DOI: 10.5061/dryad.19r5g
title: Data from: Metamorphosis is ancestral for crown euarthropods, and evolved in the Cambrian or earlier

description: Macroevolutionary developmental biology employs fossilized ontogenetic
 data and phylogenetic comparative methods to probe the evolution of
 development at ancient nodes. Despite the prevalence of ecologically
 differentiated larval forms in marine invertebrates, it has been
 frequently presumed that the ancestors of arthropods were direct
 developers, and that metamorphosis may not have evolved until the
 Ordovician or later. Using fossils and new dated phylogenies, I infer that
 metamorphosis was likely ancestral for crown arthropods, contradicting
 this assumption. Based on a published morphological dataset encompassing
 217 exceptionally preserved fossil and 96 extant taxa, fossils were
 directly incorporated into both the topology and age estimates, as in “tip
 dating” analyses. Using data from post-embryonic fossils representing 25
 species throughout stem and crown arthropod lineages (as well as most of
 the 96 extant taxa), characters for metamorphosis were assigned based on
 inferred ecological changes in development (e.g., changes in habitat and
 adaptive landscape). Under all phylogenetic hypotheses, metamorphosis was
 supported as most likely ancestral to both ecdysozoans and euarthropods.
 Care must be taken to account for potential drastic post-embryonic
 morphological changes in evolutionary analyses. Many stem group
 euarthrpods may have had ecologically differentiated larval stages that
 did not preserve in the fossil record. Moreover, a complex life cycle and
 planktonic ecology may have evolved in the Ediacaran or earlier, and may
 have typified the pre-Cambrian explosion “wormworld” prior to the origin
 of crown group euarthropods.
description: Supplementary Data
 1List
 of node calibrations, list of tip calibrations, specimen information, age
 details, and supplementary references.Supplementary Data
 2Result of MP
 phylogenetic analysis in TNT.mp_tip.treSupplementary Data 3MrBayes executable for node dating constrained to MP topology.mp_node.nexSupplementary Data 4MrBayes executable for tip dating constrained to MP topology.mp_tip.nexSupplementary Data 5MrBayes executable for node dating simultaneously inferred with BI topology.bayes_node.nexSupplementary Data 6MrBayes executable for tip dating simultaneously inferred with BI topology.bayes_tip.nexSupplementary Data 7Metamorphosis character coding. Character named "Eco" is the character mapped in this paper. Character named "Ana" represents presence (=1) or absence (=0) of anamorphic development, but this is not discussed in text.charmap.txtSupplementary Data 8R script for stochastic character mapping.simmap.txtSupplementary Data 9Result of node dating constrained to MP topology.mp_node.treSupplementary Data 10Result of tip dating constrained to MP topology.mp_tip.treSupplementary Data 11Result of node dating simultaneously inferred with BI topology.bayes_node.treSupplementary Data 12Result of tip dating simultaneously inferred with BI topology.bayes_tip.treSupplementary Data 13Results of stochastic character mapping for metamorphosis on the MP node dated tree.mp_node_label.pdfSupplementary Data 14Results of stochastic character mapping for metamorphosis on the MP tip dated tree. Tip taxon names can be zoomed.mp_tip_label.pdfSupplementary Data 15Results of stochastic character mapping for metamorphosis on the BI node dated tree.bayes_node_label.pdfSupplementary Data 16Results of stochastic character mapping for metamorphosis on the BI tip dated tree. Tip taxon names can be zoomed.bayes_tip_label.pdf