Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-23T19:16:40.818Z Has data issue: false hasContentIssue false
  • English
  • Français

Angiosperm diversification and Cretaceous floristic trends: a comparison of palynofloras and leaf macrofloras

Published online by Cambridge University Press:  08 April 2016

Scott Lidgard  and
Peter R. Crane
Scott Lidgard
Affiliation:
Department of Geology, Field Museum of Natural History, Roosevelt Road at Lake Shore Drive, Chicago, Illinois 60605
Peter R. Crane
Affiliation:
Department of Geology, Field Museum of Natural History, Roosevelt Road at Lake Shore Drive, Chicago, Illinois 60605
Get access Rights & Permissions [Opens in a new window]

Abstract

Fossil leaves and palynomorphs represent different phases of the plant life cycle, are studied as systematically independent entities, and are subject to different taphonomic, sampling, and recognition biases in the paleobotanical record. They thus provide parallel, and largely independent, documentation of long-term trends in land plant diversity, and the palynological record may be used as a comparative test of floristic trends inferred from macrofossil evidence. Analyses of relative “species” richness in 91 macrofossil and 860 palynomorph Cretaceous “floras” (assemblages) from between 25° and 65° N paleolatitude show a major mid-Cretaceous increase in the within-flora diversity of angiosperms, from near 0% prior to the Aptian (120 Ma) to 50–80% by the end of the Maastrichtian (65 Ma). This level of diversity is attained rapidly in macrofloras, but more slowly in palynofloras. In the latest Cretaceous, macrofloras and palynofloras both indicate that “pteridophytes,” conifers, and other “gymnosperms” are generally less diverse than angiosperms. In both data sets, “pteridophyte” diversity shows a clear decline through the Cretaceous, whereas conifer diversity shows no marked temporal trend. Broad congruence of these patterns, in spite of different biases in the macrofossil and palynomorph records, indicates that they provide a robust reflection of floristic trends through the Cretaceous. Nevertheless, discrepancies between the patterns do occur and underline the importance of complementary macrofossil and palynological analyses for accurate resolution of long-term vegetational change.

Type
Articles
Information
Paleobiology , Volume 16 , Issue 1 , Winter 1990 , pp. 77 - 93
Copyright
Copyright © The Paleontological Society 

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

Literature Cited

Bambach, R. K. 1977. Species richness in marine benthic habitats through the Phanerozoic. Paleobiology 3:152–167.CrossRefGoogle Scholar
Basinger, J. G., and Dilcher, D. L. 1984. Ancient bisexual flowers. Science 224:511–513.Google Scholar
Bell, W. A. 1963. Upper Cretaceous floras of the Dunvegan, Bad Heart, and Milk River Formations of western Canada. Geological Survey of Canada Bulletin 94:1–76.Google Scholar
Berry, E. W. 1916. The Upper Cretaceous Floras of the World, Thallophyta, Pteridophyta, Cycadophyta, Coniferophyta, Angiospermophyta. Pp. 183–313, 757–986. In Clark, W. B. (ed.), Upper Cretaceous. Maryland Geological Survey; Baltimore, Maryland.Google Scholar
Birks, H. H., and Mathewes, R. W. 1978. Studies in the vegetational history of Scotland. V. Late Devensian and early Flandrian pollen and macrofossil stratigraphy at Abernethy Forest, Inverness-shire. New Phytologist 80:455–484.Google Scholar
Birks, M. J. B., and Birks, H. H. 1980. Quaternary Palynology. University Park Press; Baltimore, Maryland.Google Scholar
Birks, M. J. B., and Gordon, A. D. 1985. Numerical Methods in Quaternary Pollen Analysis. Academic Press; New York.Google Scholar
Brenner, G. J. 1963. The spores and pollen of the Potomac Group of Maryland. Department of Geology, Mines and Water Resources, State of Maryland, Bulletin 27:1–215.Google Scholar
Brenner, G. J. 1976. Middle Cretaceous floral provinces and early migrations of angiosperms. Pp. 23–47. In Beck, C. B. (ed.), Origin and Early Evolution of Angiosperms. Columbia University Press; New York.Google Scholar
Brenner, G. J. 1984. Late Hauterivian angiosperm pollen from the Helez Formation, Israel. Sixth International Palynology Conference, Calgary, Abstracts 6:15.Google Scholar
Chapman, J. L. 1986. Practical difficulties in the application of the species concept in Albian angiosperm pollen. Special Papers in Palaeontology 35:41–53.Google Scholar
Cochrane, D., and Orcutt, G. H. 1949. Application of least-squares regressions to relationships containing auto-correlated error terms. Journal of the American Statistical Association 44:32–61.Google Scholar
Connor, E. F. 1986. Time series analysis of the fossil record. Pp. 119–148. In Raup, D. M., and Jablonski, D. (eds.), Patterns and Processes in the History of Life. Springer-Verlag; New York.Google Scholar
Cousminer, H. L. 1961. Palynology, paleofloras and paleoenvironments. Micropaleontology 7:365–368.Google Scholar
Crane, P. R. 1985. Phylogenetic analysis of seed plants and the origin of angiosperms. Annals of the Missouri Botanical Garden 72:716–793.Google Scholar
Crane, P. R. 1987. Vegetational consquences of the angiosperm diversification. Pp. 107–140. In Friis, E. M., Chaloner, W. G., and Crane, P. R. (eds.), The Origins of Angiosperms and their Biological Consequences. Cambridge University Press; Cambridge.Google Scholar
Crane, P. R. 1989. Paleobotanical evidence on the radiation of non-magnoliid dicotyledons. Plant Systematics and Evolution 162:165–191.Google Scholar
Crane, P. R., and Dilcher, D. L. 1984. Lesqueria: an early angiosperm fruiting axis from the mid-Cretaceous. Annals of the Missouri Botanical Garden 71:384–402.Google Scholar
Crane, P. R., and Lidgard, S. 1988. Latitudinal gradients and temporal trends in Cretaceous floristic diversity. Geological Society of America abstracts with Programs 20:257.Google Scholar
Crane, P. R., and Lidgard, S. 1989. Angiosperm diversification and paleolatitudinal gradients in Cretaceous floristic diversity. Science 246:675–678.Google Scholar
Crane, P. R., and Lidgard, S.In press. Angiosperm diversification and Cretaceous patterns of palynological diversity. In Taylor, P. D., and Larwood, G. P. (eds.), Major Evolutionary Radiations. Clarendon Press, Oxford.Google Scholar
Crane, P. R., and Upchurch, G. R. 1987. Drewria potomacensis gen. et sp. nov., an early Cretaceous member of the Gnetales from the Potomac Group of Virginia. American Journal of Botany 74:1722–1736.Google Scholar
Crane, P. R., Friis, E. M., and Pedersen, K. R. 1989. Reproductive structure and function in Cretaceous Chloranthaceae. Plant Systematics and Evolution.CrossRefGoogle Scholar
Culver, S. J., Buzas, M. A., and Collins, L. 1987. On the value of taxonomic standardization in evolutionary studies. Paleobiology 13:169–176.Google Scholar
Cushing, E. J. 1967. Evidence for differential pollen preservation in late Quaternary sediments in Minnesota. Review of Palaeobotany and Palynology 4:87–101.CrossRefGoogle Scholar
Delcourt, H. R., Delcourt, P. A., and Webb, T. III. 1983. Dynamic plant ecology: the spectrum of vegetational change in space and time. Quaternary Science Reviews 1:153–175.Google Scholar
Dilcher, D. L. 1979. Early angiosperm reproduction: an introductory report. Review of Palaeobotany and Palynology 27:291–328.Google Scholar
Dilcher, D. L., and Crane, P. R. 1984. Archaeanthus: an early angiosperm from the Cenomanian of the western interior of North America. Annals of the Missouri Botanical Garden 71:351–383.Google Scholar
Dilcher, D. L., and Farley, M. B. 1988. Cenomanian miospores and co-occurring megafossils in the mid-continent of North America. Seventh Internatinal Palynological Congress, Brisbane, Australia, Abstracts 8:39.Google Scholar
DiMichele, W. A., and Wing, S. L. (eds.). 1988. Methods and applications of plant paleoecology. Paleontological Society Special Publication 3:1–171.Google Scholar
Donoghue, M. J., and Doyle, J. A. 1989. Phylogenetic analysis of the angiosperms and the relationships of “Hamamelidae.” Pp. 17–45. In Crane, P. R., and Blackmore, S. (eds.), Evolution, Systematics and Fossil History of Hamamelidae. Clarendon Press; Oxford.Google Scholar
Dorf, E. 1955. Plants and the geologic time scale. Geological Society of America Special Paper 62:575–592.Google Scholar
Doyle, J. A. 1973. The monocotyledons: their evolution and comparative biology. V. Fossil evidence on the early evolution of the monocotyledons. Quarterly Review of Biology 48:399–413.Google Scholar
Doyle, J. A. 1978. Origin of angiosperms. Annual Review of Ecology and Systematics 9:365–392.CrossRefGoogle Scholar
Doyle, J. A., and Donoghue, M. J. 1986. Seed plant phylogeny and the origin of angiosperms: an experimental cladistic approach. Botanical Review 52:321–431.Google Scholar
Doyle, J. A., and Hickey, L. J. 1976. Pollen and leaves from the mid-Cretaceous Potomac Group and their bearing on early angiosperm evolution. Pp. 139–206. In Beck, C. B. (ed.), Origin and Early Evolution of Angiosperms. Columbia University Press; New York.Google Scholar
Doyle, J. A., and Robbins, E. I. 1977. Angiosperm pollen zonation of the continental Cretaceous of the Atlantic Coastal Plain and its application to deep wells in the Salisbury Embayment. Palynology 1:43–78.Google Scholar
Doyle, J. A., Jardiné, S., and Doerenkamp, A. 1982. Afropollis, a new genus of early angiosperm pollen, with notes on the Cretaceous palynostratigraphy and paleoenvironments of northern Gondwana. Bulletin des Centres de Recherches Exploration-Production Elf-Aquitaine 6:39–117.Google Scholar
Drinnan, A. N., and Crane, P. R. 1989. Cretaceous paleobotany and its bearing on the biogeography of austral angiosperms. Pp. 192–219. In Taylor, T. N., and Taylor, E. L. (eds.), The Paleobiology of Antarctica. Springer-Verlag; New York.Google Scholar
Eldredge, N. 1976. Differential evolutionary rates. Paleobiology 2:174–177.Google Scholar
Faegri, K. 1966. Some problems of representivity in pollen analysis. Palaeobotanist 15:135–140.Google Scholar
Faegri, K., and Iversen, J. 1975. Textbook of Pollen Analysis. Blackwell; London.Google Scholar
Farley, M. B. 1988. Environmental variation, palynofloras, and paleoecological interpretation. Paleontological Society Special Publication 3:126–146.Google Scholar
Farley, M. B., and Dilcher, D. L. 1987. Correlation between miospores and the depositional environments of the Dakota Formation (mid-Cretaceous) of north-central Kansas and adjacent Nebraska, U.S.A. Palynology 10:117–133.Google Scholar
Ferguson, D. K. 1985. The origin of leaf-assemblages—new light on an old problem. Review of Palaeobotany and Palynology 46:117–188.Google Scholar
Fontaine, W. M. 1889. The Potomac or younger Mesozoic flora. United States Geological Survey Monograph 15:1–377.Google Scholar
Frederiksen, N. O. 1980. Significance of monosulcate pollen abundance in Mesozoic sediments. Lethaia 13:1–20.Google Scholar
Frederiksen, N. O. 1985. Review of Early Tertiary sporomorph paleoecology. American Association of Stratigraphic Palynologists Contributions Series 15:1–92.Google Scholar
Friis, E. M., and Crane, P. R. 1989. Reproductive structures of Cretaceous Hamamelidae. Pp. 155–174. In Crane, P. R., and Blackmore, S. (eds.), Evolution, Systematics, and Fossil History of Hamamelidae. Oxford University Press; Oxford.Google Scholar
Friis, E. M., and Crepet, W. L. 1987. Time of appearance of floral features. Pp. 145–179. In Friis, E. M., Chaloner, W. G., and Crane, P. R. (eds.), The Origins of Angiosperms and their Biological Consequences. Cambridge University Press; Cambridge.Google Scholar
Friis, E. M., Chaloner, W. G., and Crane, P. R. (eds.). 1987. The Origins of Angiosperms and their Biological Consequences. Cambridge University Press; Cambridge.Google Scholar
Friis, E. M., Crane, P. R., and Pedersen, K. R. 1988. Reproductive structures of Cretaceous Platanaceae. Biologiske Skrifter Danske Videnskabernes Selskab 31:1–55.Google Scholar
Gastaldo, R. A. 1986. Selected aspects of plant taphonomic processes in coastal deltaic regimes. Pp. 27–44. In Broadhead, T. W. (ed.), Fossil Land Plants: Notes for a Short Course. University of Tennessee Department of Geological Sciences.Google Scholar
Gastaldo, R. A. 1988. A conspectus of phytotaphonomy. Paleontological Society Special Publication 3:14–28.CrossRefGoogle Scholar
Harland, W. B., Cox, A. V., Llewellyn, P. G., Pickton, C. A. G., Smith, A. G., and Walters, R. 1982. A Geologic Time Scale. Cambridge University Press; Cambridge.Google Scholar
Harris, T. M. 1932. The fossil flora of Scoresby Sound, East Greenland. Part 3. Caytoniales and Bennettitales. Meddelelser omGoogle Scholar
Harris, T. M. 1969. The Yorkshire Jurassic Flora. III. Bennettitales. British Museum (Natural History); London.Google Scholar
Harris, T. M., Millington, W., and Miller, J. 1974. The Yorkshire Jurassic Flora. IV. Ginkgoales, Czekanowskiales. British Museum (Natural History); London.Google Scholar
Havinga, A. J. 1964. Investigation into the differential corrosion susceptibility of pollen and spores. Pollen et Spores 6:621–635.Google Scholar
Havinga, A. J. 1967. Palynology and pollen preservation. Review of Palaeobotany and Palynology 2:81–98.Google Scholar
Havinga, A. J. 1971. An experimental investigation into the decay of pollen and spores in various soil types. Pp. 446–478. In Brooks, J., Grant, P. R., Muir, M. D., van Gijzel, P., and Shaw, G. (eds.), Sporopollenin. Academic Press; New York.Google Scholar
Heer, O. 1893. Oversigt over Grønlands fossile Flora. Meddelelser om Grønland 5:81–213.Google Scholar
Herngreen, G. F. W., and Chlonova, A. F. 1981. Cretaceous microfloral provinces. Pollen et Spores 23:442–555.Google Scholar
Hickey, L. J., and Doyle, J. A. 1977. Early Cretaceous fossil evidence for angiosperm evolution. Botanical Review 43:3–104.Google Scholar
Hufford, L. D., and Crane, P. R. 1989. A preliminary phylogenetic analysis of the “lower” Hamamelidae. Pp. 175–192. In Crane, P. R., and Blackmore, S. (eds.), Evolution, Systematics, and Fossil History of Hamamelidae. Oxford University Press; Oxford.Google Scholar
Hughes, N. F., Drewry, G. E., and Laing, J. F. 1979. Barremian earliest angiosperm pollen. Palaeontology 22:513–525.Google Scholar
Hughes, N. F., and McDougall, A. B. 1986. Records of angiospermid entry into the English Early Cretaceous succession. Review of Palaeobotany and Palynology 50:255–272.Google Scholar
Knoll, A. H. 1986. Patterns of change in plant communities through geologic time. Pp. 126–141. In Diamond, J., and Case, T. J. (eds.), Community Ecology. Harper and Row; New York.Google Scholar
Knoll, A. H., Niklas, K. J., Gensel, P. G., and Tiffney, B. H. 1984. Character diversification and patterns of evolution in early vascular plants. Paleobiology 10:34–47.Google Scholar
Koch, C. F. 1978. Bias in the published fossil record. Paleobiology 4:367–372.Google Scholar
Koch, C. F. 1987. Prediction of sample size effects on the measured temporal and geographic distribution patterns of species. Paleobiology 13:100–107.Google Scholar
Krassilov, V. A., Shilin, P. V., and Vakhrameev, V. A. 1983. Cretaceous flowers from Kazakhstan. Review of Palaeobotany and Palynology 40:91–113.Google Scholar
Lidgard, S., and Crane, P. R. 1988a. Quantitative analyses of the early angiosperm radiation. Nature 331:344–346.Google Scholar
Lidgard, S., and Crane, P. R. 1988b. What was the pattern of the angiosperm diversification? A comparative test using palynofloras and leaf macrofloras. Geological Society of America abstracts with Programs 20:257.Google Scholar
Lidgard, S., and Jackson, J. B. C. 1989. Growth in encrusting cheilostome bryozoans. I. Evolutionary trends. Paleobiology 15:255–282.CrossRefGoogle Scholar
McQueen, D. R. 1956. Leaves of Middle and Upper Cretaceous pteridophytes and cycads from New Zealand. Transactions of the Royal Society of New Zealand 83:673–685.Google Scholar
Miller, C. N. 1988. The origin of modern conifer families. Pp. 448–486. In Beck, C. B. (ed.), Origin and Evolution of Gymnosperms. Columbia University Press; New York.Google Scholar
Muller, J. 1970. Palynological evidence on early differentiation of angiosperms. Biological Reviews of the Cambridge Philosophical Society 45:417–450.Google Scholar
Muller, J. 1984. Significance of fossil pollen for angiosperm history. Annals of the Missouri Botanical Garden 71:419–433.Google Scholar
Niklas, K. J. 1988. Patterns of vascular plant differentiation in the fossil record: proof and conjecture. Annals of the Missouri Botanical Garden 75:35–54.CrossRefGoogle Scholar
Niklas, K. J., Tiffney, B. H., and Knoll, A. H. 1980. Apparent changes in the diversity of fossil plants: a preliminary assessment. Pp. 1–89. In Hecht, M. K., Steere, W. C., and Wallace, B. (eds.), Evolutionary Biology, Volume 12. Plenum Press; New York.Google Scholar
Niklas, K. J., Tiffney, B. H., and Knoll, A. H. 1985. Patterns in vascular land plant diversification: a factor analysis at the species level. Pp. 97–128. In Valentine, J. W. (ed.), Phanerozoic Diversity Patterns: Profiles in Macroevolution. Princeton University Press; Princeton, New Jersey.Google Scholar
Pease, C. M. 1985. Biases in the durations and diversities of fossil taxa. Paleobiology 11:272–292.Google Scholar
Pease, C. M. 1988a. Biases in the total extinction rates of fossil taxa. Journal of Theoretical Biology 130:1–7.Google Scholar
Pease, C. M. 1988b. Biases in the per-taxon origination and extinction rates of fossil taxa. Journal of Theoretical Biology 130:9–30.Google Scholar
Pease, C. M. 1988c. Biases in the survivorship curves of fossil taxa. Journal of Theoretical Biology 130:31–48.CrossRefGoogle Scholar
Pease, C. M. 1988d. On comparing the geologic durations of easily versus poorly fossilized taxa. Journal of Theoretical Biology 133:255–257.CrossRefGoogle Scholar
Penny, J. H. J. 1988. Early Cretaceous acolumellate semitectate pollen from Egypt. Palaeontology 31:373–418.Google Scholar
Prentice, J. C. 1985. Pollen representation, source area, and basin size: toward a unified theory of pollen analysis. Quaternary Research 23:76–86.Google Scholar
Raup, D. M. 1972. Taxonomic diversity during the Phanerozoic. Science 177:1065–1071.Google Scholar
Raup, D. M. 1976. Species diversity in the Phanerozoic: an interpretation. Paleobiology 2:289–297.Google Scholar
Raup, D. M. 1979. Biases in the fossil record of species and genera. Carnegie Museum of Natural History Bulletin 13:85–91.Google Scholar
Samylina, V. A. 1960. Angiosperms from the Lower Cretaceous of the Kolyma Basin. Botanicheskiy Zhurnal 45:335–352. [in Russian]Google Scholar
Sangster, A. G., and Dale, H. M. 1964. Pollen grain preservation of underrepresented species in fossil spectra. Canadian Journal of Botany 42:427–449.Google Scholar
Scheihing, M. H. 1980. Reduction of wind velocity by the forest canopy and the rarity of non-arborescent plants in the Upper Carboniferous fossil record. Argumenta Palaeobotanica 6:133–138.Google Scholar
Schopf, T. J. M. 1982. A critical assessment of punctuated equilibria. I. Duration of taxa. Evolution 36:1144–1157.Google ScholarPubMed
Schopf, T. J. M., Raup, D. M., Gould, S. J., and Simberloff, D. S. 1975. Genomic versus morphologic rates of evolution: influence of morphologic complexity. Paleobiology 4:223–251.Google Scholar
Signor, P. W. 1978. Species richness in the Phanerozoic: an investigation of sampling effects. Paleobiology 4:394–406.Google Scholar
Signor, P. W. 1985. Real and apparent trends in species richness through time. Pp. 129–150. In Valentine, J. W. (ed.), Phanerozoic Diversity Patterns. Princeton University Press; Princeton, New Jersey.Google Scholar
Singh, C. 1964. Microflora of the Lower Cretaceous Mannville Group, east-central Alberta. Research Council of Alberta Bulletin 15:1–238.Google Scholar
Singh, C. 1983. Cenomanian microfloras of the Peace River area, northwestern Alberta. Research Council of Alberta Bulletin 44:1–193.Google Scholar
Spicer, R. A. 1980. The importance of depositional sorting to the biostratigraphy of plant megafossils. Pp. 171–183. In Dilcher, D. L., and Taylor, T. N. (eds.), Biostratigraphy of Fossil Plants. Dowden, Hutchinson and Ross; Stroudsburg, Pennsylvania.Google Scholar
Spicer, R. A. 1986. Comparative leaf architectural analysis of Cretaceous radiating angiosperms. Pp. 221–232. In Spicer, R. A., and Thomas, B. A. (eds.), Systematic and Taxonomic Approaches in Palaeobotany. Clarendon Press; Oxford.Google Scholar
Spicer, R. A. 1988. Quantitative sampling of plant megafossil assemblages. Paleontological Society Special Publication 3:29–51.Google Scholar
Spicer, R. A., and Greer, A. G. 1986. Plant taphonomy in fluvial and lacustrine systems. Pp. 10–26. In Broadhead, T. W. (ed.), Fossil Land Plants: Notes for a Short Course. University of Tennessee Department of Geological Sciences.Google Scholar
Spicer, R. A., and Hill, C. R. 1979. Principal components and correspondence analyses of quantitative data from a Jurassic plant bed. Review of Palaeobotany and Palynology 28:273–299.Google Scholar
Spicer, R. A., and Wolfe, J. A. 1987. Plant taphonomy of late Holocene deposits in Trinity (Clair Engle) Lake, northern California. Paleobiology 13:227–245.Google Scholar
Tipper, J. C. 1979. Rarefaction and rarefiction: the use and abuse of a method in paleoecology. Paleobiology 5:423–434.Google Scholar
Traverse, A. 1988. Paleopalynology. Unwin Hyman; Boston, Massachusetts.Google Scholar
Upchurch, G. R. 1984. Cuticular evolution in early Cretaceous angiosperms from the Potomac group of Virginia and Maryland. Annals of the Missouri Botanical Garden 71:522–550.Google Scholar
Upchurch, G. R., and Dilcher, D. L.In press. Cenomanian angiosperm leaf megafossils, Dakota Formation, Rose Creek locality, Jefferson County, southeastern Nebraska. U.S. Geological Survey Bulletin.Google Scholar
Upchurch, G. R., and Wolfe, J. A.In press. Cretaceous vegetation of the western interior and adjacent regions of North America. In Kauffman, E. G., and Caldwell, W. G. E. (eds.), Cretaceous Evolution of the Western Interior Basin. Geological Association of Canada Special Papers.Google Scholar
Van Cittert, J. H. A. V. K. 1971. In situ gymnosperm pollen from the Middle Jurassic of Yorkshire. Acta Botanica Neerlandica 20:1–97.Google Scholar
Velenovský, J. 1889. Kvêtena Českého Cenomanu. Rozpravy Královské Česke Společnosti Nauk VII 3:1–75.Google Scholar
Walker, J. W., and Walker, A. G. 1984. Ultrastructure of Lower Cretaceous angiosperm pollen and the origin and early evolution of flowering plants. Annals of the Missouri Botanical Garden 71:464–521.Google Scholar
Ward, J. V., Doyle, J. A., and Hotton, C. L. 1988. Probable granular magnoliid angiosperm pollen from the Early Cretaceous. American Journal of Botany 75:2.Google Scholar
Wing, S. L. 1988. Depositional environments of plant-bearing sediments. Paleontological Society Special Publication 3:1–11.Google Scholar
Wing, S. L., and Tiffney, B. H. 1987. The reciprocal interaction of angiosperm evolution and tetrapod herbivory. Review of Palaeobotany and Palynology 50:179–210.Google Scholar
Wolfe, J. A., Doyle, J. A., and V. M. Page. 1975. The bases of angiosperm phylogeny: paleobotany. Annals of the Missouri Botanical Garden 62:801–824.Google Scholar
Ziegler, A. M., Scotese, C. R., and Barrett, S. F. 1983. Mesozoic and Cenozoic paleogeographic maps. Pp. 240–252. In Brosche, P., and Sundermann, J. (eds.), Tidal Friction and the Earth's Rotation II. Springer-Verlag; Berlin.Google Scholar