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.

  • News & Views
  • Published:

Palaeontology

Mitrates on the move

Nature volume 407, pages 849–851 (2000)Cite this article

Mitrates are fossils that look like nothing alive today, and so defy anatomists to make sense of them. They also feature in R. P. S. Jefferies's controversial ideas about vertebrate evolution, to which he and colleagues now add in a paper in Lethaia1. The evidence they describe is behavioural — inferred fossil tracks left by two specimens just before they died.

Mitrates are known from marine sediments laid down some 500–360 million years ago; they were usually just a few millimetres in length, with blobby 'heads' and long, segmented 'tails'. The key to their interpretation seems at first to lie in their armour plating, for mitrates had a skeleton made of plates, each grown from a single crystal of calcite. This kind of skeleton is characteristic of echinoderms, such as starfishes. However, the calcite skeleton is arguably the only feature that links mitrates with echinoderms2. Mitrates lacked the familiar five-fold symmetry of extant echinoderms, and the presence of the characteristic echinoderm water-vascular system in mitrates is moot.

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

Figure 1: Fossil freeze-frame.

References

  1. Sutcliffe, O. E., Südkamp, W. H. & Jefferies, R. P. S. Lethaia 33, 1– 12 (2000).

    Article  Google Scholar 

  2. Smith, A. B. Palaeontology 27, 431–459 (1984).

    Google Scholar 

  3. Budd, G. E. & Jensen, S. Biol. Rev. 75, 53–295 (2000).

    Article  Google Scholar 

  4. Jefferies, R. P. S. The Ancestry of the Vertebrates (British Museum, Natural History, London, 1986).

    Google Scholar 

  5. Peterson, K. J. Lethaia 28, 25–38 ( 1995).

    Article  Google Scholar 

  6. Cameron, C. B., Garey, J. R. & Swalla, B. J. Proc. Natl Acad. Sci. USA 97, 4469–4474 (2000).

    Article  ADS  CAS  Google Scholar 

  7. Clack, J. A. Nature 394, 66–69 ( 1998).

    Article  ADS  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. senior editor at Nature,

    Henry Gee

Authors
  1. Henry Gee
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Gee, H. Mitrates on the move. Nature 407, 849–851 (2000). https://doi.org/10.1038/35038193

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1038/35038193

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