Arratia, G., Schultze, H.-P. & Casciotta, J. Vertebral column and associated elements in dipnoans and comparison with other fishes: development and homology. J. Morphol. 250, 101–172 (2001). Article PubMed CAS Google Scholar Coates, M. The Devonian tetrapod Acanthostega gunnari Jarvik: postcranial anatomy, basal tetrapod interrelationships and patterns of skeletal evolution. Trans. R. Soc. Edinb. 87,
Arratia, G., Schultze, H.-P. & Casciotta, J. Vertebral column and associated elements in dipnoans and comparison with other fishes: development and homology. J. Morphol. 250, 101–172 (2001).
Google Scholar
Coates, M. The Devonian tetrapod Acanthostega gunnari Jarvik: postcranial anatomy, basal tetrapod interrelationships and patterns of skeletal evolution. Trans. R. Soc. Edinb. 87, 363–421 (1996).
Google Scholar
Hitchcock, E. C. A functional interpretation of the anterior-most vertebrae and skull of Eusthenopteron. Bull. Mus. Natl Hist. Nat. 4, 269–285 (1995).
Long, J. A. & Gordon, M. S. The greatest step in vertebrate history: a paleobiological review of the fish-tetrapod transition. Physiol. Biochem. Zool. 77, 700–719 (2004).
Google Scholar
Ericsson, R., Knight, R. & Johanson, Z. Evolution and development of the vertebrate neck. J. Anat. 222, 67–78 (2013).
Google Scholar
Hirasawa, T. & Kuratani, S. Evolution of the vertebrate skeleton: morphology, embryology, and development. Zool. Lett. 1, 2 (2015).
Google Scholar
Coates, M. I., Ruta, M. & Friedman, M. Ever since Owen: changing perspectives on the early evolution of tetrapods. Annu. Rev. Ecol. Evol. Syst. 39, 571–592 (2008).
Google Scholar
Clack, J. A. Gaining Ground: The Origin and Evolution of Tetrapods (Indiana Univ. Press, 2012).
Shubin, N., Daeschler, E. B. & Jenkins, F. A. Jr. Origin of the tetrapod neck and shoulder. In Great Transformations in Vertebrate Evolution (eds Dial, K. P. et al.) 63–76 (Univ. Chicago Press, 2015).
Korneisel, D. E. & Maddin, H. C. Review of the tetrapod skull–neck boundary: implications for the evolution of the atlas–axis complex. Biol. Rev. 100, 2435–2470 (2025).
Google Scholar
Pierce, S. E., Clack, J. A. & Hutchinson, J. R. Three-dimensional limb joint mobility in the early tetrapod Ichthyostega. Nature 486, 523–526 (2012).
Google Scholar
Coates, M. I. & Ruta, M. Skeletal changes in the transition from fins to limbs. In Fins into Limbs: Evolution, Development, and Transformation (ed. Hall, B. K.) 15–38 (Univ. Chicago Press, 2007).
Standen, E. M., Du, T. Y. & Larsson, H. C. E. Developmental plasticity and the origin of tetrapods. Nature 513, 54–58 (2014).
Google Scholar
Clarac, F., Cornille, A., Bijl, S. & Sanchez, S. Tetrapod terrestrialisation: a weight-bearing potential already present in the humerus of the stem-tetrapod fish Eusthenopteron foordi. Preprint at bioRxiv https://doi.org/10.1101/2024.02.09.579723 (2024).
Miyashita, T. et al. Novel assembly of a head–trunk interface in the sister group of jawed vertebrates. Nature 645, 686–691 (2025).
Google Scholar
Kuratani, S. Spatial distribution of postotic crest cells defines the head/trunk interface of the vertebrate body: embryological interpretation of peripheral nerve morphology and evolution of the vertebrate head. Anat. Embryol. 195, 1–13 (1996).
Google Scholar
Kuo, B. R. & Erickson, C. A. Vagal neural crest cell migratory behavior: a transition between the cranial and trunk crest. Dev. Dyn. 240, 2084–2100 (2011).
Google Scholar
Kuratani, S., Kusakabe, R. & Hirasawa, T. The neural crest and evolution of the head/trunk interface in vertebrates. Dev. Biol. 444, S60–S66 (2018).
Google Scholar
Martik, M. L. et al. Evolution of the new head by gradual acquisition of neural crest regulatory circuits. Nature 574, 675–678 (2019).
Google Scholar
Lescroart, F. et al. Clonal analysis reveals a common origin between nonsomite-derived neck muscles and heart myocardium. Proc. Natl Acad. Sci. USA 112, 1446–1451 (2015).
Google Scholar
Adachi, N., Bilio, M., Baldini, A. & Kelly, R. G. Cardiopharyngeal mesoderm origins of musculoskeletal and connective tissues in the mammalian pharynx. Development 147, dev185256 (2020).
Google Scholar
Swedlund, B. & Lescroart, F. Cardiopharyngeal progenitor specification: multiple roads to the heart and head muscles. Cold Spring Harb. Perspect. Biol. 12, a036731 (2020).
Google Scholar
Lours-Calet, C. et al. Evolutionarily conserved morphogenetic movements at the vertebrate head–trunk interface coordinate the transport and assembly of hypopharyngeal structures. Dev. Biol. 390, 231–246 (2014).
Google Scholar
Oisi, Y., Fujimoto, S., Ota, K. G. & Kuratani, S. On the peculiar morphology and development of the hypoglossal, glossopharyngeal and vagus nerves and hypobranchial muscles in the hagfish. Zool. Lett. 1, 6 (2015).
Google Scholar
Tada, M. N. & Kuratani, S. Evolutionary and developmental understanding of the spinal accessory nerve. Zool. Lett. 1, 4 (2015).
Google Scholar
Matsuoka, T. et al. Neural crest origins of the neck and shoulder. Nature 436, 347–355 (2005).
Google Scholar
Shubin, N. H., Daeschler, E. B. & Jenkins, F. A. Jr. The pectoral fin of Tiktaalik roseae and the origin of the tetrapod limb. Nature 440, 764–771 (2006).
Google Scholar
Camp, A. L. A neck-like vertebral motion in fish. Proc. R. Soc. B 288, 20211091 (2021).
Google Scholar
Jones, M. E. H. et al. The biomechanical role of the chondrocranium and the material properties of cartilage. Vertebr. Zool. 70, 699–715 (2020).
Andrews, S. M. & Westoll, T. S. IX.—The postcranial skeleton of Eustenopteron foordi Whiteaves. Trans. R. Soc. Edinb. 68, 207–329 (1970).
Google Scholar
Andrews, S. M. & Westoll, T. S. XII.—The Postcranial skeleton of rhipidistian fishes excluding Eusthenopteron. Trans. R. Soc. Edinb. 68, 391–489 (1970).
Google Scholar
Ahlberg, P. E., Clack, J. A. & Blom, H. The axial skeleton of the Devonian tetrapod Ichthyostega. Nature 437, 137–140 (2005).
Google Scholar
Sumida, S. S. & Lombard, R. E. The atlas-axis complex in the late Paleozoic genus Diadectes and the characteristics of the atlas-axis complex across the amphibian to amniote transition. J. Paleontol. 65, 973–983 (1991).
Google Scholar
Leprévost, A., Azaïs, T., Trichet, M. & Sire, J.-Y. Vertebral development and ossification in the Siberian sturgeon (Acipenser baerii), with new insights on bone histology and ultrastructure of vertebral elements and scutes. Anat. Rec. 300, 437–449 (2017).
Google Scholar
Long, J. H. Jr. Morphology, mechanics, and locomotion: the relation between the notochord and swimming motions in sturgeon. Environ. Biol. Fish. 44, 199–211 (1995).
Google Scholar
Long, J. H. Jr, Koob-Emunds, M., Sinwell, B. & Koob, T. J. The notochord of hagfish Myxine glutinosa: visco-elastic properties and mechanical functions during steady swimming. J. Exp. Biol. 205, 3819–3831 (2002).
Google Scholar
Kryvi, H. et al. The notochord in Atlantic salmon (Salmo salar L.) undergoes profound morphological and mechanical changes during development. J. Anat. 231, 639–654 (2017).
Google Scholar
Adams, D. S., Keller, R. & Koehl, M. A. R. The mechanics of notochord elongation, straightening and stiffening in the embryo of Xenopus laevis. Development 110, 115–130 (1990).
Google Scholar
Schnell, N. K., Britz, R. & Johnson, G. D. New insights into the complex structure and ontogeny of the occipito-vertebral gap in barbeled dragonfishes (Stomiidae, Teleostei). J. Morphol. 271, 1006–1022 (2010).
Google Scholar
Jarvik, E. Structure of a Devonian fish: Eusthenopteron foordi. In Basic Structure and Function of Vertebrates Vol. 1, 99–194 (Academic Press, 1980).
Stewart, T. A. et al. The axial skeleton of Tiktaalik roseae. Proc. Natl Acad. Sci. USA 121, e2316106121 (2024).
Google Scholar
Otoo, B. K. A., Bolt, J. R., Lombard, R. E., Angielczyk, K. D. & Coates, M. I. The postcranial anatomy of Whatcheeria deltae and its implications for the family Whatcheeriidae. Zool. J. Linn. Soc. 193, 700–745 (2021).
Google Scholar
Godfrey, S. J. The postcranial skeletal anatomy of the carboniferous tetrapod Greererpeton burkemorani Romer, 1969. Phil. Trans. R. Soc. B 323, 75–133 (1989).
Google Scholar
Case, E. C. A Revision of the Amphibia and Pisces of the Permian of North America (Carnegie Institution of Washington, 1911).
Google Scholar
Case, E. C. Description of a Collection of Associated Skeletons of Trimerorhachis (Univ. Michigan Press, 1935).
Shishkin, M. A. Evolution of the cervical vertebrae in temnospondyl amphibians and differentiation of the early tetrapods. Paleontol. J. 34, 534–546 (2000).
Pawley, K. The postcranial skeleton of Trimerorhachis insignis Cope, 1878 (Temnospondyli: Trimerorhachidae): a plesiomorphic temnospondyl from the Lower Permian of North America. J. Paleontol. 81, 873–894 (2007).
Google Scholar
Molnar, J. L., Pierce, S. E., Bhullar, B.-A. S., Turner, A. H. & Hutchinson, J. R. Morphological and functional changes in the vertebral column with increasing aquatic adaptation in crocodylomorphs. R. Soc. Open Sci. 2, 150439 (2015).
Google Scholar
Daeschler, E. B., Shubin, N. H. & Jenkins, F. A. Jr. A Devonian tetrapod-like fish and the evolution of the tetrapod body plan. Nature 440, 757–763 (2006).
Google Scholar
Coates, M. I. & Clack, J. A. Fish-like gills and breathing in the earliest known tetrapod. Nature 352, 234–236 (1991).
Google Scholar
Hohn-Schulte, B., Preuschoft, H., Witzel, U. & Distler-Hoffmann, C. Biomechanics and functional preconditions for terrestrial lifestyle in basal tetrapods, with special consideration of Tiktaalik roseae. Hist. Biol. 25, 167–181 (2013).
Google Scholar
VanBuren, C. S. & Evans, D. C. Evolution and function of anterior cervical vertebral fusion in tetrapods. Biol. Rev. 92, 608–626 (2017).
Google Scholar
Boisvert, C. A., Mark-Kurik, E. & Ahlberg, P. E. The pectoral fin of Panderichthys and the origin of digits. Nature 456, 636–638 (2008).
Google Scholar
Stewart, T. A. et al. Fin ray patterns at the fin-to-limb transition. Proc. Natl Acad. Sci. USA 117, 1612–1620 (2020).
Google Scholar
Strong, C. R. C., Bishop, P. J., Hutchinson, J. R. & Pierce, S. E. Digital volumetric modeling reveals unique body plan experimentation in the Devonian tetrapod Ichthyostega. iScience 28, 112486 (2025).
Google Scholar
Molnar, J. L., Hutchinson, J. R., Diogo, R., Clack, J. A. & Pierce, S. E. Evolution of forelimb musculoskeletal function across the fish-to-tetrapod transition. Sci. Adv. 7, eabd7457 (2021).
Google Scholar
King, H. M., Shubin, N. H., Coates, M. I. & Hale, M. E. Behavioral evidence for the evolution of walking and bounding before terrestriality in sarcopterygian fishes. Proc. Natl Acad. Sci. USA 108, 21146–21151 (2011).
Google Scholar
Pierce, S. E., Hutchinson, J. R. & Clack, J. A. Historical perspectives on the evolution of tetrapodomorph movement. Integr. Comp. Biol. 53, 209–223 (2013).
Google Scholar
Jones, K. E., Brocklehurst, R. J. & Pierce, S. E. AutoBend: an automated approach for estimating intervertebral joint function from bone-only digital models. Integr. Org. Biol. 3, obab026 (2021).
Google Scholar
Werneburg, I. et al. Modeling neck mobility in fossil turtles. J. Exp. Zool. 324, 230–243 (2015).
Google Scholar
Krings, M., Nyakatura, J. A., Boumans, M. L. L. M., Fischer, M. S. & Wagner, H. Barn owls maximize head rotations by a combination of yawing and rolling in functionally diverse regions of the neck. J. Anat. 231, 12–22 (2017).
Google Scholar
Lemberg, J. B., Daeschler, E. B. & Shubin, N. H. The feeding system of Tiktaalik roseae: an intermediate between suction feeding and biting. Proc. Natl Acad. Sci. USA 118, e2016421118 (2021).
Google Scholar
Clack, J. A. The neurocranium of Acanthostega gunnari Jarvik and the evolution of the otic region in tetrapods. Zool. J. Linn. Soc. 122, 61–97 (1998).
Porro, L. B., Rayfield, E. J. & Clack, J. A. Descriptive anatomy and three-dimensional reconstruction of the skull of the early tetrapod Acanthostega gunnari Jarvik, 1952. PLoS ONE 10, e0118882 (2015).
Rueden, C. T. et al. ImageJ2: ImageJ for the next generation of scientific image data. BMC Bioinform. 18, 529 https://doi.org/10.1186/s12859-017-1934-z (2017).
Google Scholar
Blender: a 3D modelling and rendering package v.4.0 http://www.blender.org (Stichting Blender Foundation, 2018).
Schindelin, J. et al. Fiji: an open-source platform for biological-image analysis. v1.54p. Nat. Methods 9, 676–682 (2012).
Google Scholar
R: a language and environment for statistical computing v.4.3.3 https://www.R-project.org (R Foundation for Statistical Computing, 2020).
RStudio: integrated development for R v.2023.12.1 http://www.rstudio.com (RStudio, 2019).
Donatelli, C. M. CrshR. GitHub https://github.com/CDonatelli/CrshR (2021).
Donatelli, C. M. Korneisel_TetNecks_2026. GitHub https://github.com/CDonatelli/Korneisel_TetNecks_2026 (2026).
Wickham, H. ggplot2: elegant graphics for data analysis. R v.4.0.1 https://ggplot2.tidyverse.org (2016).
Arnold, J. ggthemes: extra themes, scales and geoms for ‘ggplot2’. R v.5.1.0.9000 https://github.com/jrnold/ggthemes (2025).
Wickham, H., Hester, J. & Bryan, J. readr: read rectangular text data. R v.2.1.5 https://readr.tidyverse.org (2024).
Wickham, H., François, R., Henry, L., Müller, K. & Vaughan, D. dplyr: a grammar of data manipulation. R v.1.1.4 https://dplyr.tidyverse.org (2025).
Neuwirth, E. RColorBrewer: ColorBrewer Palettes. R v.1.1-3 https://CRAN.R-project.org/package=RColorBrewer (2022).
Hibbeler, R. C. Mechanics of Materials 8th edn (Pearson Prentice Hall, 2010).
Wickham, H., Hester, J. & Bryan, J. readr: read rectangular text data. GitHub https://github.com/tidyverse/readr (2024).
Rospars, J.-P. & Meyer-Vernet, N. Force per cross-sectional area from molecules to muscles: a general property of biological motors. R. Soc. Open Sci. 3, 160313 (2016).
Google Scholar
Gartner, S. M. et al. Suction feeding of West African lungfish (Protopterus annectens): an XROMM analysis of jaw mechanics, cranial kinesis, and hyoid mobility. Biol. Open 11, bio059447 (2022).
Google Scholar
Donatelli C. M. Korneisel_TetNecks26. figshare https://doi.org/10.6084/m9.figshare.33552199 (2026).
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