Phylogenetic data for: Upside down: ‘Cryobatrachus’ and the lydekkerinid record from Antarctica
Data files
Nov 01, 2021 version files 96.51 KB
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Gee_et_al_Supplemental_Data.pdf
96.51 KB
Aug 19, 2024 version files 179.05 KB
Abstract
Temnospondyl amphibians are a common component of non-marine Triassic assemblages, including in the Fremouw Formation (Lower to Middle Triassic) of Antarctica. Temnospondyls were among the first tetrapods to be collected from Antarctica, but their record from the lower Fremouw Formation has long been tenuous. One taxon, ‘Austrobrachyops jenseni,’ is represented by a type specimen comprising only a partial pterygoid, which is now thought to belong to a dicynodont. A second taxon, ‘Cryobatrachus kitchingi,’ is represented by a type specimen comprising a nearly complete skull, but the specimen is only exposed ventrally, and uncertainty over its ontogenetic maturity and some aspects of its anatomy has led it to be designated as a nomen dubium by previous workers. Here we redescribe the holotype of ‘C. kitchingi,’ an undertaking that is augmented by tomographic analysis. Most of the original interpretations and reconstructions cannot be substantiated, and some are clearly erroneous. Although originally classified as a lydekkerinid, the purported lydekkerinid characteristics are shown to be unfounded or no longer diagnostic for the family. We instead identify numerous features shared with highly immature capitosaurs, a large-bodied clade documented in the upper Fremouw Formation of Antarctica and elsewhere in the Lower Triassic. Additionally, we describe a newly collected partial skull from the lower Fremouw Formation that represents a relatively mature, small-bodied individual and that we provisionally refer to Lydekkerinidae; this specimen represents the most confident identification of a lydekkerinid from Antarctica to date.
README: Phylogenetic data for: Upside down: ‘Cryobatrachus’ and the lydekkerinid record from Antarctica
https://doi.org/10.5061/dryad.j3tx95xfm
GENERAL INFORMATION
Title of Dataset: Phylogenetic data for: Upside down: ‘Cryobatrachus’ and the lydekkerinid record from Antarctica
First/Corresponding Author Information
Name: Bryan M. Gee
ORCID: 0000-0003-4517-3290
Institution: University of Washington
Email: bryangee.temnospondyli@gmail.com
Principal Investigator/Alternate Contact Information
Name: Christian A. Sidor
ORCID: 0000-0003-0742-4829
Email: casidor@uw.edu
Date of data collection: 2021-08 to 2021-10
Geographic location of data collection: Seattle, WA, USA
Information about funding sources that supported the collection of the data: NSF ANT-1341304, NSF ANT-1341645, NSF ANT-1947094
SHARING/ACCESS INFORMATION
Licenses/restrictions placed on the data: CC0 license waiver (https://creativecommons.org/public-domain/cc0/)
Links to publications that cite or use the data: none
Links to other publicly accessible locations of the data: This dataset is also deposited on MorphoBank (Project #5202): http://dx.doi.org/10.7934/P5202. The CT dataset associated with this study cannot be distributed on Dryad and is hosted on MorphoSource (Project #367915): https://www.morphosource.org/projects/000367910
Links/relationships to ancillary data sets: N/A
Was data derived from another source? Yes
If yes, list source(s):
Primary source:
- Schoch, R. R., Werneburg, R., & Voigt, S. (2020). A Triassic stem-salamander from Kyrgyzstan and the origin of salamanders. Proceedings of the National Academy of Sciences, 117(21), 11584-11588.
- Pardo, J. D., Small, B. J., & Huttenlocker, A. K. (2017). Stem caecilian from the Triassic of Colorado sheds light on the origins of Lissamphibia. Proceedings of the National Academy of Sciences, 114(27), E5389-E5395.
Recommended citation for this dataset: Gee, B. M. (2024). Phylogenetic dataset for: Upside down: ‘Cryobatrachus’ and the lydekkerinid record from Antarctica. Dataset.
DATA & FILE OVERVIEW
August 2024 version
This dataset is unmodified from its original form with respect to the character scores (see supplemental information for remarks) and adds all of the character states to the NEXUS file. It also provides .tre files of MPTs for the three analyses that were visualized in the paper.
File List:
- Gee et al 2022_J Paleo_Cryobatrachus.nex: modified character matrix from Pardo et al. (2017) and Schoch et al. (2020).
- Gee et al 2022_original Cryobatrachus_unordered.tre: resultant MPTs from the analysis with AMNH FARB 9503 based on the original interpretation by Colbert & Cosgriff (1974).
- Gee et al 2022_revised Cryobatrachus_unordered.tre: resultant MPTs from the analysis with AMNH FARB 9503 based on the revised interpretation by this study.
- Gee et al 2022_FMNH PR 5020_unordered.tre: resultant MPTs from the analysis with FMNH PR 5020.
- Gee_et_al_Supplemental_Data.pdf: original version of the data in PDF format along with notes on modifications from previous matrices.
Relationship between files, if important: N/A
Additional related data collected that was not included in the current data package: None.
Are there multiple versions of the dataset? Yes, see change log above.
METHODOLOGICAL INFORMATION
Description of methods used for collection/generation of data:
Matrices were downloaded from the source literature and compiled in Mesquite v. 3.6 build 917 for MacOS on a Mid 2015 MacBook Pro running Mojave v. 10.14.6.
Methods for processing the data:
- Following previous authors, the results of the iterations that were visualized in the paper treated all multistate characters as unordered. The matrix was analyzed with each of the two focal specimens alone (i.e. only AMNH FARB 9503 not both AMNH FARB 9503 and FMNH PR 5020) and with two different iterations for AMNH FARB 9503, one based on the original interpretations by Colbert & Cosgriff (1974) and the other based on the new interpretations of this study.
The following software packages were used for this analysis:
- Mesquite v3.6 build 917 for MacOS: http://www.mesquiteproject.org/Installation.html
- PAUP* v4.0 build 169 for MacOS (GUI version): http://phylosolutions.com/paup-test/
Usage notes
This matrix has been superseded by other derivates in this family of matrices and should only be reused for the express purpose of reproducing the results of Gee et al. (2022). Reuse for other purposes risks inclusion of erroneous or outdated data. For more recent derivates, see the following:
- Kligman, B. T., Gee, B. M., Marsh, A. D., Nesbitt, S. J., Smith, M. E., Parker, W. G., & Stocker, M. R. (2023). Triassic stem caecilian supports dissorophoid origin of living amphibians. Nature, 614(7946), 102-107. https://doi.org/10.1038/s41586-022-05646-5
- Gee, B. M., Beightol, C. V., & Sidor, C. A. (2022). A new lapillopsid from Antarctica and a reappraisal of the phylogenetic relationships of early diverging stereospondyls. Journal of Vertebrate Paleontology, 42(6), e2216260. https://doi.org/10.1080/02724634.2023.2216260
- Marjanović, D., Maddin, H. C., Olori, J. C., & Laurin, M. (2024). The new problem of Chinlestegophis and the origin of caecilians (Amphibia, Gymnophionomorpha) is highly sensitive to old problems of sampling and character construction. Fossil Record, 27(1), 55-94. https://doi.org/10.3897/fr.27.e109555
- Serra Silva, A. (2024). Extended Lissamphibia: a tale of character non-independence, analytical parameters and islands of trees. Journal of Systematic Palaeontology, 22(1), 2321620. https://doi.org/10.1080/14772019.2024.2321620
Methods
We analyzed both specimens separately in the most recent version of Schoch's (2013) temnospondyl-wide matrix (Schoch et al., 2020). This matrix was selected because of its wide taxonomic coverage, which mitigates any preconceived notions of taxonomic affinities (e.g., to Stereospondyli). We omitted the lissamphibians and lepospondyls included in the original matrix since the question of lissamphibian origins is irrelevant to the position of the Antarctic temnospondyls discussed here. Two OTUs were scored for AMNH FARB 9503: one based on the interpretations of Colbert and Cosgriff (1974) and one based on our revised interpretations. We also added several small-bodied Triassic stereospondyls that share some features with these specimens: the rhinesuchid Broomistega putterilli Shishkin and Rubidge, 2000 (Broom, 1930; Shishkin and Rubidge, 2000); the rhytidosteid Nanolania anatopretia (Yates, 2000); the putative rhytidosteid Laidleria gracilis Kitching, 1958 (Warren,1998b; Dias-da-Silva and Marsicano, 2011); the putative trematosaur Almasaurus habbazi Dutuit, 1976; the lydekkerinid Chomatobatrachus halei Cosgriff, 1974 (Warren et al., 2006); and the lapillopsids Lapillopsis nana and Rotaurisaurus contundo Yates, 1999. Broomistega putterilli, C. halei, Lai. gracilis, and Lap. nana were originally scored by Schoch (2013), but either were excluded from the final analysis of that study, or were not sampled at all in the analysis of Schoch et al. (2020). Schoch's (2013) scores for these four taxa were retained by Pardo et al. (2017); their scores are expanded here for the additional 15 characters added to this matrix by Schoch et al. (2020). Our analysis was performed in PAUP* 4.0b169 (Swofford, 2002), with Greererpeton burkemorani Romer, 1969, and Proterogyrinus scheelei Romer, 1970, as the operational outgroups, a heuristic search using 10,000 random-addition sequence replicates (holding one tree per step), and tree bisection-and-reconnection (TBR). Bootstrapping was performed using 10,000 fast stepwise addition replicates. All characters were equally weighted and unordered following previous iterations of this matrix (Schoch, 2013; Pardo et al., 2017; Schoch et al., 2020).