Øyvind Hammer

Dr. Scient. Interests include quantitative paleontology, marine geology, carbonate dissolution and precipitation, growth and pattern formation.

PAST - Paleontological Statistics Software

My blog.

Publicaciones recientes:

Hammer, Ø. 1998. Diffusion and direct signaling models are numerically equivalent. Journal of Theoretical Biology 192:129-130.

Hammer, Ø. 1998. Growth, form and the history of life (in Norwegian). Naturen 122(3):163-168.

Hammer, Ø. 1998. Computer simulation of the evolution of foraging strategies: Application to the ichnological record. Palaeontologia Electronica 1(2):21p.

Hammer, Ø. 1998. Regulation of astogeny in halysitid tabulates. Acta Palaeontologica Polonica 43(4):635-651.

Hammer, Ø. & Barrett, N. 1998. Mimetic Dynamics. Organised Sound 3:211-218.

Hammer, Ø. 1999. The development of ammonoid septa: An epithelial invagination process controlled by morphogens? Historical Biology 13:153-171.

Hammer, Ø. & Sundt, H. 1999. Musical applications of decomposition methods with global support. Proceedings of 2nd COST-G6 Workshop on Digital Audio Effects.

Hammer, Ø. 1999. Computer-aided study of growth patterns in tabulate corals, exemplified by Catenipora heintzi from Ringerike, Oslo Region. Norsk Geologisk Tidsskrift 79:219-226.

Hammer, Ø. & Bucher, H. 1999. Reaction-diffusion processes: Application to the morphogenesis of ammonoid ornamentation. GeoBios 32:841-852.

Hammer, Ø. 2000. Lateral inhibition models in developmental palaeobiology. Dr. Scient. thesis. University of Oslo.

Hammer, Ø. 2000. A theory for the formation of commarginal ribs in mollusc shells by regulative oscillation. Journal of Molluscan Studies 66:383-391.

Hammer, Ø. 2000. Lateral inhibition in the astogeny of conical multistiped graptolites. Lethaia 33:39-45.

Hammer, Ø. 2000. Spatial organisation of tubercles and terrace lines in Paradoxides forchhammeri - evidence of lateral inhibition. Acta Palaeontologica Polonica 45:251-270.

Cervato, C., Gradstein, F., Hammer, Ø., Tetlie, O.E., Ore, Ch.-E., Smelror, M. & Williams, R. 2001. How to use the Mesozoic-Cenozoic fossil record in 1000+ wells, offshore Norway, in the 21st century: stamp collecting or dynamic interactive WWW-based stratigraphy. Geological Society of America, Abstracts with Programs, A121.

Hammer, Ø. & Barrett, N. 2001. Spatio-temporal distribution of animal vocalizations in two neo-tropical rain forests. Bioacoustics 12:21-35.

Hammer, Ø., Harper, D.A.T & Ryan, P.D. 2001. PAST: Paleontological statistics software package for education and data analysis. Palaeontologia Electronica 4(1).

Hammer, Ø. 2001. When Oslo was open sea - fauna and climate in the Ordovician (in Norwegian). Naturen 125(6):259-265.

Hammer, Ø. & Harper, D.A.T. 2001. Ordovician biodiversity changes across Baltica: A Baltoscandian database. Paleo Bios 21,suppl. 2:5 (abstract)

Hammer, Ø., Bengtson, S., Malzbender, T. & Gelb, D. 2002. Imaging fossils using reflectance transformation and interactive manipulation of virtual light sources. Palaeontologia Electronica 4(3).

Hammer, Ø. 2003. A database of fossil ocurrences in the Ordovician of Baltoscandia. Bulletin of the Geological Society of Denmark 50:5-9.

Hammer, Ø. 2003. A 12-14 million year faunal diversity cycle in the Ordovician of Western Baltica. Norwegian Journal of Geology 83:79-84.

Hammer, Ø. 2003. Biodiversity curves for the Ordovician of Baltoscandia. Lethaia 36:305-313.

Hammer, Ø. 2004. Trilobite biodiversity in the Ordovician of Baltica. In Webby, B.D., Paris, F., Droser, M.L. & Percival, I.G. (eds): The Great Ordovician Biodiversification Event. Columbia University Press.

Hammer, Ø. 2004. Allometric field decomposition - an attempt at morphogenetic morphometrics. In Elewa, A.M.T. (ed): Morphometrics - Applications in Biology and Paleontology, pp. 55-66. Springer.

Hammer, Ø., Jamtveit, B., Benning, L., Dysthe, D.K. 2005. Evolution of fluid chemistry during travertine formation in the Troll thermal springs, Svalbard, Norway. Geofluids 5:140-150.

Hammer, Ø., Bucher, H. 2005. Buckman's law of covariation - a case of proportionality. Lethaia 38:67-72.

Hammer, Ø., Bucher, H. 2005. Models for the morphogenesis of the molluscan shell. Lethaia 38:111-122.

Olsen, L., Hammer, Ø. 2005. A 6-ka climatic cycle during at least the last 50,000 years. NGU Bulletin 445:89-100.

Hammer, Ø., Bucher, H. 2006. Generalized ammonoid hydrostatics modelling, with application to Intornites and intraspecific variation in Amaltheus. Paleontological Research 10:91-96.

Hammer, Ø., Harper, D.A.T. 2006. Paleontological Data Analysis. Blackwell, 351 pp.

Jamtveit, B., Hammer, Ø., Anderson, C., Dysthe, D.K., Heldmann, J., Vogel, M. 2006. Travertines from the Troll thermal springs, Svalbard. Norwegian Journal of Geology 86:387-395.

Hurum, J.H., Milan, J., Hammer, Ø., Midtkandal, I., Amundsen, H., Saether, B. 2006. Tracking polar dinosaurs - new finds from the Lower Cretaceous of Svalbard. Norwegian Journal of Geology 86:397-402.

Hammer, Ø. 2007. Spectral analysis of a Plio-Pleistocene multispecies time series using the Mantel periodogram. Palaeogeography, Palaeoclimatology, Palaeoecology 243:373-377.

Hammer, Ø., Dysthe, D.K., Jamtveit, B. 2007. The dynamics of travertine dams. Earth and Planetary Science Letters 256:258-263.

Hammer, Ø. 2008. Pattern formation: Watch your step. Nature Physics 4:265-266.

Hammer, Ø., Dysthe, D.K., Lelu, B., Lund, H., Meakin, P., Jamtveit, B. 2008. Calcite precipitation instability under laminar, open-channel flow. Geochimica et Cosmochimica Acta 72:5009-5021.

Bowman, A., Gradstein, F.M., Lugowski, A., Hammer, Ø. 2008. Increasing resolution in exploration biostratigraphy - Part I. Natural Resources Research 17, 119-127.

Bowman, A., Gradstein, F.M., Lugowski, A., Hammer, Ø. 2008. Increasing resolution in exploration biostratigraphy - Part II. Natural Resources Research 17, 129-134.

Webb, K.E., Hammer, Ø, Lepland, A., Gray, J.S. 2009. Pockmarks in the Inner Oslofjord, Norway. Geo-Marine Letters 29:111-124.

Hammer, Ø. 2009. New methods for the statistical detection of point alignments. Computers & Geosciences 35:659-666.

de Mahiques, M.M., Wainer, I.K.C., Burone, L., Nagai, R., de Mello e Sousa, S.H., Figueira, R.C.L., da Silveira, I.C.A., Bicego, M.C., Alves, D.P.V., Hammer, Ø. 2009. A high-resolution Holocene record on the Southern Brazilian shelf: Paleoenvironmental implications. Quaternary International 206:52-61.

Hammer, Ø., Webb, K.E., Depreiter, D. 2009. Numerical simulation of upwelling currents in pockmarks, and data from the Inner Oslofjord, Norway. Geo-Marine Letters 29:269-275.

Kruglikova, S.B., Bjørklund, K.R., Hammer, Ø., Anderson, O.R. 2009. Endemism and speciation in the polycystine radiolarian genus Actinomma in the Arctic Ocean: Description of two new species Actinomma georgii n. sp. and Actinomma turidae n. sp. Marine Micropaleontology 72:26-48.

Svensen, H., Hammer, Ø, Mazzini, N., Onderdonk, N., Polteau, S., Planke, S., Podladchikov, Y.Y. 2009. Dynamics of hydrothermal seeps from the Salton Sea geothermal system (California, USA) constrained by temperature monitoring and time series analysis. Journal of Geophysical Research 114, doi:10.1029/2008JB006247.

Hammer, Ø. 2009. Pattern formation by local amplification and lateral inhibition: examples from biology and geology. European Physical Journal, Special Topics 178:5-12.

Galster, F., Guex, J., Hammer, Ø. 2010. Neogene biochronology of Antarctic diatoms: A comparison between two quantitative approaches, CONOP and UAgraph. Palaeogeography, Palaeoclimatology, Palaeoecology 285:237-247.

Hammer, Ø. 2010. Travertine terracing: patterns and mechanisms. In: Tufas and Speleothems: Unravelling the Microbial and Physical Controls. Geological Society of London Special Publication 336:345-355.

Hammer, Ø, Webb, K.E. 2010. Piston coring of Inner Oslofjord pockmarks: constraints on age and mechanism. Norwegian Journal of Geology 90:79-91.

Hammer, Ø. 2010. Morphometrics in Past: Integrating morphometrics with general data analysis software. In Elewa, A.M.T. (ed.): Morphometrics for Nonmorphometricians. Lecture Notes in Earth Sciences 124:357-362. Springer-Verlag Berlin Heidelberg.

Sharma, P., Uniyal, P.L., Hammer, Ø. 2010. Two new species of Ephedra (Ephedraceae) from the western Himalaya region. Systematic Botany 35:730-735.

Gradstein, F.M., Anthonissen, E., Brunstad, H., Charnock, M., Hammer, Ø, Hellem, T., Lervik, K.S. 2010. Norwegian Offshore Stratigraphic Lexicon (NORLEX). Newsletters on Stratigraphy 44:73-86.

Kruglikova, S.B., Bjørklund, K.R., Dolven, J.K., Hammer, Ø., Cortese, G. 2010. High-rank polycystine radiolarian taxa as temperature proxies in the Nordic Seas. Stratigraphy 7:265-281.

Hammer, Ø., Nakrem, H.A., Little, C.T.S., Hryniewicz, K., Sandy, M.R., Hurum, J.H., Druckenmiller, P., Knutsen, E.M., Høyberget, M. 2011. Hydrocarbon seeps from close to the Jurassic-Cretaceous boundary, Svalbard. Palaeogeography, Palaeoclimatology, Palaeoecology 306:15-26.

Wierzbowski, A., Hryniewicz, K., Hammer, Ø, Nakrem, H.A., Little, C.T.S. 2011. Ammonites from hydrocarbon seep carbonate bodies from the uppermost Jurassic-lowermost Cretaceous of Spitsbergen, Svalbard, and their biostratigraphic importance. Neues Jahrbuch fur Geologie und Palaontologie 262:267-288.

Kruglikova, S.B., Bjørklund, K.R., Hammer, Ø. 2011. High rank taxa of Polycystina (Radiolaria) as environmental bioindicators. Micropaleontology 57:483-489.

Hammer, Ø., Lauritzen, S.E., Jamtveit, B. 2011. Stability of dissolution flutes under turbulent flow. Journal of Cave and Karst Studies 73:181-186.


Parent, H., Bejas, M., Greco, A., Hammer, Ø. 2012. Relationships between dimensionless models of ammonoid shell morphology. Acta Palaeontologica Polonica 57:445-447.

Svensen, H., Corfu, F., Polteau, S., Hammer, Ø., Planke, S. 2012. Rapid magma emplacement in the Karoo Large Igneous Province. Earth and Planetary Science Letters 325:1-9.

Jamtveit, B., Hammer, Ø. 2012. Sculpting of rocks by reactive fluids. Geochemical Perspectives 1:341-481.

Agterberg, F.P., Hammer, Ø., Gradstein, F.M. 2012. Statistical procedures. In Gradstein, F.M., Ogg, J.G., Schmitz, M. & Ogg, G. (eds.): The Geologic Time Scale 2012, pp. 269-274. Elsevier.

Becker, R.T., Gradstein, F.M., Hammer, Ø. 2012. The Devonian period. In Gradstein, F.M., Ogg, J.G., Schmitz, M. & Ogg, G. (eds.): The Geologic Time Scale 2012, pp. 559-580. Elsevier.

Hammer, Ø., Collignon, M., Nakrem, H.A. 2012. Organic carbon isotope chemostratigraphy and cyclostratigraphy in the Volgian of Svalbard. Norwegian Journal of Geology 92:103-112.

Hurum, J.H., Nakrem, H.A., Hammer, Ø., Knutsen, E.M., Druckenmiller, P., Hryniewicz, K., Novis, L.K. 2012. An Arctic Lagerstätte - Slottsmøya Member of the Agardhfjellet Formation (Upper Jurassic - Lower Cretaceous) of Spitsbergen. Norwegian Journal of Geology 92:55-64.

Hryniewicz, K., Hammer, Ø., Nakrem, H.A., Little, C.T.S. 2012. Microfacies of the Volgian-Ryazanian (Jurassic-Cretaceous) Sassenfjorden hydrocarbon seep carbonates from central Spitsbergen, Svalbard. Norwegian Journal of Geology 92:113-131.

Collignon, M., Hammer, Ø. 2012. Petrography and sedimentology of the Slottsmøya Member at Janusfjellet, Spitsbergen: evidence for a condensed section. Norwegian Journal of Geology 92:89-101.


Hawkins, C., Angeluta, L., Hammer, Ø., Jamtveit, B. 2013. Precipitation dendrites in channel flow. EPL 102:54001.

Bing, H., Harper, D.A.T., Hammer, Ø. 2013. Introduction to Past: a comprehensive statistics software package for paleontological data analysis. Acta Palaeontologica Sinica 52:161-181.

Hammer, Ø., Spocova, J. 2013. Virtual whitening of fossils using polynomial texture mapping. Palaeontologia Electronica 16(2):10 pp.

Brunstad, H., Gradstein, F., Lie, J.E., Hammer, Ø., Munsterman, D., Ogg, G., Hollerbach, M. 2013. Stratigraphic guide to the Rogaland Group, Norwegian North Sea. Newsletters on Stratigraphy 46:137-286.

Nickel, J.C., di Primio, R., Kallmeyer, J., Hammer, Ø., Horsfield, B., Stoddart, D., Brunstad, H. Mangelsdorf, K. 2013. Tracing the origin of thermogenic hydrocarbon signals in pockmarks from the southwestern Barents Sea. Organic Geochemistry 63:73-84.

Gradstein, F.M., Davydov, V.I., Hammer, Ø. 2013. Carboniferous cyclic sedimentation on Bear Island (Arctic Norway). Newsletters on Stratigraphy 43:303-317.

Riyahi, S., Hammer, Ø., Arbabi, T., Sanchez, A., Roselaar, C.S., Aliabadian, M., Sætre, G.-P. 2013. Beak and skull shapes of human commensal and non-commensal house sparrows Passer domesticus (Passeriformes: Passeridae). BMC Evolutionary Biology 13:200 (8 pp).

Pau, M., Hammer, Ø. 2013. Sediment mapping and long-term monitoring of currents and sediment fluxes in pockmarks in the Oslofjord, Norway. Marine Geology 346:262-273.

Hammer, Ø., Hryniewicz, K., Hurum, J.H., Høyberget, M., Knudsen, E.M., Nakrem, H.A. 2013. Large mega-onychites (cephalopod hooks) from the Upper Jurassic of the Boreal Realm. Acta Palaeontologica Polonica 58:827-835.


Pau, M., Gisler, G., Hammer, Ø. 2014. Experimental investigation of the hydrodynamics in pockmarks using particle tracking velocimetry. Geo-Marine Letters 34:11-19.

Haverkamp, T.H.A., Hammer, Ø., Jakobsen, K.S. 2014. Linking geology and microbiology: inactive pockmarks affect sediment microbial community structure. PLOS One 9:e85990 (19 pp).

Burridge, A.K., Bjørklund, K.R., Kruglikova, S.B., Hammer, Ø. 2014. Inter- and intraspecific morphological variation of four-shelled Actinomma taxa (Radiolaria) in polar and subpolar regions. Marine Micropaleontology 110:50-71.

Pau, M., Hammer, Ø., Chand, S. 2014. Constraints on the dynamics of pockmarks in the SW Barents Sea: evidence from gravity coring and high-resolution, shallow seismic profiles. Marine Geology 355:330-345.

Sharma, P., Uniyal, P.L., Hammer, Ø. 2014. Phenotypic plasticity leading to sympatric speciation in populations of Ephedra in Lahaul and Spiti (India). Pp. 205-217 in: Sundaresan, J., Gupta, P., Santosh, K.M., Boojh, R. (eds.): Climate change and Himalaya: Natural hazards and mountain resources. Scientific Publishers.

Sandy, M.R, Hryniewicz, K., Hammer, Ø, Nakrem, H.A., Little, C.T.S. 2014. Brachiopods from Late Jurassic - Early Cretaceous hydrocarbon seep deposits, central Spitsbergen, Svalbard. Zootaxa 3884:501-532.


Svensen, H.H., Hammer, Ø., Corfu, F. 2015. Astronomically forced cyclicity in the Upper Ordovician and U-Pb ages of interlayered tephra, Oslo Region, Norway. Palaeogeography, Palaeoclimatology, Palaeoecology 418:150-159.

Ovtcharova, M., Goudemand, N., Hammer, Ø., Guodun, K., Cordey, F., Galfetti, T., Schaltegger, U., Bucher, H. 2015. Developing a strategy for accurate definition of a geological boundary through radio-isotopic and biochronological dating: the Early-Middle Triassic boundary (South China). Earth-Science Reviews 146:65-76.

Hryniewicz, K., Nakrem, H.A., Hammer, Ø., Little, C.T.S., Kaim, A., Sandy, M.R., Hurum, J.H. 2015. The palaeoecology of latest Jurassic-earliest Cretaceous hydrocarbon seep carbonates from Spitsbergen, Svalbard. Lethaia 48:353-374.

Hryniewicz, K., Hagström, J., Hammer, Ø., Kaim, A., Little, C.T.S., Nakrem, H.A. 2015. Late Jurassic - Early Cretaceous hydrocarbon seep boulders from Novaya Zemlya and their faunas. Palaeogeography, Palaeoclimatology, Palaeoecology 436:231-244.

Guex, J., Galster, F., Hammer, Ø. 2015. Discrete biochronological time scales. Springer, 160 pp.


Sigurdsen, A., Hammer, Ø. 2016. Body size trends in the Ordovician to earliest Silurian of the Oslo Region. Palaeogeography, Palaeoclimatology, Palaeoecology 443:49-56.

Amberg, C., Collart, T., Salenbien, W., Egger, L., Munnecke, A., Nielsen, A.T., Monnet, C., Hammer, Ø, Vandenbroucke, T.R.A. 2016. The nature of Ordovician limestone-mudstone alternations in the Oslo-Asker area (Norway): witnesses of primary glacio-eustasy or diagenetic rhythms? Scientific Reports 6:18787.

Hammer, Ø., Planke, S., Hafeez, A., Hjelstuen, B.O., Faleide, J.I., Kvalø, F. 2016. Agderia - a postglacial lost land in the southern Norwegian North Sea. Norwegian Journal of Geology 96:43-60.

Pau, M., Hammer, Ø. 2016. Sedimentary environments in the SW Barents Sea during the last deglaciation and the Holocene: a case study outside the Ingøydjupet trough. Polar Research 35:23104.

Koevoets, M.J., Abay, T.B., Hammer, Ø., Olaussen, S. 2016. High-resolution organic carbon-isotope stratigraphy of the Middle Jurassic - Lower Cretaceous Agardhfjellet Formation of central Spitsbergen, Svalbard. Palaeogeography, Palaeoclimatology, Palaeoecology 449:266-274.

Hurum, J., Druckenmiller, P., Hammer, Ø., Nakrem, H.A. The theropod that wasn't - an ornithopod tracksite from the Helvetiafjellet Formation (Lower Cretaceous) of Boltodden, Svalbard. Geological Society of London Special Publications 434:189-206.

Delsett, L.L., Novis, L.K., Roberts, A.J., Koeovoets, M.J., Hammer, Ø., Druckenmiller, P.S., Hurum, J.H. The Slottsmøya marine reptile Lagerstätte – depositional environments, taphonomy and diagenesis. Geological Society of London Special Publications 434:165-188.

Hammer, Ø. 2016. The Perfect Shape - spiral stories. Springer Publishing, 258 pp.


Hammer, Ø., Svensen, H.H. 2017. Biostratigraphy and carbon and nitrogen geochemistry of the SPICE event in Cambrian low-grade metamorphic black shale, Southern Norway. Palaeogeography, Palaeoclimatology, Palaeoecology 468:216-227.

Mazzini, A., Svensen, H.H., Forsberg, C.F., Linge, H., Lauritzen, S.-E., Haflidason, H., Hammer, Ø., Planke, S., Tjelta, T.I. 2017. A climatic trigger for the giant Troll pockmark field in the northern North Sea. Earth and Planetary Science Letters 464:24-34.

Piazza, V., Hammer, Ø., Jattiot, R. 2017. New late Smithian (Early Triassic) ammonoids from the Lusitaniadalen Member, Vikinghøgda Formation, Svalbard. Norwegian Journal of Geology 97:105-117.

Neumann, E.R., Svensen, H.H., Polozov, A.G., Hammer, Ø. 2017. Formation of Si-Al-Mg-Ca-rich zoned magnetite in an end-Permian phreatomagmatic pipe in the Tunguska Basin, East Siberia. Mineralium Deposita 52:12055-1222.


Hammer, Ø., Alsen P., Grundvåg, S.-A., Jelby, M.E., Nøhr-Hansen, H., Olaussen, S., Senger, K., Sliwinska, K.K., Smelror, M. Comment on 'Redox conditions, productivity, and volcanic input during deposition of uppermost Jurassic and Lower Cretaceous organic-rich siltstones in Spitsbergen, Norway' by Rakocinski et al. (2018). Cretaceous Research xxx (2018).

Tasianas, A., Bunz, S., Bellwald, B., Hammer, Ø., Planke, S., Lebedeva-Ivanova, N., Krassakis, P. 2018. High-resolution 3D seismic study of pockmarks and shallow fluid flow systems at the Snøhvit hydrocarbon field in the SW Barents Sea. Marine Geology 403:247-261.

Hurum, J.H., Engelschiøn, V.S., Økland, I., Bratvold, J., Ekeheien, C.P., Roberts, A.J., Delsett, L.L., Hansen, B.B., Mørk, A., Nakrem, H.A., Druckenmiller, P.S., Hammer, Ø. The history of exploration and stratigraphy of the Early to Middle Triassic vertebrate-bearing strata of Svalbard (Sassendalen Group, Spitsbergen). Norwegian Journal of Geology 98:165-174.

Hansen, B.B., Hammer, Ø., Nakrem, H.A. 2018. Stratigraphy and age of the Grippia niveau bonebed, Lower Triassic Vikinghøgda Formation, Spitsbergen. Norwegian Journal of Geology 98:175-187.

Gyøry, E., Hammer, Ø., Jorde, K., Nakrem, H.A., Swajda, M., Domeier, M. 2018. The origin of Telemarkites from the Mesoproterozoic of Telemark, Norway. Norwegian Journal of Geology 98:25-39.

Koevoets, M., Hammer, Ø., Olaussen, S., Senger, K., Smelror, M. 2018. Integrating subsurface and outcrop data of the Middle Jurassic to Lower Cretaceous Agardhfjellet Formation in central Spitsbergen. Norwegian Journal of Geology 99:1-34.

Koevoets, M.J., Hurum, J.H., Hammer, Ø. 2018. New Late Jurassic teleost remains from the Agardhfjellet Formation, Spitsbergen, Svalbard. Norwegian Journal of Geology 98:289-299.


Markussen, Ø., Dypvik, H., Hammer, E., Long, H. Hammer, Ø. 2019. 3D characterization of porosity and authigenic cementation in Triassic conglomerates/arenites in the Edvard Grieg field using 3D micro-CT imaging. Marine and Petroleum Geology 99:265-281.

Ballo, E.G., Augland, L.E., Svensen, H., Hammer, Ø. 2019. A new age model for the Ordovician (Sandbian) K-bentonites in Oslo, Norway. Palaeogeography, Palaeoclimatology, Palaeoecology 520:203-213.

Hammer, Ø., Jones, M.T., Schneebeli-Hermann, E., Hansen, B.B., Bucher, H. 2019. Are Early Triassic extinction events associated with mercury anomalies? A reassessment of the Smithian/Spathian boundary extinction. Earth Science Reviews ??.

Natural History Museum
University of Oslo
Sars gt. 1, 0562 Oslo
Phone: (+47) 22 85 16 58

E-mail: ohammer@nhm.uio.no