DOI: 10.5061/dryad.rn8pk0pmj
title: Supplementary figures from: Is 3D, a more accurate quantitative method than 2D, crucial for analyzing disparity patterns in extinct marine arthropods (Trilobita)?

description: Phacopid trilobites are well documented during the Paleozoic.
 Nevertheless, while 2D quantitative analyses have advanced our
 understanding of the morphological relationships among trilobites, the
 quantification of their morphological traits in 3D remains rarely
 documented. Based on two sets of morphological data (head and tail), 2D
 versus 3D shape quantification approaches were used to explore shape
 allometries as well as to explore how the shape variations can be
 explained by the phylogenetic relationships among phacopid trilobite
 species for the first time. We demonstrate that (1) there are similar
 patterns of morphological variability across taxa in 3D and 2D; (2) there
 are rather congruent results between 3D and 2D to discriminate taxa; (3)
 2D and 3D landmarks capture different levels of detail, and the third
 dimension in 3D is very important for making taxonomic distinctions at the
 genus level; (4) there is congruity between 2D and 3D datasets for
 allometric patterns with results showing similar allometric slopes among
 species exhibiting a glabellar length decrease during growth leading to
 wider cephala; (5) the phylomorphospaces show tree branches that do not
 intersect, suggesting possible phylogenetic constraints on morphospace
 occupation for each species and supporting the idea that the Austerops and
 Morocops groups are sister clades that experienced different modes of
 morphological evolution; and (6) the morphological descriptors in
 morphometric analyses in 2D and 3D throughout phacopid evolution are
 effective.
description: The pdf file is structured to provide six supplementary figures
 from: Is 3D, a more accurate quantitative method than 2D, crucial for
 analyzing disparity patterns in extinct marine arthropods
 (Trilobita)?
description: # Supplementary figures from: Is 3D, a more accurate quantitative method
 than 2D, crucial for analyzing disparity patterns in extinct marine
 arthropods (Trilobita)? Dataset DOI:
 [10.5061/dryad.rn8pk0pmj](10.5061/dryad.rn8pk0pmj) ## Description of the
 data and file structure The pdf file is structured to provide six
 supplementary figures from: Is 3D, a more accurate quantitative method
 than 2D, crucial for analyzing disparity patterns in extinct marine
 arthropods (Trilobita)? ### Files and variables #### File:
 SupplementaryFigures.pdf **Description:**  *Supplementary Figure A. 3D
 plot of shape change vector after a generalized Procrustes analysis (GPA)
 on 60 specimen configurations (cephala) associated with PC1 min and max,
 PC2 min and max and PC3 min and max, respectively in 1) frontal view; 2)
 dorsal view; and 3) lateral view. Exaggerated displacement factor along
 axes 0.1. *Supplementary Figure B. 3D plot of shape change vector after a
 generalized Procrustes analysis (GPA) on 41 specimen configurations
 (pygidia) associated with PC1 min and max, PC2 min and max and PC3 min and
 max, respectively in 1) dorsal view; 2) frontal view; and 3) lateral view.
 Scale 0.1. *Supplementary Figure C. Min and max mesh warping (3D) in
 dorsal view depicting allometric shape variations between the six studied
 species having at least 3 individuals for 60 cephala. Scale 0.1.
 *Supplementary Figure F. Scatter plots of 3D partial Procrustes distances
 against 2D partial Procrustes distances for 1) cephala, and 2) pygidia; as
 well as scatter plots of centroid sizes from 2D and 3D configurations for
 3) cephala, and 4) pygidia. *Supplementary Figure D. 3D mesh warping and
 2D thin plate spline deformation grids in dorsal view after a generalized
 Procrustes analysis (GPA) performed for five species having at least 3
 individuals for 41 pygidia. Scale 0.1. *Supplementary Figure E. Scatter
 plot of fitted PC1 scores (shape scores predicted by multivariate
 regression of shape on size) against predictor as the log-transformed
 centroid sizes showing allometric trajectories among five studied species
 for 60 cephala in 3D and 2D. 95% CIs account for nearly 75% of fitted
 value variation. *Supplementary Figure F. Scatter plots of 3D partial
 Procrustes distances against 2D partial Procrustes distances for 1)
 cephala, and 2) pygidia; as well as scatter plots of centroid sizes from
 2D and 3D configurations for 3) cephala, and 4) pygidia.