Skip to main content

Thank you for visiting 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.

Facts and fancies about early fossil chordates and vertebrates



The interrelationships between major living vertebrate, and even chordate, groups are now reasonably well resolved thanks to a large amount of generally congruent data derived from molecular sequences, anatomy and physiology. But fossils provide unexpected combinations of characters that help us to understand how the anatomy of modern groups was progressively shaped over millions of years. The dawn of vertebrates is documented by fossils that are preserved as either soft-tissue imprints, or minute skeletal fragments, and it is sometimes difficult for palaeontologists to tell which of them are reliable vertebrate remains and which merely reflect our idea of an ancestral vertebrate.

This is a preview of subscription content

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Interrelationships of the major extant deuterostome clades.
Figure 2: Soft-bodied presumed fossil chordates and vertebrates, from the Cambrian (green), Silurian (pink), Devonian (yellow) and Carboniferous (purple) periods.
Figure 3: Late Cambrian, Ordovician and early Silurian vertebrate exoskeletons.
Figure 4: Distribution through geological time (black bars), and patterns of interrelationships (red) of the major Palaeozoic jawless vertebrate groups and their extant relatives.


  1. 1

    Hou, X.-G. et al. The Cambrian Fossils of Chengjiang, China: the Flowering of Early Animal Life (Blackwell Publishing, 2007).

    Google Scholar 

  2. 2

    Royal Ontario Museum. The Burgess Shale (Royal Ontario Museum, 2011).

  3. 3

    Briggs, D. E. G. The role of decay and mineralization in the preservation of soft-bodied fossils. Annu. Rev. Earth Planet. Sci. 31, 275–301 (2003).

    ADS  CAS  Google Scholar 

  4. 4

    Sansom, R. S., Gabbott, S. E. & Purnell, M. A. Decay of chordate characters causes bias in fossil interpretation. Nature 463, 797–800 (2010).

    ADS  CAS  PubMed  Google Scholar 

  5. 5

    Sansom, R. S. Gabbott, S. E. & Purnell M. A. Decay of vertebrate characters in hagfish and lamprey (Cyclostomata) and the implications for the vertebrate fossil record. Proc. R. Soc. Lond. B 278, 1150–1157 (2011).

    Google Scholar 

  6. 6

    Sansom, R. S., Gabbott, S. E. & Purnell, M. A. Atlas of vertebrate decay: a visual and taphonomic guide to fossil interpretation. Palaeontology 56, 457–474 (2013).

    Google Scholar 

  7. 7

    Turner, S. in Advances in the Origin and Early Radiation of Vertebrates (eds Arratia, G., Wilson, M.V.H. & Cloutier, R.) 67–94 (Pfeil, 2004).

    Google Scholar 

  8. 8

    Karatayute-Talimaa, V. N. Determination methods for the exoskeletal remains of early vertebrates. Fossil Record 1, 21–51 (1998). An important review of the tissue structure in Early Palaeozoic microremains.

    Google Scholar 

  9. 9

    Zhu, M., Zhao, W., Jia, L., Qiao, T. & Qu, Q. The oldest articulated osteichthyan reveals mosaic gnathostome characters. Nature 458, 469–474 (2009).

    ADS  CAS  PubMed  Google Scholar 

  10. 10

    Zhu, M. et al. A Silurian placoderm with osteichthyan-like marginal jaw bones. Nature 502, 188–193 (2013).

    ADS  CAS  PubMed  Google Scholar 

  11. 11

    Ritchie, A. & Gilbert-Tomlinson, J. First Ordovician vertebrates from the southern hemisphere. Alcheringa 1, 351–368 (1977).

    Google Scholar 

  12. 12

    Gagnier, P.-Y. Sacabambaspis janvieri, vertébré ordovicien de Bolivie. 1, analyse morphologique [in French]. Ann. Paleontol. 79, 19–69 (1993).

    Google Scholar 

  13. 13

    Sansom, I. J., Smith, M. P., Smith, M. M. & Turner, P. Astraspis — the anatomy and histology of an Ordovician fish. Palaeontology 40, 625–643 (1997).

    Google Scholar 

  14. 14

    Donoghue, P. C. J. & Purnell, M. A. Genome duplication, extinction and vertebrate evolution. Trends Ecol. Evol. 20, 312–319 (2005).

    PubMed  Google Scholar 

  15. 15

    Bardack, D. & Zangerl, R. First fossil lamprey: a record from the Pennsylvanian of Illinois. Science 162, 1265–1267 (1968).

    ADS  CAS  PubMed  Google Scholar 

  16. 16

    Janvier, P. & Lund, R. Hardistiella montanensis N. gen. et sp. (Petromyzontida) from the Lower Carboniferous of Montana, with remarks on the affinities of lampreys. J. Vert. Paleontol. 2, 407–413 (1983).

    Google Scholar 

  17. 17

    Gess, R. W., Coates, M. I. & Rubidge, B. S. A lamprey from the Devonian of South Africa. Nature 443, 981–984 (2006).

    ADS  CAS  PubMed  Google Scholar 

  18. 18

    Chang, M. M., Zhang, J. & Miao, D. A lamprey from the Cretaceous Jehol biota of China. Nature 441, 972–974 (2006).

    ADS  CAS  PubMed  Google Scholar 

  19. 19

    Bardack, D. First fossil hagfish (Myxinoidea): a record from the Pennsylvanian of Illinois. Science 254, 701–703 (1991).

    ADS  CAS  PubMed  Google Scholar 

  20. 20

    Poplin, C., Sotty, D. & Janvier, P. Un Myxinoïde (Craniata, Hyperotreti) dans le Konservat-Lagerstätte Carbonifère supérieur de Montceau-les-Mines (Allier, France) [in French]. CR. Acad. Sci. II A 332, 345–350 (2001).

    Google Scholar 

  21. 21

    Graham, A., Butts, T., Lumsden, A. & Kiecker, C. What can vertebrates tell us about segmentation? EvoDevo 5, 24 (2014).

    PubMed  PubMed Central  Google Scholar 

  22. 22

    Conway Morris, S. & Caron, J.-B. Pikaia gracilens Walcott, a stem-group chordate from the Middle Cambrian of British Columbia. Biol. Rev. Camb. Philos. Soc. 87, 480–512 (2012).

    Google Scholar 

  23. 23

    Gould, S. J. Wonderful Life: The Burgess Shale and the Nature of History (W.W. Norton & Co, 1990).

    Google Scholar 

  24. 24

    Chen, J. Y., Dzik, J., Edgecombe, G. D., Ramskjöld, L. & Zhou, G. Q. A possible Early Cambrian chordate. Nature 377, 720–722 (2002).

    ADS  Google Scholar 

  25. 25

    Shu, D. et al. A new species of Yunnanozoan with implications for deuterostome evolution. Science 299, 1380–1384 (2003).

    CAS  PubMed  Google Scholar 

  26. 26

    Chen, J.-Y., Huang, D.-Y. & Li, C.-W. An early Cambrian craniate-like chordate. Nature 402, 518–522 (1999).

    ADS  CAS  Google Scholar 

  27. 27

    Holland, N. D. & Chen, J. Origin and early evolution of the vertebrates: new insights from advances in molecular biology, anatomy, and palaeontology. Bioessays 23, 142–151 (2001).

    CAS  PubMed  Google Scholar 

  28. 28

    Mallatt, J. & Chen, J. Fossil sister group of craniates: predicted and found. J. Morphol. 258, 1–31 (2003). The most detailed description of Yunnanozoan anatomy.

    PubMed  Google Scholar 

  29. 29

    Mallatt, J., Chen, J. & Holland, N. D. Comment on “A new species of ynnanozoan, with implications for deuterostome evolution”. Science 300, 1372 (2003).

    PubMed  Google Scholar 

  30. 30

    Shu, D. & Conway Morris, S. Response to Comment on “A new species of yunna-nozoan with implications for deuterostome evolution”. Science 300, 1372 (2003).

    CAS  Google Scholar 

  31. 31

    Shu, D.-G. et al. Primitive deuterostomes from the Chengjiang Lagerstätte (Lower Cambrian, China). Nature 414, 419–424 (2001).

    ADS  CAS  PubMed  Google Scholar 

  32. 32

    Gee, H. On being vetulicolian. Nature 414, 407–409 (2001).

    ADS  CAS  PubMed  Google Scholar 

  33. 33

    Caron, J.-B. Banffia constricta, a putative vetulicolid from the Middle Cambrian Burgess Shale. Trans. R. Soc. Edinb. Earth Sci. 96, 95–111 (2005).

    Google Scholar 

  34. 34

    Shu, D.-G., Conway Morris, S. & Zhang, X.-L. A Pikaia-like chordate from the Lower Cambrian of China. Nature 384, 157–158 (1996).

    ADS  CAS  Google Scholar 

  35. 35

    Shu, D.-G., Chen, L., Han, J. & Zhang, X. L. An Early Cambian tunicate from China. Nature 411, 472–473 (2001).

    ADS  CAS  PubMed  Google Scholar 

  36. 36

    Chen, J. Y. et al. The first tunicate from the early Cambrian of South China. Proc. Natl Acad. Sci. USA 100, 8314–8318 (2003).

    ADS  CAS  PubMed  Google Scholar 

  37. 37

    Ritchie, A. Ainiktozoon loganense Scourfield, a protochordate? From the Silurian of Scotland. Alcheringa 9, 117–142 (1985).

    Google Scholar 

  38. 38

    Van der Brugghen, W., Schram, F. R. & Martill, D. M. The fossil Ainiktozoon is an Arthropod. Nature 385, 589–590 (1997).

    ADS  CAS  Google Scholar 

  39. 39

    Shu, D.-G. et al. Lower Cambrian vertebrates from South China. Nature 402, 42–46 (1999).

    ADS  CAS  Google Scholar 

  40. 40

    Shu, D. G. et al. Head and backbone of the Early Cambrian vertebrate Haikouichthys. Nature 421, 526–529 (2003).

    ADS  CAS  PubMed  Google Scholar 

  41. 41

    Conway Morris, S. & Caron, J.-B. A primitive fish from the Cambrian of North America. Nature 512, 419–422 (2014).

    ADS  Google Scholar 

  42. 42

    Holmgren, N. & Stensiö, E. in Handbuch des Vergleichenden Anatomie der Wirbeltiere [in German] Vol. 4 (eds Bolk, L., Göppert, E., Kallius, E. & Lubosch, W.) 233–500 (Urban & Schwarzenberg, 1936).

    Google Scholar 

  43. 43

    Murdock, D. J. E. et al. The origin of conodonts and of vertebrate mineralized skeletons. Nature 502, 546–549 (2013).

    ADS  CAS  PubMed  Google Scholar 

  44. 44

    Briggs, D. E. G., Clarkson, E. N. K. & Aldridge, R. J. The conodont animal. Lethaia 20, 1–14 (1983).

    Google Scholar 

  45. 45

    Gabbott, S. E., Aldridge, R. J. & Theron, J. N. A giant conodont with preserved muscle tissue from the Upper Ordovician of South Africa. Nature 374, 800–803 (1994).

    ADS  Google Scholar 

  46. 46

    Aldridge, R. J., Briggs, D. E. G., Smith, M. P., Clarkson, E. N. K. & Clark, D. N. L. The anatomy of conodonts. Philos. Trans. R. Soc. Lond. B 340, 405–421 (1993).

    Google Scholar 

  47. 47

    Purnell, M. A. Large eyes and vision in conodonts. Lethaia 28, 187–188 (1995).

    Google Scholar 

  48. 48

    Donoghue, P. C. J. Growth and patterning in the conodont skeleton. Philos. Trans. R. Soc. Lond. B 353, 633–666 (1998).

    Google Scholar 

  49. 49

    Turner, S. et al. False teeth: conodont-vertebrate phylogenetic relationships revisited. Geodiversitas 32, 545–594 (2010).

    Google Scholar 

  50. 50

    Donoghue, P. C. J., Forey, P. L. & Aldridge, R. J. Conodont affinity and chordate phylogeny. Biol. Rev. Camb. Philos. Soc. 75, 191–251 (2000).

    CAS  PubMed  Google Scholar 

  51. 51

    Kreijsa, R. J., Bringas, P. & Slavkin, H. A neontological interpretation of conodont elements based on agnathan cyclostome tooth structure, function and development. Lethaia 23, 359–378 (1990).

    Google Scholar 

  52. 52

    Dzik, J. Conodont affinity of the enigmatic Carboniferous chordate Conopiscius. Lethaia 42, 31–38 (2009).

    Google Scholar 

  53. 53

    Goudemand, N., Orchard, M. J., Urdy, S., Bucher, H. & Tafforeau, P. Synchrotron-aided reconstruction of the conodont feeding apparatus and implications for the mouth of the first vertebrates. Proc. Natl Acad. Sci. USA 108, 8720–8724 (2011).

    ADS  CAS  PubMed  Google Scholar 

  54. 54

    Briggs, D. E. G. & Clarkson, E. N. K. An enigmatic chordate from the Lower Carboniferous Granton “shrimp-bed” of the Edinburgh district, Scotland. Lethaia 20, 107–115 (1987).

    Google Scholar 

  55. 55

    Aldridge, R. J. & Donoghue, P. C. J. in The Biology of Hagfishes (eds Jørgensen, J. M., Lomholt, J. P., Weber, R. E. & Malte, H.) 16–31 (Chapman and Hall, 1998).

    Google Scholar 

  56. 56

    Bardack, D. & Richardson, E. S. Jr. New agnathous fishes from the Pennsylvanian of Illinois. Fieldiana: Geology 33, 489–510 (1977).

    Google Scholar 

  57. 57

    Janvier, P. Early Vertebrates (Oxford Univ. Press, 1996). This text is a general overview of early vertebrate anatomy and relationships.

    Google Scholar 

  58. 58

    Bardack, D. in The Biology of Hagfishes (eds Jørgensen, J. M., Lomholt, J. P., Weber, R. E. & Malte, H.) 3–14 (Chapman and Hall, London, 1998).

    Google Scholar 

  59. 59

    White, E. I. Jamoytius kerwoodi, a new chordate from the Silurian of Lanarkshire. Geol. Mag. 83, 89–97 (1946).

    ADS  Google Scholar 

  60. 60

    Sansom, R. S., Freedman, K., Gabbott, S. E., Aldridge, R. J. & Purnell, M. A. Taphonomy and affinity of an enigmatic Silurian vertebrate, Jamoytius kerwoodi White. Palaeontology 53, 1393–1409 (2010).

    Google Scholar 

  61. 61

    Janvier, P. & Arsenault, M. The anatomy of Euphanerops longaevus Woodward, 1900, an anaspid-like jawless vertebrate from the Upper Devonian of Miguasha, Quebec, Canada. Geodiversitas 29, 143–216 (2007).

    Google Scholar 

  62. 62

    Janvier, P., Desbiens, S. & Willett, J. A. & Arsenault, M. Lamprey-like gills in a gnatho-stome-related Devonian jawless vertebrate. Nature 440, 1183–1185 (2006).

    ADS  CAS  PubMed  Google Scholar 

  63. 63

    Blom, H. New birkeniid anaspid from the Lower Devonian of Scotland and its phylogenetic implications. Palaeontology 55, 641–652 (2012).

    Google Scholar 

  64. 64

    Sansom, R. S., Gabbott, S. E. & Purnell, M. A. Unusual anal fin in a Devonian jawless vertebrate reveals complex origins of paired appendages. Biol. Lett. 9, 20130002 (2013).

    PubMed  PubMed Central  Google Scholar 

  65. 65

    Janvier, P. Modern look for ancient lamprey. Nature 443, 921–924 (2006).

    ADS  CAS  PubMed  Google Scholar 

  66. 66

    Sollas, W. J. & Sollas, I. B. An account of the Devonian fish, Palaeospondylus gunni, Traquair. Phil. Trans. R. Soc. Lond. B 196, 267–294 (1904).

    ADS  Google Scholar 

  67. 67

    Moy Thomas, J. A. The Devonian fish Palaeospondylus gunni Traquair. Philos. Trans. R. Soc. Lond. B 230, 391–413 (1940).

    ADS  Google Scholar 

  68. 68

    Johanson, Z., Kearsley, A., Den Blaauwen, J., Newman, M. & Smith, M. M. No bone about it: an enigmatic Devonian fossil reveals a new skeletal framework – a potential loss of gene regulation. Semin. Cell Dev. Biol. 21, 414–423 (2010).

    PubMed  Google Scholar 

  69. 69

    Oisi, Y., Ota, K. G., Fujimoto, S. & Kuratani, S. S. Development of the chondrocranium in hagfishes, with special reference to the early evolution of vertebrates. Zoolog. Sci. 30, 944–961 (2013).

    PubMed  Google Scholar 

  70. 70

    Janvier, P. All vertebrates do have vertebrae. Curr. Biol. 21, R661–R663 (2011).

    CAS  PubMed  Google Scholar 

  71. 71

    Sanchez, S., Ahlberg, P. E., Trinajstic, K. M., Mirone, A. & Tafforeau, P. Three-dimensional synchrotron virtual palaeohistology: A new insight into the world of fossil bone microstructure. Microsc. Microanal. 18, 1095–1105 (2012).

    ADS  CAS  PubMed  Google Scholar 

  72. 72

    Sansom, I. J., Donoghue, P. C. J. & Albanesi, G. Histology and affinity of the earliest armoured vertebrate. Biol. Lett. 1, 446–449 (2005).

    PubMed  PubMed Central  Google Scholar 

  73. 73

    Sire, J.-Y., Donoghue, P. C. J. & Vikaryous, M. K. Origin and evolution of the integumentary skeleton in non-tetrapod vertebrates. J. Anat. 214, 409–440 (2009). This is an updated review of exoskeletal hard tissues in early fishes.

    PubMed  PubMed Central  Google Scholar 

  74. 74

    Wang, N.-Z., Donoghue, P. C. J., Smith, M. M. & Sansom, I. J. Histology of the galeaspid dermoskeleton and endoskeleton, and the origin and early evolution of the vertebrate cranial endoskeleton. J. Vert. Paleontol. 25, 745–756 (2005).

    Google Scholar 

  75. 75

    Bockelie, T. G. & Fortey, R. A. An early Ordovician vertebrate. Nature 260, 36–38 (1976).

    ADS  Google Scholar 

  76. 76

    Repetski, J. E. A fish from the Upper Cambrian of North America. Science 200, 529–531 (1978).

    ADS  CAS  PubMed  Google Scholar 

  77. 77

    Smith, M. P., Sansom, I. J. & Repetski, J. E. Histology of the first fish. Nature 380, 702–704 (1996).

    ADS  CAS  Google Scholar 

  78. 78

    Smith, M. P., Sansom, I. J. & Cochrane, K. D. in Major Events in Early Vertebrate Evolution (ed. Ahlberg, P. E.) 67–84 (Taylor and Francis, 2001).

    Google Scholar 

  79. 79

    Young, G. C., Karatayute-Talimaa, V. N. & Smith, M. M. A possible Late Cambrian vertebrate from Australia. Nature 383, 810–812 (1996).

    ADS  CAS  Google Scholar 

  80. 80

    Sansom, I. J., Smith, M. M. & Smith, M. P. in Major Events in Early Vertebrate Evolution (ed. Ahlberg, P. E.) 156–171 (Taylor and Francis, 2001).

    Google Scholar 

  81. 81

    Smith, M. M. & Sansom, I. J. Exoskeletal micro-remains of an Ordovician fish from the Harding Sandstone of Colorado. Palaeontology 40, 645–658 (1997).

    Google Scholar 

  82. 82

    Young, G. C. Ordovician microvertebrate remains from the Amadeus Basin, central Australia. J. Vert. Paleontol. 17, 1–25 (1997).

    Google Scholar 

  83. 83

    Denison, R. H. Ordovician vertebrates from Western United States. Fieldiana: Geology 16, 131–192 (1967).

    Google Scholar 

  84. 84

    Sansom, I. J., Haines, P. W., Andreev, P. & Nicoll, R. S. A new pteraspidomorph from the Nibil Formation (Katian, Late Ordovician) of the Canning Basin, Western Australia. J. Vert. Paleontol. 33, 764–769 (2013).

    Google Scholar 

  85. 85

    Pradel, A., Sansom, I. J., Gagnier, P.-Y., Cespedes, R. & Janvier, P. The tail of the Ordovician fish Sacabambaspis. Biol. Lett. 3, 72–75 (2007).

    PubMed  Google Scholar 

  86. 86

    Janvier, P. in Recent Advances in the Origin and Early Radiation of Vertebrates (eds Arratia, G., Wilson, M. V. H. & Cloutier, R.) 29–52 (Pfeil, 2004).

    Google Scholar 

  87. 87

    Purnell, M. A. Feeding in extinct jawless heterostracan fishes and testing scenarios of early vertebrate evolution. Proc. R. Soc. 269, 83–88 (2002).

    Google Scholar 

  88. 88

    Janvier, P. in Major Events in Early Vertebrate Evolution (ed. Ahlberg, P. E.) 172–186 (Taylor and Francis, 2001).

    Google Scholar 

  89. 89

    Janvier, P., Arsenault, M. & Desbiens, S. Calcified cartilage in the paired fins of the osteostracan Escuminaspis laticeps (Traquair 1880), from the Late Devonian of Miguasha (Québec, Canada), with a consideration of the early evolution of the pectoral fin endoskeleton in vertebrates. J. Vert. Paleontol. 24, 773–779 (2004).

    Google Scholar 

  90. 90

    Donoghue, P. C. J. & Smith, M. P. The anatomy of Turinia pagei (Powrie) and the phylogenetic status of the Thelodonti. Trans. R. Soc. Edinb. Earth Sci. 92, 15–37 (2001).

    Google Scholar 

  91. 91

    Märss, T. & Wilson, M. V. H. Buccopharyngo-branchial denticles of Phlebolepis elegans Pander (Thelodonti, Agnatha). J. Vert. Paleontol. 23, 601–612 (2008).

    Google Scholar 

  92. 92

    Stensiö, E. A. The Devonian and Downtonian vertebrates of Spitsbergen. 1. Family Cephalaspidae. Skr. Svalbard Ishav. 12, 1–391 (1927).

    Google Scholar 

  93. 93

    Janvier, P. Early jawless vertebrates and cyclostome origins. Zoolog. Sci. 25, 1045–1056 (2008).

    PubMed  Google Scholar 

  94. 94

    Gai, Z., Donoghue, P. C. J., Zhu, M., Janvier, P. & Stampanoni, M. Fossil jawless fish from China foreshadows early jawed vertebrate anatomy. Nature 476, 324–327 (2011).

    ADS  CAS  PubMed  Google Scholar 

  95. 95

    Patterson, C. Significance of fossils in determining evolutionary relationships. Annu. Rev. Ecol. Syst. 12, 195–223 (1981).

    Google Scholar 

  96. 96

    Jefferies, R. P. S. The Ancestry of the Vertebrates (British Museum (Natural History), 1996). This is an extensive account of the calcichordate theory.

    Google Scholar 

  97. 97

    Gee, H. Before the Backbone: Views on the Origin of the Vertebrates (Chapman & Hall, 1996). This text is a review of fossil-based theories about the origin of vertebrates.

    Google Scholar 

  98. 98

    Delsuc, F., Brinkmann, H., Chourrout, D. & Philippe, H. Tunicate and not cephalochordate are the closest living relatives of vertebrates. Nature 439, 965–968 (2006).

    ADS  CAS  PubMed  Google Scholar 

  99. 99

    Løvtrup, S. The Phylogeny of Vertebrata (Wiley, 1977).

    Google Scholar 

  100. 100

    Dupret, V., Sanchez, S., Goujet, D., Tafforeau, P. & Ahlberg, P. E. A primitive placoderm sheds light on the origin of the jawed vertebrate face. Nature 507, 500–503 (2014).

    ADS  CAS  PubMed  Google Scholar 

Download references


I thank M. Friedman, M. Brazeau, P. Donoghue, R. Sansom and J. Keating for their helpful discussions. I also thank all the authors who allowed me to adapt their published figures.

Author information



Corresponding author

Correspondence to Philippe Janvier.

Ethics declarations

Competing interests

The author declares no competing financial interests.

Additional information

Reprints and permissions information is available at

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Janvier, P. Facts and fancies about early fossil chordates and vertebrates. Nature 520, 483–489 (2015).

Download citation


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.


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