New insights on metabolic rates and aerobic of the tapejarid pterosaur Caiuajara dobruskii
Data files
Jun 24, 2026 version files 1.97 GB
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Ancrestal_state_analysis.R
4 KB
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humerusCPV1032.txt
1.42 KB
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humerusCPV5698.txt
1.43 KB
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MMRdata1.txt
2.42 KB
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phylotree_humerus.trees.nex
6.64 KB
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phylotree.trees_femur.nex
6.81 KB
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phylotree.trees_MMR.nex
8.33 KB
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phylotree.trees_tibia.nex
6.43 KB
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README.md
20.40 KB
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RMRdataCPV2057.txt
1.18 KB
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RMRdataCPV2058.txt
1.17 KB
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Script_7.RPtero_FEMUR.R
8.19 KB
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Script_7.RPtero_Humerus.R
7.70 KB
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Script_7.RPtero_tibia.R
7.71 KB
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Script_PEM_exp_087_1.R
7.53 KB
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Script._Boxplot_analysis.R
5.42 KB
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Segmentation_Femur_CP.V8657.stl
889.82 MB
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SLICES_-_FEMUR_CP.V8657.zip
1.08 GB
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Supp_Figure_1.png
5.40 KB
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Supp_Table_1.pdf
192.74 KB
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Supp_Table_2.pdf
233.80 KB
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tibiaCPV2059.txt
1.34 KB
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tibiaCPV2750a.txt
1.34 KB
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zscoreRMRdataCPV2057.txt
1.18 KB
Abstract
Studies on paleophysiology and thermoregulation are central topics in fossil vertebrate paleobiology because they allow inferences about extinct organismal function beyond anatomical description. Pterosaur thermophysiology remains actively debated: evidence such as relatively rapid growth and elevated metabolic rate estimates has been used to argue for endothermic-like physiologies consistent with the energetic demands of powered flight, whereas reproductive traits, including burial incubation and precocial development, have led some authors to propose ectothermic strategies more akin to those of extant non-avian diapsids. Here, we provide quantitative estimates of resting metabolic rate (RMR) for the tapejarid pterosaur Caiuajara dobruskii using phylogenetic eigenvector maps and osteocyte lacunar density as a proxy. Analysis of six histological sections from three appendicular elements (femur, tibia, humerus) at different ontogenetic stages (adult and juvenile) yielded mass-independent RMR estimates of 0.24–0.76 mL O₂ h⁻¹ g⁻⁰·⁸⁶, substantially higher than those of lepidosaurs but lower than typical mammalian and avian values, indicating an intermediate yet clearly elevated metabolic level. The retrodicted mass-independent maximum metabolic rate (MMR) of 5.68 mL O₂ h⁻¹ g⁻⁰·⁸⁷ falls between values for highly active reptiles and birds, suggesting sufficient aerobic capacity to sustain powered flight without fully matching the maximal performance of small endotherms. Together, these results indicate an intermediate metabolic level in C. dobruskii spanning both ectothermic and endothermic ranges, limiting the use of strict actualistic analogues to infer its thermoregulatory strategy.
Dataset DOI: 10.5061/dryad.t1g1jwtfv
Repository: Dryad Digital Repository
License: Creative Commons Zero (CC0) Public Domain Dedication
Authors
Esaú Victor de Araújo¹², Mariana Valeria Haase³, Jorge Cubo³, Luiz Carlos Weinschütz⁴, Alexander Wilhelm Armin Kellner¹², Juliana Manso Sayão¹²
¹ Laboratório de Sistemática e Paleontologia de Vertebrados Fósseis (LAPUG), Departamento de Geologia e Paleontologia, Museu Nacional/Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
² Programa de Pós-graduação em Zoologia (PPGZoo), Museu Nacional/Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
³ Sorbonne Université, Muséum National d'Histoire Naturelle, CNRS, Centre de Recherche en Paléontologie–Paris (CR2P, UMR 7207), Paris, France.
⁴ Centro Paleontológico (CENPALEO), Universidade do Contestado, Campus Mafra, Brazil.
Corresponding author: Esaú V. Araújo (esauvictor@ufrj.br)
Overview
This dataset contains phylogenetic, osteohistological, comparative physiological, and imaging data used to estimate resting metabolic rate (RMR) and maximum metabolic rate (MMR) in the tapejarid pterosaur Caiuajara dobruskii. The inferences are based on osteocyte lacunar density, relative primary osteon area, and nutrient foramen size, and were analyzed using phylogenetic eigenvector map (PEM) methods and ancestral character estimation (ACE).
The repository includes tab-delimited data tables, phylogenetic trees in Nexus format, R scripts used for comparative analyses and figure generation, a 3D segmented femur mesh in STL format, a ZIP archive of CT slice images, and supplementary files associated with the study.
Related study
We request that future users cite the associated article and this Dryad dataset when reusing these files:
Araújo, E.V., Sena, M.V.A., Cubo, J., Weinschütz, L.C., Kellner, A.W.A., & Sayão, J.M. (2025). Evidence for elevated metabolic rates in the tapejarid pterosaur Caiuajara dobruskii. Paleobiology. DOI pending at the time of dataset submission.
Complete file list
Ancrestal_state_analysis.R– R script for ancestral character estimation (ACE) of resting metabolic rate across the phylogeny.humerusCPV1032.txt– Tab-delimited osteohistological dataset for Caiuajara dobruskii specimen CP.V 1032 and comparative taxa.humerusCPV5698.txt– Tab-delimited osteohistological dataset for Caiuajara dobruskii specimen CP.V 5698 and comparative taxa.MMRdata1.txt– Tab-delimited dataset used to infer mass-independent maximum metabolic rate (MMR).phylotree_humerus.trees.nex– Phylogenetic tree used for humerus-based PEM analyses.phylotree.trees_femur.nex– Phylogenetic tree used for femur-based PEM analyses.phylotree.trees_MMR.nex– Phylogenetic tree used for MMR-based analyses.phylotree.trees_tibia.nex– Phylogenetic tree used for tibia-based PEM analyses.RMRdataCPV2057.txt– Tab-delimited resting metabolic rate (RMR) dataset associated with specimen CP.V 2057.RMRdataCPV2058.txt– Tab-delimited resting metabolic rate (RMR) dataset associated with specimen CP.V 2058.Script_7.RPtero_FEMUR.R– R script for PEM analysis of the femur dataset.Script_7.RPtero_Humerus.R– R script for PEM analysis of the humerus dataset.Script_7.RPtero_tibia.R– R script for PEM analysis of the tibia dataset.Script_PEM_exp_087_1.R– R script for PEM analysis of the MMR dataset using a body-mass exponent of 0.87.Script._Boxplot_analysis.R– R script used to generate the boxplot/stripchart visualization of mass-independent RMR.Segmentation_Femur_CP.V8657.stl– 3D surface mesh of femur specimen CP.V 8657 generated from micro-CT data.SLICES_-_FEMUR_CP.V8657.zip– ZIP archive of CT slice images documenting the femur CP.V 8657 tomographic dataset.Supp_Figure_1.png– Supplementary Figure 1 showing mass-independent RMR of Caiuajara dobruskii relative to extant ectotherms and endotherms.Supp_Table_1.pdf– Supplementary Table 1 containing RMR values for 22 extant species used to construct the mass-independent RMR inference model.Supp_Table_2.pdf– Supplementary Table 2 containing the dataset used to infer mass-independent MMR in Caiuajara dobruskii.tibiaCPV2059.txt– Tab-delimited osteohistological dataset for Caiuajara dobruskii specimen CP.V 2059 and comparative taxa.tibiaCPV2750a.txt– Tab-delimited osteohistological dataset for Caiuajara dobruskii specimen CP.V 2750a and comparative taxa.zscoreRMRdataCPV2057.txt– Tab-delimited calibration dataset and derived values used for z-score and linear-distance analyses of mass-independent RMR.
Files and variables
1. Osteohistological data tables
The files humerusCPV1032.txt, humerusCPV5698.txt, tibiaCPV2059.txt, and tibiaCPV2750a.txt are tab-delimited data tables used in PEM analyses of osteohistological correlates of metabolic rate.
These files contain the same type of information but correspond to different skeletal elements and/or specimens. Variable names should be reported exactly as they appear in each file. If a short code such as V0, V1, or V2 is used in a given table, its meaning should be interpreted according to the table below and checked directly against the file header.
| Variable name | Description |
|---|---|
Species |
Taxon name or specimen identifier used to label each row in the comparative dataset. |
V0 |
Resting metabolic rate (RMR) or the response variable used in the PEM model for calibration with extant taxa. |
V1 |
Osteocyte lacunar density (OLD) or equivalent osteohistological predictor variable used in the PEM analysis. |
V2 |
Relative primary osteon area (RPOA) or equivalent histological variable included in the analysis. |
V3 |
Additional quantitative variable included in the comparative dataset, when present; this may represent transformed or standardized data used by the script. |
V4 |
Additional quantitative variable included in the comparative dataset, when present; see the relevant script for how it is used in the model. |
V5 |
Additional quantitative or identifying variable included in some versions of the table, when present. |
Additional notes for these files:
- Values are tab-delimited plain text.
- Missing values are coded as
NA. - OLD values are osteohistological measurements derived from bone thin sections.
- RPOA means relative primary osteon area.
- Where a script applies transformation or scaling to any of these variables, the transformed values are calculated from the variables listed above rather than stored as separate raw measurements unless explicitly indicated in the table.
2. MMR data table
MMRdata1.txt is a tab-delimited table used to infer mass-independent maximum metabolic rate (MMR) in Caiuajara dobruskii.
| Variable name | Description |
|---|---|
species |
Taxon name or specimen identifier. |
MMR087 |
Maximum metabolic rate (MMR) value or model response variable used for calibration with extant taxa. |
Qdot |
Nutrient foramen measurement or equivalent proxy related to blood flow capacity. |
Additional notes:
- This file underlies the inference of mass-independent MMR in the fossil taxon.
- Measurements are provided as tab-delimited values.
- The body-mass exponent applied in the associated script is 0.87.
- If a transformed variable is included in the file, it is used to generate the mass-independent estimate reported in the manuscript.
3. Raw RMR data tables
RMRdataCPV2057.txt and RMRdataCPV2058.txt contain resting metabolic rate calibration data associated with the femur-based analyses.
| Variable name | Description |
|---|---|
species |
Taxon name or specimen identifier. |
RMR |
Resting metabolic rate (RMR) value used in the comparative calibration dataset. |
OsteocyteDensity |
Osteocyte lacunar density or other histological predictor used to infer RMR. |
RPOA |
Relative primary osteon area (RPOA) or related osteohistological variable. |
Additional notes:
- These files are raw comparative/calibration tables linked to the femur-based RMR analyses.
- They contain the data used to estimate the fossil value for Caiuajara dobruskii specimen CP.V 2057 or CP.V 2058.
- Missing values are coded as
NA.
4. Z-score calibration table
zscoreRMRdataCPV2057.txt is a tab-delimited table containing the RMR calibration dataset and derived values used for z-score and linear-distance analyses.
| Variable name | Description |
|---|---|
Species |
Taxon name or group label. |
RMR |
Resting metabolic rate value used in the comparative dataset. |
OsteocyteDensity |
Osteocity lacunae density. |
RPOA |
relative primary osteon area. |
Additional notes:
- This file is used by
Script._Boxplot_analysis.R. - The figure associated with this file expresses mass-independent RMR as
mL O2 h-1 g^-0.86. - The file combines comparative extant values with the inferred fossil estimate used in the supplementary figure.
5. Phylogenetic tree files
The files phylotree_humerus.trees.nex, phylotree.trees_femur.nex, phylotree.trees_MMR.nex, and phylotree.trees_tibia.nex are phylogenetic trees in Nexus format.
These files include:
- the taxon names used in the PEM and ACE analyses;
- the topology required for phylogenetic comparative methods; and
- the branch-length information used by the corresponding R scripts.
6. R scripts
The R scripts are provided as reproducible analytical workflows. They are listed below with their main purpose, expected input files, and main output or analytical result. These descriptions are intended to help users understand the workflow without needing to read R code.
File: Ancrestal_state_analysis.R
- Description: Performs ancestral character estimation (ACE) of resting metabolic rate across the phylogeny. The script uses a phylogenetic tree and comparative RMR data to reconstruct estimated ancestral values at internal nodes and to generate the ancestral-state figure used to interpret evolutionary patterns in metabolic physiology.
- Main input files: Phylogenetic tree file and comparative RMR dataset used by the script
- Main output or use: Ancestral-state reconstruction output and figure.
File: Script_7.RPtero_FEMUR.R
- Description: Runs the phylogenetic eigenvector map (PEM) analysis for the femur-based osteohistological dataset. The script reads the femur data table and the corresponding phylogenetic tree, fits the comparative model, and generates the femur-based metabolic-rate inference for Caiuajara dobruskii.
- Main input files: Femur data table(s), phylotree.trees_femur.nex
- Main output or use: Femur-based inferred RMR values and model output used in the manuscript.
File: Script_7.RPtero_Humerus.R
- Description: Runs the PEM analysis for the humerus-based osteohistological dataset. The script links humeral osteohistological variables with comparative physiological data in a phylogenetic framework in order to estimate metabolic parameters for the fossil taxon.
- Main input files: humerusCPV1032.txt, humerusCPV5698.txt, phylotree_humerus.trees.nex
- Main output or use: Humerus-based model results and inferred metabolic values.
File: Script_7.RPtero_tibia.R
- Description: Runs the PEM analysis for the tibia-based osteohistological dataset. The script uses tibial histological measurements and the tibia phylogeny to estimate fossil metabolic parameters within the comparative dataset.
- Main input files: tibiaCPV2059.txt, tibiaCPV2750a.txt, phylotree.trees_tibia.nex
- Main output or use: Tibia-based model results and inferred metabolic values.
File: Script_PEM_exp_087_1.R
- Description: Runs the PEM analysis for maximum metabolic rate (MMR) using a body-mass exponent of 0.87. The script uses nutrient foramen measurements and comparative physiological data to estimate mass-independent MMR in Caiuajara dobruskii.
- Main input files: MMRdata1.txt, phylotree.trees_MMR.nex
- Main output or use: Inferred mass-independent MMR estimate and comparative model output.
File: Script._Boxplot_analysis.R
- Description: Reads the RMR calibration table and generates the supplementary boxplot/stripchart comparing mass-independent RMR values of extant ectotherms, extant endotherms, and the inferred value for Caiuajara dobruskii. The script also summarizes the comparative distributions used to position the fossil estimate relative to living taxa.
- Main input files: zscoreRMRdataCPV2057.txt
- Main output or use: Supplementary figure showing the distribution of mass-independent RMR values and the fossil estimate.
General script notes:
- Scripts are provided as runnable analytical workflows.
- Users may need to set the working directory to the folder containing the data files.
- Some scripts require editing file paths before execution, depending on the local environment.
- Any data transformations used in a script, such as mass correction, z-score calculation, or ancestral-state inference, should be interpreted together with the corresponding input data table described in this README.
7. 3D and tomographic files
| File | Description |
|---|---|
Segmentation_Femur_CP.V8657.stl |
3D surface mesh of the femur of Caiuajara dobruskii specimen CP.V 8657. Generated from micro-CT scans and used for segmentation, visualization, and remeasurement of the metaphyseal nutrient foramen. |
SLICES_-_FEMUR_CP.V8657.zip |
Compressed archive containing CT slice images of femur CP.V 8657. These images document the tomographic basis for the segmentation, nutrient foramen measurements, and 3D reconstruction. |
Recommended software for viewing:
- MeshLab
- Blender
- Avizo
- VGStudio
- Other standard CT or mesh-visualization software
8. Supplementary files
| File | Description |
|---|---|
Supp_Figure_1.png |
Supplementary Figure 1. Mass-independent resting metabolic rate (RMR) of Caiuajara dobruskii compared with extant ectotherms and endotherms. The figure includes individual ectotherm and endotherm data points, group distribution summaries, the femur-based PEM estimate, and its confidence interval. |
Supp_Table_1.pdf |
Supplementary Table 1. Resting metabolic rate (RMR) values for 22 extant species used to construct a model of mass-independent RMR inference. This table includes data obtained in the present study from femoral thin sections of Ramphastos toco (MN-52692), Fregata magnificens (MNA-2067), Coragyps atratus (MN-52365), and Anhinga anhinga (MN-52134). |
Supp_Table_2.pdf |
Supplementary Table 2. Dataset used to infer mass-independent maximum metabolic rate (MMR) in Caiuajara dobruskii. |
Data relationships
The tabular data files provide the measured or compiled variables used as input for comparative analyses. The Nexus files provide the phylogenetic framework required for PEM and ACE analyses. The R scripts connect these inputs to the analytical outputs, including metabolic-rate estimates, boxplot visualizations, and ancestral-state reconstructions.
The STL mesh and CT slice archive document the anatomical basis of the nutrient foramen measurements used in the MMR component of the study. The supplementary figure and tables provide visual and tabular support for the results presented in the manuscript.
Software requirements
Required for analysis
- R version 4.0 or later
- R packages:
MPSEM,phytools,ape,ggplot2
Optional for 3D visualization
- MeshLab
- Blender
- Avizo
- VGStudio
Original acquisition/segmentation environment
- Zeiss Xradia 510 Versa
- Mimics Innovation Suite v24
Data format and standards
- Text tables are UTF-8 encoded.
- Delimited text files can be opened in any text editor, spreadsheet program, or statistical environment.
- Missing data are indicated by
NA. - Nexus files follow standard phylogenetic tree formatting.
- STL files are polygon mesh files for 3D visualization.
- ZIP files contain image-based tomographic slices.
Abbreviations
| Abbreviation | Meaning |
|---|---|
RMR |
Resting metabolic rate |
MMR |
Maximum metabolic rate |
RPOA |
Relative primary osteon area |
OLD |
Osteocyte lacunar density |
PEM |
Phylogenetic eigenvector map |
ACE |
Ancestral character estimation |
CP.V |
Collection/specimen identifier prefix |
Usage notes
To reproduce the analyses, place the data tables, tree files, and scripts in the same working directory or edit the file paths in each R script accordingly. Users should verify the exact column names in each data file before rerunning analyses, especially in files where variables are represented by generic labels such as V0–V6.
The fossil physiological values in this dataset are inferred from comparative models and should not be interpreted as directly measured metabolic rates. The 3D and CT-based files can also be reused for anatomical visualization, remeasurement of the nutrient foramen, or independent morphometric and biomechanical analyses.
Access information
Some comparative frameworks used in this dataset were derived from previously published sources, including:
Cubo, J., Sena, M. V. A., Pellarin, R., Faure-Brac, M. G., Aubier, P., Cheyron, C., Jouve, S., Allain, R., & Jalil, N.-E. (2025). Integrative paleophysiology of the metriorhynchoid Pelagosaurus typus (Pseudosuchia, Thalattosuchia). The Anatomical Record, 308(2), 394–411. https://doi.org/10.1002/ar.25548
License
This dataset is distributed under the Creative Commons Zero (CC0) Public Domain Dedication.
Preferred citation
If this dataset is reused, we request that you cite both the associated article and the Dryad dataset record.
