Cervical ligament systems in sauropod dinosaurs: what support is there?
DOI:
https://doi.org/10.18435/vamp29412Keywords:
sauropod dinosaur, anatomy, neck, nuchal ligament, supraspinous ligament, interspinal elastic ligament, osteohistology, micro-CT, functional morphologyAbstract
Sauropod dinosaurs, such as Diplodocus and Dicraeosaurus, have been the subject of numerous
hypotheses about what ligamentous structures could have aided in lifting and supporting their long necks. Because the supportive tissues rarely fossilize, palaeontologists historically have relied on assumptions and on presumed osteological correlates, such as rugosities, on cervical vertebrae to infer their nature. Based on comparisons with extant animals, options for supportive cervical ligaments in sauropods include mammal-style nuchal ligaments, avian-style interlaminar elastic ligaments, reptilian-style supraspinal ligaments, or some combination thereof. This study tested for the presence of a mammal-style nuchal ligament using histology and micro-computed tomography of cervical hemispinous processes of Apatosaurus and Diplodocus, as well as the examination of gross morphological features of the cervical vertebrae of Apatosaurus, Diplodocus, and Camarasaurus. A non-uniform bone orientation in the thin sections from a hemispinous processes of Diplodocus and from micro-CT imaging of a hemispinous process of Apatosaurus suggests that a dorsally or dorsolaterally positioned supraspinal ligament, rather than a mammal-like nuchal ligament, attached to the distal tips of the spines. Additionally, initial observations of pseudospinous tubercula in Diplodocus and Apatosaurus suggests that they also possessed interlaminar elastic ligaments in at least portions of their necks. Whether or not such ligaments were the sole means of cervical support and whether or not such ligaments were capable of providing entirely passive (non- or minimally muscle aided) neck support remain unclear. These findings could be incorporated into future models of sauropod neck mobility and further the understanding of sauropod feeding styles and mechanics.
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References
Aaron, J.E. 2012. Periosteal Sharpey’s fibers: a novel bone matrix regulatory system? Frontiers in Endocrinology 3(98). DOI 10.3389/fendo.2012.00098
Apostolaki, N.E., E.J. Rayfield, and P.M. Barrett. 2015. Osteological and soft-tissue evidence for pneumatization in the cervical column of the ostrich (Struthio camelus) and observations on the vertebral columns of non-volant, semi-volant and semi-aquatic birds. PLoS ONE 10(12):e0143834. DOI 10.1371/journal.pone.0143834
Apostolakos, J., T.J. Durant, C.R. Dwyer, R.P. Russell, J.H. Weinreb, F. Alaee, K. Beitzel, M.B. McCarthy, M.P. Cote, and A.D. Mazzocca. 2014. The enthesis: a review of the tendon-to-bone insertion. Muscles, Ligaments and Tendons Journal 4(3):333–342. DOI 10.32098/mltj.03.2014.12
Bajpai, S., D. Datta, P. Pandey, T. Ghosh, K. Kumar, and D. Bhattacharya. 2023. Fossils of the oldest diplodocoid dinosaur suggest India was a major centre for neosauropod radiation. Scientific Reports 13:12680. DOI 10.1038/s41598-023-39759-2
Barkow, H.C.L. 1856. Syndesmologie der Vögel. Königlichen Universitdit Universität zu Breslau. Ferdinand Hirt’s Buchhandlung, Breslau, Germany.
Baumel, J.J. and R.J. Raikow. 1993. Arthrologia; pp. 133–187 in J.J. Baumel (ed.), Handbook of Avian Anatomy: Nomina Anatomica Avium, 2nd Ed. Nuttall Ornithological Club, Cambridge, MA.
Bayrak, E. and P.Y. Huri. 2018. Engineering musculoskeletal tissue interfaces. Frontiers in Materials 5(24). DOI 10.3389/fmats.2018.00024
Bennett, M.B. and R. McN. Alexander. 1987. Properties and function of extensible ligaments in the necks of turkeys (Meleagris gallopavo) and other birds. Journal of Zoology 212(2):275–281. DOI 10.1111/j.1469-7998.1987.tb05990.x
Bentolila, V., T.M. Boyce, D.P. Fyhrie, R. Drumb, T.M. Skerry, and M.B. Schaffler. 1998. Intracortical remodeling in adult rat long bones after fatigue loading. Bone 23(3):275–281. DOI 10.1016/S8756-3282(98)00104-5
Boas, J.E.V. 1929. Biologisch-anatomische Studien über den Hals der Vögel. Det Kongelige Danske Videnskabernes Selskabs Skrifter, 9th Series: Naturvidenskabelig og Mathematisk Afdeling 1:105–222
Böhmer, C., J. Prevoteau, O. Duriez, and A. Abourachid. 2020. Gulper, ripper and scrapper: anatomy of the neck in three species of vultures. Journal of Anatomy 236(4):701–723. DOI 10.1111/joa.13129
Boisvert, C.D. 2024. The osteological neutral pose of the neck of an apatosaurine sauropod based on virtual and physical models. Master’s thesis. Department of Geological Sciences. Brigham Young University. Provo, Utah. 50 pp.
Cerda, I.A., G.A. Casal, R.D. Martinez and L.M. Ibiricu. 2015. Histological evidence for a supraspinous ligament in sauropod dinosaurs. Royal Society Open Science 2:150369. DOI 10.1098/rsos.150369
Cerda, I.A., F.E. Novas, J.L. Carballido, and L. Salgado. 2022. Osteohistology of the hyperelongate hemispinous processes of Amargasaurus cazaui (Dinosauria: Sauropoda): implications for soft tissue reconstruction and functional significance. Journal of Anatomy 240(6):1005–1019. DOI 10.1111/joa.13659
Chang, B. and X. Liu. 2022. Osteon: structure, turnover, and regeneration. Tissue Engineering Part B: Reviews 28(2):261–278. DOI 10.1089/ten.TEB.2020.0322
Charig, A.J. 1980. A diplodocid sauropod from the Lower Cretaceous of England; pp. 231–244 in L.L. Jacobs (ed.), Aspects of Vertebrate History: Essays in Honor of Edwin Harris Colbert. Museum of Northern Arizona Press, Flagstaff, AZ.
Christian, A., G. Peng, T. Sekiya, Y. Ye, M.G. Wulf, and T. Steuer. 2013. Biomechanical reconstructions and selective advantages of neck poses and feeding strategies of sauropods with the example of Mamenchisaurus youngi. PLoS ONE 8(10):e71172. DOI 10.1371/journal.pone.0071172
Cong, L., L. Hou, X. Wu, and J. Hou. 1998. The Gross Anatomy of Alligator sinensis Fauvel. Science Press, Beijing. 388 pp.
Conti, S. 2024. Biomechanics of dinosaurs studies by means of engineering techniques. Doctoral dissertation. Geology Program. NOVA University. Lisbon, Portugal. 153 pp.
Coria, R.A., G.J. Windholz, F. Ortega, and P.J. Currie. 2019. A new dicraeosaurid sauropod from the Lower Cretaceous (Mulichinco Formation, Valanginian, Neuquén Basin) of Argentina. Cretaceous Research 93:33–48. DOI 10.1016/j.cretres.2018.08.019
Cuccu, A., T. Calderón, B. Azanza, and D. Demiguel. 2024. Hard tissue thin-sectioning techniques in vertebrate paleohistology: review, synthesis and improvements. Methods in Ecology and Evolution 16(1):66–83. DOI 10.1111/2041-210X.14469
Currey, J. 1984. The Mechanical Adaptations of Bones. Princeton University Press, Princeton, New Jersey. 294 pp.
Dimery, N.J., R. Mc.N. Alexander, and K.A. Deyst. 1985. Mechanics of the ligamentum nuchae of some artiodactyls. Journal of Zoology 206(3):341–351. DOI 10.1111/j.1469-7998.1985.tb05663.x
Dodson, P. and J.D. Harris. 2001. Necks of sauropod dinosaurs: support for a nuchal ligament? Journal of Morphology 248:224.
du Plessis, A., C. Broeckhoven, A. Guelpa, and S.G. le Roux. 2017. Laboratory x-ray micro-computed tomography: a user guideline for biological samples. Gigascience 6(6):1–11. DOI 10.1093/gigascience/gix027
Dzemski, G. and A. Christian. 2007. Flexibility along the neck of the ostrich (Struthio camelus) and consequences for the reconstruction of dinosaurs with extreme neck length. Journal of Morphology 268(8):701–714. DOI 10.1002/jmor.10542
Enlow, D.H. 1962. Functions of the Haversian system. American Journal of Anatomy 110(3):203–331. DOI 10.1002/aja.1001100305
Frey, E. 1988. Anatomie des Körperstammes von Alligator mississippiensis Daudin. Stuttgarter Beiträge zur Naturkunde Serie A Biologie 424:1–106.
Gallina, P.A., S. Apesteguía, J.I. Canale, and A. Haluza. 2019. A new long-spined dinosaur from Patagonia sheds light on sauropod defense system. Scientific Reports 9:1392. DOI 10.1038/s41598-018-37943-3
Gellman, K.S. and J.E.A. Bertram. 2002. The equine nuchal ligament 2: passive dynamic energy exchange in locomotion. Veterinary and Comparative Orthopaedics and Traumatology 15(1):7–14. DOI 10.1055/s-0038-1632706
Gilmore, C.W. 1936. Osteology of Apatosaurus with special reference to specimens in the Carnegie Museum. Memoirs of the Carnegie Museum 11(4):175–301.
Graff, V.I., M.J. Wedel, and M.P. Taylor. 2012. Evaluating hypotheses of neck support in sauropod dinosaurs. CalPaleo, 2012 Meeting Proceedings, p. 9.
Harris, J.D. 2006. The axial skeleton of the dinosaur Suuwassea emilieae (Sauropoda: Flagellicaudata) from the Upper Jurassic Morrison Formation of Montana, USA. Palaeontology 49(5):1091–1121. DOI 10.1111/j.1475-4983.2006.00577.x
Harris, J.D. 2024. What exactly is a nuchal ligament and who exactly has one? Vertebrate Anatomy Morphology Palaeontology 12(1):59–80. DOI 10.18435/vamp29405
Hatcher, J.B. 1901. Diplodocus (Marsh): its osteology, taxonomy, and probable habits with a restoration of the skeleton. Memoirs of the Carnegie Museum 1(1): 1–90.
Hipsley, C.A., R. Aguilar, J.R. Black, and S.A. Hocknull. 2020. High-throughput microCT scanning of small specimens: preparation, packing, parameters and post-processing. Scientific Reports 10:13863. DOI 10.1038/s41598-020-70970-7
Holland, W.J. 1924. Description of the type of Uintasaurus douglassi Holland. Annals of the Carnegie Museum 15(2–3):119–138.
Horner, J.R., H.N. Woodward, and A.M. Bailleul. 2016. Mineralized tissues in dinosaurs interpreted as having formed through metaplasia: a preliminary evaluation. Comptes Rendus Palevol 15(1–2):176–196. DOI 10.1016/j.crpv.2015.01.006
Ikejiri, T., P.S. Watkins, and D.J. Gray. 2006. Stratigraphy, sedimentology, and taphonomy of a quarry from the upper Morrison Formation of Thermopolis, central Wyoming; pp. 39–45 in J.R. Foster and S.G. Lucas (eds.), Paleontology and Geology of the Upper Jurassic Morrison Formation. New Mexico Museum of Natural History and Science Bulletin 36.
Janensch, W. 1929. Die Wirbelsäule der Gattung Dicraeosaurus. Palaeontographica Suppl. 8, Part 1, 2:37–133.
Klein, N., K. Remes, C.T. Gee, and P.M. Sander. (eds.) 2011. Biology of the Sauropod Dinosaurs: Understanding the Life of Giants. Indiana University Press, Bloomington, IN.
Leanza, H.A., S. Apesteguı́a, F.E. Novas, and M.S. de la Fuente. 2004. Cretaceous terrestrial beds from the Neuquén Basin (Argentina) and their tetrapod assemblages. Cretaceous Research 25(1):61–87. DOI 10.1016/j.cretres.2003.10.005
Mannion, P.D. and A.J. Moore. 2025. Critical reappraisal of a putative dicraeosaurid sauropod dinosaur from the Middle Jurassic of Gondwana and a revised view of diplodocoid evolutionary relationships and biogeography. Journal of Systematic Palaeontology 23(1):2550760. DOI 10.1080/14772019.2025.2550760
McGowan, C. 1999. A Practical Guide to Vertebrate Mechanics. Cambridge University Press, Cambridge, England. 301 pp.
O'Brien, F.J., D. Taylor, and T.C. Lee. 2003. Microcrack accumulation at different intervals during fatigue testing of compact bone. Journal of Biomechanics 36(7):973–980. DOI 10.1016/s0021-9290(03)00066-6
Osborn, H.F. and C.C. Mook. 1921. Camarasaurus, Amphicoelias, and other sauropods of Cope. Memoirs of the American Museum of Natural History, New Series 3(3):249–387.
Ouyang, H. and Y. Ye. 2002. The First Mamenchisaurian Skeleton with Complete Skull: Mamenchisaurus youngi. Sichuan Science and Technology Press, Chengdu, China. 111 pp.
Paul, G.S. 1988. The brachiosaur giants of the Morrison and Tendaguru with a description of a new subgenus, Giraffatitan, and a comparison of the world’s largest dinosaurs. Hunteria 2(3):1–14.
Paul, G.S. 2017. Restoring maximum vertical browsing reach in sauropod dinosaurs. Anatomical Record 300:1802–1825. DOI 10.1002/ar.23617
Petrtýl, M., J. Hert, and P. Fiala. 1996. Spatial organization of the haversian bone in man. Journal of Biomechanics 29(2):161–169. DOI 10.1016/0021-9290(94)00035-2
Preuschoft, H. and N. Klein. 2013. Torsion and bending in the neck and tail of sauropod dinosaurs and the function of cervical ribs: insights from functional morphology and biomechanics. PLoS ONE 8(10):e78574. DOI 10.1371/journal.pone.0078574
Salgado, L. and J.F. Bonaparte. 1991. Un nuevo sauropodo Dicraeosauridae, Amargasaurus cazaui gen. et sp. nov. de la Formación La Amarga, Neocomiano de la Provincia del Neuquén, Argentina. Ameghiniana 28(3–4):333–346.
Sander P.M., A. Christian,. M. Clauss, R. Fechner, C.T. Gee, E.M. Griebeler, H.C. Gunga, J. Hummel, H. Mallison, S.F. Perry, H. Preuschoft, O.W. Rauhut, K. Remes T. Tütken, O. Wings, and U. Witzel. 2011. Biology of the sauropod dinosaurs: the evolution of gigantism. Biological Reviews 86(1):117–155. DOI 10.1111/j.1469-185X.2010.00137.x
Schwartz, A. and S. Thomopoulos. 2012. The role of mechanobiology in the attachment of tendon to bone; pp. 229–257 in S. Thomopoulos, V. Birman, and G.M. Genin (eds.), Structural Interfaces and Attachments in Biology. Springer, New York, NY.
Schwarz, D., E. Frey, and C.A. Meyer. 2007. Pneumaticity and soft-tissue reconstructions in the neck of diplodocid and dicraeosaurid sauropods. Acta Palaeontologica Polonica 52(1):167–188.
Schwarz-Wings, D. and E. Frey. 2008. Is there an option for a pneumatic stabilization of sauropod necks?—An experimental and anatomical approach. Palaeontologia Electronica 11(3):17A.
Stevens, K.A. and J.M. Parrish. 1999. Neck posture and feeding habits of two Jurassic sauropod dinosaurs. Science 284(5415):798–800. DOI 10.1126/science.284.5415.798
Taylor, M.P. 2014. Quantifying the effect of intervertebral cartilage on neutral posture in the necks of sauropod dinosaurs. PeerJ 2:e712. DOI 10.7717/peerj.712
Taylor, M.P. and M.J. Wedel. 2013. The effect of intervertebral cartilage on neutral posture and range of motion in the necks of sauropod dinosaurs. PLoS ONE 8(10):e78214. DOI 10.1371/journal.pone.0078214
Taylor, M.P., M.J. Wedel, and D. Naish. 2009. Head and neck posture in sauropod dinosaurs inferred from extant animals. Acta Palaeontologica Polonica 54(2):213–220.
Tellado, S.F., E.R. Balmayor, and M.V. Griensven. 2015. Strategies to engineer tendon/ligament-to-bone interface: biomaterials, cells and growth factors. Advanced Drug Delivery Reviews 94:126–40. DOI 10.1016/j.addr.2015.03.004
Tsuihiji, T. 2004. The ligament system in the neck of Rhea americana and its implication for the bifurcated neural spines of sauropod dinosaurs. Journal of Vertebrate Paleontology 24(1):165–172. DOI 10.1671/A1129-12
Van der Linden, T.T.P., M.P. Taylor, A. Campbell, B.D. Curtice, R. Dederichs, L.N. Lerzo, J.A. Whitlock, D.C. Woodruff, and E. Tschopp. 2025. Introduction to Diplodocoidea. Palaeontologica Electronica 28.2.a27. DOI 10.26879/1518
Vidal, D., P. Mocho, A. Aberasturi, J.L. Sanz, and F. Ortega. 2020a. High browsing skeletal adaptations in Spinophorosaurus reveal an evolutionary innovation in sauropod dinosaurs. Scientific Reports 10:6638. DOI 10.1038/s41598-020-63439-0
Vidal, D., P. Mocho, A. Páramo, J.L. Sanz, and F. Ortega. 2020b. Ontogenetic similarities between giraffe and sauropod neck osteological mobility. PLoS ONE 15(1):e0227537. DOI 10.1371/journal.pone.0227537
Wedel, M.J. 2003. Vertebral pneumaticity, air sacs, and the physiology of sauropod dinosaurs. Paleobiology 29(2):243–255. DOI 10.1666/0094-8373(2003)029<0243:VPASAT>2.0.CO;2
Whitlock, J.A. 2011. A phylogenetic analysis of Diplodocoidea (Saurischia: Sauropoda). Zoological Journal of the Linnean Society 161:872–915. DOI 10.1111/j.1096-3642.2010.00665.x
Wilson, J.A. 1999. A nomenclature for vertebral laminae in sauropods and other saurischian dinosaurs. Journal of Vertebrate Paleontology 19(4):639–653. DOI 10.1080/02724634.1999.10011178
Wilson, J.P., D.C. Woodruff, J.D. Gardner, H.M. Flora, J.R. Horner, and C.L. Organ. 2016. Vertebral adaptations to large body size in theropod dinosaurs. PLoS ONE 11(7):e0158962. DOI 10.1371/journal.pone.0158962
Witmer, L.M. 1995. The extant phylogenetic bracket and the importance of reconstructing soft tissues in fossils; pp. 19–33 in J. Thomason (ed.). Functional Morphology in Vertebrate Paleontology. Cambridge University Press, Cambridge, England.
Woodruff, D.C. 2014. The anatomy of the bifurcated neural spine and its occurrence within Tetrapoda. Journal of Morphology 275(9):1053–1065. DOI 10.1002/jmor.20283
Woodruff, D.C. 2016. Nuchal ligament reconstructions in diplodocid sauropods support horizontal neck feeding postures. Historical Biology 29(3):308–319. DOI 10.1080/08912963.2016.1158257
Woodruff, D.C., N.J. Atwood, and A. Madill. 2016. The structural preservation of a titanosaurid (Dinosauria: Sauropoda) vertebral ligament. Cretaceous Research 60:253–266. DOI 10.1016/j.cretres.2015.12.009
Xu, X., P. Upchurch, P.D. Mannion, P.M. Barrett, O.R. Regalado-Fernandez, J. Mo, J. Ma, and H. Liu. 2018. A new Middle Jurassic diplodocoid suggests an earlier dispersal and diversification of sauropod dinosaurs. Nature Communications 9:2700. DOI 10.1038/s41467-018-05128-1
Yasuda, E. 2002. The Anatomical Atlas of Gallus. University of Tokyo Press, Tokyo, Japan, 445 pp.
Young, C.C. and X. Zhao. 1972. Mamenchisaurus hochuanensis sp. nov. Institute of Vertebrate Paleontology and Paleoanthropology Monograph Series 1(8):1–30.
Zweers, G., R. Bout, and J. Heidweiller. 1994. Motor organization of the avian head–neck system; pp. 201–221 in M.N.O. Davies and P.R. Green (eds.), Perception and Motor Control in Birds. Springer-Verlag, Berlin, Germany.
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