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Evolution in the sabre‐tooth cat, S milodon fatalis , in response to P leistocene climate change
Author(s) -
Meachen J. A.,
O'Keefe F. R.,
Sadleir R. W.
Publication year - 2014
Publication title -
journal of evolutionary biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.289
H-Index - 128
eISSN - 1420-9101
pISSN - 1010-061X
DOI - 10.1111/jeb.12340
Subject(s) - biology , carnivore , extinction (optical mineralogy) , climate change , fossil record , pleistocene , morphometrics , ecosystem , evolution of mammals , paleontology , adaptation (eye) , ecology , event (particle physics) , zoology , predation , physics , quantum mechanics , biochemistry , neuroscience , gene
The late P leistocene was a time of environmental change, culminating in an extinction event. Few fossil localities record a temporal series of carnivore fossil populations from this interesting interval as well as R ancho L a B rea ( RLB ). We analysed mandibles of S milodon fatalis from RLB using 2‐ D geometric morphometrics to examine whether, and how, mandibular shape changes through time. S milodon fatalis shows mandibular evolution with oscillations between a small, ancestral‐type morph in pits 77 (≈37 Kybp) and 2051 (≈26 Kybp), a larger, more derived morph in pits 91 (≈28 Kybp) and 61‐67 (≈13.6 Kybp), and an intermediate morph from pit 13 (≈17.7 Kybp). These oscillations end in pit 61‐67, with greatest body size, and are estimated to have its widest gape and lowest bite force. Additionally, variation is lowest in pit 61‐67, which was deposited concurrent with the B ølling– A llerød warming event, which may have important implications for the timing or conditions during the extinction event. Contra to a temporal B ergmann's rule, such rapid warming events appear to be correlated with larger, derived, morphologies whereas static, cooler, climates correlate with gracile, ancestral morphologies.