Multiple optimality criteria support Ornithoscelida

Parry, Luke A. and Baron, Matthew G. and Vinther, Jakob (2017) Multiple optimality criteria support Ornithoscelida. Royal Society Open Science, 4 (10). p. 170833. ISSN 2054-5703 DOI

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A recent study of early dinosaur evolution using equal-weights parsimony recovered a scheme of dinosaur interrelationships and classification that differed from historical consensus in a single, but significant, respect; Ornithischia and Saurischia were not recovered as monophyletic sister-taxa, but rather Ornithischia and Theropoda formed a novel clade named Ornithoscelida. However, these analyses only used maximum parsimony, and numerous recent simulation studies have questioned the accuracy of parsimony under equal weights. Here, we provide additional support for this alternative hypothesis using Bayesian implementation of the Mkv model, as well as through number of additional parsimony analyses, including implied weighting. Using Bayesian inference and implied weighting, we recover the same fundamental topology for Dinosauria as the original study, with a monophyletic Ornithoscelida, demonstrating that the main suite of methods used in morphological phylogenetics recover this novel hypothesis. This result was further scrutinized through the systematic exclusion of different character sets. Novel characters from the original study (those not taken or adapted from previous phylogenetic studies) were found to be more important for resolving the relationships within Dinosauromorpha than the relationships within Dinosauria. Reanalysis of a modified version of the character matrix that supports the Ornithischia–Saurischia dichotomy under maximum parsimony also supports this hypothesis under implied weighting, but not under the Mkv model, with both Theropoda and Sauropodomorpha becoming paraphyletic with respect to Ornithischia.

Item Type: Article
Uncontrolled Keywords: 2017AREP; IA74
Subjects: 04 - Palaeobiology
Divisions: 04 - Palaeobiology
07 - Gold Open Access
12 - PhD
Journal or Publication Title: Royal Society Open Science
Volume: 4
Page Range: p. 170833
Identification Number:
Depositing User: Sarah Humbert
Date Deposited: 01 Mar 2018 17:37
Last Modified: 03 Dec 2018 12:11

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