Hostname: page-component-78c5997874-g7gxr Total loading time: 0 Render date: 2024-11-16T05:20:06.919Z Has data issue: false hasContentIssue false
  • English
  • Français

Cranial anatomy of the Late Triassic phytosaur Machaeroprosopus, with the description of a new species from West Texas

Published online by Cambridge University Press:  07 October 2013

Axel Hungerbühler ,
Bill Mueller ,
Sankar Chatterjee  and
Douglas P. Cunningham
Axel Hungerbühler
Affiliation:
Mesalands Community College, 911 S. Tenth Street, Tucumcari, NM 88401, USA. Email: [email protected]
Bill Mueller
Affiliation:
Division of Paleontology, Museum of Texas Tech University, Box 43191, Lubbock, TX 79409, USA
Sankar Chatterjee
Affiliation:
Division of Paleontology, Museum of Texas Tech University, Box 43191, Lubbock, TX 79409, USA
Douglas P. Cunningham
Affiliation:
Division of Paleontology, Museum of Texas Tech University, Box 43191, Lubbock, TX 79409, USA
Get access Rights & Permissions [Opens in a new window]

Abstract

The skull anatomy of a new species of the phytosaur Machaeroprosopus is described for the first time on the basis of two specimens from the Upper Triassic Cooper Canyon Formation of Texas. Additional information is provided by a third specimen referred to Machaeroprosopus sp. A paranasal bone, an additional paired element of the narial region, is identified. Important new data are presented for the braincase, including the morphology of the epipterygoid and presphenoid, an anterior process of the prootic, an anteroventral process of the laterosphenoid, and a parasphenoid process. Machaeroprosopus lottorum n. sp. is characterised by four apomorphies: a supratemporal fenestra closed on the skull roof with bevelled anterior rim, a comparatively short squamosal, a flat and rugose narial rim, and medially extended palatines that come close to form an ossified secondary palate. With respect to the supratemporal fenestra, the supraoccipital–parietal complex and several features of the squamosal, Machaeroprosopus lottorum n. sp. bridges the morphological gap between species previously referred to the genera Pseudopalatus and Redondasaurus. A parsimony analysis of known species of Machaeroprosopus supports the hypothesis that the development of the rostral crest in Machaeroprosopus is a sexually dimorphic feature, and questions the validity of the genus Redondasaurus. Consequently, Redondasaurus is here considered a junior synonym of Machaeroprosopus.

Keywords

DockumNorianPseudopalatusRedondasaurus
Type
Articles
Information
Earth and Environmental Science Transactions of The Royal Society of Edinburgh , Volume 103 , Issue 3-4: The Full Profession: A Celebration of the Life and Career of Wann Langston, Jr., Quintessential Vertebrate Palaeontologist , September 2012 , pp. 269 - 312
Copyright
Copyright © The Royal Society of Edinburgh 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

10. References

Alcober, O. 2000. Redescription of the skull of Saurosuchus galilei (Archosauria: Rauisuchidae). Journal of Paleontology 20, 302–16.Google Scholar
Anderson, H. T. 1936. The jaw musculature of the phytosaur, Machaeroprosopus. Journal of Morphology 59, 549–74.Google Scholar
Ballew, K. L. 1989. A phylogenetic analysis of Phytosauria from the Late Triassic of the western United States. In Lucas, S. G. & Hunt, A. P. (eds) Dawn of the Age of Dinosaurs in the American Southwest, 309–39. Albuquerque: New Mexico Museum of Natural History.Google Scholar
Broili, F. & Schröder, J. 1934. Beobachtungen an Wirbeltieren der Karrooformation. V. Über Chasmatosaurus van hoepeni Haughton. Sitzungsberichte der Bayerischen Akademie der Wissenschaften, mathematisch-naturwissenschaftliche Abteilung 1934, 225–64.Google Scholar
Camp, C. L. 1930. A study of the phytosaurs with description of new material from western North America. Memoirs of the University of California 10. 161 pp.Google Scholar
Camp, C. L. 1942. California mosasaurs. Memoirs of the University of California 13. VI+68 pp.Google Scholar
Case, E. C. 1922. New reptiles and stegocephalians from the upper Triassic of western Texas. Carnegie Institution of Washington 321, 1–84.Google Scholar
Case, E. C. 1929. Description of the skull of a new form of phytosaur with notes on the characters of described North American phytosaurs. Memoirs of the University of Michigan Museums, Museum of Paleontology 2, VI+56 pp.Google Scholar
Case, E. C. & White, T. E. 1934. Two new specimens of phytosaurs from the Upper Triassic of Western Texas. Contributions from the Museum of Paleontology, University of Michigan 4, 133–42.Google Scholar
Chatterjee, S. 1978. A primitive parasuchid (phytosaur) reptile from the Upper Triassic Maleri Formation of India. Palaeontology 21, 83–127.Google Scholar
Chatterjee, S. 1985. Postosuchus, a new thecodontian reptile from the Triassic of Texas and the origin of tyrannosaurs. Philosophical Transactions of the Royal Society, London B 309, 395–460.Google Scholar
Clark, J. M., Welman, J., Gauthier, J. A. & Parrish, J. M. 1993. The laterosphenoid bone of early archosauriforms. Journal of Vertebrate Palaeontology 13, 48–57.Google Scholar
Colbert, E. H. 1947. Studies of the phytosaurs Machaeroprosopus and Rutiodon. Bulletin of the American Museum of Natural History 88, 53–96.Google Scholar
Colbert, E. & Russel, D. A. 1969. The small Cretaceous Dinosaur Dromaeosaurus. American Museum Novitates 2380. 49 pp.Google Scholar
Cope, E. D. 1869–71. Synopsis of the extinct Batrachia, Reptilia, and Aves of North America. Transactions of the American Philosophical Society, New Series 14. VIII+252 pp.Google Scholar
Cope, E. D. 1881. Belodon in New Mexico. The American Naturalist 15, 922–23.Google Scholar
Cunningham, D. P., Hungerbühler, A., Chatterjee, S. & McQuilkin, K. 2002. Late Triassic vertebrates from the Patricia Site near Post, Texas. Journal of Vertebrate Paleontology 22, 47A.Google Scholar
Currie, P. J. 1985. Cranial anatomy of Stenonychosaurus inequivalis (Saurischia, Theropoda) and its bearings on the origin of birds. Canadian Journal of Earth Sciences 22, 1643–58.CrossRefGoogle Scholar
Currie, P. J. & Zhao, X.-J. 1993. A new carnosaur (Dinosauria, Theropoda) from the Jurassic of Xinjang, People's Republic of China. Canadian Journal of Earth Sciences 30, 2037–81.Google Scholar
Doyle, K. D. & Sues, H.-D. 1995. Phytosaurs (Reptilia: Archosauria) from the Upper Triassic New Oxford Formation of York County, Pennsylvania. Journal of Vertebrate Paleontology 15, 545–53.Google Scholar
Dutuit, J.-M. 1977. Description du crâne de Angistorhinus talainti n. sp., un nouveau Phytosaure du Trias atlasique marocain. Bulletin du Muséum National d'Histoire Naturelle, Paris, 3. Series 489, 297–336.Google Scholar
Emmons, E. 1856. Geological report of the midland counties of North Carolina. New York: George P. Putnam and Co. XX+352 pp.Google Scholar
Eriksson, T. 1998. Autodecay 4.0. Stockholm, Sweden: Department of Botany, Stockholm University.Google Scholar
Fraas, E. 1896. Die schwäbischen Trias-Saurier nach dem Material der Kgl. Naturalien-Sammlung in Stuttgart zusammengestellt. Stuttgart: Schweizerbart. 18 pp.Google Scholar
Frey, E. 1988. Anatomie des Körperstammes von Alligator mississippiensis Daudin. Stuttgarter Beiträge zur Naturkunde Reihe A 424. 106 pp.Google Scholar
Galton, P. M. 1985. Cranial anatomy of the prosauropod dinosaur Plateosaurus from the Knollenmergel (Middle Keuper, Upper Triassic) of Germany. II. All the cranial material and details of the soft-part anatomy. Geologica et Palaeontologica 19, 119–59.Google Scholar
Gauthier, J. A., Kluge, A. G. & Rowe, T. 1988. Amniote phylogeny and the importance of fossils. Cladistics 4, 105–209.Google Scholar
Gower, D. J. 1997. The braincase of the early archosaurian reptile Erythrosuchus africanus. Journal of Zoology 242, 557–76.Google Scholar
Gower, D. J. 2002. Braincase evolution in suchian archosaurs (Reptilia: Diapsida): evidence from the rauisuchian Batrachotomus kupferzellensis. Zoological Journal of the Linnean Society 136, 49–76.Google Scholar
Gower, D. J. & Sennikov, A. G. 1996. Morphology and phylogenetic informativeness of early archosaur braincases. Palaeontology 39, 883–906.Google Scholar
Gower, D. J. & Walker, A. D. 2002. New data on the braincase of the aetosaurian archosaur (Reptilia: Diapsida) Stagonolepis robertsoni Agassiz. Zoological Journal of the Linnean Society 136, 7–23.Google Scholar
Gregory, J. T. 1962. The genera of phytosaurs. American Journal of Science 260, 652–90.Google Scholar
Heckert, A. B., Harris, J. & Lucas, S. G. 2000. A giant, incomplete Redondasaurus skull from the Redonda Formation (Upper Triassic: Apachean) of east-central New Mexico. In McCord, R. D. & Boaz, D. (eds) Southwest Paleontological Symposium – Proceedings 2000. Mesa Southwest Museum Bulletin 7, 59. Mesa, Arizona: Mesa Southwest Museum and Southwest Paleontological Society. 125 pp.Google Scholar
Heckert, A. B. & Lucas, S. G. 2000. Phytosaurs (Archosauria: Crocodylotarsi) from the Upper Triassic Owl Rock Formation, Arizona, and their biochronological significance. In McCord, R. D. & Boaz, D. (eds) Southwest Paleontological Symposium – Proceedings 2000. Mesa Southwest Museum Bulletin 7, 37. Mesa, Arizona: Mesa Southwest Museum and Southwest Paleontological Society. 125 pp.Google Scholar
Heckert, A. B. & Lucas, S. G. 2002. Revised Upper Triassic stratigraphy of the Petrified Forest National Park, Arizona, U.S.A.In Heckert, A. B. & Lucas, S. G. (eds) Upper Triassic stratigraphy and paleontology. New Mexico Museum of Natural History and Science Bulletin 21, 1–36. Albuquerque: New Mexico Museum of Natural History and Science. 301 pp.Google Scholar
Huene, F. v. 1909. Vorläufige Mitteilung über einen neuen Phytosaurus-Schädel aus dem schwäbischen Keuper. Centralblatt für Mineralogie, Geologie und Paläontologie 1909, 583–92.Google Scholar
Huene, F. v. 1911. Beiträge zur Kenntnis und Beurteilung der Parasuchier. Geologische und Palaeontologische Abhandlungen, Neue Folge 10, 67–121.Google Scholar
Huene, F. v. 1915. On reptiles of the New Mexican Trias in the Cope Collection. Bulletin of the American Museum of Natural History 34, 485–507.Google Scholar
Huene, F. v. 1922. Neue Beiträge zur Kenntnis der Parasuchier. Jahrbuch der Preussischen Geologischen Landesanstalt 42, 59–160.Google Scholar
Hungerbühler, A. 1998. Cranial anatomy and diversity of the Norian phytosaurs of Southwestern Germany. Unpublished PhD Dissertation, University of Bristol, Bristol, UK. 465 pp.Google Scholar
Hungerbühler, A. 2000. Heterodonty in the European phytosaur Nicrosaurus kapffi and its implications for the taxonomic utility and functional morphology of phytosaur dentitions. Journal of Vertebrate Paleontology 20, 31–48.Google Scholar
Hungerbühler, A. 2002. The Late Triassic phytosaur Mystriosuchus westphali, with a revision of the genus. Paleontology 45, 377–418.Google Scholar
Hungerbühler, A. & Hunt, A. P. 2000. Two new phytosaur species (Archosauria, Crurotarsi) from the Upper Triassic of Southwest Germany. Neues Jahrbuch für Geologie und Paläontologie, Monatshefte 2000, 467–84.Google Scholar
Hungerbühler, A. & Sues, H.-D. 2001. Status and phylogenetic relationships of the Late Triassic phytosaur Rutiodon carolinensis. Journal of Vertebrate Paleontology 21, 64A.Google Scholar
Hunt, A. P. 1989. Cranial morphology and ecology among phytosaurs. In Lucas, S. G. & Hunt, A. P. (eds) Dawn of the Age of Dinosaurs in the American Southwest, 349–54. Albuquerque: New Mexico Museum of Natural History.Google Scholar
Hunt, A. P. 1993. Taxonomy of phytosaurs (Reptilia: Archosauria) from the Canjilon Quarry, Petrified Forest Formation, north-central New Mexico. In Lucas, S. G. & Morales, M. (eds) The nonmarine Triassic. New Mexico Museum of Natural History and Science Bulletin 3, G13. Albuquerque: New Mexico Museum of Natural History and Science. 478+59 pp.Google Scholar
Hunt, A. P. 1994. Vertebrate paleontology and biostratigraphy of the Bull Canyon Formation (Chinle Group, Upper Triassic), east-central New Mexico with revisions of the families Metoposauridae (Amphibia: Temnospondyli) and Parasuchidae (Reptilia: Archosauria). Unpublished PhD Dissertation, University of New Mexico, Albuquerque, New Mexico. 403 pp.Google Scholar
Hunt, A. P. 2001. The vertebrate fauna, biostratigraphy and biochronology of the type Revueltian land-vertebrate faunachron, Bull Canyon Formation (Upper Triassic), east-central New Mexico. In Lucas, S. G. & Ulmer-Scholle, D. S. (eds) New Mexico Geological Society, Field Conference Guidebook, 52, Geology of the Llano Estacado, 123–51. Socorro: New Mexico Geological Society.CrossRefGoogle Scholar
Hunt, A. P., Lucas, S. G. & Heckert, A. B. 2002. A Revueltian (Norian) phytosaur from the Sonsela member of the Petrified Forest Formation (Chinle Group: Upper Triassic), Petrified Forest National Park, Arizona. In Heckert, A. B. & Lucas, S. G. (eds) Upper Triassic stratigraphy and paleontology. New Mexico Museum of Natural History and Science Bulletin 21, 165–69. Albuquerque: New Mexico Museum of Natural History and Science. 301 pp.Google Scholar
Hunt, A. P., Lucas, S. G. & Spielmann, J. A. 2006. Sexual dimorphism in a large brachyrostral phytosaur (Archosauria: Crurotarsi) from the Late Triassic of western North America. New Mexico Museum of Natural History and Science Bulletin 37, 563–67.Google Scholar
Hunt, A. P. & Downs, A. 2002. Taphonomy of the Late Triassic Canjilon Quarry (Petrified Forest Formation), north-central New Mexico: Data from new excavations. In Heckert, A. B. & Lucas, S. G. (eds) Upper Triassic stratigraphy and paleontology. New Mexico Museum of Natural History and Science Bulletin 21, 291–95. Albuquerque: New Mexico Museum of Natural History and Science. 301 pp.Google Scholar
Hunt, A. P. & Lucas, S. G. 1993. A new phytosaur (Reptilia: Archosauria) genus from the uppermost Triassic of the western United States and its biochronological significance. In Lucas, S. G. & Morales, M. (eds) The nonmarine Triassic. New Mexico Museum of Natural History and Science Bulletin 3, 193–96. Albuquerque: New Mexico Museum of Natural History and Science. 478+59 pp.Google Scholar
Irmis, R. B. 2005. The vertebrate fauna of the Upper Triassic Chinle Formation in northern Arizona. Mesa Southwest Museum Bulletin 9, 63–88.Google Scholar
Iordansky, N. N. 1973. The skull of the Crocodilia. In Gans, C. & Parsons, T. S. (eds) Biology of the Reptilia 4, Morphology D, 201–62. London and New York; Academic Press.Google Scholar
Jaeger, G. F. 1828. Über die fossilen Reptilien, welche in Würtemberg aufgefunden worden sind. Stuttgart, Germany: Metzler. 48 pp.Google Scholar
Janensch, W. 1936. Über Bahnen von Hirnvenen bei Saurischiern und Ornithischiern, sowie einigen anderen fossilen und rezenten Reptilien. Palaeontologische Zeitschrift 18, 181–98.Google Scholar
Kimmig, J. 2009. Functional morphology and systematic palaeontology of the Phytosauria (Archosauria; Crurotarsi) and the development of their Late Triassic habitats. Unpublished MSc Thesis, Imperial College, London, UK. 118 pp.Google Scholar
Kirby, R. E. 1989. Late Triassic vertebrate localities of the Owl Rock Member (Chinle Formation) in the Ward Terrace area of northern Arizona. In Lucas, S. G. & Hunt, A. P. (eds) Dawn of the Age of Dinosaurs in the American Southwest, 12–28. Albuquerque: New Mexico Museum of Natural History.Google Scholar
Langston, W. Jr. 1949. A new species of Paleorhinus from the Triassic of Texas. American Journal of Science 247, 324–41.CrossRefGoogle Scholar
Lees, J. H. 1907. The skull of Paleorhinus. Journal of Geology 15, 121–51.Google Scholar
Lehman, T. M. 1994a. The saga of the Dockum Group and the case of the Texas/New Mexico boundary fault. In Ahlen, J., Peterson, J. & Bowsher, A. L. (eds) Geologic Activities in the 90s – Southwest Section of AAPG 1994, Ruidosa, New Mexico. New Mexico Bureau of Mines & Mineral Resources Bulletin 150, 37–51. Socorro: New Mexico Bureau of Mines & Mineral Resources. 137 pp.Google Scholar
Lehman, T. M. 1994b. Save the Dockum Group! West Texas Geological Society Bulletin 34, 5–10.Google Scholar
Lehman, T. M. & Chatterjee, S. 2005. Depositional setting and vertebrate biostratigraphy of the Triassic Dockum Group of Texas. Journal of Earth System Sciences 114, 325–51.Google Scholar
Long, R. A. & Murry, P. A. 1995. Late Triassic (Carnian and Norian) tetrapods from the southwestern United States. New Mexico Museum of Natural History and Science Bulletin 4. Albuquerque: New Mexico Museum of Natural History and Science. V+254 pp.Google Scholar
Lucas, S. G. 1993. The Chinle Group: Revised stratigraphy and biochronology of Upper Triassic nonmarine strata in the western United States. Museum of Northern Arizona Bulletin 59, 27–50.Google Scholar
Lucas, S. G. 1997. The Upper Triassic Chinle Group, western United States, nonmarine standard for Late Triassic time. In Dickins, J. M., Yang, Z., Yin, H., Lucas, S. G. & Acharyya, S. K. (eds) Permo-Triassic of the circum-Pacific, 200–28. Cambridge, Massachusetts: Cambridge University Press.Google Scholar
Lucas, S. G., Anderson, O. J. & Hunt, A. P. 1994. Triassic stratigraphy and correlations, southern High Plains of New Mexico and Texas. In Ahlen, J., Peterson, J. & Bowsher, A. L. (eds) Geologic Activities in the 90s – Southwest Section of AAPG 1994, Ruidosa, New Mexico. New Mexico Bureau of Mines and Mineral Resources Bulletin 150, 105–126. Socorro: New Mexico Bureau of Mines & Mineral Resources. 137 pp.Google Scholar
Lucas, S. G., Heckert, A. B. & Hunt, A. P. 2001. Triassic stratigraphy, biostratigraphy and correlation in east-central New Mexico. In Lucas, S. G. & Ulmer-Scholle, D. S. (eds) New Mexico Geological Society, Field Conference Guidebook, 52, Geology of the Llano Estacado, 85–102. Socorro, New Mexico: New Mexico Geological Society,Google Scholar
Lucas, S. G., Heckert, A. B., Zeigler, K. E. & Hunt, A. P. 2002. The type locality of Belodon buceros Cope, 1881, a phytosaur (Archosauria: Parasuchidae) from the Upper Triassic of north-central New Mexico. In Heckert, A. B. & Lucas, S. G. (eds) Upper Triassic stratigraphy and paleontology. New Mexico Museum of Natural History and Science Bulletin 21, 189–92. Albuquerque: New Mexico Museum of Natural History and Science. 301 pp.Google Scholar
Lucas, S. G. & Hunt, A. P. 1989. Revised Triassic stratigraphy in the Tucumcari Basin, east-central New Mexico. In Lucas, S. G. & Hunt, A. P. (eds) Dawn of the Age of Dinosaurs in the American Southwest, 150–70. Albuquerque: New Mexico Museum of Natural History.Google Scholar
Lucas, S. G. & Hunt, A. P. 1992. Triassic stratigraphy and paleontology, Chama Basin and adjacent areas, north-central New Mexico. In Lucas, S. G., Kues, B. S., Williamson, T. E. & Hunt, A. P. (eds) New Mexico Geological Society, Field Conference Guidebook, 43, San Juan Basin IV, 151–72. Socorro: New Mexico Geological Society.Google Scholar
Maddison, W. P. & Maddison, D. R. 1997. MacClade 3.0.7. Sunderland, Massachusetts: Sinauer Associates.Google Scholar
Madsen, J. H. Jr. 1976. Allosaurus fragilis: A revised osteology. Utah Geological Survey Bulletin 109. Salt Lake City: Utah Geological Survey. xii+164 pp. [Reprinted 1993.]Google Scholar
Madsen, J. H. Jr. & Welles, S. P. 2000. Ceratosaurus (Dinosauria, Theropoda) A revised osteology. Utah Geological Survey Miscellaneous Publications 2. 80 pp.Google Scholar
Martz, J. W. 2008. Lithostratigraphy, chemostratigraphy, and vertebrate biostratigraphy of the Dockum Group (Upper Triassic), of southern Garza County, West Texas. Unpublished PhD Dissertation, Texas Tech University, Lubbock, Texas, USA. 504 pp.Google Scholar
McGregor, J. H. 1906. The Phytosauria, with especial reference to Mystriosuchus and Rhytidodon. Memoirs of the American Museum of Natural History 9. 27–100.Google Scholar
Mehl, M. G. 1916. New or little known phytosaurs from Arizona. Quarterly Bulletin, University of Oklahoma, New Series 108, 5–28.Google Scholar
Mehl, M. G. 1922. A new phytosaur from the Trias of Arizona. Journal of Geology 30, 44–157.Google Scholar
Mehl, M. G. 1928. Pseudopalatus Pristinus, a new genus and species of phytosaurs from Arizona. University of Missouri Studies 3, 1–22.Google Scholar
Meyer, H. v. 1860. Briefliche Mittheilung an Prof. Bronn [13. Juli 1860]. Neues Jahrbuch für Mineralogie, Geognosie, Geologie und Petrefakten-Kunde 1860, 556–60.Google Scholar
Meyer, H. v. 1865. Reptilien aus dem Stubensandstein des oberen Keupers (Dritte Folge). Palaeontographica 14, 99–124.Google Scholar
Nesbitt, S. J. 2011. The early evolution of archosaurs: Relationships and origin of major clades. Bulletin of the American Museum of Natural History 352. 292 pp.Google Scholar
Parker, W. G., Hungerbühler, A. & Martz, J. W. 2013. The taxonomic status of the phytosaurs (Archosauriformes) Machaeroprosopus and Pseudopalatus from the Late Triassic of the western United States. Earth and Environmental Science Transactions of the Royal Society of Edinburgh 103 (for 2012), 265–68.Google Scholar
Parker, W. G. & Irmis, R. B. 2006. A new species of the Late Triassic phytosaur Pseudopalatus (Archosauria: Pseudosuchia) from Petrified Forest National Park. Museum of Northern Arizona Bulletin 62, 126–43.Google Scholar
Parker, W. G. & Martz, J. W, 2011. The Late Triassic (Norian) Adamanian–Revueltian tetrapod faunal transition in the Chinle Formation of Petrified Forest National Park, Arizona. Earth and Environmental Science Transactions of the Royal Society of Edinburgh 101 (for 2010), 231–60.Google Scholar
Parrish, J. M. 1994. Cranial osteology of Longosuchus meadei and the phylogeny and distribution of the Aetosauria. Journal of Vertebrate Paleontology 14, 196–209.Google Scholar
Rieppel, O. 1993. Studies on the skeleton formation in reptiles. V. Patterns of ossification in the skeleton of Alligator mississippiensis DAUDIN (Reptilia, Crocodylia). Zoological Journal of the Linnean Society 109, 301–25.Google Scholar
Romer, A. S. 1956. Osteology of the reptiles. Chicago and London: University of Chicago Press. XXI+772 pp.Google Scholar
Roth, J. J. & Roth, C. R. 1980. The parietal–pineal complex among paleovertebrates: Evidence for temperature regulation. In Thomas, R. D. K. & Olson, E. C. (eds) A cold look at the warm-blooded dinosaurs, 189–231. Boulder, Colorado: Westview Press, for the American Association for the Advancement of Science. 514 pp.Google Scholar
Senter, P. 2002. Lack of a pheromonal sense in phytosaurs and other archosaurs, and its implications for reproductive communication. Paleobiology 28, 544–50.Google Scholar
Sereno, P. C. 1991. Basal archosaurs: phylogenetic relationships and functional implications. Society of Vertebrate Paleontology Memoir 2. 53 pp.Google Scholar
Simpson, E. O. 1998. The phylogeny and biostratigraphic utility of parasuchids from the Dockum Group of West Texas. Unpublished MSc Thesis, Texas Tech University, Lubbock, Texas, USA. 137 pp.Google Scholar
Small, B. J. 2002. Cranial anatomy of Desmatosuchus haplocerus (Reptilia: Archosauria: Stagonolepididae). Zoological Journal of the Linnean Society 136, 97–111.Google Scholar
Smith, J. B. & Dodson, P. 2003. A proposal for a standard terminology of anatomical notation and orientation in fossil vertebrate dentitions. Journal of Vertebrate Paleontology 23, 1–12.Google Scholar
Spielmann, J. A. & Lucas, S. G. 2012. Tetrapod fauna of the Upper Triassic Redonda Formation, east-central New Mexico: The characteristic assemblage of the Apachean land-vertebrate faunachron. New Mexico Museum of Natural History and Science Bulletin 55. Albuquerque: New Mexico Museum of Natural History and Science. 119 pp.Google Scholar
Stocker, M. R. 2010. A new taxon of phytosaur (Archosauria: Pseudosuchia) from the Norian (Late Triassic) Sonsela Member (Chinle Formation) in Arizona, and a critical re-evaluation of Leptosuchus Case, 1922. Palaeontology 53, 997–1022.Google Scholar
Swofford, D. L. & Begle, D. P. 1993. PAUP – Phylogenetic Analysis Using Parsimony 3.1.1. Laboratory of Molecular Systematic. Washington, DC: Smithsonian Institution.Google Scholar
Trueb, L. 1993. Patterns of cranial diversity among the Lissamphibia. In Hanken, J. & Hall, B. K. (eds) The skull, 2, Patterns of structural and systematic diversity, 255–342. Chicago and London: University of Chicago Press.Google Scholar
Walker, A. D. 1990. A revision of Sphenosuchus acutus Haughton, a crocodylomorph reptile from the Elliot Formation (late Triassic or early Jurassic) of South Africa. Philosophical Transactions of the Royal Society, London, Series B 330, 1–120.Google Scholar
Weinbaum, J. C. 2011. The skull of Postosuchus kirkpatricki (Archosauria: Paracrocodyliformes) from the Upper Triassic of the United States. Palaeobios 30, 18–44.Google Scholar
Westphal, K. W. 1979. Missing holotype Machaeroprosopus validus (Mehl, 1916). Journal of Paleontology 53, 741.Google Scholar
Wible, J. R., Miao, D. & Hopson, J. A. 1990. The septomaxilla of fossil and recent synapsids and the problem of the septomaxilla of monotremes and armadillos. Zoological Journal of the Linnean Society 98, 203–28.Google Scholar
Wilkinson, M. 1995. A comparison of two methods of character construction. Cladistics 11, 297–308.Google Scholar
Wilkinson, M. & Benton, M. J. 1996. Sphenodontid phylogeny and the problem of multiple trees. Philosophical Transactions of the Royal Society, London Series B 351, 1–16.Google Scholar
Witmer, L. M. 1997. The evolution of the antorbital cavity in archosaurs: A study in soft-tissue reconstruction in the fossil record with analysis of the function of pneumaticity. Society of Vertebrate Paleontology Memoir 3. 73 pp.Google Scholar
Zeigler, K. E. 2003. Taphonomic analysis of the Snyder quarry: A fire-related Upper Triassic vertebrate fossil assemblage from north-central New Mexico. In Zeigler, K. E., Heckert, A. B. & Lucas, S. G. (eds) Paleontology and geology of the Upper Triassic (Revueltian) Snyder quarry, New Mexico, U.S.A. New Mexico Museum of Natural History and Science Bulletin 24, 49–62. Albuquerque: New Mexico Museum of Natural History and Science. 132 pp.Google Scholar
Zeigler, K. E., Lucas, S. G. & Heckert, A. B. 2002a. The Late Triassic Canjilon Quarry (Upper Chinle Group) phytosaur skulls: evidence of sexual dimorphism in phytosaurs. In Heckert, A. B. & Lucas, S. G. (eds) Upper Triassic stratigraphy and paleontology. New Mexico Museum of Natural History and Science Bulletin 21, 179–88. Albuquerque: New Mexico Museum of Natural History and Science. 301 pp.Google Scholar
Zeigler, K. E., Lucas, S. G. & Heckert, A. B. 2002b. A phytosaur skull from the Upper Triassic Snyder Quarry (Petrified Forest Formation, Chinle Group) of north-central New Mexico. In Heckert, A. B. & Lucas, S. G. (eds) Upper Triassic stratigraphy and paleontology. New Mexico Museum of Natural History and Science Bulletin 21, 171–77. Albuquerque: New Mexico Museum of Natural History and Science. 301 pp.Google Scholar
Zeigler, K. E., Heckert, A. B. & Lucas, S. G. 2003a. Phytosaur (Archosauria: Parasuchidae) cranial and mandibular material from the Upper Triassic Snyder quarry (Petrified Forest Formation, Chinle Group. In Zeigler, K. E., Heckert, A. B. & Lucas, S. G. (eds) Paleontology and geology of the Upper Triassic (Revueltian) Snyder quarry, New Mexico, U.S.A. New Mexico Museum of Natural History and Science Bulletin 24, 81–88. Albuquerque: New Mexico Museum of Natural History and Science. 132 pp.Google Scholar
Zeigler, K. E., Lucas, S. G. & Heckert, A. B. 2003b. Variation in the Late Triassic Canjilon quarry (Upper Chinle Group, New Mexico) phytosaur skulls: a case for sexual dimorphism. Paläontologische Zeitschrift 77, 341–51.Google Scholar