Hostname: page-component-76fb5796d-vvkck Total loading time: 0 Render date: 2024-04-27T02:40:57.647Z Has data issue: false hasContentIssue false
  • English
  • Français

An Ordovician Pycnogonid (Sea Spider) with Serially Subdivided ‘Head’ Region

Published online by Cambridge University Press:  15 October 2015

David M. Rudkin ,
Michael B. Cuggy ,
Graham A. Young  and
Deborah P. Thompson
David M. Rudkin
Affiliation:
Department of Natural History (Palaeobiology) Royal Ontario Museum, Toronto, Ontario, Canada M5S 2C6,
Michael B. Cuggy
Affiliation:
Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5E2,
Graham A. Young
Affiliation:
Geology & Paleontology, The Manitoba Museum, Winnipeg, Manitoba Canada R3B 0N2,
Deborah P. Thompson
Affiliation:
Geology & Paleontology, The Manitoba Museum, Winnipeg, Manitoba Canada R3B 0N2,
Get access Rights & Permissions [Opens in a new window]

Abstract

The bizarre morphology of living Pycnogonida, known colloquially as sea spiders, has long fueled dissent over their status within the arthropods. Pycnogonids figure prominently in recent analyses of anterior limb homologies and ancestral crown-group euarthropod relationships, with support for the concept of Pycnogonida as sister taxon to Euchelicerata now contested by proponents of a more basal position between Radiodonta and all other arthropods. A challenge to further elucidation of their phylogenetic position is the exceptional rarity and disjunct distribution of pycnogonids in the fossil record, due largely to their fragile unmineralized exoskeletons. New fossil discoveries therefore have the potential to add significantly to knowledge of their evolution, paleoecology, and paleobiogeography. Here we report the first known occurrence of fossil pycnogonids from rocks of Ordovician age, bridging a 65 Myr gap between controversial late Cambrian larval forms and a single documented Silurian specimen. The new taxon, Palaeomarachne granulata n. gen. n. sp., from the Upper Ordovician (ca. 450 Ma) William Lake Konservat-Lagerstätte deposit in Manitoba, Canada, is also the first reported from Laurentia. It is the only record thus far of a fossil sea spider in rocks of demonstrably shallow marine origin. Four incomplete, partially disarticulated molts represent a relatively large, robust animal with a series of five segment-like elements in a ‘head’ region that does not incorporate the first of four preserved limb-bearing trunk segments. This unique pattern may reflect the plesiomorphic condition prior to complete fusion of anterior ‘head’ elements and first trunk segment to form a cephalosoma, as seen in all eupycnogonids. Palaeomarachne granulata is interpreted as occupying a basal stem-group position in the Pycnogonida.

Type
Research Article
Information
Journal of Paleontology , Volume 87 , Issue 3 , May 2013 , pp. 395 - 405
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

Arango, C. P. 2002. Morphological phylogenetics of the sea spiders (Arthropoda: Pycnogonida). Organisms Diversity and Evolution, 2:107–125.CrossRefGoogle Scholar
Arango, C. P. 2003. Sea spiders (Pycnogonida, Arthropoda) from the Great Barrier Reef, Australia: New species, new records and ecological considerations. Journal of Natural History, 37:2723–2772.CrossRefGoogle Scholar
Arango, C. P. and Wheeler, W. C. 2007. Phylogeny of the sea spiders (Arthropoda, Pycnogonida) based on direct optimization of six loci and morphology. Cladistics, 23:255–293.CrossRefGoogle ScholarPubMed
Arnaud, F. and Bamber, R. N. 1987. The biology of Pycnogonida. Advances in Marine Biology, 24:1–96.Google Scholar
Bamber, R. N. 2007. A holistic re-interpretation of the phylogeny of the Pycnogonida Latreille, 1810 (Arthropoda). Zootaxa, 1668:295–312.CrossRefGoogle Scholar
Bell, T. 1853. Account of the Crustacea, p. 400–410. InThe Last of the Arctic Voyages: Being a Narrative of the Expedition in H.M.S. Assistance, Under the Command of Captain Sir Edward Belcher, C. B., In search of Sir John Franklin, During the Years 1852-53-54. With notes on the Natural History by SirRichardson, John, Professor, Owen, Bell, Thomas, Salter, J. W., and Reeve, Lovell, Volume 2, London, 1855, 419 p.Google Scholar
Bergström, J., Stürmer, W., and Winter, G. 1980. Palaeoisopus, Palaeopantopus and Palaeothea, pycnogonid arthropods from the Lower Devonian Hunsrück Slate, West Germany. Paläontologische Zeitschrift, 54:7–54.CrossRefGoogle Scholar
Bitsch, J. and Bitsch, C. 2007. The segmental organization of the head region in Chelicerata: A critical review of recent studies and hypotheses. Acta Zoologica, 88:317–335.CrossRefGoogle Scholar
Brenneis, G., Ungerer, P., and Scholtz, G. 2008. The chelifores of sea spiders (Arthropoda, Pycnogonida) are the appendages of the deutocerebral segment. Evolution and Development, 10:717–724.CrossRefGoogle ScholarPubMed
Briggs, D. E. G., Siveter, D. J., Siveter, D. J., Sutton, M. D., Garwood, R. J., and Legg, D. A. 2012. Silurian horseshoe crab illuminates the evolution of arthropod limbs. Prceedings of the National Academy of Sciences, 109:15702–15705.CrossRefGoogle ScholarPubMed
Broili, F. 1928. Crustaceenfunde aus dem rheinischen Unterdevon. Sitzungsberichte der Bayerischen Akademie der Wissenschaften, 1928:197–204.Google Scholar
Charbonnier, S., Vannier, J., and Riou, B. 2007. New sea spiders from the Jurassic La Voulte-sur-Rhône Lagerstätte. Proceedings of the Royal Society B: Biological Sciences, 274:2555–2561.CrossRefGoogle ScholarPubMed
Dunlop, J. A. 2010. Geological history and phylogeny of Chelicerata. Arthropod Structure and Development, 39:124–142.CrossRefGoogle ScholarPubMed
Dunlop, J. A. and Arango, C. P. 2005. Pycnogonid affinities: A review. Journal of Zoological Systematics and Evolutionary Research, 43:8–21.CrossRefGoogle Scholar
Dunlop, J. A. and Selden, P. A. 2009. Calibrating the chelicerate clock: A paleontological reply to Jeyaprakash and Hoy. Experimental and Applied Acarology, 48:183–197.CrossRefGoogle Scholar
Dunn, C. W., Hejnol, A., Matus, D. Q., Pang, K., Browne, W. E., Smith, S. A., Seaver, E., Rouse, G. W., Obst, M., Edgecombe, G. D., Sorensen, M. V., Haddock, S. H. D., Schmidt-Rhaesa, A., Okusu, A., Kristensen, R. M., Wheeler, W. C., Martindale, M. Q., and Giribet, G. 2008. Broad phylogenomic sampling improves resolution of the animal tree of life. Nature, 452:745–749.CrossRefGoogle ScholarPubMed
Giribet, G., Edgecombe, G. D., and Wheeler, W. C. 2001. Arthropod phylogeny based on eight molecular loci and morphology. Nature, 413:157–161.CrossRefGoogle ScholarPubMed
Heymons, R. 1901. Die Entwicklungsgescichte der Scolopender. Zoologica, 13:1–244.Google Scholar
Jager, M., Murienne, J., Clabaut, C., Deutsch, J., Le Guyader, H., and Manuel, M. 2006. Homology of arthropod anterior appendages revealed by Hox gene expression in a sea spider. Nature, 441:506–508.CrossRefGoogle Scholar
King, P. E. 1973. Pycnogonids. Hutchinson and Co., London, U.K., 114p.Google Scholar
Latreille, P. A. 1810. Considérations générales sur l'Ordre Naturel des Animaux composant les Classes des Crustacés, des Arachnides et des Insectes, Paris, 446p.CrossRefGoogle Scholar
Legg, D. A., Sutton, M. D., Edgecombe, G. D., and Caron, J.-B. 2012. Cambrian bivalved arthropod reveals origin of arthrodization. Proceedings of the Royal Society B: Biological Sciences. doi: 10.1098/rspb.2012.1958CrossRefGoogle Scholar
Lotz, G. and Bückmann, D. 1968. Die Hautung und die Exuvie von Pycnogonum litorale (Strom.) (Pantopoda). Zoologische Jahrbuecher (Anatomie und Ontogenie der Tiere), 85:529–536.Google Scholar
Machner, J. and Scholtz, G. 2010. A scanning electron microscopy study of the embryonic development of Pycnogonum litorale (Arthropoda, Pycnogonida). Journal of Morphology, 271:1306–1318.CrossRefGoogle ScholarPubMed
Manuel, M., Jager, M., Murienne, J., Clabaut, C., and Guyader, H. L. 2006. Hox genes in sea spiders (Pycnogonida) and the homology of arthropod head segments. Development Genes and Evolution, 216:481–491.CrossRefGoogle ScholarPubMed
Maxmen, A., Browne, W. E., Martindale, M. Q., and Giribet, G. 2005. Neuroanatomy of sea spiders implies an appendicular origin of the protocerebral segment. Nature, 437:1144–1148.CrossRefGoogle ScholarPubMed
Meyer, K. E. and Bückmann, D. 1963. Die Hautungen des Pantopoden Pycnogonum litorale (Strom). Verhandlungen der Deutschen Zoologischen Gesellschaft, 26:604–609.Google Scholar
Nakamura, K. 1981. Post embryonic-development of a pycnogonid, Propallene longiceps. Journal of Natural History, 15:49–62.CrossRefGoogle Scholar
Nowlan, G. S. and Haidl, F. M. 2001. Biostratigraphy and paleoecology of Late Ordovician conodonts from a composite section in the subsurface of Saskatchewan. Saskatchewan Energy and Mines Miscellaneous Report 2001–4.1, 14–31.Google Scholar
Poschmann, M. and Dunlop, J. A. 2006. A new sea spider (Arthropoda: Pycnogonida) with a flagelliform telson from the Lower Devonian Hunsrück Slate, Germany. Palaeontology, 49:983–989.CrossRefGoogle Scholar
Rota-Stabelli, O., Campbell, L., Brinkmann, H., Edgecombe, G. D., Longhorn, S. J., Peterson, K. J., Pisani, D., Philippe, H., and Telford, M. J. 2011. A congruent solution to arthropod phylogeny: Phylogenomics, microRNAs and morphology support monophyletic Mandibulata. Proceedings of the Royal Society B: Biological Sciences, 278:298–306.CrossRefGoogle ScholarPubMed
Rudkin, D. M., Young, G. A., and Nowlan, G. S. 2008. The oldest horseshoe crab: A new xiphosurid from Late Ordovician Konservat-Lagerstätten deposits, Manitoba, Canada. Palaeontology, 51:1–9.CrossRefGoogle Scholar
Scholtz, G. and Edgecombe, G. D. 2005. Heads, Hox and the phylogenetic position of trilobites, p. 139–165. InKoenemann, S. and Jenner, R. A.(eds.), Crustacean Issues 16, Crustacean and Arthropod Relationships. CRC Press, Boca Raton.CrossRefGoogle Scholar
Scholtz, G. and Edgecombe, G. D. 2006. The evolution of arthropod heads: Reconciling morphological, developmental and palaeontological evidence. Development Genes and Evolution, 216:395–415.CrossRefGoogle ScholarPubMed
Siveter, D. J., Sutton, M. D., and Briggs, D. E. G. 2004. A Silurian sea spider. Nature, 431:978–980.CrossRefGoogle ScholarPubMed
Staples, D. A. 2007. A new species of Colossendeis (Pycnogonida: Colossendeidae) together with records from Australian and New Zealand waters. Memoirs of Museum Victoria, 64:79–94.CrossRefGoogle Scholar
Sutcliffe, O. E., Tibbs, L. E., and Briggs, D. E. G. 2002. Sedimentology and environmental interpretation of fine-grained turbidites in the Kaub Formation of the Hunsrück Slate: Analysis of a section excavated for Project Nahecaris. Metalla (Bochum), 9:89–104.Google Scholar
Tetlie, O. E., Brandt, D. S., and Briggs, D. E. G. 2008. Ecdysis in sea scorpions (Chelicerata, Eurypterida). Palaeogeography, Palaeoclimatology, Palaeoecology, 265:182–194.CrossRefGoogle Scholar
Vilpoux, K. and Waloszek, D. 2003 . Larval development and morphogenesis of the sea spider Pycnogonum litorale (Ström, 1762) and the tagmosis of the body of Pantopoda. Arthropod Structure and Development, 32:349–383.CrossRefGoogle ScholarPubMed
Waloszek, D. and Dunlop, J. A. 2002. A larval sea spider (Arthropoda, Pycnogonida) from the upper Cambrian “Orsten” of Sweden, and the phylogenetic position of pycnogonids. Palaeontology, 45:421–446.CrossRefGoogle Scholar
Whittington, H. B. 1997. Morphology of the exoskeleton, p. 1–85. InKaesler, R. L.(ed.), Treatise on Invertebrate Paleontology, Pt. O, Arthropoda 1, Trilobita (revised edition).Geological Society of America and the University of Kansas Press, Boulder, Colorado and Lawrence, Kansas.Google Scholar
Young, G. A., Rudkin, D. M., Dobrzanski, E. P., Robson, S. P., Cuggy, M. B., and Thompson, D. P. 2010. Late Ordovician Lagerstätten in Manitoba, Canada: Glimpses of softbodied diversity. IPC3–Third International Palaeontological Congress, London, UK, Programme and Abstracts, 419.Google Scholar
Young, G. A., Rudkin, D. M., Dobrzanski, E. P., Robson, S. P., and Nowlan, G. S. 2007. Exceptionally preserved Late Ordovician biotas from Manitoba, Canada. Geology, 35:883–886.CrossRefGoogle Scholar