Hostname: page-component-cd9895bd7-q99xh Total loading time: 0 Render date: 2024-12-26T20:42:45.811Z Has data issue: false hasContentIssue false
  • English
  • Français

Going round the twist—an empirical analysis of shell coiling in helicospiral gastropods

Published online by Cambridge University Press:  23 March 2021

Katie S. Collins Open the ORCID record for Katie S. Collins [Opens in a new window] ,
Roman Klapaukh ,
James S. Crampton Open the ORCID record for James S. Crampton [Opens in a new window] ,
Michael F. Gazley ,
C. Ian Schipper ,
Anton Maksimenko  and
Benjamin R. Hines
Katie S. Collins*
Affiliation:
Natural History Museum, Cromwell Road, LondonSW7 5BD, U.K. E-mail: [email protected]
Roman Klapaukh
Affiliation:
University College London, Gower Street, Bloomsbury, London WC1E 6BT, U.K. E-mail: [email protected]
James S. Crampton
Affiliation:
School of Geography, Environment and Earth Sciences, Victoria University of Wellington, P.O. Box 600, Wellington, New Zealand. E-mail: [email protected], [email protected], [email protected]
Michael F. Gazley
Affiliation:
RSC Mining and Mineral Exploration, 93 The Terrace, Wellington, New Zealand. E-mail: [email protected]
C. Ian Schipper
Affiliation:
School of Geography, Environment and Earth Sciences, Victoria University of Wellington, P.O. Box 600, Wellington, New Zealand. E-mail: [email protected], [email protected], [email protected]
Anton Maksimenko
Affiliation:
Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria3168, Australia. E-mail: [email protected]
Benjamin R. Hines
Affiliation:
School of Geography, Environment and Earth Sciences, Victoria University of Wellington, P.O. Box 600, Wellington, New Zealand. E-mail: [email protected], [email protected], [email protected]
*
*Corresponding author.
Get access Rights & Permissions [Opens in a new window]

Abstract

The logarithmic helicospiral has been the most widely accepted model of regularly coiled molluscan form since it was proposed by Moseley and popularized by Thompson and Raup. It is based on an explicit assumption that shells are isometric and grow exponentially, and an implicit assumption that the external form of the shell follows the internal shape, which implies that the parameters of the spiral could be reconstructed from the external whorl profile. In this contribution, we show that these assumptions fail on all 25 gastropod species we examine. Using a dataset of 176 fossil and modern gastropod shells, we construct an empirical morphospace of coiling using the parameters of whorl expansion rate, translation rate, and rate of increasing distance from coiling axis, plus rate of aperture shape change, from their best-fit models. We present a case study of change in shell form through geologic time in the austral family Struthiolariidae to demonstrate the utility of our approach for evolutionary paleobiology. We fit various functions to the shell-coiling parameters to demonstrate that the best morphological model is not the same for each parameter. We present a set of R routines that will calculate helicospiral parameters from sagittal sections through coiled shells and allow workers to compare models and choose appropriate sets of parameters for their own datasets. Shell-form parameters in the Struthiolariidae highlight a hitherto neglected hypothesis of relationship between Antarctic Perissodonta and the enigmatic Australian genus Tylospira that fits the biogeographic and stratigraphic distribution of both genera.

Type
Articles
Information
Paleobiology , Volume 47 , Issue 4 , November 2021 , pp. 648 - 665
Check for updates
Copyright
Copyright © The Author(s), 2021. Published by Cambridge University Press on behalf of 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

Aguirre, M. L., Richiano, S., Álvarez, A., and Farinati, E. A.. 2016. Reading shell shape: implications for palaeoenvironmental reconstructions. A case study for bivalves from the marine Quaternary of Argentina (south-western Atlantic). Historical Biology 28:753–773.Google Scholar
Appeltans, W., Ahyong, S. T., Anderson, G., Angel, M. V., Artois, T., Bailly, N., Bamber, R., Barber, A., Bartsch, I., Berta, A., Błażewicz-Paszkowycz, M., Bock, P., Boxshall, G., Boyko, C. B., Brandão, S. N., Bray, R. A., Bruce, N. L., Cairns, S. D., Chan, T.-Y., Cheng, L., Collins, A. G., Cribb, T., Curini-Galletti, M., Dahdouh-Guebas, F., Davie, P. J. F., Dawson, M. N., De Clerck, O., Decock, W., De Grave, S., de Voogd, N. J., Domning, D. P., Emig, C. C., Erséus, C., Eschmeyer, W., Fauchald, K., Fautin, D. G., Feist, S. W., Fransen, C. H. J. M., Furuya, H., Garcia-Alvarez, O., Gerken, S., Gibson, D., Gittenberger, A., Gofas, S., Gómez-Daglio, L., Gordon, D. P., Guiry, M. D., Hernandez, F., Hoeksema, B. W., Hopcroft, R. R., Jaume, D., Kirk, P., Koedam, N., Koenemann, S., Kolb, J. B., Kristensen, R. M., Kroh, A., Lambert, G., Lazarus, D. B., Lemaitre, R., Longshaw, M., Lowry, J., Macpherson, E., Madin, L. P., Mah, C., Mapstone, G., McLaughlin, P. A., Mees, J., Meland, K., Messing, C. G., Mills, C. E., Molodtsova, T. N., Mooi, R., Neuhaus, B., Ng, P. K. L., Nielsen, C., Norenburg, J., Opresko, D. M., Osawa, M., Paulay, G., Perrin, W., Pilger, J. F., Poore, G. C. B., Pugh, P., Read, G. B., Reimer, J. D., Rius, M., Rocha, R. M., Saiz-Salinas, J. I., Scarabino, V., Schierwater, B., Schmidt-Rhaesa, A., Schnabel, K. E., Schotte, M., Schuchert, P., Schwabe, E., Segers, H., Self-Sullivan, C., Shenkar, N., Siegel, V., Sterrer, W., Stöhr, S., Swalla, B., Tasker, M. L., Thuesen, E. V., Timm, T., Todaro, M. A., Turon, X., Tyler, S., Uetz, P., van der Land, J., Vanhoorne, B., van Ofwegen, L. P., van Soest, R. W. M., Vanaverbeke, J., Walker-Smith, G., Walter, T. C., Warren, A., Williams, G. C., Wilson, S. P., and Costello, M. J.. 2012. The magnitude of global marine species diversity. Current Biology 22:2189–2202.CrossRefGoogle ScholarPubMed
Auguie, B. 2017. GridExtra: miscellaneous functions for “grid” graphics, R package version 2.3. https://CRAN.R-project.org/package=gridExtra, accessed 12 January 2021.Google Scholar
Bache, S. M., and Wickham, H.. 2014. Magrittr: a forward-pipe operator for R, R package version 1.5, https://CRAN.R-project.org/package=magrittr, accessed 12 January 2021.Google Scholar
Beu, A. G. 2009. Before the ice: biogeography of Antarctic Paleogene molluscan faunas. Palaeogeography, Palaeoclimatology, Palaeoecology 284:191–226.CrossRefGoogle Scholar
Beu, A. G., and Maxwell, P. A.. 1990. Cenozoic Mollusca of New Zealand. New Zealand Geological Survey Bulletin 58.Google Scholar
Beu, A. G., Griffin, M., and Maxwell, P. A.. 1997. Opening of Drake Passage gateway and Late Miocene to Pleistocene cooling reflected in Southern Ocean molluscan dispersal: evidence from New Zealand and Argentina. Tectonophysics 281:83–97.CrossRefGoogle Scholar
Bieler, R. 1992. Gastropod phylogeny and systematics. Annual Review of Ecology and Systematics 2:311–338.CrossRefGoogle Scholar
Bookstein, F. L. 1991. Morphometric tools for landmark data: geometry and biology. Cambridge University Press, Cambridge.Google Scholar
Brookes, J. I., and Rochette, R.. 2007. Mechanism of a plastic phenotypic response: predator-induced shell thickening in the intertidal gastropod Littorina obtusata. Journal of Evolutionary Biology 20:1015–1027.CrossRefGoogle ScholarPubMed
Burnham, K. P., and Anderson, D. R. 2002. Model selection and multimodel inference—a practical information-theoretic approach. Springer, New York.Google Scholar
Claxton, W. T., Wilson, A. B., Mackie, G. L., and Boulding, E. G.. 1998. A genetic and morphological comparison of shallow- and deep-water populations of the introduced dreissenid bivalve Dreissena bugensis. Canadian Journal of Zoology 76:1269–1276.CrossRefGoogle Scholar
Collins, K. S., Crampton, J. S., and Hannah, M.. 2013. Identification and independence: morphometrics of Cenozoic New Zealand Spissatella and Eucrassatella (Bivalvia, Crassatellidae). Paleobiology 39:525–537.CrossRefGoogle Scholar
Crampton, J. S., and Haines, A. J.. 1996. User's manual for the programs Hangle, Hmatch and Hcurve for the Fourier shape analysis of two-dimensional outlines. Science Report of the Institute of Geological and Nuclear Sciences, 96/37. Institute of Geological and Nuclear Sciences, Lower Hutt, New Zealand.Google Scholar
Crampton, J. S., and Maxwell, P. A.. 2000. Size: all it's shaped up to be? Evolution of shape through the lifespan of the Cenozoic bivalve Spissatella (Crassatellidae). In Harper, E. M., Taylor, J. D., and Crame, J. A., eds. Evolutionary biology of the Bivalvia. Geological Society of London Special Publication 177:399–423.Google Scholar
Da Costa, M. E. 1778. Historia naturalis testaceorum Britanniæ, or, the British conchology; containing the descriptions and other particulars of natural history of the shells of Great Britain and Ireland: illustrated with figures. Millan, White, Emsley & Robson, London.Google Scholar
Dalziel, B., and Boulding, E. G.. 2005. Water-borne cues from a shell-crushing predator induce a more massive shell in experimental populations of an intertidal snail. Journal of Experimental Marine Biology and Ecology 317:25–35.CrossRefGoogle Scholar
Daróczi, G., and Tsegelskyi, R.. 2018. Pander: an R “pandoc” writer, R package version 0.6.3. https://CRAN.R-project.org/package=pander, accessed 12 January 2021.Google Scholar
Darragh, T. A. 1991. A revision of the Australian genus Tylospira Harris, 1897 (Gastropoda: Struthiolariidae). Alcheringa: An Australasian Journal of Palaeontology 15:151–175.CrossRefGoogle Scholar
d'Orbigny, A.D. 1850–1852. Prodrome de paléontologie stratigraphique universelle des animaux mollusques et rayonnés faisant suite au cours élémentaire de paléontologie et de géologie stratigraphiques, Vol. 1, January 1850 (“1849”); vol. 2, November 1850. Masson, Paris.CrossRefGoogle Scholar
Dowle, M., and Srinivasan, A.. 2019. Data.table: extension of ‘data.frame’, R package version 1.13.0. https://CRAN.R-project.org/package=data.table, accessed 12 January 2021.Google Scholar
Finlay, H. J., and Marwick, J.. 1937. The Wangaloan and associated molluscan faunas. In Finlay, H. J., ed. The Wangaloan and associated molluscan faunas of Kaitangata-Green Island subdivision. New Zealand Geological Survey Paleontological Bulletin 15.Google Scholar
Gerber, S. 2011. Comparing the differential filling of morphospace and allometric space through time: the morphological and developmental dynamics of Early Jurassic ammonoids. Paleobiology 37:369–382.CrossRefGoogle Scholar
Gerber, S., Neige, P., and Eble, G. J.. 2007. Combining ontogenetic and evolutionary scales of morphological disparity: a study of early Jurassic ammonites: morphological disparity and developmental dynamics. Evolution and Development 9:472–482.CrossRefGoogle Scholar
Gmelin, J. F. 1791. Vermes. In Gmelin, J. F., ed. Caroli a Linnaei Systema Naturae per Regna Tria Naturae, Ed. 13. Tome 1(6). G.E. Beer, Lipsiae [Leipzig].Google Scholar
Gordillo, S. 2006. The presence of Tawera gayi (Hupé in Gay, 1854) (Veneridae, Bivalvia) in southern South America: Did Tawera achieve a Late Cenozoic circumpolar traverse? Palaeogeography, Palaeoclimatology, Palaeoecology 240:587–601.CrossRefGoogle Scholar
Gray, J.E. 1857. Guide to the systematic distribution of Mollusca in the British Museum, Part I. London, p. XII.Google Scholar
Guettard, J. E. 1770. Mémoires sur différentes parties des sciences et arts, Vol. 3. Prault.Google Scholar
Haines, A. J., and Crampton, J. S.. 2000. Improvements to the method of Fourier shape analysis as applied in morphometric studies. Palaeontology 43:765–783.CrossRefGoogle Scholar
Hammer, Ø., and Bucher, H.. 2005. Models for the morphogenesis of the molluscan shell. Lethaia 38:111–122.CrossRefGoogle Scholar
Harasewych, M. G., and Petit, R. E.. 2013. Extractrix dockeryi, a new species from the Eocene of the southeastern United States, with notes on open coiling in the Cancellariidae (Gastropoda: Neogastropoda). The Nautilus 127:147–152.Google Scholar
Harris, G. F. 1897. Catalogue of Tertiary Mollusca in the Department of Geology, British Museum (Natural History). Pt. 1. The Australasian Tertiary Mollusca. British Museum of Natural History, London.Google Scholar
Hutchinson, J. M. C. 1989. Control of gastropod shell shape: the role of the preceding whorl. Journal of Theoretical Biology 140:431–444.CrossRefGoogle Scholar
Hutchinson, J. M. C. 1990. Control of gastropod shell form via apertural growth rates. Journal of Morphology 206:259–264.CrossRefGoogle Scholar
Hutton, F. W. 1877. Descriptions of some new Tertiary Mollusca from Canterbury. Transactions of the New Zealand Institute 9:593–598.Google Scholar
Hutton, F. W. 1885. Descriptions of new Tertiary shells. Transactions of the New Zealand Institute 18:333–335.Google Scholar
Johnston, M. R., Tabachnick, R. E., and Bookstein, F. L.. 1991. Landmark-based morphometrics of spiral accretionary growth. Paleobiology 17:19–36.CrossRefGoogle Scholar
Korobkov, I.A. 1955. Spravochnik i methodicheskoe rukovodstvopo tretichnym molljuskam. Briukonogie [Reference and methodological guide to Tertiary mollusks. Gastropoda]. Gostopteckhizdat, Leningrad.Google Scholar
Lamarck, J.-B. M. de, 1816. Histoire naturelle des animaux sans vertèbres. Tome second. Verdière, Paris.Google Scholar
Lamarck, J.-B. M. de, 1822. Histoire naturelle des animaux sans vertèbres. Tome septième. Published by the Author, Paris.Google Scholar
Lewis, B. W. 2020. Threejs: interactive 3D scatter plots, networks and globes, R package version 0.3.3. https://CRAN.R-project.org/package=threejs, accessed 12 January 2021.Google Scholar
Liew, T.-S., Kok, A. C. M., Schilthuizen, M., and Urdy, S.. 2014. On growth and form of irregular coiled-shell of a terrestrial snail: Plectostoma concinnum (Fulton, 1901) (Mollusca: Caenogastropoda: Diplommatinidae). PeerJ 2:e383.CrossRefGoogle Scholar
Ligges, U., and Mächler, M.. 2003. Scatterplot3d—an R package for visualizing multivariate data. Journal of Statistical Software 8:1–20.CrossRefGoogle Scholar
Linnaeus, C. 1758. Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Editio decima, reformata. Laurentius Salvius, Holmiae [Stockholm].Google Scholar
Løvtrup, S., and Løvtrup, M.. 1988. The morphogenesis of molluscan shells: a mathematical account using biological parameters. Journal of Morphology 197:53–62.CrossRefGoogle ScholarPubMed
Márquez, F., Robledo, J., Peñaloza, G. E., and Van der Molen, S.. 2010. Use of different geometric morphometrics tools for the discrimination of phenotypic stocks of the striped clam Ameghinomya antiqua (Veneridae) in north Patagonia, Argentina. Fisheries Research 101:127–131.CrossRefGoogle Scholar
Martens, E. 1878. Einige Conchylien aus den kaelteren Meeresgegenden der suedlichen Erdhaelfte. Sitzungsberichte der Gesellschaft Naturforschender Freunde zu Berlin, pp. 20–26.Google Scholar
Martyn, T. 1784–1787. The universal conchologist, exhibiting the figure of every known shells. Published by the author, London.Google Scholar
Marwick, J. 1924. The Struthiolariidae. Transactions of the New Zealand Institute 55:161–190.Google Scholar
Marwick, J. 1951. Notes on the southern family Struthiolariidae. Journal de Conchyliologie 90:234–239.Google Scholar
McClain, C. R. 2004. Connecting species richness, abundance and body size in deep-sea gastropods. Global Ecology and Biogeography 13:327–334.CrossRefGoogle Scholar
McGhee, G. R. 1980. Shell form in the biconvex articulate brachiopoda: a geometric analysis. Paleobiology 6:57–76.CrossRefGoogle Scholar
McGhee, G. R. 1999. Theoretical morphology: the concept and its applications. Perspectives in paleobiology and Earth history. Columbia University Press, New York.Google Scholar
McNair, C. G., Kier, W. M., LaCroix, P. D., and Linsley, R. M.. 1981. The functional significance of aperture form in gastropods. Lethaia 14:63–70.CrossRefGoogle Scholar
Merle, D. 2005. The spiral cords of the Muricidae (Gastropoda, Neogastropoda): importance of ontogenetic and topological correspondences for delineating structural homologies. Lethaia 38:367–379.CrossRefGoogle Scholar
Mörch [as Moerch], O. A. L, . 1860. Étude sur la famille des vermets (suite). Journal de Conchyliologie 8:27–48.Google Scholar
Morton, J. E. 1950. The Struthiolariidae: reproduction, life history and relationships. Transactions of the Royal Society of New Zealand 78:451–463.Google Scholar
Morton, J. E. 1951. The ecology and digestive system of the Struthiolariidae (Gastropoda). Quarterly Journal of Microscopical Science 91:2–24.Google Scholar
Morton, J. E. 1956. The evolution of Perissodonta and Tylospira (Struthiolariidae). Transactions of the Royal Society of New Zealand 83:515–524.Google Scholar
Moseley, H. 1838. XVII. On the geometrical forms of turbinated and discoid shells. Philosophical Transactions of the Royal Society of London 128:351–370.Google Scholar
Noshita, K. 2014. Quantification and geometric analysis of coiling patterns in gastropod shells based on 3D and 2D image data. Journal of Theoretical Biology 363:93–104.CrossRefGoogle ScholarPubMed
Noshita, K., Asami, T., and Ubukata, T.. 2012. Functional constraints on coiling geometry and aperture inclination in gastropods. Paleobiology 38:322–334.CrossRefGoogle Scholar
Okamoto, T. 1984. Theoretical morphology of Nipponites (a heteromorph ammonoid). [In Japanese.] Kaseki 36:37–51.Google Scholar
Ooms, J. 2020. Magick: advanced graphics and image-processing in R, R package version 2.4.0. https://CRAN.R-project.org/package=magick, accessed 12 January 2021.Google Scholar
Ponder, W. F., and Vokes, E. H., 1988. A revision of the Indo-West Pacific fossil and Recent species of Murex s.s. and Haustellum (Mollusca: Gastropoda: Muricidae). Records of the Australian Museum Suppl. 8:1–160.CrossRefGoogle Scholar
Quoy, J. R. C., and Gaimard, J. P., 1832–1835. Voyage de découvertes de l’“Astrolabe” exécuté par ordre du Roi, pendant les années 1826–1829, sous le commandement de M. J. Dumont d'Urville. Tastu, Paris.Google Scholar
Raup, D. M. 1966. Geometric analysis of shell coiling: general problems. Journal of Paleontology 40:1178–1190.Google Scholar
Raup, D. M., and Michelson, A.. 1965. Theoretical morphology of the coiled shell. Science 147:1294–1295.CrossRefGoogle ScholarPubMed
R Core Team. 2020. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria.Google Scholar
Reeve, L.A. 1844. Description of new species of Tritons collected chiefly by H. Cuming, Esq. in the Philippine Islands. The Annals and Magazine of Natural History, including Zoology, Botany, and Geology. 15:199–210.Google Scholar
Rice, S. H. 1998. The bio-geometry of mollusc shells. Paleobiology 24:133–149.CrossRefGoogle Scholar
Röding, P.F., 1798. Museum Boltenianum. Trapp, Hamburg.Google Scholar
Rohlf, F. J. 2017. tpsDig, digitize landmarks and outlines, version 2.0. Department of Ecology and Evolution, State University of New York at Stony Brook. https://www.swmath.org/software/18407, accessed 16 March 2020.Google Scholar
Rosenberg, G. 2014. A New critical estimate of named species-level diversity of the Recent Mollusca. American Malacological Bulletin 32:308–322.CrossRefGoogle Scholar
Roy, K., Balch, D. P., and Hellberg, M. E.. 2001. Spatial patterns of morphological diversity across the Indo-Pacific: analyses using strombid gastropods. Proceedings of the Royal Society of London B 268:2503–2508.CrossRefGoogle ScholarPubMed
Savazzi, E. 1990. Biological aspects of theoretical shell morphology. Lethaia 23:195–212.CrossRefGoogle Scholar
Schindel, D. E. 1990. Unoccupied morphospace and the coiled geometry of gastropods: architectural constraints of geometric covariation? Pp. 270–304 in Ross, W. R. and Allmon, W. D., eds. Causes of evolution. A paleontological perspective. University of Chicago Press, Chicago.Google Scholar
Seilacher, A., and Gishlick, A. D.. 2015. Morphodynamics. CRC Press, Boca Raton, Fla.Google Scholar
Seton, M., Miller, R. D., Zahirovic, S., Gaina, C., Torsvik, T., Shephard, G., Talsma, A., Gurnis, M., Turner, M., Maus, S. and Chandler, M.. 2012. Global continental and ocean basin reconstructions since 200 Ma. Earth-Science Reviews 113:212–270.CrossRefGoogle Scholar
Sheets, H.D. 2014. Integrated Morphometrics package (IMP) 8 [software package].Google Scholar
Smith, E. A. 1875. Descriptions of some new shells from Kerguelen's Island. Journal of Natural History, series 4, 16(91):67–73.Google Scholar
Soetaert, K. 2019. Plot3D: plotting multi-dimensional data, R package version 1.3. https://CRAN.R-project.org/package=plot3D, accessed 12 January 2021.Google Scholar
Sowerby, G. B. I, and Sowerby, G. B. II. 1832–1841. The conchological illustrations or, Coloured figures of all the hitherto unfigured recent shells. Privately published, London.CrossRefGoogle Scholar
Steinmann, G., and Wilckens, O. 1908. Kreide-und Tertiärfossilien aus den Magellansländern gesammelt von der Schwedischen Expedition 1895–1897. Almqvist & Wiksells.Google Scholar
Stilwell, J. D. 2001. Early evolutionary history of Monalaria (Mollusca: Gastropoda: Struthiolariidae) from the Palaeogene of New Zealand. Alcheringa: An Australasian Journal of Palaeontology 25:395–405.CrossRefGoogle Scholar
Stone, J. R. 1995. CerioShell: a computer program designed to simulate variation in shell form. Paleobiology 21: 509–519.CrossRefGoogle Scholar
Stone, J. R. 1996. The evolution of ideas: a phylogeny of shell models. American Naturalist 148:904–929.CrossRefGoogle Scholar
Stone, J. R. 1998. Landmark-based thin-plate spline relative warp analysis of gastropod shells. Systematic Biology 47:254–263.CrossRefGoogle Scholar
Strebel, H. 1908. Die Gastropoden. In: Wissenschaftliche Ergebnisse der Schwedischen Südpolar-Expedition 1901–1903 unter Leitung von Dr. Otto Nordenskjöld, Bd 6, Lief. 1. Stockholm.Google Scholar
Suter, H. 1917. Descriptions of new Tertiary Mollusca occurring in New Zealand, accompanied by a few notes on necessary changes in nomenclature. New Zealand Geological Survey Paleontological Bulletin 5.Google Scholar
Tate, R. 1885. Miscellaneous contributions to the palaeontology of the older rocks of Australia. Southern Science Record and Magazine of Natural History l:1–5.Google Scholar
Tate, R. 1889. The gastropods of the Older Tertiary of Australia. Part H. Transactions of the Royal Society of South Australia 11:116–147.Google Scholar
Thompson, D. W. 1942. On growth and form. Cambridge University Press, Cambridge.Google Scholar
Trechmann, C. T., 1917. Cretaceous Mollusca from New Zealand. Geological Magazine 4:294–305.CrossRefGoogle Scholar
Tursch, B. 1997. Spiral growth: the “Museum of All Shells” revisited. Journal of Molluscan Studies 63:547–554.CrossRefGoogle Scholar
Urbanek, S. 2019. Jpeg: read and write JPEG images, R package version 8.1. https://CRAN.R-project.org/package=jpeg, accessed 12 January 2021.Google Scholar
Urdy, S., Goudemand, N., Bucher, H., and Chirat, R.. 2010. Allometries and the morphogenesis of the molluscan shell: a quantitative and theoretical model. Journal of Experimental Zoology B 314B:280–302.CrossRefGoogle Scholar
Van Bocxlaer, B., and Schultheiß, R.. 2010. Comparison of morphometric techniques for shapes with few homologous landmarks based on machine-learning approaches to biological discrimination. Paleobiology 36:497–515.CrossRefGoogle Scholar
Vaux, F., Crampton, J. S., Marshall, B. A., Trewick, S. A., and Morgan-Richards, M.. 2017. Geometric morphometric analysis reveals that the shells of male and female siphon whelks Penion chathamensis are the same size and shape. Molluscan Research 37:194–201.CrossRefGoogle Scholar
Vaux, F., Trewick, S. A., Crampton, J. S., Marshall, B. A., Beu, A. G., Hills, S. F. K., and Morgan-Richards, M.. 2018. Evolutionary lineages of marine snails identified using molecular phylogenetics and geometric morphometric analysis of shells. Molecular Phylogenetics and Evolution 127:626–637.CrossRefGoogle ScholarPubMed
Vermeij, G. J. 2010. Gastropod evolution and morphological diversity in relation to shell geometry. Journal of Zoology 163:15–23.CrossRefGoogle Scholar
Wickham, H. 2007. Reshaping data with the reshape package. Journal of Statistical Software 21:1–20.CrossRefGoogle Scholar
Wickham, H. 2016. Ggplot2: elegant graphics for data analysis. Springer, New York.CrossRefGoogle Scholar
Wickham, H. 2019. Stringr: simple, consistent wrappers for common string operations, R package version 1.4.0. https://CRAN.R-project.org/package=stringr, accessed 12 January 2021.Google Scholar
Wickham, H., Averick, M., Bryan, J., Chang, W., McGowan, L., François, R., Grolemund, G., Hayes, A., Henry, L., Hester, J., Kuhn, M., Pedersen, T., Miller, E., Bache, S., Müller, K., Ooms, J., Robinson, D., Seidel, D., Spinu, V., Takahashi, K., Vaughan, D., Wilke, C., Woo, K., and Yutani, H.. 2019. Welcome to the tidyverse. Journal of Open Source Software 4:1686.CrossRefGoogle Scholar
Wickham, H., François, R., Henry, L., and Müller, K.. 2020. Dplyr: a grammar of data manipulation, R package version 1.0.1. https://CRAN.R-project.org/package=dplyr, accessed 12 January 2021.Google Scholar
Wilckens, O. 1911. Die Mollusken der antarktischen Tertiärformation. Wissenschaftliche Ergebnisse der Schwedischen Südpolar-Expedition 1901–1903 unter Mitwirkung zahlreicher Fachgenossen herausgegeben von Otto Nordenskjöld, Leiter der Expedition. Bd. III. Geologie und Paläontologie 13.Google Scholar
Wilson, A. B., Glaubrecht, M., and Meyer, A.. 2004. Ancient lakes as evolutionary reservoirs: evidence from the thalassoid gastropods of Lake Tanganyika. Proceedings of the Royal Society of London B 271:529–536.CrossRefGoogle ScholarPubMed
Wood, S. V., 1848. A monograph of the Crag Mollusca, Or descriptions of shells from the Middle and Upper Tertiaries of the east of England: Univalves. Palaeontographical Society.CrossRefGoogle Scholar
Xie, Y., Cheng, J., and Tan, X.. 2020. DT: a wrapper of the JavaScript Library “DataTables,” R package version 0.15. https://CRAN.R-project.org/package=DT, accessed 12 January 2021.Google Scholar
Zinsmeister, W. J. 1976. A new genus and species of the gastropod family Struthiolariidae, Antarctodarwinella ellioti, from Seymour Island, Antarctica. Ohio Journal of Science 76:111–114.Google Scholar
Zinsmeister, W. J., and Camacho, H. H.. 1980. Late Eocene Struthiolariidae (Mollusca: Gastropoda) from Seymour Island, Antarctic Peninsula and their significance to the biogeography of Early Tertiary shallow-water faunas of the Southern Hemisphere. Journal of Paleontology 54:1–14.Google Scholar