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Macroecological responses of terrestrial vegetation to climatic and atmospheric change across the Triassic/Jurassic boundary in East Greenland

Published online by Cambridge University Press:  08 April 2016

Jennifer C. McElwain ,
Mihai E. Popa ,
Stephen P. Hesselbo ,
Matthew Haworth  and
Finn Surlyk
Jennifer C. McElwain
Affiliation:
Department of Geology, The Field Museum, 1400 South Lake Shore Drive, Chicago, Illinois 60605. E-mail: Jennifer.McElwain@ucd.ie
Mihai E. Popa
Affiliation:
University of Bucharest, Faculty of Geology and Geophysics, Department of Geology and Palaeontology, 1, Nicolae Balcescu Avenue, 010041, Bucharest. E-mail: mihai@mepopa.com
Stephen P. Hesselbo
Affiliation:
Department of Earth Sciences, University of Oxford, Oxford, OX1 3PR, United Kingdom. E-mail: Stephen.Hesselbo@earth.ox.ac.uk
Matthew Haworth
Affiliation:
UCD School of Biology and Environmental Science, University College Dublin, National University of Ireland, Belfield, Dublin 4, Ireland. E-mail: Matthew.Haworth@ucd.ie
Finn Surlyk
Affiliation:
Institute of Geography and Geology, University of Copenhagen, Øster Voldgade 5-7, DK-1350 Copenhagen, Denmark. E-mail: FINNS@geol.ku.dk
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Abstract

The magnitude and pace of terrestrial plant extinction and macroecological change associated with the Triassic/Jurassic (Tr/J) mass extinction boundary have not been quantified using paleoecological data. However, tracking the diversity and ecology of primary producers provides an ideal surrogate with which to explore patterns of ecosystem stability, collapse, and recovery and to explicitly test for gradual versus catastrophic causal mechanisms of extinction.

We present an analysis of the vegetation dynamics in the Jameson Land Basin, East Greenland, spanning the Tr/J extinction event, from a census collected paleoecological data set of 4303 fossil leaf specimens, in an attempt to better constrain our understanding of the causes and consequences of the fourth greatest extinction event in earth history. Our analyses reveal (1) regional turnover of ecological dominants between Triassic and Jurassic plant communities, (2) marked structural changes in the vegetation as reflected by potential loss of a mid-canopy habit, and (3) decline in generic-level richness and evenness and change in ecological composition prior to the Tr/J boundary; all of these findings argue against a single catastrophic causal mechanism, such as a meteorite impact for Tr/J extinctions. We identify various key ecological and biological traits that increased extinction risk at the Tr/J boundary and corroborate predictions of meta-population theory or plant ecophysiological models. These include ecological rarity, complex reproductive biology, and large leaf size.

Recovery in terms of generic-level richness was quite rapid following Tr/J extinctions; however, species-level turnover in earliest Jurassic plant communities remained an order of magnitude higher than observed for the Triassic. We hypothesize, on the basis of evidence for geographically extensive macrofossil and palynological turnover across the entire Jameson Land Basin, that the nature and magnitude of paleoecological changes recorded in this study reflect wider vegetation change across the whole region. How exactly these changes in dominance patterns of plant primary production affected the entire ecosystem remains an important avenue of future research.

Type
Articles
Information
Paleobiology , Volume 33 , Issue 4 , Fall 2007 , pp. 547 - 573
Copyright
Copyright © The Paleontological Society 

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References

Literature Cited

Archangelsky, A., Andreis, R. R., Archangelsky, S., and Artabe, A. 1995. Cuticular characters adapted to volcanic stress in a new Cretaceous cycad leaf from Patagonia, Argentina: considerations on the stratigraphy and depositional history of the Baquero Formation. Review of Palaeobotany and Palynology 89: 213–233.CrossRefGoogle Scholar
Ash, S. 1986. Fossil plants and the Triassic-Jurassic boundary. Pp. 21–30 in Padian, K., ed. The beginning of the age of dinosaurs. Cambridge University Press, Cambridge.Google Scholar
Axsmith, B. J., Krings, M., and Waselkov, K. 2004. Conifer pollen cones from the Cretaceous of Arkansas: implications for diversity and reproduction in the Cheirolepidaceae. Journal of Paleontology 78: 402–409.2.0.CO;2>CrossRefGoogle Scholar
Bambach, R. K., Knoll, A. H., and Wang, S. C. 2004. Origination, extinction, and mass depletions of marine diversity. Paleobiology 30: 522–542.2.0.CO;2>CrossRefGoogle Scholar
Beerling, D. J., and Berner, R. A. 2002. Biogeochemical constraints on the Triassic-Jurassic boundary carbon cycle event. Global Biogeochemical Cycles 16.CrossRefGoogle Scholar
Behrensmeyer, A. K., Kidwell, S. M., and Gastaldo, R. A. 2000. Taphonomy and paleobiology. In Erwin, D. H. and Wing, S. L., eds. Deep time: Paleobiology's perspective. Paleobiology 26(Suppl. to No. 4): 103–148.CrossRefGoogle Scholar
Burnham, R. J. 1989. Relationships between standing vegetation and leaf litter in a paratropical forest: implications for paleobotany. Review of Palaeobotany and Palynology 58: 5–32.CrossRefGoogle Scholar
Burnham, R. J. 1993. Reconstructing richness in the plant fossil record. Palaios 8: 376–384.CrossRefGoogle Scholar
Burnham, R. J., Wing, S. L., and Parker, G. G. 1992. The reflection of deciduous forest communities in leaf litter: implications for autochthonous litter assemblages from the fossil record. Paleobiology 18: 30–49.CrossRefGoogle Scholar
Cantor, B. M., Aigler, B. V., Pace, D. W., Reid, S. B., Thomson, C. Y., and Gastaldo, R. A. 2006. Intra- and interspecific variation in stomatal proxies for Quercus and Nyssa in the subtropical southeastern USA. Geological Society of America Abstracts with Programs 38: 487.Google Scholar
Carter, E. S., and Hori, R. S. 2005. Global correlation of the radiolarian faunal change across the Triassic-Jurassic boundary. Canadian Journal of Earth Sciences 42: 777–790.CrossRefGoogle Scholar
Crane, P. R. 1985. Phylogenetic analysis of seed plants and the origin of angiosperms. Annals of the Missouri Botanical Garden 72: 716–793.CrossRefGoogle Scholar
Crepet, L. 1974. Investigations of North American cycadeoids: the reproductive biology of Cycadeoidea. Palaeontographica, Abteilung B 148: 144–169.Google Scholar
Dam, G., and Surlyk, F. 1993a. Cyclic sedimentation in a large wave- and storm-dominated anoxic lake, Kap Stewart Formation (Rhaetian-Sinemurian), Jameson Land, East Greenland. International Association of Sedimentologists Special Publication 18: 419–448.Google Scholar
Dam, G., and Surlyk, F. 1993b. Forced regressions in a large wave- and storm dominated anoxic lake; Kap Stewart Formation East Greenland. Geology 20: 748–751.Google Scholar
Delevoryas, T. 1963. Investigations of North American cycadeoids: cones of Cycadeoidea. American Journal of Botany 50: 45–52.CrossRefGoogle Scholar
DiMichele, W. A., Pfefferkorn, H., and Phillips, T. L. 1996. Persistence of Late Carboniferous tropical vegetation during glacially driven climatic and sea-level fluctuations. Palaeogeography, Palaeoclimatology, Palaeoecology 125: 105–128.CrossRefGoogle Scholar
Donaldson, J. S. 1997. Is there a floral parasite mutualism in cycad pollination? The pollination biology of Encpharlatos villosus (Zamiaceae). American Journal of Botany 84: 1398–1406.CrossRefGoogle Scholar
Droser, M. L., Bottjer, D. J., and Sheehan, P. M. 1997. Evaluating the ecological architecture of major events in the Phanerozoic history of marine invertebrate life. Geology 25: 167–170.2.3.CO;2>CrossRefGoogle Scholar
Droser, M. L., Bottjer, D. J., Sheehan, P. M., and McGhee, G. R. 2000. Decoupling of taxonomic and ecologic severity of Phanerozoic marine mass extinctions. Geology 28: 675–678.2.0.CO;2>CrossRefGoogle Scholar
Ferguson, D. K. 1985. The origin of leaf assemblages—new light on an old problem. Review of Palaeobotany and Palynology 46: 117–188.CrossRefGoogle Scholar
Foote, M. 2000. Origination and extinction components of taxonomic diversity: general problems. In Erwin, D. H. and Wing, S. L., eds. Deep time: Paleobiology's perspective. Paleobiology 26(Suppl. to No. 4): 74–102.CrossRefGoogle Scholar
Fowell, S. J., and Olsen, P. E. 1993. Time calibration of Triassic-Jurassic microfloral turnover, Eastern North America. Tectonophysics 222: 361–369.CrossRefGoogle Scholar
Galli, M. T., Jadoul, F., Bernasconi, S. M., Cirilli, S., and Weissert, H. 2006. Stratigraphy and paleoenvironmental analysis of the Triassic-Jurassic boundary interval in the Zleichov Basin, Western Carpathians. Palaeogeography, Palaeoclimatology, Palaeoecology 244: 52–71.CrossRefGoogle Scholar
Galli, M. T., Jadoul, F., Bernasconi, S. M., and Weissert, H. 2005. Anomalies in global carbon cycling and extinction at the Triassic/Jurassic boundary: evidence from a marine C-isotope record. Palaeogeography, Palaeoclimatology, Palaeoecology 216: 203–214.CrossRefGoogle Scholar
Gastaldo, R. A. 1989. Preliminary observations on phytotaphonomic assemblages in a subtropical/temperate Holocene bay-head delta: Mobile Delta, Gulf Coastal Plain, Alabama. Review of Palaeobotany and Palynology 58: 61–83.CrossRefGoogle Scholar
Gastaldo, R. A. 2001. Plant taphonomy. Pp. 314–317 in Briggs, D. E. G. and Crowther, P. R., eds. Paleobiology II. Blackwell Science, Oxford.Google Scholar
Gaston, K. J. 1994. Rarity. Chapman and Hall, London.CrossRefGoogle Scholar
Gauslaa, Y. 1984. A comparison between heat resistance and heat exchange capacity in different vascular plants. Holarctic Ecology 7: 64–70.Google Scholar
Guex, J., Bartolini, A., Atudorei, V., and Taylor, D. 2004. High-resolution ammonite and carbon isotope stratigraphy across the Triassic-Jurassic boundary at New York Canyon (Nevada). Earth and Planetary Science Letters 225: 29–41.CrossRefGoogle Scholar
Hallam, A. 1997. Estimates for the amount and rate of sea level change across the Rhaetic-Hettangian and Pliensbachian-Toarcian boundaries (latest Triassic to Early Jurassic). Journal of the Geological Society, London 154: 773–779.CrossRefGoogle Scholar
Hallam, A. 2002. How catastrophic was the end-Triassic mass extinction? Lethaia 35: 147–157.Google Scholar
Hammer, O., Harper, D. A. T., and Ryan, P. D. 2001. PAST: paleontological statistics software package for education and data analysis, Version 1. 33. Available online at http://folk.uio.no/ohammer/past.Google Scholar
Harris, T. M. 1926. The Rhaetic flora of Scoresby Sound, East Greenland. Meddelelser om Grønland 68: 1–43.Google Scholar
Harris, T. M. 1931. The fossil flora of Scoresby Sound, East Greenland, Part 1. Cryptogams. Meddelelser om Grønland 85: 1–102.Google Scholar
Harris, T. M. 1932a. The fossil flora of Scoresby Sound, East Greenland, Part 2. Seed plants incertae sedis. Meddelelser om Grønland 85(3): 1–112.Google Scholar
Harris, T. M. 1932b. The fossil flora of Scoresby Sound, East Greenland, Part 3. Caytoniales and Bennettitales. Meddelelser om Grønland 85(5): 1–133.Google Scholar
Harris, T. M. 1935. The fossil flora of Scoresby Sound, East Greenland, Part 4. Ginkgoales, Lycopodiales and isolated fructifications. Meddelelser om Grønland 112(1): 1–121.Google Scholar
Harris, T. M. 1937. The fossil flora of Scoresby Sound East Greenland, Part 5. Stratigraphic relations of the plant beds. Meddelelser om Grønland 112(2): 1–112.Google Scholar
Harris, T. M. 1974. Williamsoniella lignieri: its pollen and the compression of spherical pollen grains. Palaeontology 17: 125–148.Google Scholar
Hay, W. W., and DeConto, R. M. 1999. Comparison of modern and Late Cretaceous meridonal energy transport and oceanology. In Barrera, E. and Johnson, C. C., eds. Evolution of the Cretaceous ocean-climate system. Geological Society of America Special Paper 332: 283–300.Google Scholar
Hesselbo, S. P., Robinson, S. A., Surlyk, F., and Piasecki, S. 2002. Terrestrial and marine extinction at the Triassic-Jurassic boundary synchronized with major carbon-cycle perturbation: a link to initiation of massive volcanism? Geology 30: 251–254.2.0.CO;2>CrossRefGoogle Scholar
Hesselbo, S. P., Robinson, S. A., and Surlyk, F. 2004. Sea-level change and facies development across potential Triassic-Jurassic boundary horizons, SW Britain. Journal of the Geological Society 161: 365–379.CrossRefGoogle Scholar
Hill, M. O., and Gauch, H. G. J. 1980. Detrended correspondence analysis: an improved ordination technique. Vegetatio 42: 47–58.CrossRefGoogle Scholar
Hodych, J. P., and Dunning, G. R. 1992. Did the Manicouagan impact trigger end-of-Triassic mass extinction? Geology 20: 51–54.2.3.CO;2>CrossRefGoogle Scholar
Howe, J., and Cantrill, D. J. 2001. Palaeoecology and taxonomy of Pentoxylales from the Albian of Antarctica. Cretaceous Research 22: 779–793.CrossRefGoogle Scholar
Hubbard, R., and Boulter, M. C. 2000. Phytogeography and paleoecology in Western Europe and eastern Greenland near the Triassic-Jurassic boundary. Palaios 15: 120–131.2.0.CO;2>CrossRefGoogle Scholar
Huynh, T. T., and Poulsen, C. J. 2005. Rising atmospheric CO2 as a possible trigger for the end-Triassic mass extinction. Palaeogeography, Palaeoclimatology, Palaeoecology 217: 223–242.CrossRefGoogle Scholar
Kerp, H., Abu Hamad, A., Vording, B., and Bandel, K. 2006. Typical Triassic Gondwanan floral elements in the Upper Permian of the paleotropics. Geology 34: 265–268.CrossRefGoogle Scholar
Kiessling, W. 2001. Paleoclimatic significance of Phanerozoic reefs. Geology 29: 751–754.2.0.CO;2>CrossRefGoogle Scholar
Kiessling, W. 2005. Long-term relationships between ecological stability and biodiversity in Phanerozoic reefs. Nature 433: 410–413.CrossRefGoogle ScholarPubMed
Kimura, T., and Sekido, S. 1975. Nilssoniocladus n. gen. (Nilssoniaceae n. fam.) newly found from the Early Lower Cretaceous of Japan. Palaeontographica 153: 111–118.Google Scholar
Klavins, S. D., Taylor, E. L., Krings, M., and Taylor, T. N. 2003. Gymnosperms from the middle Triassic of Antarctica: the first structurally preserved cycad pollen cone. International Journal of Plant Sciences 164: 1007–1020.CrossRefGoogle Scholar
Klavins, S. D., Kellogg, D. W., Krings, M., Taylor, E. L., and Taylor, T. N. 2005. Coprolites in a Middle Triassic cycad pollen cone: evidence for insect pollination in early cycads? Evolutionary Ecology Research 7: 479–488.Google Scholar
Knight, K. B., Nomade, S., Renne, P. R., Marzoli, A., Bertrand, H., and Youbi, N. 2004. The central Atlantic magmatic province at the Triassic-Jurassic boundary: paleomagnetic and Ar-40/Ar-39 evidence from Morocco for brief, episodic volcanism. Earth and Planetary Science Letters 228: 143–160.CrossRefGoogle Scholar
Koppelhus, E. B. 1997. Palynology of the lacustrine Kap Stewart Formation, Jameson Land, East Greenland. Danmark og Grønlands Geologiske Undersøgelse Rapport 1996/30, Appendix 5.Google Scholar
Krings, M., Kerp, H., Taylor, T. N., and Taylor, E. L. 2003. How Paleozoic vines and lianas got off the ground: on scrambling and climbing Carboniferous-early Permian pteridosperms. Botanical Review 69: 204–224.CrossRefGoogle Scholar
Larcher, W. 1994. Photosynthesis as a tool for indicating temperature stress events. P. 513 in Schulze, E.-D. and Caldwell, M. M., eds. Ecophysiology of photosynthesis. Ecological Studies, Vol. 10. Springer, New York.Google Scholar
Lawton, J. H., Daily, G., and Newton, I. 1994. Population-dynamic principles. Philosophical Transactions of the Royal Society of London B 344: 61–68.Google Scholar
Loreau, M., Naeem, S., Inchausti, P., Bengtsson, J., Grime, J. P., Hector, A., Hooper, D. U., Huston, M. A., Raffaelli, D., Schmid, B., Tilman, D., and Wardle, D. A. 2001. Ecology—biodiversity and ecosystem functioning: current knowledge and future challenges. Science 294: 804–808.CrossRefGoogle Scholar
Loreau, M., Mouquet, N., and Gonzalez, A. 2003. Biodiversity as spatial insurance in heterogeneous landscapes. Proceedings of the National Academy of Sciences USA 100: 12765–12770.CrossRefGoogle ScholarPubMed
Marzoli, A., Renne, P. R., Piccirillo, E. M., Ernesto, M., Bellieni, G., and De Min, A. 1999. Extensive 200-million-year-old continental flood basalts of the Central Atlantic Magmatic Province. Science 284: 616–618.CrossRefGoogle ScholarPubMed
Marzoli, A., Bertrand, H., Knight, K. B., Cirilli, S., Buratti, N., Verati, C., Nomade, S., Renne, P. R., Youbi, N., Martini, R., Allenbach, K., Neuwerth, R., Rapaille, C., Zaninetti, L., and Bellieni, G. 2004. Synchrony of the Central Atlantic Magmatic Province and the Triassic-Jurassic boundary climatic and biotic crisis. Geology 32: 973–976.CrossRefGoogle Scholar
McElwain, J. C., Beerling, D. J., and Woodward, F. I. 1999. Fossil plants and global warming at the Triassic-Jurassic boundary. Science 285: 1386–1390.CrossRefGoogle ScholarPubMed
McElwain, J. C., Wade-Murphy, J., and Hesselbo, S. P. 2005. Changes in carbon dioxide during an oceanic anoxic event linked to intrusion into Gondwana coals. Nature 435: 479–482.CrossRefGoogle ScholarPubMed
McKinney, M. L. 1997. Extinction vulnerability and selectivity: combining ecological and paleontological views. Annual Review of Ecology and Systematics 28: 495–516.CrossRefGoogle Scholar
McRoberts, C. A., and Newton, C. R. 1995. Selective extinction among end-Triassic European bivalves. Geology 23: 102–104.2.3.CO;2>CrossRefGoogle Scholar
Mossman, D. J., Grantham, R. G., and Langenhorst, F. 1998. A search for shocked quarts at the Triassic-Jurassic boundary in the Fundy and Newark basins of the Newark supergroup. Canadian Journal of Earth Sciences 35: 101–109.CrossRefGoogle Scholar
Mound, L. A., and Terry, I. 2001. Thrips pollination of the central Australian cycad, Macrozamia macdonnellii (Cycadales). International Journal of Plant Sciences 162: 147–154.CrossRefGoogle Scholar
Newell, N. D. 1963. Crises in the history of life. Scientific American 208: 76–92.CrossRefGoogle Scholar
Oberprieler, R. G. 1995a. The weevils (Coleoptera: Curculionidae) associated with cycads. 1. Classification, relationships, and biology. Pp. 295–334 in Vorster, P., ed. Proceedings of the third international conference on cycad biology, Pretoria, 1993. Cycad Society of South Africa, Stellenbosch.Google Scholar
Oberprieler, R. G. 1995b. The weevils (Coleoptera: Curculionidae) associated with cycads. 2. Host specificity and implications for cycad taxonomy. Pp. 335–365 in Vorster, P., ed. Proceedings of the third international conference on cycad biology, Pretoria, 1993. Cycad Society of South Africa, Stellenbosch.Google Scholar
Olsen, P. E., Shubin, N. H., and Anders, M. H. 1987. New Early Jurassic tetrapod assemblages constrain Triassic-Jurassic tetrapod extinction event. Science 237: 1025–1029.CrossRefGoogle ScholarPubMed
Olsen, P. E., Kent, D. V., Sues, H. D., Koeberl, C., Huber, H., Montanari, A., Rainforth, E. C., Fowell, S. J., Szajna, M. J., and Hartline, B. W. 2002. Ascent of dinosaurs linked to an iridium anomaly at the Triassic-Jurassic boundary. Science 296: 1305–1307.CrossRefGoogle Scholar
Palfy, J., Smith, P. L., and Mortensen, J. K. 2000. A U-Pb and 40Ar/39Ar time scale for the Jurassic. Canadian Journal of Earth Sciences 37: 923–944.CrossRefGoogle Scholar
Palfy, J., Demeny, A., Haas, J., Hetenyi, M., Orchard, M. J., and Veto, I. 2001. Carbon isotope anomaly and other geochemical changes at the Triassic-Jurassic boundary from a marine section in Hungary. Geology 29: 1047–1050.2.0.CO;2>CrossRefGoogle Scholar
Parolin, P. 2001. Seed masses in Amazonian floodplains forests with contrasting nutrient supplies. Journal of Tropical Ecology 16: 417–428.CrossRefGoogle Scholar
Pedersen, K. R., and Lund, J. J. 1980. Palynology of the plant-bearing Rhaetian to Hettangian Kap Stewart Formation, Scoresby Sund, East Greenland. Review of Palaeobotany and Palynology 31: 1–69.CrossRefGoogle Scholar
Peters, S. E. 2004. Evenness of Cambrian-Ordovician benthic marine communities in North America. Paleobiology 30: 325–346.2.0.CO;2>CrossRefGoogle Scholar
Pfefferkorn, H. W., Mustafa, H., and Hass, H. 1975. Quantitative Charakteriseirung ober-karboner Abdruckfloren. Neues Jahrbuch für Geologie und Paläontologie 150: 253–269.Google Scholar
Popa, M. E. 2000. Early Jurassic land flora of the Getic Nappe. . University of Bucharest, Bucharest.Google Scholar
Rees, P. M., Ziegler, A. M., and Valdes, P. J. 2000. Jurassic phytogeography and climates: new data and model comparisons. Pp. 297–318 in Huber, B. T., MacLeod, K. G., and Wing, S. L., eds. Warm climates in earth history. Cambridge University Press, Cambridge.Google Scholar
Sepkoski, J. J. Jr. 1981. A factor analytic description of the Phanerozoic marine fossil record. Paleobiology 7: 36–53.CrossRefGoogle Scholar
Sepkoski, J. J. Jr. 1993. 10 years in the library: new data confirm paleontological patterns. Paleobiology 19: 43–51.CrossRefGoogle Scholar
Signor, P. W. III, and Lipps, J. H. 1982. Sampling bias, gradual extinction patterns and catastrophes in the fossil record. In Silver, L. T. and Shultz, P. H., eds. Geological implications of impacts of large asteroids and comets on the earth. Geological Society of America Special Paper 190: 291–296.CrossRefGoogle Scholar
Spicer, R. A. 1989. The formation and interpretation of plant fossil assemblages. Advances in Botanical Research Incorporating Advances in Plant Pathology 16: 95–191.Google Scholar
Spicer, R. A., and Herman, A. B. 1996. Nilssoniocladus in the Cretaceous Arctic: new species and biological insights. Review of Palaeobotany and Palynology 92: 229–243.CrossRefGoogle Scholar
Steart, D. C., Greenwood, D. R., and Boon, P. I. 2005. Paleoecological implications of differential biomass and litter production in canopy trees in Australian Nothofagus and Eucalyptus forests. Palaios 20: 452–462.CrossRefGoogle Scholar
Surlyk, F. 2003. The Jurassic of East Greenland: a sedimentary record of thermal subsidence, onset and culmination of rifting. Pp. 659–723 in Ineson, J. R. and Surlyk, F., eds. The Jurassic of Denmark and Greenland. Geological Survey of Denmark and Greenland, Copenhagen.Google Scholar
Sykes, R. M. 1974. Sedimentological studies in southern Jameson Land, East Greenland. I. Fluviatile sequences in the Kap Stewart Formation (Rhaetian-Hettangian). Bulletin of the Geological Society of Denmark 23: 213–224.Google Scholar
Tanner, L. H., Lucas, S. G., and Chapman, M. G. 2004. Assessing the record and causes of Late Triassic extinctions. Earth-Science Reviews 65: 103–139.CrossRefGoogle Scholar
Terry, L. I., Walter, G. H., Donaldson, J. S., Snow, E., Forster, P. I., and Machin, P. J. 2005. Pollination of Australian Macrozamia cycads (Zamiaceae): effectiveness and behavior of specialist vectors in a dependent mutualism. American Journal of Botany 92: 931–940.CrossRefGoogle Scholar
Tipper, H. W., Carter, E. S., Orchard, M. J., and Tozer, E. T. 1994. The Triassic-Jurassic (T-J) boundary in Queen Charlotte Islands, British Colombia. Geobios Mémoire Spécial 17: 484–492.Google Scholar
Townrow, J. A. 1960. The Peltaspermaceae, a pteridosperm family of Permian and Triassic age. Palaeontology 3: 331–361.Google Scholar
Tozer, E. T. 1979. Latest Triassic ammonoid faunas and biochronology, western Canada. Geological Survey of Canada Papers 79-1B: 127–135.Google Scholar
Ufnar, D. F., Gonzalez, L. A., Ludvigson, G. A., Brenner, R. L., and Witzke, B. J. 2004. Evidence for increased latent heat transport during the Cretaceous (Albian) greenhouse warming. Geology 32: 1049–1052.CrossRefGoogle Scholar
Vakhrameev, V. A. 1991. Jurassic and Cretaceous floras and climates of the Earth. Cambridge University Press, Cambridge.Google Scholar
Vermeij, G. J. 2004. Ecological avalanches and the two kinds of extinction. Evolutionary Ecology Research 6: 315–337.Google Scholar
Ward, P. D., Haggart, J. W., Carter, E. S., Wilbur, D., Tipper, H. W., and Evans, T. 2001. Sudden productivity collapse associated with the Triassic-Jurassic boundary mass extinction. Science 292: 1148–1151.CrossRefGoogle ScholarPubMed
Ward, P. D., Garrison, G. H., Williford, K. H., Kring, D. A., Goodwin, D., Beattie, M., and McRoberts, C. A. 2006. The organic carbon isotopic and paleontological record across the Triassic-Jurassic boundary at the candidate GSSP section at Ferguson Hill, Muller Canyon, Nevada, USA. Palaeogeography, Palaeoclimatology, Palaeoecology 244: 281–290.CrossRefGoogle Scholar
White, M. E. 1994. The greening of Gondwana. Reed, Chatswood, Australia.Google Scholar
Wilf, P., and Johnson, K. R. 2004. Land plant extinction at the end of the Cretaceous: a quantitative analysis of the North Dakota megafloral record. Paleobiology 30: 347–368.2.0.CO;2>CrossRefGoogle Scholar
Williford, K. H., Ward, P. D., Garrison, G. H., and Buick, R. 2006. An extended stable organic carbon isotope record across the Triassic-Jurassic boundary in the Queen Charlotte Islands, British Columbia, Canada. Palaeogeography, Palaeoclimatology, Palaeoecology 244: 290–297.CrossRefGoogle Scholar
Wing, S. L., and DiMichele, W. A. 1995. Conflict between local and global changes in plant diversity through geological time. Palaios 10: 551–564.CrossRefGoogle Scholar
Wing, S. L., Hickey, L. J., and Swisher, C. C. 1993. Implications of an exceptional fossil flora for Late Cretaceous vegetation. Nature 363: 342–344.CrossRefGoogle Scholar