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

  • Axel Hungerbühler (a1), Bill Mueller (a2), Sankar Chatterjee (a2) and Douglas P. Cunningham (a2)
Abstract
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.

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Alcober O. 2000. Redescription of the skull of Saurosuchus galilei (Archosauria: Rauisuchidae). Journal of Paleontology 20, 302–16.
Anderson H. T. 1936. The jaw musculature of the phytosaur, Machaeroprosopus. Journal of Morphology 59, 549–74.
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.
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.
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.
Camp C. L. 1942. California mosasaurs. Memoirs of the University of California 13. VI+68 pp.
Case E. C. 1922. New reptiles and stegocephalians from the upper Triassic of western Texas. Carnegie Institution of Washington 321, 184.
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.
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.
Chatterjee S. 1978. A primitive parasuchid (phytosaur) reptile from the Upper Triassic Maleri Formation of India. Palaeontology 21, 83127.
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, 395460.
Clark J. M., Welman J., Gauthier J. A. & Parrish J. M. 1993. The laterosphenoid bone of early archosauriforms. Journal of Vertebrate Palaeontology 13, 4857.
Colbert E. H. 1947. Studies of the phytosaurs Machaeroprosopus and Rutiodon. Bulletin of the American Museum of Natural History 88, 5396.
Colbert E. & Russel D. A. 1969. The small Cretaceous Dinosaur Dromaeosaurus. American Museum Novitates 2380. 49 pp.
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.
Cope E. D. 1881. Belodon in New Mexico. The American Naturalist 15, 922–23.
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.
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.
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.
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.
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, 297336.
Emmons E. 1856. Geological report of the midland counties of North Carolina. New York: George P. Putnam and Co. XX+352 pp.
Eriksson T. 1998. Autodecay 4.0. Stockholm, Sweden: Department of Botany, Stockholm University.
Fraas E. 1896. Die schwäbischen Trias-Saurier nach dem Material der Kgl. Naturalien-Sammlung in Stuttgart zusammengestellt. Stuttgart: Schweizerbart. 18 pp.
Frey E. 1988. Anatomie des Körperstammes von Alligator mississippiensis Daudin. Stuttgarter Beiträge zur Naturkunde Reihe A 424. 106 pp.
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.
Gauthier J. A., Kluge A. G. & Rowe T. 1988. Amniote phylogeny and the importance of fossils. Cladistics 4, 105209.
Gower D. J. 1997. The braincase of the early archosaurian reptile Erythrosuchus africanus. Journal of Zoology 242, 557–76.
Gower D. J. 2002. Braincase evolution in suchian archosaurs (Reptilia: Diapsida): evidence from the rauisuchian Batrachotomus kupferzellensis. Zoological Journal of the Linnean Society 136, 4976.
Gower D. J. & Sennikov A. G. 1996. Morphology and phylogenetic informativeness of early archosaur braincases. Palaeontology 39, 883906.
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, 723.
Gregory J. T. 1962. The genera of phytosaurs. American Journal of Science 260, 652–90.
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.
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.
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, 136. Albuquerque: New Mexico Museum of Natural History and Science. 301 pp.
Huene F. v. 1909. Vorläufige Mitteilung über einen neuen Phytosaurus-Schädel aus dem schwäbischen Keuper. Centralblatt für Mineralogie, Geologie und Paläontologie 1909, 583–92.
Huene F. v. 1911. Beiträge zur Kenntnis und Beurteilung der Parasuchier. Geologische und Palaeontologische Abhandlungen, Neue Folge 10, 67121.
Huene F. v. 1915. On reptiles of the New Mexican Trias in the Cope Collection. Bulletin of the American Museum of Natural History 34, 485507.
Huene F. v. 1922. Neue Beiträge zur Kenntnis der Parasuchier. Jahrbuch der Preussischen Geologischen Landesanstalt 42, 59160.
Hungerbühler A. 1998. Cranial anatomy and diversity of the Norian phytosaurs of Southwestern Germany. Unpublished PhD Dissertation, University of Bristol, Bristol, UK. 465 pp.
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, 3148.
Hungerbühler A. 2002. The Late Triassic phytosaur Mystriosuchus westphali, with a revision of the genus. Paleontology 45, 377418.
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.
Hungerbühler A. & Sues H.-D. 2001. Status and phylogenetic relationships of the Late Triassic phytosaur Rutiodon carolinensis. Journal of Vertebrate Paleontology 21, 64A.
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.
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.
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.
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.
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.
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.
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.
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.
Irmis R. B. 2005. The vertebrate fauna of the Upper Triassic Chinle Formation in northern Arizona. Mesa Southwest Museum Bulletin 9, 6388.
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.
Jaeger G. F. 1828. Über die fossilen Reptilien, welche in Würtemberg aufgefunden worden sind. Stuttgart, Germany: Metzler. 48 pp.
Janensch W. 1936. Über Bahnen von Hirnvenen bei Saurischiern und Ornithischiern, sowie einigen anderen fossilen und rezenten Reptilien. Palaeontologische Zeitschrift 18, 181–98.
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.
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, 1228. Albuquerque: New Mexico Museum of Natural History.
Langston W. Jr. 1949. A new species of Paleorhinus from the Triassic of Texas. American Journal of Science 247, 324–41.
Lees J. H. 1907. The skull of Paleorhinus. Journal of Geology 15, 121–51.
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, 3751. Socorro: New Mexico Bureau of Mines & Mineral Resources. 137 pp.
Lehman T. M. 1994b. Save the Dockum Group! West Texas Geological Society Bulletin 34, 510.
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.
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.
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, 2750.
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.
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, 105126. Socorro: New Mexico Bureau of Mines & Mineral Resources. 137 pp.
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, 85102. Socorro, New Mexico: New Mexico Geological Society,
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.
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.
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.
Maddison W. P. & Maddison D. R. 1997. MacClade 3.0.7. Sunderland, Massachusetts: Sinauer Associates.
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.]
Madsen J. H. Jr. & Welles S. P. 2000. Ceratosaurus (Dinosauria, Theropoda) A revised osteology. Utah Geological Survey Miscellaneous Publications 2. 80 pp.
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.
McGregor J. H. 1906. The Phytosauria, with especial reference to Mystriosuchus and Rhytidodon. Memoirs of the American Museum of Natural History 9. 27100.
Mehl M. G. 1916. New or little known phytosaurs from Arizona. Quarterly Bulletin, University of Oklahoma, New Series 108, 528.
Mehl M. G. 1922. A new phytosaur from the Trias of Arizona. Journal of Geology 30, 44157.
Mehl M. G. 1928. Pseudopalatus Pristinus, a new genus and species of phytosaurs from Arizona. University of Missouri Studies 3, 122.
Meyer H. v. 1860. Briefliche Mittheilung an Prof. Bronn [13. Juli 1860]. Neues Jahrbuch für Mineralogie, Geognosie, Geologie und Petrefakten-Kunde 1860, 556–60.
Meyer H. v. 1865. Reptilien aus dem Stubensandstein des oberen Keupers (Dritte Folge). Palaeontographica 14, 99124.
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.
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.
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.
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.
Parrish J. M. 1994. Cranial osteology of Longosuchus meadei and the phylogeny and distribution of the Aetosauria. Journal of Vertebrate Paleontology 14, 196209.
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.
Romer A. S. 1956. Osteology of the reptiles. Chicago and London: University of Chicago Press. XXI+772 pp.
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, 189231. Boulder, Colorado: Westview Press, for the American Association for the Advancement of Science. 514 pp.
Senter P. 2002. Lack of a pheromonal sense in phytosaurs and other archosaurs, and its implications for reproductive communication. Paleobiology 28, 544–50.
Sereno P. C. 1991. Basal archosaurs: phylogenetic relationships and functional implications. Society of Vertebrate Paleontology Memoir 2. 53 pp.
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.
Small B. J. 2002. Cranial anatomy of Desmatosuchus haplocerus (Reptilia: Archosauria: Stagonolepididae). Zoological Journal of the Linnean Society 136, 97111.
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, 112.
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.
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, 9971022.
Swofford D. L. & Begle D. P. 1993. PAUP – Phylogenetic Analysis Using Parsimony 3.1.1. Laboratory of Molecular Systematic. Washington, DC: Smithsonian Institution.
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, 255342. Chicago and London: University of Chicago Press.
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, 1120.
Weinbaum J. C. 2011. The skull of Postosuchus kirkpatricki (Archosauria: Paracrocodyliformes) from the Upper Triassic of the United States. Palaeobios 30, 1844.
Westphal K. W. 1979. Missing holotype Machaeroprosopus validus (Mehl, 1916). Journal of Paleontology 53, 741.
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.
Wilkinson M. 1995. A comparison of two methods of character construction. Cladistics 11, 297308.
Wilkinson M. & Benton M. J. 1996. Sphenodontid phylogeny and the problem of multiple trees. Philosophical Transactions of the Royal Society, London Series B 351, 116.
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.
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, 4962. Albuquerque: New Mexico Museum of Natural History and Science. 132 pp.
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.
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.
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, 8188. Albuquerque: New Mexico Museum of Natural History and Science. 132 pp.
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.
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