Potential pitfalls of reconstructing deep time evolutionary history with only extant data, a case study using the Canidae (Mammalia, Carnivora) Running Title: Impact of fossil data on canid body size evolution John A. Finarelli1,2,* and Anjali Goswami3,4 1School of Biology & Environmental Science, University College Dublin, Science Education and Research Centre – West, Belfield, Dublin 4, Ireland. 2UCD Earth institute, University College Dublin, Belfield, Dublin 4, Ireland. Email:
[email protected] 3Department of Genetics, Evolution & Environment, University College London, Gower Street, London, WC1E 6BT, U.K 4Department of Earth Sciences, University College London, Gower Street, London, WC1E 6BT, U.K. Email:
[email protected] *corresponding author Accepted Article This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1111/evo.12222. This article is protected by copyright. All rights reserved. 1 Abstract Reconstructing evolutionary patterns and their underlying processes is a central goal in biology. Yet many analyses of deep evolutionary histories assume that data from the fossil record is too incomplete to include, and rely solely on databases of extant taxa. Excluding fossil taxa assumes that character state distributions across living taxa are faithful representations of a clade’s entire evolutionary history. Many factors can make this assumption problematic. Fossil taxa do not simply lead-up to extant taxa; they represent now- extinct lineages that can substantially impact interpretations of character evolution for extant groups.