The fossil record of the large terrestrial mammals of the North American Cenozoic has previously been quantitatively summarized in six sequential episodes of faunal associations –“evolutionary faunas”– that correspond well with previously proposed qualitative “Chronofaunas”. Here we investigate the ecological spectrum of these faunas by classifying their major taxonomic components into discrete ecomorphological categories of diet, locomotion and body size. To specifically address the potential influence of long-term climatic shifts on the ecomorphological composition of these faunas, we analyze via Contingency Tables and Detrended Correspondence Analyses the frequency distribution of ecomorph types within faunas. We show that each evolutionary fauna has a unique, non-random association of ecomorphs, and we identify a long-term trend towards greater ecomorphological specialization over successive faunas during the past 66 Myrs. Major vegetation shifts induced by climatic changes appear to underlie the ecomorphological dynamics of these six temporal associations that summarize Cenozoic North American mammalian evolutionary history.
|Number of pages||6|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|Early online date||10 Jun 2019|
|Publication status||Published - 25 Jun 2019|
- Cenozoic mammals
- Cenozoic climate change
- evolutionary faunas