Hostname: page-component-848d4c4894-m9kch Total loading time: 0 Render date: 2024-06-02T00:26:53.529Z Has data issue: false hasContentIssue false
  • English
  • Français

The feeding apparatus of dyrosaurids (Crocodyliformes)

Published online by Cambridge University Press:  19 August 2013

DANIELA SCHWARZ-WINGS
DANIELA SCHWARZ-WINGS*
Affiliation:
Museum für Naturkunde, Leibniz Institute for Evolutionary and Biodiversity Research, Invalidenstr. 43, D-10115 Berlin, Germany
*
*E-mail: d.schwarz-wings@mfn-berlin.de
Get access Rights & Permissions [Opens in a new window]

Abstract

Reconstructed soft-tissues of the craniocervical region of dyrosaurids are analysed under functional aspects to determine their prey-catching capabilities. Jaw adductors and jaw abductors are enlarged and possess longer muscle fibres that are increased by a long retroarticular process. This muscle enlargement resulted in a more forceful and quicker contraction, effective for movement of the long rostrum. The occipital joint and the cervical ribs, the long retroarticular process and the high cervical neural spines of dyrosaurids suggest a higher dorsoventral flexibility of the craniocervical region, whereas lateromedial flexibility was reduced. The epaxial muscles of the neck and scapular muscles were enlarged, and the supraspinal ligament most likely fanned out into a nuchal ligament. Suspension of the neck and skull of dyrosaurids was achieved by the scapular muscles, dorsal neck ligaments and epaxial muscles, whereas ventral bracing was reduced. From the reconstructed specializations of the feeding apparatus, an enhanced capability for movements in the vertical plane is postulated for dyrosaurids, together with reduced lateral movements of the craniocervical region. Besides laterally directed strokes for fish-catching, behaviours such as poking in the substrate, bottom feeding, multidirectional prey-catching strokes and improvement of diving skills were options for dyrosaurids and suggest a possible expansion of their diet. The longirostrine skull limited prey size, but the dentition allowed shelly prey items. The specialization of the food-capturing system in dyrosaurids and the resulting expansion of their food spectrum is one possible explanation for their evolutionary success, including their undisturbed transition of the Cretaceous–Palaeogene boundary.

Keywords

reconstructionmusculatureadductorabductorligamentsskullneck
Type
Original Articles
Information
Geological Magazine , Volume 151 , Issue 1 , January 2014 , pp. 144 - 166
Copyright
Copyright © Cambridge University Press 2013 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Argollo, J., Buffetaut, E., Cappetta, H., Fornari, M., Herail, G., Laubacher, G., Sige, B. & Vizcarra, G. 1987. Découverte de vertébrés aquatiques présumés paléocènes dans les Andes Septentrinales de Bolivie (Rio Suches, Sinclinorium de Putina). Geobios 20, 123–27.Google Scholar
Barbosa, J. A., Kellner, A. W. A. & Sales Viana, M. S. 2008. New dyrosaurid crocodylomorph and evidences for faunal turnover at the K-P transition in Brazil. Proceedings of the Royal Society London, B 275, 1385–91.Google ScholarPubMed
Bardet, N., Pereda Superbiola, X., Jouve, S., Bourdon, E., Vincent, P., Houssaye, A., Rage, J.-C., Jalil, N.-E., Bouya, B. & Amaghzaz, M. 2010. Reptilian assemblages from the latest Cretaceous - Palaeogene phosphates of Morocco: from Arambourg to present time. Historical Biology 22, 186–99.CrossRefGoogle Scholar
Bennett, M. B. & Alexander, R. M. 1987. Properties and function of extensible ligaments in the necks of turkeys (Meleagris gallopavo) and other birds. Journal of Zoology, London 212, 275–81.Google Scholar
Benton, M. J. & Clark, J. M. 1988. Archosaur phylogeny and the relationships of the Crocodilia. In The Phylogeny and Classification of Tetrapods, Vol. 1: Amphibians and Reptiles (ed. Benton, M. J.), pp. 295–338. Oxford: Clarendon Press.Google Scholar
Boas, J. E. V. 1929. Biologisch-Anatomische Studien über den Hals der Vögel. Det Kongelige Danske Videnskabernes Selskabs Skrifter, Naturvidenskabelig og Mathematisk Afdeling 9 (1), 10–222.Google Scholar
Bona, P. & Desojo, J. B. 2011. Osteology and cranial musculature of Caiman latirostris (Crocodylia: Alligatoridae). Journal of Morphology 272, 780–95.CrossRefGoogle ScholarPubMed
Brochu, C. A. 2003. Phylogenetic approaches toward crocodylian history. Annual Review of Earth and Planetary Sciences 31, 357–97.Google Scholar
Brochu, C. A., Bouaré, M. L., Sissoko, F., Roberts, E. M. & O'Leary, M. A. 2002. A dyrosaurid crocodyliform braincase from Mali. Journal of Paleontology 76, 1060–71.2.0.CO;2>CrossRefGoogle Scholar
Brochu, C. A., Wagner, J. R., Jouve, S., Sumrall, C. D. & Densmore, L. D. 2009. A correction corrected: consensus over the meaning of Crocodylia and why it matters. Systematic Biology 58, 537–43.CrossRefGoogle ScholarPubMed
Bronzati, M., Montefeltro, F. C. & Langer, M. C. 2012. A species-level supertree of Crocodyliformes. Historical Biology 24, 598–606.Google Scholar
Buckley, G. A. & Brochu, C. A. 1999. An enigmatic new crocodile from the Upper Cretaceous of Madagascar. Special Papers in Palaeontology 60, 149–75.Google Scholar
Buffetaut, E. 1977. Données nouvelles sur les Crocodiliens paléogènes du Pakistan et de Birmanie. Comptes Rendus de l'Academie des Sciences Paris, Série D 285, 869–72.Google Scholar
Buffetaut, E. 1978 a. Crocodilian remains from the Eocene of Pakistan. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 156, 262–83.Google Scholar
Buffetaut, E. 1978 b. A dyrosaurid (Crocodylia, Mesosuchia) from the Upper Eocene of Burma. Neues Jahrbuch für Geologie und Paläontologie, Monatshefte 5, 273–81.Google Scholar
Buffetaut, E. 1978 c. Les Dyrosauridae (Crocodylia, Mesosuchia) des phosphates de l'Eocene inferieur de Tunisie: Dyrosaurus, Rhabdognathus, Phosphatosaurus . Annales de l'Université de Provence, Géologie Mediterranéenne 5, 237–56.Google Scholar
Buffetaut, E. 1979 a. Présence du crocodilien Phosphatosaurus (Mesosuchia, Dyrosauridae) dans le Paléocène du Niger et Mali. Paläontologische Zeitschrift 53, 323–33.CrossRefGoogle Scholar
Buffetaut, E. 1979 b. Sokotosuchus ianwilsoni and the evolution of the dyrosaurid crocodilians. Nigerian Field Monograph 1, 31–41.Google Scholar
Buffetaut, E., Bussert, R. & Brinkmann, W. 1990. A new nonmarine vertebrate fauna in the Upper Cretaceous of northern Sudan. Berliner geowissenschaftliche Abhandlungen, Reihe A 120, 183–202.Google Scholar
Buffetaut, E. & Lauverjat, J. 1978. Un Crocodilien d'un type particulier dans le Cénomanien de Nazarè. Comptes Rendus Sommaire des Seances de la Societe geologique de France 1978 (2), 79–82.Google Scholar
Busbey, A. B. I. 1995. The structural consequences of skull flattening in crocodilians. In Functional Morphology in Vertebrate Paleontology (ed. Thomasson, J.), pp. 173–92. Cambridge: Cambridge University Press.Google Scholar
Busbey, A. B. I. 1989. Form and function of the feeding apparatus of Alligator mississippiensis . Journal of Morphology 202, 99–127.Google Scholar
Carter, D. R. & Beaupré, G. S. 2001. Skeletal Function and Form. Cambridge: Cambridge University Press.Google Scholar
Cassens, I., Vicario, S., Waddell, V. G., Balchowsky, H., Van Belle, D., Ding, W., Fan, C., Lal Mohan, R. S., Simőes-Lopes, P. C., Bastida, R., Meyer, A., Stanhope, M. J. & Milinkovitch, M. C. 2000. Independent adaptation to riverine hapitats allowed survival of ancient cetacean lineages. Proceedings of the National Academy of Sciences 97, 11343–47.Google Scholar
Clark, J. M. 1994. Patterns of evolution in Mesozoic crocodyliformes. In In the Shadow of the Dinosaurs (eds Frazer, N. C. & Sues, H.-D.), pp. 84–97. Cambridge, New York, Melbourne: Cambridge University Press.Google Scholar
Cleuren, J., Aerts, P. & De Vree, F. 1995. Bite and joint force analysis in Caiman crocodilus . Belgian Journal of Zoology 125, 79–94.Google Scholar
Cleuren, J. & De Vree, F. 1990. An electromyographic study of the cervical musculature during feeding in Caiman crocodilus . Belgian Journal of Zoology 120 (Suppl. 1), 15.Google Scholar
Cleuren, J. & De Vree, F. 1991. The neck of Caiman crocodilus, an important structure during inertial feeding. Belgian Journal of Zoology 121 (Suppl. 1), 9.Google Scholar
Cleuren, J. & De Vree, F. 2000. Feeding in Crocodilians. In Feeding, Form, Function, and Evolution in Tetrapod Vertebrates (ed. Schwenk, K.), pp. 337–58. San Diego: Academic Press.Google Scholar
Cong, L., Hou, L. H., Wu, X.-C. & Hou, F. J. 1998. The Gross Anatomy of Alligator sinensis Fauvel. Beijing: Beijing Science Press (in Chinese with English summary).Google Scholar
de Stefano, G. 1903. Nuovi rettili degli stratia fosfato della Tunisia. Bolletino della Societa Geologica Italiana (Roma) 22 (1), 51–80.Google Scholar
Denton, R. K. J., Dobie, J. L. & Parris, D. C. 1994. The marine crocodilian Hyposaurus in North America. Journal of Vertebrate Paleontology 14 (Suppl. 3), 23A.Google Scholar
Denton, R. K. J., Dobie, J. L. & Parris, D. C. 1997. The marine crocodilian Hyposaurus in North America. In Ancient Marine Reptiles (eds Callaway, J. M. & Nicholls, E. L.), pp. 375–97. London: Academic Press.Google Scholar
Dimery, N. J., Alexander, R. M. & Deyst, K. A. 1985. Mechanics of the ligamentum nuchae of some artiodactyls. Journal of Zoology, London 206, 341–51.CrossRefGoogle Scholar
Dodson, P. 1975. Functional and ecological significance of relative growth in Alligator . Journal of Zoology, London 175, 315–55.Google Scholar
Dzemski, G. & Christian, A. 2007. Flexibility along the neck of the ostrich (Struthio camelus) and consequences for the reconstruction of dinosaurs with extreme neck lengths. Journal of Morphology 268, 701–14.Google Scholar
Endo, H., Aoki, R., Taru, H., Kimura, J., Sasaki, M., Yamamoto, M., Arishima, K. & Hayashi, Y. 2002. Comparative functional morphology of the masticatory apparatus in the long-snouted crocodiles. Anatomy, Histology, Embryology 31, 206–13.CrossRefGoogle ScholarPubMed
Erickson, G. M., Gignac, P. M., Steppan, S. J., Lappin, A. K., Vliet, K. A., Brueggen, J. D., Inouye, B. D., Kledzik, D. & Webb, G. J. W. 2012. Insights into the ecology and evolutionary success of crocodilians revealed through bite-force and tooth-pressure experimentation. PLoS ONE 7 (3), e31784.Google Scholar
Erickson, G. M., Lappin, A. K. & Vliet, K. A. 2003. The ontogeny of bite-force performance in American alligator (Alligator mississippiensis). Journal of Zoology, London A 260, 317–27.Google Scholar
Fish, F. E. 2002. Balancing requirements for stability and maneuverability in cetaceans. Integrative and Comparative Biology 42, 85–93.Google Scholar
Frey, E. 1988 a. Das Tragsystem der Krokodile – eine biomechanische und phylogenetische Analyse. Stuttgarter Beiträge zur Naturkunde, A 26, 1–60.Google Scholar
Frey, E. 1988 b. Anatomie des Körperstammes von Alligator mississippiensis Daudin. Stuttgarter Beiträge zur Naturkunde, A 24, 1–106.Google Scholar
Fürbringer, M. 1876. Zur vergleichenden Anatomie der Schultermuskeln – 3. Teil: Capitel IV: Saurier und Crocodile. Gegenbaurs Morphologisches Jahrbuch 1, 636–816.Google Scholar
Gans, C. 1966. Some limitations and approaches to problems in functional anatomy. Folia Biotheoretica, B 6, 41–50.Google Scholar
Gasparini, Z. & Spalletti, L. A. 1990. Un nuevo cocodrilo en los depósitos mareales Maastrichtianos de la Patagonia noroccidental. Ameghiniana 27, 141–50.Google Scholar
Geisler, J. H., McGowan, M. R., Yang, G. & Gatesy, J. 2011. A supermatrix analysis of genomic, morphological, and paleontological data from crown Cetacea. Evolutionary Biology 11, 112.Google Scholar
Gellman, K. S., Bertram, J. E. A. & Hermanson, J. W. 2002. Morphology, histochemistry, and function of epaxial cervical musculature in the horse (Equus caballus). Journal of Morphology 251, 182–94.Google Scholar
Georgi, J. 2006. Dyrosaur inner ear morphology as evidence for locomotor behaviour. Journal of Vertebrate Paleontology 26, 66A.Google Scholar
Gingerich, P. D. 2003. Stratigraphic and micropaleontological constraints on the middle Eocene age of the mammal-bearing Kuldana formation of Pakistan. Journal of Vertebrate Paleontology 23, 643–51.Google Scholar
Gingerich, P. D., Russell, D., Sigogneau-Russell, D., Hartenberger, J., Shah, S., Hassan, M., Rose, K. & Ardrey, R. 1979. Reconnaissance survey and vertebrate paleontology of some Paleocene and Eocene formations in Pakistan. Contributions from the Museum of Paleontology, The University of Michigan 25, 105–16.Google Scholar
Greaves, W. S. 1995. Functional predictions from theoretical models of the skull and jaws in reptiles and mammals. In Functional Morphology in Vertebrate Paleontology (ed. Thomasson, J.), pp. 99–115. Cambridge: Cambridge University Press.Google Scholar
Hastings, A. K., Bloch, J. I., Cadena, E. A. & Jaramillo, C. A. 2010. A new small short-snouted dyrosaurid (Crocodylomorpha, Mesoeucrocodylia) from the Paleocene of Northeastern Colombia. Journal of Vertebrate Paleontology 30, 139–62.Google Scholar
Hastings, A. K., Bloch, J. I. & Jaramillo, C. A. 2011. A new longirostrine dyrosaurid (Crocodylomorpha, Mesoeucrocodylia) from the Paleocene of Northeastern Colombia: biogeographic and behavioural implications for new-world Dyrosauridae. Palaeontology 54, 1095–116.Google Scholar
Hill, R. V., McCartney, J. A., Roberts, E. M., Bouaré, M. L., Sissoko, F. & O'Leary, M. A. 2008. Dyrosaurid (Crocodyliformes: Mesoeucrocodylia) fossils from the Upper Cretaceous and Paleogene of Mali: implications for phylogeny and survivorship across the K/T boundary. American Museum Novitates 3631, 1–19.Google Scholar
Holliday, C. M. & Witmer, L. M. 2007. Archosaur adductor chamber evolution: integration of musculoskeletal and topological criteria in jaw muscle homology. Journal of Morphology 268, 457–84.Google Scholar
Holliday, C. M. & Witmer, L. M. 2009. The epipterygoid of crocodyliforms and its significance for the evolution of the orbitotempiral region of eusuchians. Journal of Vertebrate Paleontology 29, 715–33.Google Scholar
Iordansky, N. N. 1964. The jaw muscles of the crocodiles and some relating structures of the crocodilian skull. Anatomischer Anzeiger 115, 256–80.Google Scholar
Iordansky, N. N. 1973. The skull of the Crocodilia. In Biology of the Reptilia (ed. Gans, C.), pp. 201–62. London: Academic Press.Google Scholar
Iordansky, N. N. 1994. Tendons of jaw muscles in Amphibia and Reptilia: homology and evolution. Russian Journal of Herpetology 1, 13–20.Google Scholar
Iordansky, N. N. 2000. Jaw muscles of the crocodiles: structure, synonymy, and some implications on homology and functions. Russian Journal of Herpetology 7, 41–50.Google Scholar
Jouve, S. 2005. A new description of the skull of Dyrosaurus phosphaticus (Thomas, 1893) (Mesoeucrocodylia: Dyrosauridae) from the Lower Eocene of North Africa. Canadian Journal of Earth Sciences 42, 323–37.Google Scholar
Jouve, S. 2007. Taxonomic revision of the dyrosaurid assemblage (Crocodyliformes: Mesoeucrocodylia) from the Paleocene of the Iullemmeden Basin, West Africa. Journal of Paleontology 81, 163–75.Google Scholar
Jouve, S., Bouya, B. & Amaghzaz, M. 2005. A short-snouted dyrosaurid (Crocodyliformes, Mesoeucrocodylia) from the Palaeocene of Morocco. Palaeontology 48, 359–69.Google Scholar
Jouve, S., Bouya, B. & Amaghzaz, M. 2008. A long-snouted dyrosaurid (Crocodyliformes, Mesoeucrocodylia) from the Paleocene of Morocco: phylogenetic and palaeobiogeographic implications. Palaeontology 51, 281–94.Google Scholar
Jouve, S., Iarochene, M., Bouya, B. & Amaghzaz, M. 2005. A new dyrosaurid crocodyliform from the Palaeoene of Morocco and a phylogenetic analyis of Dyrosauridae. Acta Palaeontologica Polonica 50, 581–94.Google Scholar
Jouve, S., Iarochène, M., Bouya, B. & Amaghzaz, M. 2006. A new species of Dyrosaurus (Crocodylomorpha, Dyrosauridae) from the early Eocene of Morocco: phylogenetic implications. Zoological Journal of the Linnean Society 148, 603–56.Google Scholar
Jouve, S. & Schwarz, D. 2004. Congosaurus bequaerti, a Paleocene dyrosaurid (Crocodyliformes, Mesoeucrocodylia) from Landana (Angola). Bulletin de l'Institut Royale des Sciences Naturelles de Belguique, Sciences de la Terre 74, 129–46.Google Scholar
Kälin, J. A. 1933. Beiträge zur vergleichenden Osteologie des Crocodilienschädels. Zoologische Jahrbücher, Abteilung für Anatomie und Ontogenie der Tiere 57, 535–714.Google Scholar
Kastelein, R. A., Neurohr, B., Nieuwstraten, S. H. & Wiepkema, P. R. 1999. Food consumption and body measurements of Amazon river dolphins (Inia geoffrensis). Aquatic Mammals 25.3, 173–82.Google Scholar
Langston, W. J. 1973. The crocodilian skull in historical perspective. In Biology of the Reptilia (ed. Gans, C.), pp. 263–85. London: Academic Press.Google Scholar
Langston, W. J. 1995. Dyrosaurs (Crocodilia: Mesosuchia) from the Paleocene Umm Himar Formation, Kingdom of Saudi Arabia. US Geological Survey Bulletin 2093-F, 1–36.Google Scholar
Lubosch, W. 1914. Zwei vorläufige Mitteilungen über die Anatomie der Kaumuskeln der Krokodile. Jenaische Zeitschrift für Naturwissenschaften 51 (44), 697–707.Google Scholar
Massare, J. A. 1987. Tooth morphology and prey preference of Mesozoic marine reptiles. Journal of Vertebrate Paleontology 7, 121–37.CrossRefGoogle Scholar
McHenry, C. R., Clausen, P. D., Daniel, W. J. T., Meers, M. B. & Pendharkar, A. 2006. Biomechanics of the rostrum in crocodilians: a comparative analysis using finite-element modeling. Anatomical Record 288, 827–49.Google Scholar
Meers, M. B. 2003. Crocodylian forelimb musculature and its relevance to Archosauria. The Anatomical Record Part A 274, 891–916.Google Scholar
Moody, R. T. J. & Buffetaut, E. 1981. Notes on the systematics and palaeoecology of the crocodiles and turtles of the Metlaoui Phosphates (Eocene) of Southern Tunisia. Tertiary Research 3, 125–40.Google Scholar
Norell, M. A. & Clark, J. M. 1990. A reanalysis of Bernissartia fagesii, with comments on its phylogenetic position and its bearing on the origin and diagnosis of the Eusuchia. Bulletin de l'Institut Royal des Sciences Naturelles de Belgique 60, 115–28.Google Scholar
Parris, D. C. 1986. Biostratigraphy of the fossil crocodile Hyposaurus Owen from New Jersey. Investigations of the New Jersey State Museum 4, 1–16.Google Scholar
Pierce, S. E., Angielczyk, K. D. & Rayfield, E. J. 2008. Patterns of morphospace occupation and mechanical performance in extant crocodilian skulls: a combined geometric morphometric and finite element modeling approach. Journal of Morphology 269, 840–64.Google Scholar
Poglayen-Neuwall, I. 1953. Untersuchungen der Kiefermuskulatur und deren Innervation an Krokodilen. Anatomischer Anzeiger 99, 258–76.Google Scholar
Pol, D. 2003. New remains of Sphagesaurus huenei (Crocodylomorpha: Mesoeucrocodylia) from the Late Cretaceous of Brazil. Journal of Vertebrate Paleontology 23, 817–31.Google Scholar
Pooley, A. C. 1989. Food and feeding habits. In Crocodiles and Alligators (ed. Ross, C. A.), pp. 76–91. Sydney: Weldon Owen.Google Scholar
Porro, L. B., Holliday, C. M., Anapol, F., Ontiveros, L. C., Ontiveros, L. T. & Ross, C. F. 2011. Free body analysis, beam mechanics, and finite element modeling of the mandible of Alligator mississippiensis . Journal of Morphology 272, 910–37.CrossRefGoogle ScholarPubMed
Preuschoft, H. & Witzel, U. 2002. Biomechanical investigations on the skulls of reptiles and mammals. Senckenbergiana Lethaea 82, 207–22.Google Scholar
Ridgway, S. H. & Harrison, R. 1989. Handbook of Marine Mammals Volume 4: River Dolphins and the Larger Toothed Whales. London: Academic Press, 442 pp.Google Scholar
Rodríguez, D., Rivero, L. & Bastida, R. 2002. Feeding ecology of the franciscana (Pontoporia blainvillei) in marine and estuarine waters of Argentina. Latin American Journal of Aquatic Mammals 1, 77–94.Google Scholar
Ross, F. D. & Mayer, G. C. 1983. On the dorsal armor of the Crocodilia. In Advances in Herpetology and Evolutionary Biology (eds Rhodin, A. G. J. & Miyata, K.), pp. 305–331. Cambridge, Massachussetts: Museum of Comparative Zoology.Google Scholar
Salisbury, S. W. & Frey, E. 2001. A biomechanical transformation model for the evolution of semi-spheroidal articulations between adjoining vertebral bodies in crocodilians. In Crocodilian Biology and Evolution (eds Grigg, G. C., Seebacher, F. & Franklin, C. E.), pp. 85–134. Chipping Norton, Australia: Surrey Beatty & Sons.Google Scholar
Sato, I., Shimada, K., Sato, T. & Kitagawa, T. 1992. Histochemical study of jaw muscle fibers in the American alligator (Alligator mississippiensis). Journal of Morphology 211, 187–99.Google Scholar
Schumacher, G. H. 1973. Head muscles and hyolaryngeal skeleton of turtles and crocodylians. In Biology of the Reptilia (eds Gans, C., Bellairs, A. d. A. & Parsons, T. S.). London: Academic Press.Google Scholar
Schwarz, D., Frey, E. & Martin, T. 2006. The postcranial skeleton of the Hyposaurinae (Dyrosauridae; Crocodylomorpha). Palaeontology 49, 695–718.Google Scholar
Schwarz-Wings, D., Frey, E. & Martin, T. 2009. Reconstruction of the bracing system of the trunk and tail in hyposaurine dyrosaurs (Crocodylomorpha; Mesoeucrocodylia). Journal of Vertebrate Paleontology 29, 453–72.Google Scholar
Sereno, P. C., Larsson, H. C. E., Sidoe, C. A. & Gado, B. 2001. The giant crododyliform Sarcosuchus from the Cretaceous of Africa. Science 294, 1516–19.Google Scholar
Sereno, P. C., Sidor, C. A., Larsson, C. E. & Gado, B. 2003. A new notosuchian from the Early Cretaceous of Niger. Journal of Vertebrate Paleontology 23, 477–82.Google Scholar
Sinclair, A. G. & Alexander, R. M. 1987. Estimates of forces exerted by the muscles of some reptiles. Journal of Zoology, London 213, 107–15.Google Scholar
Slijper, E. J. 1946. Comparative biologic-anatomical investigation on the vertebral column and spinal musculatur of mammals. Verhandelingen Der Koninklijke Ned. Akademie Van Wetenschappen, Afdeeling Natuurkunde, Tweede Sectie 42, 1–128.Google Scholar
Storrs, G. W. 1986. A dyrosaurid crocodile (Crocodylia: Mesosuchia) from the Paleocene of Pakistan. Postilla, Yale Peabody Museum 197, 1–16.Google Scholar
Swinton, W. E. 1930. On fossil reptilia from Sokoto Province. Geological Survey of Nigeria Bulletins 13, 9–61.Google Scholar
Swinton, W. E. 1950. On Congosaurus bequaerti Dollo. Annales du Musée du Congo Belge, Sciences Geologiques 8 (4), 1–60.Google Scholar
Thorbjarnarson, J. B. 1990. Notes on the feeding behavior of the Gharial (Gavialis gangeticus) under semi-natural conditions. Journal of Herpetology 24, 99–100.Google Scholar
Troxell, E. L. 1925. Hyposaurus, a marine crocodilian. American Journal of Science 9 (54), 489–514.Google Scholar
Trutnau, L. 1994. Krokodile. Neue Brehm Bücherei Band 593. Magdeburg: Westarp Wissenschaften.Google Scholar
Tsuihiji, T. 2005. Homologies of the transversospinalis muscles in the anterior presacral region of Sauria (Crown Diapsida). Journal of Morphology 263, 151–78.Google Scholar
Tsuihiji, T. 2007. Homologies of the longissimus, iliocostalis, and hypaxial muscles in the anterior presacral region of extant Diapsida. Journal of Morphology 268, 986–1020.Google Scholar
Van Drongelen, W. & Dullemeijer, P. 1982. The feeding apparatus of Caiman crocodilus; a functional-morphological study. Anatomischer Anzeiger 151, 337–66.Google Scholar
Virchow, H. J. P. 1914. Über die Alligatorwirbelsäule. Archiv für Anatomie und Physiologie 1914, 103–42.Google Scholar
Witmer, L. M. 1995. Homology of facial structures in extant archosaurs (birds and crocodilians), with special reference to paranasal pneumaticity and nasal conchae. Journal of Morphology 225, 269–327.Google Scholar
Wu, X.-C., Russell, A. P. & Cumbaa, S. L. 2001. Terminonaris (Archosauria: Crocodyliformes): new material from Saskatchewan, Canada, and comments on its phylogenetic relationship. Journal of Vertebrate Paleontology 21, 492–514.Google Scholar
Wu, X.-C., Sues, H.-D. & Dong, Z.-M. 1997. Sichuanosuchus shuhangensis, a new? Early Cretaceous protosuchian (Archosauria: Crocodyliformes) from Sichuan (China), and the monophyly of Protosuchia. Journal of Vertebrate Paleontology 17, 89–103.Google Scholar