DOI: 10.5061/dryad.zpc866tg2
title: Data from: The latest freshwater giants: a new Peltocephalus (Pleurodira: Podocnemididae) turtle from the Late Pleistocene of the Brazilian Amazon

description: Overkill of large mammals is recognised as a key driver of Pleistocene
 megafaunal extinctions in the Americas and Australia. While this
 phenomenon primarily affected mega-mammals, its impact on large Quaternary
 reptiles has been debated. Freshwater turtles, due to the scarcity of
 giant forms in the Quaternary record, have been largely neglected in such
 discussions. Here we present a new giant podocnemidid turtle,
 Peltocephalus maturin sp. nov., from the Late Pleistocene Rio Madeira
 Formation in the Brazilian Amazon, that challenges this assumption.
 Morphological and phylogenetic analyses of the holotype, a massive partial
 lower jaw, reveal close affinities to extant Amazonian species and
 suggests an omnivorous diet. Body size regressions indicate Pe. maturin
 possibly reached about 180 cm in carapace length and is amongst the
 largest freshwater turtles ever found. This finding presents the latest
 known occurrence of giant freshwater turtles, hinting at coexistence with
 early human inhabitants in the Amazon.
description: # The latest freshwater giants: a new <i>Peltocephalus
 </i>(Pleurodira: Podocnemididae) turtle from the Late Pleistocene of
 the Brazilian Amazon
 [https://doi.org/10.5061/dryad.zpc866tg2](https://doi.org/10.5061/dryad.zpc866tg2) This dataset contains a file with a detailed description of methodology, materials and results obtained in this publication, as well as original raw and processed data, and R scripts used for the analyses. ## Description of the data and file structure This dataset contains: 1. Suppl_File_S2: morphometric dataset related to the analyses in the R script (Suppl_File_S7) * Eight linear measurements of the dentary bone in mm (ML, maximum length in lateral view, MW, maximum width, MiL, midline length, HC, height at the coronoid process, SH, symphysis height, TSL, triturating surface length, TSW, triturating surface width, TSML, triturating surface midline length) * One angular measurement (JRA) of the jaw rami 2. Suppl_File_S3: body size dataset related to the analyses in the R script (Suppl_File_S7) * Four linear measurements in mm: MiL, midline length of the dentary, JL, lower jaw length, SCm, snout-condylus mandibularis length, SCL, straight midline carapace length 3. Suppl_File_S4: size corrected and log-transformed morphometric dataset related to the analyses in the R script (Suppl_File_S7) * Measurements of S2 divided by ML (size-correction) and log-transformed 4. Suppl_File_S5: Micro-Raman measurements for mineralogical and organic characterization * Samples analyzed: bone fossil fragments and associated sediments * Number of samples analysed: five (bone fragments = 2; sediment sampled = 3) * Sample processing: powdered bones (0.1 - 0.5mg) and sediments (0.5 - 1 mg) * Data generated: .wdf converted to .txt files for spectra treatment and peak characterization in Spectragryph software. * Files: Four folders related to supplementary figures S2, S3, S4 and S5, with .txt files treated in Spectragryph software. Those files can also be opened and treated in other software such as Wire or Origin. Files were saved with following information: * Bone sample = name = fossilMEROPVH007 * Sediment sample = sediment * S5_a = data used to plot supplementary figure 2 * S5_b = data used to plot supplementary figure 3 * S5_c = data used to plot supplementary figure 4 * S5_d = data used to plot supplementary figure 5 * Each Raman acquisition (measurement) was represented by letters: A, B, C, D, E … in each .txt file saved * Laser = 785 nm * Power = “pt” followed by the power %. Example: 0,1% power = pt_0_1; 5% power = pt_5 * Acquisition time in seconds: 1s, 2s etc * Accumulation numbers: “number”_”ac”. Example: 1ac, 30ac * Example: Sample_SupplementaryFigureNumber_Measurement_Laser_Power_Acquisitiontime_AccumulationNumbers = bonefossilMEROPVH007_S2_C_bone_785_pt_5_1s_1ac 5. Suppl_File_S6: EDXRF measurements for chemical elementary characterization * Samples analyzed: bone fossil fragments and associated sediments * Number of samples analysed: five (bone fragments = 2; sediment sampled = 3) * Sample processing: powdered bones (0.1 - 0.5mg) and sediments (0.5 - 1 mg) * Number of acquisitions/time per sample: two (with and without iron filters)/300 seconds * Data generated: .mca files converted to .csv in WinqXas software for comparisons of counts per second of each element detected 6. Suppl_File_S7: R script containing all analyses as well as the code for generating the figures in the publication * The script contains all the detail about the size prediction based on linear regressions (using data on S3) and the morphometric analysis of the data in S4 using Principal Component Analyses * All code to make the plots contained in publication is also explained in detail Missing values are denoted by NA. A detailed description of the methods and the results can be accessed on Suppl_File_S1, available as online Supplemental Material at: [https://royalsocietypublishing.org/doi/10.1098/rsbl.2024.0010](https://royalsocietypublishing.org/doi/10.1098/rsbl.2024.0010) ## Sharing/Access information This publication has also micro-computed tomographic datasets which are available on the Morphosource Repository under the Project ID: 000553087 and can be freely accessed.