Untangling the Multiple Ecological Radiations of Early Mammals

David M Grossnickle; Stephanie M Smith; Gregory P Wilson

doi:10.1016/j.tree.2019.05.008

Untangling the Multiple Ecological Radiations of Early Mammals

Trends Ecol Evol. 2019 Oct;34(10):936-949. doi: 10.1016/j.tree.2019.05.008. Epub 2019 Jun 19.

Authors

David M Grossnickle¹, Stephanie M Smith², Gregory P Wilson³

Affiliations

¹ Department of Biology, University of Washington, Seattle, WA, USA. Electronic address: dmgrossn@uw.edu.
² Integrative Research Center, Field Museum of Natural History, Chicago, IL, USA.
³ Department of Biology, University of Washington, Seattle, WA, USA.

PMID: 31229335
DOI: 10.1016/j.tree.2019.05.008

Abstract

The ecological diversification of early mammals is one of the most globally transformative events in Earth's history and the Cretaceous Terrestrial Revolution (KTR) and end-Cretaceous mass extinction are commonly hailed as catalysts. However, a confounding issue when examining this diversification is that it comprised nested radiations of mammalian subclades within the broader scope of mammalian evolution. In the past 200 million years, various independent groups experienced large-scale radiations, each involving ecological diversification from ancestral lineages of small insectivores; examples include Jurassic mammaliaforms, Late Cretaceous metatherians, and Cenozoic placentals. Here, we review these ecological radiations, highlighting the nuanced complexity of early mammal evolution, the value of ecomorphological fossil data, and the importance of phylogenetic context in macroevolutionary studies.

Keywords: adaptive radiation; early mammals; ecological diversity; end-Cretaceous mass extinction; macroevolution; paleoecology.

Publication types

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

MeSH terms

Animals
Biological Evolution*
Extinction, Biological
Fossils
Mammals*
Phylogeny