Biostratigraphy of selected K/T boundary sections in southwestern North Dakota, USA: toward a refinement of palynological identification criteria

Cretaceous Research

Volumn 30, Issue 3, 2009, Pages 632-658

  Bercovici, Antoine ^a   Pearson, Dean ^b   Nichols, Douglas ^c   Wood, Jacqueline ^d  

^a UNIVERSITÉ DE RENNES 1   (France)

^b Pioneer Trails Regional Museum   (United States)

^c DENVER MUSEUM OF NATURE AND SCIENCE   (United States)

^d Delgado Community College   (United States)

Author keywords

Cretaceous Tertiary boundary; Extinction; Fort Union Formation; Hell Creek Formation; Paleoenvironment; Palynology

Indexed keywords

ABUNDANCE; BIOSTRATIGRAPHY; CRETACEOUS-TERTIARY BOUNDARY; EXTINCTION; FOSSIL RECORD; GEOLOGICAL RECORD; IDENTIFICATION KEY; MIOSPORE; NEW RECORD; PALEOENVIRONMENT; PALYNOLOGY; TAXONOMY; TREND ANALYSIS;

NORTH AMERICA; NORTH DAKOTA; UNITED STATES;

VERTEBRATA;

EID: 64149114604     PISSN: 01956671     EISSN: 1095998X     Source Type: Journal    
DOI: 10.1016/j.cretres.2008.12.007     Document Type: Article

References (98)

1. Alvarez L.W., Alvarez W., Asaro F., and Michel H.V. Extraterrestrial cause for the Cretaceous-Tertiary extinction. Science 208 (1980) 1095-1108
2. Alvarez W., Claeys P., and Kieffer S.W. Emplacement of Cretaceous-Tertiary boundary shocked quartz from Chicxulub crater. Science 269 (1995) 930-935
3. Alvarez W., Kauffman E.G., Surlyk F., Alvarez L.W., Asaro F., and Michel H.V. Impact theory of mass extinctions and the invertebrate fossil record. Science 223 (1984) 1135-1141
4. Archibald J.D. A study of Mammalia and geology across the Cretaceous-Tertiary boundary in Garfield County, Montana. University of California Publications in Geological Sciences 122 (1982) 1-286
5. Archibald J.D. Dinosaur Extinction and the End of an Era: What the Fossils Say (1996), Columbia University Press, New York pp. 237
6. Archibald J.D., and Bryant L.J. Differential Cretaceous/Tertiary extinctions of nonmarine vertebrates: evidence from northeastern Montana. In: Sharpton V.L., and Ward P.D. (Eds). Global Catastrophes in Earth History: An Interdisciplinary Conference on Impacts, Volcanism, and Mass Mortality. Geological Society of America Special Paper 247 (1990) 549-562
7. Barclay R.S., Johnson K.R., Betterton W.J., and Dilcher D.L. Stratigraphy and megaflora of a K-T boundary section in the eastern Denver Basin. Rocky Mountain Geology 38 1 (2003) 45-71
8. Behrensmeyer A.K., and Kidwell S.M. Taphonomy's contribution to paleobiology. Paleobiology 11 1 (1985) 105-119
9. Behrensmeyer A.K., Kidwell S.M., and Gastaldo R.A. Taphonomy and paleobiology. Paleobiology 26 4 (2000) 103-147
10. Bercovici A., Pearson D.A., Nichols D.J., and Wood J. Enhancing the Recognition of the Palynologically Defined K/T Boundary in Southwestern North Dakota, USA: Using Multiproxy Datasets for Paleoenvironmental Reconstruction to Minimize Effects of Taphonomic Biases. Paléobotanique et évolution du monde végétal: quelques problèmes d'actualité (2007), Collège de France, Paris pp. 46
11. Bercovici A., Wood J., and Pearson D.A. Detailed paleontologic and taphonomic techniques to reconstruct an earliest Paleocene fossil flora: an example from southwestern North Dakota, USA. Review of Palaeobotany and Palynology 151 (2008) 136-146
12. Bohor B.F. Shock-induced microdeformation in quartz and other mineralogical indications of an impact event at the Cretaceous/Tertiary boundary. Tectonophysics 171 (1990) 359-372
13. Bohor B.F., Foord E.E., Modreski P.J., and Triplehorn D.M. Mineralogic evidence for an extraterrestrial impact event at the Cretaceous-Tertiary boundary. Science 224 (1984) 867-869
14. Bohor B.F., and Izett G. World-wide size distribution of shocked quartz at the K/T boundary: evidence for a North American impact site. Lunar and Planetary Sciences 52 (1986) 68-69
15. Bohor B.F., Triplehorn D.M., Nichols D.J., and Millard H.T. Dinosaurs, spherules and the "magic layer"; a new K-T boundary clay site in Wyoming. Geology 15 (1987) 896-899
16. Brown R.W. Tertiary strata in eastern Montana and western North and South Dakota. In: Sonnenberg F.P. (Ed). Billings Geological Society Guidebook. Billings, Montana, Billings Geological Society, Third Annual Field Conference (1952) 89-92
17. Brown R.W. Paleocene Flora of the Rocky Mountains and Great Plains. U.S. Geological Survey Professional Paper 375 (1962) pp. 119
18. Bryant L.J. Non-Dinosaurian lower vertebrates across the Cretaceous-Tertiary boundary in northeast Montana. University of California Publications in Geological Sciences 134 (1989) 1-107
19. Calvert W.R. Geology of certain lignite fields in eastern Montana. United States Geological Survey Bulletin 471 (1912) 187-201
20. Clemens W.A., Archibald J.D., and Hickey L.J. Out with a whimper, not a bang. Paleobiology 7 (1981) 293-298
21. Eberle J.J. Bridging the transition between didelphodonts and taeniodonts. Journal of Paleontology 73 (1999) 936-944
22. Fastovsky D.E. Paleoenvironments of vertebrate-bearing strata during the Cretaceous-Paleogene transition, eastern Montana and western North Dakota. Palaios 2 (1987) 282-295
23. Fastovsky D.E., and McSweeney K. Paleosol spanning the Cretaceous-Paleocene transition, eastern Montana and western North Dakota. Geological Society of America Bulletin 99 (1987) 66-77
24. Fastovsky D.E., McSweeney K., and Norton L.D. Pedogenic development at the Cretaceous-Tertiary boundary, Garfield County. Montana. Journal of Sedimentary Petrology 59 (1989) 758-767
25. Fleming R.F., and Nichols D.J. The fern-spore abundance anomaly at the Cretaceous-Tertiary Boundary: a regional bio-event in western North America. In: Kauffman E.G., and Walliser O.H. (Eds). Extinction Events in Earth History. Lecture Notes in Earth Sciences vol. 30 (1990), Springer Verlag, Heidelberg 351-364
26. Fox R.C. The Wounded Knee local fauna and mammalian evolution near the Cretaceous-Tertiary boundary, Saskatchewan, Canada. Palaeontographica 208 (1989) 11-59
27. Fox R.C. Late Cretaceous and Paleocene mammals, Cypress Hills region, Saskatchewan, and mammalian evolution across the Cretaceous- Tertiary boundary. In: McKenzie-McAnally L. (Ed). Upper Cretaceous and Tertiary Stratigraphy and Paleontology of Southern Saskatchewan. Paper 6 of Canadian Paleontology Conference Field Trip Guidebook (1997), Geological Association of Canada, St. John's, Newfoundland 70-85
28. Ganapathy R. A major meteorite impact on the earth 65 million years ago: evidence from the Cretaceous-Tertiary boundary clay. Science 209 (1980) 921-923
29. Gaston K.J. Global patterns in biodiversity. Nature 405 (2000) 220-227
30. Gotelli N.J., and Colwell R.K. Quantifying biodiversity: procedures and pitfalls in the measurement and comparison of species richness. Ecology Letters 4 (2001) 379-391
31. Hadley A. CombineZM and CZBatch - Free image stacking software for depth of field correction. Available from: (2006). http://www.hadleyweb.pwp.blueyonder.co.uk/
32. Hartman J.H., Johnson K.R., and Nichols D.J. The Hell Creek Formation and the Cretaceous-Tertiary Boundary in the Northern Great Plains: an Integrated Continental Record of the End of the Cretaceous. Geological Society of America Special Paper 361 (2002) pp. 520
33. Heck Jr. K.L., Van Belle G., and Simberloff D. Explicit calculation of the rarefaction diversity measurement and the determination of sufficient sample size. Ecology 56 (1975) 1459-1461
34. Herngreen G.F.W., and Chlonova A.F. Cretaceous microfloral provinces. Pollen et Spores 23 (1981) 441-555
35. Herngreen G.F.W., Kedves M., Rovnina L.V., and Smirnova S.B. Cretaceous palynofloral provinces: a review. In: Jansonius J., and McGregor D.C. (Eds). Palynology: Principles and Applications 3 (1996), American Association of Stratigraphic Palynologists Foundation, Dallas, Texas, USA 1157-1188
36. Hickey L.J. Paleocene stratigraphy and flora of the Clark's Fork Basin. In: Gingerich P.D. (Ed). Early Cenozoic Paleontology and Stratigraphy of the Bighorn Basin, Wyoming. University of Michigan Papers in Paleontology 24 (1980) 33-49
37. Hicks J.F., Johnson K.R., Tauxe L., Clark D., and Obradovich J.D. Magnetostratigraphy and geochronology of the Hell Creek and basal Fort Union Formations of southwestern North Dakota and a recalibration of the Cretaceous-Tertiary boundary. In: Hartman J.H., Johnson K.R., and Nichols D.J. (Eds). The Hell Creek Formation and the Cretaceous-Tertiary boundary in the Northern Great Plains: an Integrated Continental Record of the End of the Cretaceous. Geological Society of America Special Paper 361 (2002) 35-56
38. Hotton, C.L., 1988. Palynology of the Cretaceous-Tertiary boundary in central Montana, U.S.A., and its implication for extraterrestrial impact. Ph.D. dissertation, University of California, Davis, California, pp. 732.
39. Hotton C.L. Palynology of the Cretaceous-Tertiary boundary in central Montana: evidence for extraterrestrial impact as a cause for the terminal Cretaceous extinction. In: Hartman J.H., Johnson K.R., and Nichols D.J. (Eds). The Hell Creek Formation and the Cretaceous-Tertiary Boundary in the Northern Great Plains: an Integrated Continental Record of the End of the Cretaceous. Geological Society of America Special Paper 361 (2002) 191-216
40. Hunter J.P. The radiation of Paleocene mammals with the demise of the dinosaurs: evidence from southwestern North Dakota. North Dakota Academy of Science Proceedings 53 (1999) 141-144
41. Hunter J.P., and Archibald J.D. Mammals from the end of the age of dinosaurs in North Dakota and southwestern Montana, with a reappraisal on geographic differentiation among Lancian mammals. In: Hartman J.H., Johnson K.R., and Nichols D.J. (Eds). The Hell Creek Formation and the Cretaceous-Tertiary boundary in the Northern Great Plains: an Integrated Continental Record of the End of the Cretaceous. Geological Society of America Special Paper 361 (2002) 473-501
42. Hunter J.P., and Pearson D.A. First record of Lancian (Late Cretaceous) mammals from the Hell Creek Formation of North Dakota, USA. Cretaceous Research 17 (1996) 633-643
43. Hunter J.P., Pearson D.A., and Hartman J.H. Additions to the Puercan mammals of North Dakota and a framework for the study of post-K/T vertebrate recovery. Society of Vertebrate Palaeontology Abstracts 23 (2003) 64A
44. Izett G.A. The Cretaceous/Tertiary boundary interval, Raton Basin, Colorado and New Mexico, and its content of shock-metamorphosed minerals: evidence relevant to the K-T boundary impact-extinction theory. Geological Society of America Special Paper 249 (1990) 100
45. Jerzykiewicz T. Stratigraphic framework of the uppermost Cretaceous to Paleocene strata of the Alberta Basin. Geological Survey of Canada, Bulletin 510 (1997)
46. Jerzykiewicz T., and Sweet A.R. The Cretaceous-Tertiary boundary in the central Alberta Foothills: stratigraphy. Canadian Journal of Earth Sciences 23 (1986) 1356-1374
47. Johnson, K.R., 1989. A high-resolution megafloral biostratigraphy spanning the Cretaceous-Tertiary boundary in the northern Great Plains. Ph.D. thesis, New Haven, Connecticut Yale University, pp. 556.
48. Johnson K.R. Leaf-fossil evidence for extensive floral extinction at the Cretaceous-Tertiary boundary, North Dakota, USA. Cretaceous Research 13 (1992) 91-117
49. Johnson K.R. Megaflora of the Hell Creek and lower Fort Union Formations in the western Dakotas: vegetational response to climate change, the Cretaceous-Tertiary boundary event, and rapid marine transgression. In: Hartman J.H., Johnson K.R., and Nichols D.J. (Eds). The Hell Creek Formation and the Cretaceous-Tertiary Boundary in the Northern Great Plains: an Integrated Continental Record of the End of the Cretaceous. Geological Society of America Special Paper 361 (2002) 329-391
50. Johnson K.R., and Hickey L.J. Megafloral change across the Cretaceous/Tertiary boundary in the northern Great Plains and Rocky Mountains, USA. In: Sharpton V.L., and Ward P.D. (Eds). Global Catastrophes in Earth History: An Interdisciplinary Conference on Impacts, Volcanism and Mass Mortality. Geological Society of America Special Paper 247 (1990) 433-444
51. Johnson K.R., Nichols D.J., and Hartman J.H. Hell Creek formation: a 2001 synthesis. In: Hartman J.H., Johnson K.R., and Nichols D.J. (Eds). The Hell Creek Formation and the Cretaceous-Tertiary boundary in the Northern Great Plains: an Integrated Continental Record of the End of the Cretaceous. Geological Society of America Special Paper 361 (2002) 503-510
52. Leffingwell H.A. Palynology of Lance (Late Cretaceous) and Fort Union (Paleocene) formations of the type Lance area, Wyoming. In: Kosanke R.M., and Cross A.T. (Eds). Symposium on Palynology of the Late Cretaceous and Early Tertiary. Geological Society of America Special Paper 127 (1971) 1-64
53. Lerbekmo J.F., Sweet A.R., and St. Louis R.M. The relationship between the iridium and palynological floral events at three Cretaceous-Tertiary boundary localities in western Canada. Geological Society of America Bulletin 99 (1987) 325-330
54. Lerbekmo J.F., Demchuk T.D., Evans M.E., and Hoye G.S. Magnetostratigraphy and biostratigraphy of the continental Paleocene of the Red Deer Valley, Alberta, Canada. Bulletin of Canadian Petroleum Geology 40 (1992) 24-35
55. Lerbekmo J.F., Sweet A.R., and Duke M.J.M. A normal polarity subchron that embraces the K/T boundary: a measure of sedimentary continuity across the boundary and synchroneity of boundary events. In: Ryder G., Gartner S., and Fastovsky D. (Eds). Proceedings of the Conference on the New Developments Regarding the KT Event and Other Catastrophes in Earth History. Geological Society of America Special Paper 307 (1996) 465-476
56. Lillegraven J.A., and Eberle J.J. Vertebrate faunal changes through Lancian and Puercan time in southern Wyoming. Journal of Paleontology 73 (1999) 691-710
57. Magurran A.E. Ecological Diversity and its Measurement (1988), Princeton University Press, Princeton, U.S.A
58. Murphy E.C., Hoganson J.W., and Johnson K.R. Lithostratigraphy of the Hell Creek Formation in North Dakota. In: Hartman J.H., Johnson K.R., and Nichols D.J. (Eds). The Hell Creek Formation and the Cretaceous-Tertiary boundary in the Northern Great Plains: an Integrated Continental Record of the End of the Cretaceous. Geological Society of America, Special Paper 361 (2002) 9-34
59. Nichols D.J. Geologic and biostratigraphic framework of the non-marine Cretaceous-Tertiary boundary interval in western North America. Review of Palaeobotany and Palynology 70 (1990) 77-88
60. Nichols D.J. A revised palynostratigraphic zonation of the nonmarine Upper Cretaceous, Rocky Mountain region, United States. In: Caputo M.V., Peterson J.A., and Franczyk K.J. (Eds). Mesozoic Systems of the Rocky Mountain Region, USA: Society of Economic Paleontologists and Mineralogists, Rocky Mountain Section (1994)
61. Nichols D.J. Palynology and palynostratigraphy of the Hell Creek Formation in North Dakota: a microfossil record of plants at the end of Cretaceous time. In: Hartman J.H., Johnson K.R., and Nichols D.J. (Eds). The Hell Creek Formation and the Cretaceous-Tertiary boundary in the Northern Great Plains: an Integrated Continental Record of the End of the Cretaceous. Geological Society of America Special Paper 361 (2002) 393-456
62. Nichols D.J. Selected plant-microfossil records of the terminal Cretaceous event in terrestrial rocks, western North America. Palaeogeography, Palaeoclimatology, Palaeoecology 255 (2007) 22-34
63. Nichols D.J., Fleming R.F., and Frederiksen N.O. Palynological evidence of effects of the terminal Cretaceous event on terrestrial floras in western North America. In: Kauffman E.G., and Walliser O.H. (Eds). Extinction Events in Earth History. Lectures Notes in Earth Sciences 30 (1990), Springer-Verlag, New York 351-364
64. Nichols D.J., Jacobson S.R., and Tschudy R.H. Cretaceous palynomorph biozones for the central and northern Rocky Mountain region of the United States. In: Powers R.B. (Ed). Geologic Studies of the Cordilleran Thrust Belt vol. 2 (1982), Rocky Mountain Association of Geologists, Denver 721-733
65. Nichols D.J., Jarzen D.M., Orth C.J., and Oliver P.Q. Palynological and iridium anomalies at Cretaceous-Tertiary boundary, south-central Saskatchewan. Science 231 (1986) 714-717
66. Nichols D.J., and Johnson K.R. Palynostratigraphy and microstratigraphy of Cretaceous-Tertiary boundary sections in southwestern North Dakota. In: Hartman J.H., Johnson K.R., and Nichols D.J. (Eds). The Hell Creek Formation and the Cretaceous-Tertiary Boundary in the Northern Great Plains: an Integrated Continental Record of the End of the Cretaceous. Geological Society of America Special Paper 361 (2002) 95-143
67. Nichols D.J., and Johnson K.R. Plants and the K-T Boundary (2008), Cambridge University Press pp. 280
68. Nichols D.J., Murphy E.C., Johnson K.R., and Betterton W.J. A second K-T boundary locality in North Dakota verified by palynostratigraphy and shocked quartz. Geological Society of America Annual Meeting Abstract with Program 32 7 (2000) 130
69. Norton N.J., and Hall J.W. Guide sporomorphae in the Upper Cretaceous-Lower Tertiary of eastern Montana (U.S.A.). Review of Palaeobotany and Palynology 2 (1967) 99-110
70. Orth C.J., Gilmore J.S., Knight J.D., Pillmore C.L., Tschudy R.H., and Fassett J.E. An iridium abundance anomaly at the palynological Cretaceous-Tertiary boundary in northern New Mexico. Science 214 (1981) 1341-1343
71. Palmer M.W. The estimation of species richness by extrapolation. Ecology 71 (1990) 1195-1198
72. Pearson D.A. Paleontology and stratigraphy of the basal Fort Union Formation (Paleocene: Puercan) from Slope county, North Dakota. North Dakota Academy of Science Proceedings 55 (2001) 62
73. Pearson D.A., Schaefer T., Johnson K.R., and Nichols D.J. A gap in the record of all vertebrates at the K-T boundary in North Dakota supports abrupt dinosaur extinction. Geology 29 (2001) 39-42
74. Pearson D.A., Schaefer T., Johnson K.R., Nichols D.J., and Hunter J.P. Vertebrate biostratigraphy of the Hell Creek Formation in southwestern North Dakota and northwestern South Dakota. In: Hartman J.H., Johnson K.R., and Nichols D.J. (Eds). The Hell Creek Formation and the Cretaceous-Tertiary boundary in the Northern Great Plains: an Integrated Continental Record of the End of the Cretaceous. Geological Society of America Special Paper 361 (2002) 145-167
75. Pillmore C.L., and Flores R.M. Stratigraphy and depositional environments of the Cretaceous-Tertiary boundary clay and associated rocks, Raton Basin, New Mexico and Colorado. In: Fassett J.E., and Rigby K. (Eds). The Cretaceous-Tertiary Boundary in the San Juan and Raton Basin, New Mexico and Colorado. Geological Society of America Special Paper 209 (1987) 111-130
76. Pillmore C.L., Tschudy R.H., Orth C.J., Gilmore J.S., and Knight J.D. Geologic framework of nonmarine Cretaceous-Tertiary boundary sites, Raton Basin, New Mexico and Colorado. Science 223 (1984) 1180-1183
77. Pollastro R.M., and Bohor B.F. Origin and clay-mineral genesis of the Cretaceous-Tertiary boundary unit, western interior of North America. Clays and Clay Minerals 41 (1993) 7-25
78. Rampino M.R., and Reynolds R. Clay mineralogy of the Cretaceous-Tertiary boundary clay. Science 219 (1983) 495-498
79. Reynolds R.G., and Johnson K.R. Synopsis of the stratigraphy and paleontology of the uppermost Cretaceous and lower Tertiary strata in the Denver Basin, Colorado. Rocky Mountain Geology 38 1 (2003) 171-181
80. Sheehan P.M., and Fastovsky D.E. Major extinction of land-dwelling vertebrates at the Cretaceous-Tertiary boundary, eastern Montana. Geology 20 (1992) 556-560
81. Sheehan P.M., Fastovsky D.E., Barreto C., and Hoffman R.G. Dinosaur abundance was not declining in a "3 m gap" at the top of the Hell Creek Formation, Montana and North Dakota. Geology 28 (2000) 523-526
82. Sheehan P.M., Fastovsky D.E., Hoffmann R.G., Berghaus C.B., and Gabriel D.L. Sudden extinction of the dinosaurs: latest Cretaceous, upper Great Plains, USA. Science 254 (1991) 835-839
83. Simberloff D. Use of rarefaction and related methods in ecology. In: Dickson K.L., Cairns Jr. J., and Livingston R.J. (Eds). Biological Data in Water Pollution Assessment: Quantitative and Statistical Analyses (1978), American Society for Testing and Materials, Philadelphia 150-165
84. Smit J., and Van der Kaars S. Terminal Cretaceous extinction in the Hell Creek area, Montana; Compatible with catastrophic extinction. Science 223 (1984) 1177-1179
85. Srivastava S.K. Palynology of the Cretaceous-Tertiary boundary in the Scollard Formation of Alberta, Canada, and global KTB events. Review of Palaeobotany and Palynology 83 (1994) 137-158
86. Stanley E.A. Upper Cretaceous and Paleocene plant microfossils and Paleocene dinoflagellates and hystrichosphaerids from northwestern South Dakota. Bulletins and American Paleontology 49 222 (1965) 384
87. Sweet A.R. The Cretaceous-Tertiary boundary in the central Alberta Foothills, II. Miospores and pollen taxonomy. Canadian Journal of Earth Sciences 23 (1986) 1375-1388
88. Sweet A.R., and Braman D.R. The K-T boundary and the contiguous strata in western Canada: interactions between paleoenvironments and palynological assemblages. Cretaceous Research 13 (1992) 31-79
89. Sweet A.R., and Braman D.R. Cretaceous-Tertiary palynoflora perturbations and extinctions within the Aquilapollenites phytogeographic province. Canadian Journal of Earth Sciences 38 (2001) 249-269
90. Sweet A.R., Braman D.R., and Lerbekmo J.F. Sequential palynological changes across the composite Cretaceous-Tertiary boundary claystone and contiguous strata, western Canada and Montana, U.S.A. Canadian Journal of Earth Sciences 36 (1999) 743-768
91. Tipper J.C. Rarefaction and rarefiction, the use and abuse of a method in paleoecology. Paleobiology 5 (1979) 423-434
92. Traverse A. Paleopalynology. Topics in Geobiology. second edn. vol. 28 (2007), Springer, Dordrecht, Netherlands pp. 813
93. Tschudy R.H. Palynology of the Cretaceous-Tertiary boundary in the northern Rocky Mountain and Mississippi Embayment regions. In: Kosanke R.M., and Cross A.T. (Eds). Symposium on Palynology of the Late Cretaceous and Early Tertiary. Geological Society of America Special Paper 127 (1971) 65-111
94. Tschudy R.H., Pillmore C.L., Orth C.J., Gilmore J.S., and Knight J.D. Disruption of the terrestrial plant ecosystem at the Cretaceous-Tertiary boundary, Western Interior. Science 225 (1984) 1030-1032
95. Vajda V., Raine J.I., and Hollis C.J. Indication of global deforestation at the Cretaceous-Tertiary boundary by New Zealand fern spike. Science 294 (2001) 1700-1702
96. Vajda, V., Raine, J.I., Hollis, C.J., Strong, C.P., 2003. Global effects of the Chicxulub impact on terrestrial vegetation - Review of the palynological record from New Zealand Cretaceous/Tertiary boundary, In: Claeys, P. (Ed.), Impact Studies. Springer Verlag Series, 57-74.
97. Verbruggen, F., 2004. Lower Paleocene palynostratigraphy of the Kiowa core (Denver Basin, Colorado, U.S.A.). Denver Museum of Nature and Science Technical Report n. 2004-4.
98. Williams M.E. Catastrophic versus non-catastrophic extinction of the dinosaurs, Testing, falsifiability, and the burden of proof. Journal of Paleontology 68 (1994) 183-190