Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Matters Arising
  • Published:

Reply to: Palaeospondylus and the early evolution of gnathostomes

Nature volume 620, pages E23–E24 (2023)Cite this article

Subjects

The Original Article was published on 23 August 2023

replying to C. D. Brownstein. Nature https://doi.org/10.1038/s41586-023-06434-5 (2023)

Hirasawa et al.1 presented high-quality morphological data of the Middle Devonian enigmatic fossil vertebrate Palaeospondylus gunni, using synchrotron radiation X-ray micro-computed tomography, and revealed homologies of cranial skeletal elements. This advance in our knowledge about the morphological features of the Palaeospondylus cranial skeleton enabled us to perform phylogenetic analyses with a modified version of the character matrix2, showing the inference that Palaeospondylus was a tetrapodomorph. Here we performed additional phylogenetic analyses of Palaeospondylus within total-group jawed vertebrates (97 ingroup taxa, plus Galeaspida and Osteostraci as outgroup taxa), with a modified version of the different character matrix3 (see Supplementary Information for a detailed explanation of the character states), and reply to the Comment by Brownstein4.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Phylogenetic inferences of Palaeospondylus.

Data availability

TNT and MrBayes executable files are presented in the Supplementary Information (Supplementary Data). All morphological data discussed here have been previously published.

References

  1. Hirasawa, T. et al. Morphology of Palaeospondylus shows affinity to tetrapod ancestors. Nature 606, 109–112 (2022).

    Article  ADS  CAS  PubMed  Google Scholar 

  2. Cloutier, R. et al. Elpistostege and the origin of the vertebrate hand. Nature 579, 549–554 (2020).

    Article  ADS  CAS  PubMed  Google Scholar 

  3. Brazeau, M. D. et al. Endochondral bone in an Early Devonian ‘placoderm’ from Mongolia. Nat. Ecol. Evol. 4, 1477–1484 (2020).

    Article  PubMed  Google Scholar 

  4. Brownstein, C. D. Palaeospondylus and the early evolution of gnathostomes. Nature https://doi.org/10.1038/s41586-023-06434-5 (2023).

  5. Johanson, Z., Kearsley, A., den Blaauwen, J., Newman, M. & Smith, M. M. Ontogenetic development of an exceptionally preserved Devonian cartilaginous skeleton. J. Exp. Zool. B 318B, 50–58 (2012).

    Article  Google Scholar 

  6. Goloboff, P. A. & Catalano, S. A. TNT version 1.5, including a full implementation of phylogenetic morphometrics. Cladistics 32, 221–238 (2016).

    Article  PubMed  Google Scholar 

  7. Ronquist, F. et al. MrBayes 3.2: efficient Bayesian phylogenetic inference and model choice across a large model space. Syst. Biol. 61, 539–542 (2012).

    Article  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

We thank N. Minaka for discussion of the phylogenetic analyses. This work was supported by JSPS KAKENHI grant numbers JP17K18354 (to T.H.) and JP17H06385 (to S.K.).

Author information

Authors and Affiliations

  1. Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, Tokyo, Japan

    Tatsuya Hirasawa

  2. Evolutionary Morphology Laboratory, RIKEN Cluster for Pioneering Research (CPR), Kobe, Japan

    Tatsuya Hirasawa & Shigeru Kuratani

  3. Laboratory for Evolutionary Morphology, RIKEN Center for Biosystems Dynamics Research (BDR), Kobe, Japan

    Shigeru Kuratani

Authors
  1. Tatsuya Hirasawa
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Shigeru Kuratani
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

T.H. conceived the idea for the response, conducted the phylogenetic analyses and wrote the manuscript. S.K. helped to write the manuscript. The four other co-authors of the original study1 (Y. Hu, K. Uesugi, M. Hoshino and M. Manabe) did not participate in this Reply, because the subject of this Reply had been developed by T.H. and S.K. in the original study, but all continue to support it.

Corresponding author

Correspondence to Tatsuya Hirasawa.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

This file contains: 1. List of character state codings for Palaeospondylus, Panderichthys, Acanthostega, and Tiktaalik, and their grounds. 2. Phylogenetic analyses. 3. MrBayes block. 4. References.

Reporting Summary

Supplementary Data

Supplementary Data files 1 and 2. Supplementary Data 1 contains the TNT executable file (Fig. 1a) in TNT format and Supplementary Data 2 contains the MrBayes executable file (Fig. 1b) in NEXUS format.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Hirasawa, T., Kuratani, S. Reply to: Palaeospondylus and the early evolution of gnathostomes. Nature 620, E23–E24 (2023). https://doi.org/10.1038/s41586-023-06435-4

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41586-023-06435-4

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing