Senior Lecturer, Department of Earth Sciences, UCL
MSc Micropalaeontology Course Director
St. Margarets High School Liverpool
Geology BSc University of Sheffield
Micropalaeontology PhD UCL
+44 (0)20 7679 2431
Calcareous nannofossils - What are they?
Calcareous nannofossils are tiny (micron-sized, i.e. measured in thousandths of a millimetre) fossil calcite plates that formed the protective covering of marine phytoplanktonic (i.e. photosynthesising, floating) algae. With diatoms and dinoflagellates, they are, and were, the ‘grass’ of the oceans, i.e. important primary producers at the base of the food web. These algae are still living in the oceans today and the dominant group is called the coccolithophores. The fossil record contains many examples of coccolithophores (see Emiliania huxleyi and Watznaueria britannica, below), but also includes extinct types that may or may not have been closely related to the modern forms (see Schizosphaerella punctulata, below).
As well as the inherent beauty of calcareous nannofossils, they are of great importance for a number of different reasons. Firstly, as oceanic primary producers, they play a key role in the marine ecosystem, and in marine biogeochemical cycles as producers of organic carbon, carbonate and dimethyl sulphide. Secondly, their calcareous skeletons are incorporated into seafloor sediments, providing a remarkably complete fossil record from the Late Triassic (225 Ma) to the present day. This fossil record provides an excellent way in which to determine the age of rocks, using biostratigraphy, but also gives an indication of the environments in which the rocks were formed, thus informing ocean and climate history, and reveals details of evolutionary patterns and processes.
On the left is a coccosphere (the complete cell-wall covering) of the dominant living species, Emiliania huxleyi (each coccolith is about 4 microns) (seen from space below, it even has its own web page http://www.noc.soton.ac.uk/soes/staff/tt/eh/), and on the right, a nannofossil of uncertain biological affinities (because of its strange morphology) from the Early Jurassic, called Schizosphaerella punctulata (each bar on the image is 1 micron)
From left to right: atomic-scale view of Coccolithus pelagicus (image by Karen Henriksen from Henriksen et al. 2004); Watznaueria britannica (image Hiliary Dockerill) – was the most abundant Jurassic species; a satellite image of innumerable living coccoliths in a bloom off NW Scotland (image by ?NERC); innumerable fossil coccoliths (billions per square centimetre) making up the chalk at Durdle Door, Dorset
My research career has focused on three main themes of calcareous nannofossil science, namely: 1) the classification and evolution of fossil representatives; 2) stratigraphic and biostratigraphic applications; and 3) palaeoenvironmental/palaeoceanographic and palaeoclimate applications.
1) The classification and evolution of nannofossils
My PhD research comprised one of the first comprehensive accounts of the early evolution and radiation of calcareous nannofossils (Upper Triassic-Lower Jurassic), and provided a thorough taxonomic account and preliminary phylogentic model for the initiation of Mesozoic diversification. Building on this understanding of early diversification, I, in collaboration with colleagues, have produced taxonomic guides and phylogenetic models that incorporate Mesozoic, Cenozoic and extant nannoplankton. I have also published on the diversity history of calcareous nannofossils, and records for specific critical events, such as the Triassic/Jurassic and Cretaceous/Tertiary boundary intervals. Other strands within this theme have included work on the ultrastructure, crystallography and biomineralisation of coccoliths, and the description of over 130 new species. Development of the V/R model, explaining the crystallographic architecture of coccoliths and their mode of intracellular growth, together with atomic forcing microscopy observations of coccolith crystals, represent significant steps in our understanding of these biogenic structures.
Phylogeny of coccolith families (after Bown et al. 2004)
An overview of current nannofossil taxonomy is online at:
A guide to descriptive terminology is online at:
New species from the Palaeogene of Tanzania (Bown 2005; Pearson et al. 2005)
2) Stratigraphic and biostratigraphic applications
Stratigraphic work during my PhD provided a new, refined biostratigraphic zonation scheme for the Lower Jurassic, which was then expanded to incorporate the entire Jurassic System. A pioneering stratigraphic study in southern Italy demonstrated the value of nannofossils in Lower Jurassic sequences lacking ammonites. Following on from this, biostratigraphic work was extended to encompass the Lower and Upper Cretaceous, and in 1998 a complete stratigraphic synthesis volume was compiled, representing a state-of-the-art nannofossil biostratigraphy handbook. The book contained new and revised biostratigraphic zonation schemes for all stratigraphic intervals, comments on zonal use, palaeobiogeography and evolution, and included over 2000 images representing much of the known nannofossil biodiversity. I have published biostratigraphic research from the entire geological history of nannofossils, as part of the Ocean Drilling Program, and other programs and expeditions.
Calcareous nannofossil biostratigraphy
Ben Walsworth Bell standing at the Triassic-Jurassic boundary at Pinhay Bay, Dorset. Jurassic rocks can be dated using the nannofossil species below
Early Jurassic coccolith species: 1-2 Crepidolithus crassus, 3-4 Tubirhabdus patulus, 5-6 Parhabdolithus robustus, 7-8 Parhabdolithus liasicus (from Bown 1987)
3) Palaeoenvironmental and palaeoceanographic applications
Calcareous nannoplankton are important contributors to modern global biogeochemical cycles and, as such, record and potentially drive environmental change. Like most plankton they are rather insensitive to environmental parameters, living as they do throughout much of the world ocean’s photic zone, and the challenge for nannopalaeontologists has been to unlock the key to their use as environmental proxies. I have supervised a number of students who have applied quantitative nannofossil assemblage data approaches to palaeoenvironmental studies in the Jurassic and Cretaceous (Dawn Windley, Ben Walsworth-Bell, Chris Street), and published studies addressing Early Cretaceous palaeobiogeography and Jurassic, mid-Maastrichtian, K/T boundary, and Miocene palaeoenvironments. Similar studies on mid-Cretaceous oceanic anoxic events, the Paleogene/Eocene thermal maximum and the Eocene/Oligocene boundary are in train (Tom Dunkley Jones).
Nannofossil and other abundance data from the Cretaceous-Tertiary mass extinction level at Shatsky Rise (NW Pacific) (after Bown 2005)
Markalius inversus, a Cretaceous survivor species (green), and Praeprinsius sp., a tiny(-ier), newly evolved Paleocene species (pink), from the lowermost Paleocene of Shatsky Rise (NW Pacific)
Abundance data for the Cretaceous survivor species and newly evolving Paleocene species above the Cretaceous-Tertiary boundary at Shatsky Rise (NW Pacific) (after Bown 2005)
Find out more about the Ocean Drilling Program Leg 198 to Shatsky Rise at:
Recent scientific activity
2005 The Paleobiology Database, Micropalaeontology Workshop, Santa Barbara, CA, USA, February 2005 http://paleodb.org/cgi-bin/bridge.pl
2004 NSF Chronos Database Workshop, St. Petersburg, FL, USA, Oct. 2004 http://www.chronos.org/
2003 Coccolithophore Biodiversity Workshop, Rutgers University, NJ, USA, December 16-17 2003
2003 Guest Editor for Marine Micropalaeontology (volume 52)
2002 Organising Committee member, 6th International Symposium on the Jurassic System, Sicily, Italy.
2002 Organising Committee member, 9th International Nannoplankton Association Conference, Parma, Italy
2001 Shipboard Scientist, Ocean Drilling Program 198 (Shatsky Rise, NW Pacific Ocean)
Bown, P.R. 1998. Calcareous Nannofossil Biostratigraphy, British Micropalaeontological Society Publication Series, Chapman and Hall (Kluwer Academic Publishers): 1-315.
Bown, P.R., Lees, J.A. & Young, J.R. 2004. Calcareous nannoplankton evolution and diversity. In: H. Thierstein & J.R. Young (eds.) Coccolithophores - From molecular processes to global impact, 481-508, Springer-Verlag.
Bown, P.R. 1987. Taxonomy, biostratigraphy, and evolution of late Triassic-early Jurassic calcareous nannofossils. Special papers in Palaeontology, 38: 1-118.
Bown, P.R., Cooper, M.K.E. and Lord, A.R. 1988. A calcareous nannofossil biozonation scheme for the early to mid Mesozoic. Newsletters on Stratigraphy, 20: 91-114.
Bralower, T.J., Bown, P.R. & Siesser, W.G. 1991. Significance of Upper Triassic nannofossils from the Southern Hemisphere (ODP Leg 122, Wombat Plateau, NW Australia). Marine Micropaleontology, 17: 119-154.
Baumgartner, P.O., Bown, P.R., Marcoux, J., Mutterlose, Kaminski, M., Haig, D. & McMinn, A. 1992. Early Cretaceous biogeographic and oceanographic synthesis of Leg 123: Sites 765 and 766 (Argo Abyssal Plain) and lower Exmouth Plateau). Ocean Drilling Program, Scientific Results, 123: 739-758.
Young, J.R., Didymus, Bown, P.R., Prins, B. & Mann, S. 1992. Crystal assembly and phylogenetic evolution in heterococcoliths. Nature, 356: 516-518.
Bown, P.R. 1992. Late Triassic-Early Jurassic Calcareous Nannofossils of the Queen Charlotte Islands, British Columbia, Journal of Micropalaeontology, 11: 177-188.
Bown, P.R. 1993. New holococcoliths from the Toarcian-Aalenian (Jurassic) of northern Germany. Senckenbergiana Lethaea, 73: 407-419.
Young, J.R. & Bown, P.R. 1997. Higher classification of calcareous nannofossils. Journal of Nannoplankton Research, 19: 15-20.
Bown, P.R. & Young, J.R. 1997. Mesozoic calcareous nannoplankton classification. Journal of Nannoplankton Research, 19: 21-36.
Young, J.R. & Bown, P.R. 1997. Cenozoic calcareous nannoplankton classification. Journal of Nannoplankton Research, 19: 36-47.
Young, J.R. et al. including Bown, P.R. 1997. Guidelines for coccolith and calcareous nannofossil terminology. Palaeontology, 40: 875-912.
Young, J.R., Davis, S.A., Bown, P.R., & Mann, S. 1999. Coccolith ultrastructure and biomineralisation. Journal of Structural Biology, 126: 195-215.
Street, C. & Bown, P.R. 2000. Palaeobiogeography of Early Cretaceous (Berriasian-Barremian) calcareous nannoplankton. Marine Micropaleontology, 39: 265-291.
Bralower, T.J., Premoli-Silva, I., Malone, M.J. & Ocean Drilling Program Leg 198 Shipboard Party including Bown, P.R. 2002. Ocean Drilling Program Leg 198 Preliminary Report. Extreme Warmth in the Cretaceous and Paleogene: a depth transect on Shatsky Rise, Central Pacific (27 August-23 October 2001). www-odp.tamu.edu/ publications/prelim/198_prel/198toc.html
Henriksen, K., Young, J.R., Bown, P.R., & Stipp, S.L.S. 2004. Coccolith biominerlization studied with Atomic Force Microscopy. Palaeontology, 47: 725-743.
Bown, P.R. & Concheyro, A. 2004. Lower Cretaceous nannoplankton from the Neuquén Basin, Argentina. Marine Micropalaeontology, 52: 51-84.
Pearson, P., Nicholas, C.J., Singano, J., Bown, P.R., Coxall, H.K., van Dongen, B.E., Huber, B.T., Karega, A., Lees, J.A., Msaky, E., Pancost, R.D., Pearson, M. & Roberts, A.P. 2004. Paleogene and Cretaceous sediments cores from from the Kilwa and Lindi areas of coastal Tanzania: Tanzania Drilling Project Sites 1 to 5. Journal of African Earth Sciences, 39: 25-62.
Lees, J.A., Bown, P.R. and Young, J.R. 2004. Evidence for annual records of phytoplankton productivity in the Kimmeridge Clay Formation coccolith stone bands (Upper Jurassic, Dorset, UK). Marine Micropaleontology, 52: 29-49.
Robinson, S., Williams, T. & Bown, P.R. 2004. Fluctuations in biosiliceous production and generation of Early Cretaceous oceanic anoxic events in the Pacific Ocean (Shatsky Rise, ODP Leg 198). Paleoceanography, 19: PA4024, doi: 10.1029/2004PA001010, 2004.
Frank, T., Thomas, D., Leckie, M., Arthur, M., Bown, P.R., Jones, K. & Lees, J.A. 2005. The Maastrichtian record from Shatsky Rise (northwest Pacific): a tropical perspective on global ecological and oceanographic changes. Paleoceanography, 20: PA1008, doi: 10.1029/2004PA001052, 2005.
Bown, P.R. 2005. Paleogene calcareous nannofossils from the Kilwa and Lindi areas of coastal Tanzania: Tanzania Drilling Project Sites 1 to 10. Journal of Nannoplankton Research, 27: 21-95.
Bown, P.R. 2005. Selective calcareous nannoplankton survivorship at the Cretaceous-Tertiary boundary. Geology, 33/8: 653-656.
Bown, P.R. In press. Early to mid-Cretaceous calcareous nannoplankton from the northwest Pacific Ocean (ODP Leg 198). In Bralower, T.J., Premoli Silva, I., and Malone, M.J. (Eds.), Proceedings of the Ocean Drilling Program, Scientific Results, 198 [Online]. Available from World Wide Web: <http://www-odp.tamu.edu/ publications/198_SR/103/103.htm>.
Bown, P.R. In press. Calcareous nannoplankton evolution: a tale of two oceans. Micropaleontology.
Wade, B. & Bown, P.R. Accepted with revision. Calcareous nannofossils in extreme environments: The Messinian Salinity Crisis, Polemi Basin, Cyprus. Palaeogeography, Palaeoclimatology, Palaeoecology
2005-2008 NERC - Exploiting a novel technique to extract biological and ecological information from fossil calcareous nannoplankton: £262,189 PI
2004-2007 NERC - Do Paleogene sediments in the Andaman Flysch, Sylhet Trough and Iranian Makran record early erosion of the Himalayas? PI Dr. Andy Carter (Birkbeck): £167, 836 CO
2002-2005 NERC - Double proxy investigation of Cretaceous and Paleogene CO2 levels, Tanzania. : £257,695 PI Prof. Paul Pearson and others (Cardiff), Contributor
1996-1998 NERC - Phytoplankton dynamics and environmental cycles in the Late Jurassic (Kimmeridge Clay Formation, UK) PI with Dr. J.R. Young (NHM) and Dr. J. Riding (BGS)
1993-1995 NERC - Coccolith phylogeny and patterns of evolution using new morphological and crystallographic methods of analysis (NERC Standard Grant GR3/8496). PI With Dr. J.R. Young (NHM) and Dr. N. Ross (UCL)
MSc Micropalaeontology Calcareous Nannofossil Module
A three- to four-week (35-40 lectures, 40 practicals) module taught as part of the Micropalaeontology MSc. The course is internationally unique in providing extensive postgraduate training in a fossil-extant group that is widely utilised in Earth Sciences and the hydrocarbon exploration industry. The course covers all aspects of the biology, palaeobiology and evolutionary/stratigraphic history of calcareous nannofossils.
B163 History of Life (see link to webpage below)
This half course-unit course (20 lectures, 8 practical classes) gives an account of the development of life on Earth and the way in which life and the physical environment have interacted through 3800 million years of Earth’s history. The course begins with the formation of the Solar System and goes on to discuss the origins and development of life and the planet through the Precambrian and Phanerozoic. The course includes introductions to all aspects of palaeontology - palaeobiology, biostratigraphy, evolution, palaeoecology and taxonomy - and practical classes cover the description and classification of major invertebrate fossil groups, and the manipulation and application of palaeontological data.
In both courses, there is a common teaching philosophy, stressing the academic, economic, environmental and cultural impacts of palaeontology and palaeobiology. Economically and academically, palaeontology has been at the forefront of the development and refinement of the geological timescale, providing the underlying framework for all of our understanding of Earth history, and, practically, the chronology for economic deposits exploration. Living and fossil organisms are also fundamental in the tracking of global environmental change that has profoundly influenced the way in which we view Earth history, revealing both catastrophic (e.g. mass extinctions) and gradual (e.g. biotic response to greenhouse-icehouse climate mode transitions) change. Culturally, palaeontology provides a unique context for humans and society, with respect to the remaining life on Earth and the planet itself – a fact clearly evidenced by society’s continuing fascination with all aspects of past life on Earth and other planets, most obviously with dinosaurs but actually reaching across the diversity of life.
Degree Course Director:
2002-Present: MSc Micropalaeontology LINK
1999-2002: BSc/MSci Palaeobiology
1991-1996: BSc Geology
1989-Present: Calcareous Nannofossils – three- to four-week (35-40 lectures, 40 practicals) module as part of the Micropalaeontology MSc
Foraminifer covered with nannofossils – scale bars are 100 microns
1992-Present: B163 History of Life – first year half course-unit
Left, dinosaur trackway near Moab, Utah (Jackie Lees for scale); right, Jurassic ammonites in Argentina
1993-Present: B176 Southwest England Field Course – first year field class (10 days)
First year undergraduate fieldcourse (~40-50 students) that introduces all aspects of field geology, including historical geology, stratigraphy, sedimentology, palaeontology, and igneous and metamorphic rocks
Left, Blue Lias ammonites, looking east along the Jurassic Coast from Lyme Regis, Dorset; right, at least the under-4s are listening to the geological history of Cornwall!, at Ledden Cove
photo album at
2003-Present: MSc Micropalaeontology Field Training Course (4-7 days)
Postgraduate fieldcourse to Cyprus, Spain or the Isle of Wight, which includes geological problem solving, sedimentary logging and field collection of micropalaeontological samples
2000-Present: B231 Isle of Wight Field Course - second year Palaeobiology field class (4 days)
Second year undergraduate fieldcourse teaching palaeontological field techniques
1992-2001: C6 Independent Mapping Project – third year course-unit (14 days +)
Second/third year undergraduate field mapping course to the Cantabrian Cordillera, northern Spain, which precedes their 6-week independent mapping project. The area comprises a tectonised early Palaeozoic shallow marine succession.
1992-2000: C412 Micropalaeontology – third year half course-unit
2000-2003: B275 Geoscience Report – second year half course-unit
2003 Maths and Physical Sciences (MAPS) Faculty Teaching Award
2001-Present Member of the Geological Society Stratigraphy Commission
2000-Present Editor of the Journal of Nannoplankton Research, Special Publications
1999-Present Secretary of the International Subcommission on Jurassic Stratigraphy LINK
1995-Present Member of the Palaeontological Association http://palass.org/index.html
1989-Present Co-editor of the Journal of Nannoplankton Research 1986-Present 1995-Present
1989-Present Council Member, International Nannoplankton Association
1986-Present Member of The Micropalaeontological Association (Council member 1988-1990)
A few links
Champions of Europe 2005
Best bands in the world
actually, too many to mention
INA – International Nannoplankton Association http://www.nhm.ac.uk/hosted_sites/ina/
Miracle – some microfossil images from UCL Micropalaeontology
UCL Earth Sciences http://www.es.ucl.ac.uk/
KCRW radio http://www.kcrw/
Last revised: August 2005