Data from: Geometric morphometrics suggests different environmental pressures on small and large Polygnathus conodonts during the recovery after the Hangenberg crisis (latest Devonian-earliest Carboniferous)
Data files
Nov 04, 2025 version files 870.36 KB
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2D_R_script_for_publication.Rmd
23.93 KB
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README.md
4.65 KB
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Supplementary_data_info_specimens.csv
841.78 KB
Abstract
The morphology of feeding structures is driven by the nature of the food source, itself influenced by environmental factors, resulting in an indirect relationship between the form of feeding structures and the surrounding environment. However, food sources may change along growth, leading to potentially complex interactions between ontogenetic trajectories and environmental variation. The present study investigates these interactions by analysing the platform shape of P1 elements in unornamented Polygnathus from a latest Devonian - early Carboniferous succession from the Montagne Noire, France, deposited after the Hangenberg Event mass extinction. Allometric trajectories were found to vary along the record, starting from different small-sized shapes but converging towards a common adult morphology. To assess variation of environmental forcing along ontogeny, the specimens from each stratigraphic level were split into three size classes. The shape of the small size class varied primarily with conodont biofacies, the medium size class with sedimentary microfacies, while the large size class followed a random walk unrelated to environmental variation. These results agree with a change of diet along ontogeny, and with an increase of functional constraints related to occlusion in large-sized elements, leading to their convergent adult morphology. Biofacies and microfacies trace different signatures of bathymetry and distance from the coast, suggesting that post-Hangenberg unornamented Polygnathus varied in their exploitation of the water column along ontogeny. Finally, the high disparity of small-sized elements suggests a relaxation of selective constraints related to occlusion, and/or different foraging strategies, making them more susceptible to environmental influences than the large-sized elements.
GENERAL INFORMATION
- Title of Dataset: Raw data of the morphometric analysis and R script.
Author/Principal Investigator Information
Name: Felix Nesme
ORCID: https://orcid.org/0009-0001-2489-7647
Institution: Institut des Sciences de l'Evolution, University of Montpellier, France
Address:
Email: felixnesme@hotmail.com
Author/Associate or Co-investigator Information
Name: Catherine Girard
ORCID:https://orcid.org/0000-0003-3123-8276
Institution: Institut des Sciences de l'Evolution, University of Montpellier, France
Address:
Email: catherine.girard@umontpellier.fr
- Date of data collection: The landmark coordinates have been acquired between 2020 and 2024
- Geographic location of data collection: Institut des Sciences de l'Evolution de Montpellier (ISEM) Universite de Montpellier, campus Triolet, cc065, 34095 Montpellier cedex 05 Batiments 21, 22 et 24?
- Information about funding sources that supported the collection of the data: None
SHARING/ACCESS INFORMATION
- Licenses/restrictions placed on the data: NONE for the dataset; GL2PS License for the script.
- Links to publications that cite or use the data: To be completed under condition of acceptance.
- Links to other publicly accessible locations of the data: NONE
- Links/relationships to ancillary data sets: None
- Was data derived from another source? No
- If yes, list source(s):
- Recommended citation for this dataset:
DATA & FILE OVERVIEW
File List: list all files (or folders, as appropriate for dataset organization) contained in the dataset, with a brief description
The file Supplementary_data_info_specimens.csv contains the aligned coordinates of 1106 conodont specimens from a section of the Montagne Noire (France) covering the latest Devonian-earliest Carboniferous period. The aligned coordinates correspond to the residual coordinates after a Procrustes superimposition. Names of the specimens (Name), stratigraphic level (Level_strat), and sinistral/dextral side are provided in the first three columns. The logarithm of the centroid size (LogCS) is provided in the fourth column. The following columns correspond to the X, Y aligned coordinates of the 29 landmarks and semi-landmarks.
The file 2D_R_script_for_publication.Rmd corresponds to the R script which allows to reproduce the analyses and figures included in the main article. It is in a R Markdown format.
- Relationship between files, if important:
The script in R Markdown format will import the the aligned coordinates included in the first file. - Additional related data collected that was not included in the current data package: No
- Are there multiple versions of the dataset? No
- If yes, name of file(s) that was updated:
- Why was the file updated?
- When was the file updated?
Instrument- or software-specific information needed to interpret the data:
The file Supplementary_data_info_specimens.csv is in csv format and can be read as any basic spreadsheet with software such as Excel.
The script is in R Markdown format and can be run with R version 4.3.2.
The packages geomorph (version 3.3.2.), Morpho (version 2.12), dplyr (version 1.1.4), ade4 (version 1.7-23), nlme (version 3.1-168), paleoTS (version 0.6.2 ) are required to run the analyses.
- Standards and calibration information, if appropriate:
- Environmental/experimental conditions:
- Describe any quality-assurance procedures performed on the data:
- People involved with sample collection, processing, analysis and/or submission: Nesme, Felix; Girard, Catherine; Joachimski, Michael; Corradini, Carlo; Cornee, Jean-Jacques; Renaud, Sabrina
DATA-SPECIFIC INFORMATION FOR: 2D_R_script_for_publication.Rmd
R script to analyze the data from the Supplementary_data_info_specimens file
DATA-SPECIFIC INFORMATION FOR: Supplementary_data_info_specimens
- Number of variables: 62
- Number of cases/rows: 1107
- Variable List: Name;Level_strat;Sinistral_Dextral;LogCS;X1;Y1;X2;Y2;X3;Y3;X4;Y4;X5;Y5;X6;Y6;X7;Y7;X8;Y8;X9;Y9;X10;Y10;X11;Y11;X12;Y12;X13;Y13;X14;Y14;X15;Y15;X16;Y16;X17;Y17;X18;Y18;X19;Y19;X20;Y20;X21;Y21;X22;Y22;X23;Y23;X24;Y24;X25;Y25;X26;Y26;X27;Y27;X28;Y28;X29;Y29
- Missing data codes:* *NO MISSING DATA
- Specialized formats or other abbreviations used: None
Description of methods used for the collection/generation of data:
Polygnathus P1 elements were photographed in oral view using a Nikon DS U3 stereomicroscope camera, a digital camera, and the associated NIS software. Images of dextral specimens were mirrored in order to measure all conodonts with a comparable orientation. The two-dimensional outline of the platform was quantified using a set of three landmarks positioned at the rostral insertion point, the tip of the platfor,m and the caudal insertion point, complemented by 13 sliding semi-landmarks positioned at equal intervals along the margins between the tip of the platform and the respective insertion point. Landmarking was performed using TPSdig.
Methods for processing the data:
A Generalized Procrustes Analysis (GPA) was performed on the coordinates of the landmarks and semi-landmarks to standardize the size, orientation, and position of the specimens. During the GPA, the semi-landmarks are allowed to slide between the previous and next (semi-)landmark, according to the bending energy criterion. The logarithm of the centroid size (i.e., the square root of the sum of squared distances from the landmarks and semi-landmarks to the centroid of the configuration, referred to as (LogCS) was considered as a size proxy for the Polygnathus P1 elements. Aligned coordinates and LogCS are provided in the present dataset.