Carnivora; Pleistocene; Rancho La Brea; Smilodon; dental microwear; diet; mammals; paleoecology; stable isotopes.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Animals
Biodiversity*
California
Climate Change*
Diet*
Ecosystem
Extinction, Biological*
Felidae / physiology*
Fossils
Mammals
Wolves / physiology*