Higher‐level Relationships of the Recent Eutherian Orders: Morphological Evidence

Abstract- Diverse morphological evidence from both living and fossil taxa suggests several higher-level groupings of the Recent orders of eutherian mammals. The strongest hypotheses closely relate rodents and lagomorphs within Glires, proboscideans and sirenians within Tethytheria, hyracoids and tethytheres within Paenungulata, chiropterans and dermopterans, and pholidotans and edentates. Somewhat weaker evidence supports groupings of Glires with macroscelideans, primates and tree-shrews with bats and flying lemurs (Archonta), and all Eutheria excluding pangolins and edentates (Epitheria). There is some tenuous evidence for the monophyly of all modern ungulate orders (including cetaceans), and for the division between artiodactyls and other ungulates. Rather than providing only a confusing and unresolved picture of higher eutherian relationships, comparative morphology and paleontology offer some compelling hypotheses that comprise a framework for studies of macromolecular traits.