DOI: 10.5061/dryad.7h44j1087
title: Sexual dimorphism in a Late Ordovician caryocaridid (Malacostraca, Phyllocarida) identified by carapace geometric morphometrics

description: This dataset contains morphometric measurements of 95 caryocaridid
 phyllocarid carapaces (Soomicaris ordosensis) from the Upper Ordovician
 (Katian) Lashizhong Formation of North China. Parameters include height,
 length, anterior-horn angle, projected area and perimeter obtained via
 geometric morphometrics. Three carapace types (T1–T3) were distinguished
 and are provided together with raw TIFF images of modern analogues,
 stratigraphic columns and PCA results. The data support the accepted
 article in Paleobiology and can be reused for evolutionary, biogeographic
 or taxonomic studies of Paleozoic phyllocarids.
description: # Sexual dimorphism in a Late Ordovician caryocaridid (Malacostraca,
 Phyllocarida) identified by carapace geometric morphometrics ## 1. Brief
 description This dataset contains morphometric measurements of *Soomicaris
 ordosensis* carapaces from the Upper Ordovician of the North China and
 Tarim plates, associated with the accepted article in *Paleobiology*
 (2025). Three carapace types (T1–T3) were distinguished based on geometric
 morphometrics. ## 2. File list | File name | Description | |
 ----------------------------------------- |
 ------------------------------------------------------------- | |
 `caryocaridid_measurements.csv` | Raw measurements for 95 specimens (see
 Variables below). | | `Fig_S1.tif` | Figure S1 – sexual dimorphism in
 modern leptostracans. | | `Fig_S2.tif` | Figure S2 – palaeogeographical
 & geological maps. | | `Fig_S3.tif` | Figure S3 – PCA factor loadings.
 | | `Fig_S4.tif` | Figure S4 – shape vs size scatter plot. | |
 `Liu_et_al_Paleobiology_SuppMaterial.pdf` | Full original Supplemental
 Material (text + figures + table). | ## 3. Variables in CSV | Column |
 Unit | Description | | ------------- | ---- |
 ---------------------------------------------- | | `specimen_id` | — |
 Original specimen label (e.g., T1-WHJ-3-1). | | `type` | — | Carapace type
 (T1, T2, T3). | | `H_m` | mm | Measured height. | | `H_o` | mm | Original
 height (after taphonomic correction). | | `L` | mm | Measured length. | |
 `L_H_o` | — | Length / original height ratio. | | `alpha` | ° | Angle of
 the anterior horn of carapace. | | `area` | mm² | 2-D projected area. | |
 `perimeter` | mm | 2-D projected perimeter. | ## 4. Software & scripts
 * R ≥ 4.2 required; packages: `geomorph`, `tidyverse`, `Morpho`. * PCA
 & shape analysis code available on GitHub:
 [https://github.com/yourhandle/caryocaridid_morphometrics](https://github.com/yourhandle/caryocaridid_morphometrics) (will be made public upon publication). ## 5. Geographic & stratigraphic context * Wuhai area, Inner Mongolia (North China Plate) – Lashizhong Fm. * Kuruktagh area, Xinjiang (Tarim Plate) – Queerqueke Fm. * Both formations: Upper Ordovician (Katian). ## Files in this dataset * `caryocaridid_measurements.csv` – Tabular morphometric data (95 specimens). * `Liu_et_al.---Paleobiology---Supplemental_Material.pdf` – Original combined supplemental text and figures. * `Fig._S1.tif` – Sexual dimorphism in modern leptostracans * `Fig._S2.tif` – Palaeogeographical & geological maps. * `Fig._S3.tif` – PCA factor loadings. * `Fig._S4.tif` – Shape vs size scatter plot.