DOI: 10.5061/dryad.j3tx95xfm
title: Phylogenetic data for: Upside down: ‘Cryobatrachus’ and the lydekkerinid record from Antarctica

description: 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.
description: 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 <em>Broomistega putterilli</em> Shishkin and
 Rubidge, 2000 (Broom, 1930; Shishkin and Rubidge, 2000); the rhytidosteid
 <em>Nanolania anatopretia</em> (Yates, 2000); the putative
 rhytidosteid <em>Laidleria gracilis</em> Kitching, 1958
 (Warren,1998b; Dias-da-Silva and Marsicano, 2011); the putative
 trematosaur <em>Almasaurus habbazi </em>Dutuit, 1976; the
 lydekkerinid <em>Chomatobatrachus halei</em> Cosgriff, 1974
 (Warren et al., 2006); and the lapillopsids <em>Lapillopsis
 nana</em> and <em>Rotaurisaurus contundo</em>
 Yates, 1999. <em>Broomistega putterilli</em>,
 <em>C</em>. <em>halei</em>,
 <em>Lai</em>. <em>gracilis</em>, and
 <em>Lap</em>. <em>nana</em> 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 <em>Greererpeton
 burkemorani</em> Romer, 1969, and <em>Proterogyrinus
 scheelei</em> 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).
description: # Phylogenetic data for: Upside down: ‘Cryobatrachus’ and the lydekkerinid
 record from Antarctica
 [https://doi.org/10.5061/dryad.j3tx95xfm](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](mailto:bryangee.temnospondyli@gmail.com) Principal Investigator/Alternate Contact Information Name: Christian A. Sidor ORCID: 0000-0003-0742-4829 Email: [casidor@uw.edu](mailto: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/](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](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](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: 1. Gee et al 2022_J Paleo_Cryobatrachus.nex: modified character matrix from Pardo et al. (2017) and Schoch et al. (2020). 2. 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). 3. 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. 4. Gee et al 2022_FMNH PR 5020_unordered.tre: resultant MPTs from the analysis with FMNH PR 5020. 5. 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: 1. 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](http://www.mesquiteproject.org/Installation.html) * PAUP* v4.0 build 169 for MacOS (GUI version): [http://phylosolutions.com/paup-test/](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](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](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](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](https://doi.org/10.1080/14772019.2024.2321620)