Hostname: page-component-848d4c4894-xm8r8 Total loading time: 0 Render date: 2024-07-03T12:21:06.653Z Has data issue: false hasContentIssue false

Cambrian and Recent disparity: the picture from priapulids

Published online by Cambridge University Press:  20 May 2016

Matthew A. Wills*
Affiliation:
Department of Geology, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, United Kingdom. E-mail: m.a.wills@bris.ac.uk

Abstract

An understanding of several macroevolutionary trends has been greatly advanced in recent years by a focus on disparity (morphological variety) rather than taxic diversity. A seminal issue has been the nature of the Cambrian Radiation, and the question of whether problematical Cambrian fossils embody a range of anatomical design far exceeding that observed thereafter. Arthropods have hitherto furnished the only case study, revealing comparable levels of Cambrian and Recent disparity. The generality of this observation needs to be tested in other groups, and the priapulid worms provide a well-documented example. Cladistic analysis of morphological characters for priapulids reveals a paraphyletic series of Cambrian taxa below a crown-group of post-Cambrian genera. However, one extant family (the Tubiluchidae) may be more closely related to Cambrian forms or resolve basally. Character-based morphospace analysis demonstrates greater disparity amongst Recent taxa than amongst their Cambrian counterparts. There is relatively little overlap between the regions of morphospace occupied by Cambrian and Recent genera (contrasting with the situation in arthropods). The Tubiluchidae are morphologically intermediate between Cambrian and other Recent families using several measures of phenetic proximity, and they inhabit environments more comparable with their Cambrian cousins. This work confirms the extensive morphological diversification of major clades by the Cambrian but lends no support to models of a post-Cambrian “decimation” of disparity.

Type
Articles
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

Literature Cited

Adrianov, A. V., Malakhov, A. V., and Yushin, V. V. 1989. Loricifera—a new taxon of marine invertebrates. Biologiya Morya 2: 7072. [In Russian.].Google Scholar
Alberti, G. and Storch, V. 1986. Zur Ultrastructur der Protonephridien von Tubiluchus philippensis (Tubiluchidae, Priapulida). Zoologischer Anzeiger 217: 259271.Google Scholar
Banta, W. C. and Rice, M. E. 1976. A restudy of the Middle Cambrian Burgess Shale fossil worm, Ottoia prolifica. Pp. 7990. Rice, M. E.Proceedings of the First International Symposium on the Biology of Sipunculids 2. Belgrade, Yugoslavia.Google Scholar
Barnes, R. D. 1987. Invertebrate zoology. 5th ed.W. B. Saunders, Philadelphia.Google Scholar
Bergström, J. 1991. Metazoan evolution around the Precambrian-Cambrian transition. Pp. 2534. Simonetta, A. M., Morris, S. ConwayThe early evolution of metazoa and the significance of problematic taxa Cambridge University Press, Cambridge.Google Scholar
M. van den, Boogaard 1988. Some data on Milaculum Müller, 1973. Scripta Geologica 88: 125.Google Scholar
M. van den, Boogaard 1989. Isolated tubercles of some Palaeoscolecida. Scripta Geologica 90: 112.Google Scholar
Boykin, J. C. 1965. The anatomy of Trachydemus ilyocryptus (Kinorhyncha). M. S. thesis, University of Washington, Seattle.Google Scholar
Briggs, D. E. G., Fortey, R. A., and Wills, M. A. 1992. Morphological disparity in the Cambrian. Science 256: 1679-1673.Google Scholar
Brown, R. 1989. Morphology and ultrastructure of the sensory appendages of a kinorhynch introvert. Zoologica Scripta 18: 471482.Google Scholar
Calloway, C. B. 1975. Morphology of the introvert and associated structures of the priapulid Tubiluchus corrallicola from Bermuda. Marine Biology 31: 161174.Google Scholar
Calloway, C. B. 1982. Priapulida. Pp. 939944. Parker, S. P.Synopsis and classification of living organisms McGraw-Hill, New York.Google Scholar
Calloway, C. B. 1988. Priapulida. Pp. 322327. Higgins, R. P., Thiel, H.Introduction to the study of meiofauna Smithsonian Institution Press, Washington, D.C.Google Scholar
Collins, D. 1996. The evolution of Anomalocaris and its classification in the arthropod Class Dinocarida (nov.) and Order Radiodonta (nov). Journal of Paleontology 70: 280293.Google Scholar
Morris, S. Conway 1977. Fossil priapulid worms. Special Papers in Palaeontology 20: 1155. Palaeontological Association, London.Google Scholar
Morris, S. Conway 1997. The cuticular structure of the 495-Myr-old type species of the fossil worm Palaeoscolex, P. piscatorum (?Priapulida). Zoological Journal of the Linnean Society 119: 6982.Google Scholar
Morris, S. Conway 1989. The persistence of Burgess Shale-type faunas: implications for the evolution of deeper-water faunas. Transactions of the Royal Society of Edinburgh 80: 271283.Google Scholar
Morris, S. Conway and Robison, R. A. 1986. Middle Cambrian priapulids and other soft-bodied fossils from Utah and Spain. Paleontological Contributions to the University of Kansas 117: 122. Lawrence, Kans.Google Scholar
Morris, S. Conway, Peel, J. S., Higgins, A. K., Soper, N. J., and Davis, N. C. 1987. A Burgess Shale-like fauna from the Lower Cambrian of North Greenland. Nature 326: 181183.Google Scholar
Erwin, D. H. 1992. A preliminary classification of evolutionary radiations. Historical Biology 6: 133147.Google Scholar
Fänge, R. and Mattisson, A. 1961. Function of the caudal appendage of Priapulus caudatus. Nature 190: 12161217.Google Scholar
Farris, J. S. 1969. A successive approximations approach to character weighting. Systematic Zoology 18: 374385.Google Scholar
Farris, J. S. 1989. The Retention Index and the Rescaled Consistency Index. Cladistics 5: 417419.Google Scholar
Foote, M. 1989. Perimeter-based Fourier analysis: a new morphometric method applied to the trilobite cranidium. Journal of Paleontology 63: 880885.Google Scholar
Foote, M. 1992a. Rarefaction analysis of morphological and taxonomic diversity. Paleobiology 18: 1729.Google Scholar
Foote, M. 1992b. Paleozoic record of morphological diversity in blastozoan echinoderms. Proceedings of the National Academy of Sciences USA. 89: 73257329.Google Scholar
Foote, M. 1993. Contributions of individual taxa to overall morphological disparity. Paleobiology 19: 403419.Google Scholar
Foote, M. 1994. Morphological disparity in Ordovician-Devonian crinoids and the early saturation of morphological space. Paleobiology 20: 320344.Google Scholar
Fortey, R. A., Briggs, D. E. G., and Wills, M. A. 1997. The Cambrian evolutionary ‘explosion’ recalibrated. Bioessays 19: 429434.Google Scholar
Garey, J. R., Krotec, M., Nelson, D. R., and Brooks, J. 1996. Molecular analysis supports a tardigrade-arthropod association. Invertebrate Biology 115: 7988.Google Scholar
Golvan, Y. J. 1958. Le phylum des Acanthocephala. Annales de Parasitologie Humaine et Comparée 33: 538602.Google Scholar
Golvan, Y. J. 1959. Le phylum des Acanthocephala. Deuxième note. La Classe des Eoacanthocephala (Van Cleave, 1936). Annales de Parasitologie Humaine et Comparée 34: 552.Google Scholar
Gould, S. J. 1989. Wonderful life. The Burgess Shale and the nature of history Norton, New York.Google Scholar
Gould, S. J. 1991. The disparity of the Burgess Shale arthropod fauna and the limits of cladistic analysis: why we must strive to quantify morphospace. Paleobiology 17: 411423.Google Scholar
Gower, J. C. and Ross, G. J. S. 1969. Minimum spanning trees and single-linkage cluster analysis. Applied Statistics 18: 5464.Google Scholar
Hammond, R. 1970. The surface of Priapulus caudatus (Lamarck 1816). Zeitschrift für Morphologie und Ökologie der Tiere. 68: 225268.Google Scholar
Higgins, R. P. 1981. Kinorhyncha. Pp. 873877. Parker, S. P.Synopsis and classification of living organisms McGraw-Hill, New York.Google Scholar
Higgins, R. P. 1983. The Atlantic Barrier Reef ecosystem at Carrie Bow Cay; Belize, II. Kinorhyncha Smithsonian Contributions to Marine Science. 18: 1131. Washington, D. C.Google Scholar
Higgins, R. P. and Storch, V. 1989. Ultrastructural observations of the larva of Tubiluchus corallicola (Priapulida). Hegoländer Meeresuntersuchungen. 43: 111.Google Scholar
Higgins, R. P. and Storch, V. 1991. Evidence for direct development in Meiopriapulus fijiensis (Priapulida). Transactions of the American Microscopical Society 110: 3746.Google Scholar
Higgins, R. P., Storch, V., and Shirley, T. C. 1993. Scanning and transmission electron microscopical observations on the larvae of Priapulus caudatus (Priapulida). Acta Zoologica 74: 301319.Google Scholar
Holmquist, C. 1969. Arktis-Sverige. Funderingar i djurgeografiska, limniska och andra fragor. Fauna och Flora 64: 7486.Google Scholar
Hope, W. D. 1988. Ultrastructure of the feeding apparatus of Rhabdodemania minima Chitwood, 1936 (Enoplida: Rhabdodemaniidae). Journal of Parasitology 20: 118140.Google Scholar
Hou, X-G. and Bergström, J. 1994. Palaeoscolecid worms may be nematomorphs rather than annelids. Lethaia 27: 1117.Google Scholar
Hou, X-G. and Sun, W. G. 1988. Discovery of Chengjiang fauna at Meischucan, Jinning, Yunnan. Acta Palaeontologica Sinica 27: 112.Google Scholar
Hyman, L. 1959. The invertebrates. Vol. 3. Acanthocephala, Aschelminthes and Entoprocta McGraw-Hill, New York.Google Scholar
Ivanov, A. V. 1963. Pogonophora. Academic Press, London.Google Scholar
Jägersten, G. 1972. Evolution of the metazoan life cycle. Academic Press, London.Google Scholar
Joffe, B. I. and Kotikova, E. A. 1988. Nervous system of Priapulus caudatus and Halicryptus spinulosus (Priapulida). Proceedings of the Zoological Institute of Leningrad 183: 5277. [In Russian.].Google Scholar
Kirsteuer, E. and Rützler, K. 1973. Additional notes on Tubiluchus corallicola (Priapulida), based on scanning electron microscope observations. Marine Biology 20: 7887.Google Scholar
Kozloff, E. N. 1990. Invertebrates. W. B. Saunders, Philadelphia.Google Scholar
Kristensen, R. M. 1976. On the fine structure of Batillipes noerrevangi Kristensen, 1976. I. Tegument and moulting cycle. Zoologischer Anzeiger 198: 129150.Google Scholar
Kristensen, R. M. 1983. Loricifera, a new phylum with Aschelminthes characters from the meiobenthos. Zeitschrift für zoologische Systematik und Evolutionsforschung 21: 163180.Google Scholar
Kristensen, R. M. 1986. Loricifera. Pp. 119121. Botosaneanu, L.Mundi, StygofaunaBrill, E. J. and DrBackhuys, W. Leiden.Google Scholar
Kristensen, R. M. 1991a. Loricifera. Pp. 351375. Harrison, F. W.Microscopic anatomy of invertebrates Vol. 4. Aschelminthes. Wiley, New York.Google Scholar
Kristensen, R. M. 1991b. Loricifera—a general biological and phylogenetic overview. Verhandlungen der Zoologische Gesellschaft 84: 231246.Google Scholar
Kristensen, R. M. and Hay-Schmidt, A. 1989. The protonephridia of the Arctic kinorhynch Echinoderes aquiloinius (Cyclorhagida, Echinoderidae). Acta Zoologica 70: 1327.Google Scholar
J. van der, Land 1968. A new aschelminth, probably related to the Priapulida. Zoologische Mededeelingen, Leiden 42: 237250.Google Scholar
J. van der, Land 1970. Systematics, Zoogeography, and Ecology of the Priapulida. Zoologische Verhandelingen 112: 1118.Google Scholar
J. van der, Land 1985. Two new species of Tubiluchus (Priapulida) from the Pacific Ocean. Proceedings Koninkliske Nederlandse Akademie Vanwetenschappen (Biological and Medical Sciences) 88: 371377.Google Scholar
J. van der, Land and N⊘rrevang, A. 1985. Affinities and intraphyletic relationships of the Priapulida. Pp. 261273. Morris, S. Conway, George, J. D., Gibson, R., Platt, H. M.The origins and relationships of lower invertebrates (The Systematics Association Special Volume No. 28.) Clarendon, Oxford.Google Scholar
Lorenzen, S. 1985. Phylogenetic aspects of pseudocoelomate evolution. Pp. 210223. Morris, S. Conway, George, J. D., Gibson, R., Platt, H. M.The origins and relationships of lower invertebrates (The Systematics Association Special Volume No. 28.) Clarendon, Oxford.Google Scholar
Madsen, F. J. 1957. On Walcott's supposed Cambrian holothurians. Journal of Paleontology 31: 281282.Google Scholar
Malakhov, V. V. 1980. Cephalorhyncha, a new type of animal kingdom uniting Priapulida, Kinorhyncha, Gordiacea, and a system of aschelminthes worms. Zoologicheskii Zhurnal 54: 481499. [In Russian.].Google Scholar
Meglitsch, P. A. and Schram, F. R. 1991. Invertebrate zoology, 3rd ed. Oxford University Press, Oxford.Google Scholar
Merriman, J. A. 1972. A phyletic interpretation of anatomical structures of Echinoderes capitatus (Kinorhynca). Ph.D. thesis, University of Pittsburgh, Pittsburgh, Penn.Google Scholar
Merriman, J. A. 1981. Cuticular structures of the priapulid Halicryptus spinulosus: a scanning electron microscopical study. Zoomorphology 97: 285295.Google Scholar
Merriman, J. A. and Corwin, H. O. 1973. An electron microscopical examination of Echinoderes dujardini Claparède (Kinorhyncha). Zeitschrift für Morphologie und ökologie der Tiere 76: 227242.Google Scholar
Morse, M. P. 1981. Meiopriapulus fijiensis n. gen., n. sp.: an interstitial priapulid from coarse sand in Fiji. Transactions of the American Microscopical Society 100: 239252.Google Scholar
Mulicki, Z. 1957. Ecology of the more important Baltic invertebrates. Prace Morskiego Instytutu Rybackiego w Gdyni 9: 313379. [In Russian.].Google Scholar
Nebelsick, M. 1990. Antygomonas incomitata gen. et sp. n. (Cyclorhagida, Kinorhyncha) and its phylogenetic relationships. Zoologica Scripta 19: 143152.Google Scholar
Nebelsick, M. 1992a. Sensory spots of Echinoderes capitatus (Zelinka, 1928) (Kinorhyncha, Cyclorhagida). Acta Zoologica 73: 185195.Google Scholar
Nebelsick, M. 1992b. Ultrastructural investigations of three taxonomic characters in the trunk region of Echinoderes capitatus (Kinorhyncha, Cyclorhagida). Zoologica Scripta 21: 335345.Google Scholar
Nebelsick, M. 1993. Introvert, mouth cone, and nervous system of Echinoderes capitatus (Kinorhyncha, Cyclorhagida) and implications for the phylogenetic relationships of Kinorhyncha. Zoomorphology 113: 211232.Google Scholar
Nicholas, W. L. 1973. The biology of the Acanthocephala. Advances in Parasitology 11: 671706.Google Scholar
Nielsen, C. 1985. Animal phylogeny in the light of the trochaea theory. Biological Journal of the Linnean Society 74: 243299.Google Scholar
Nyholm, K-G. and Bornö, C. 1969. Introductory studies of the oxygen intake of Priapulus caudatus Lam. Zoologiska Bijdragen från Uppsala 38: 262264.Google Scholar
Por, F. D. and Bromley, H. J. 1974. Morphology and anatomy of Maccebeus tentaculatus (Priapulida, Seticoronaria). Journal of Zoology 173: 173197.Google Scholar
Purasjoki, K. J. 1944. Beiträge zur kenntnis der entwicklung und ökologie der Halicryptus spinulosus-larve (Priapulida). Annales Zoologici Societatis Zoologicae-Botanicae Fennicae 9: 114.Google Scholar
Remane, A. 1928. Kinorhyncha. Tierwedlt der Nord-und Ostee. Leif. 11, VII5784.Google Scholar
Robison, R. A. 1969. Annelids from the Middle Cambrian Spence Shale of Utah. Journal of Paleontology 43: 11691173.Google Scholar
Rohlf, F. J. 1990. Morphometrics. Annual Review of Ecology and Systematics 21: 299316.Google Scholar
Ruppert, E. E. 1982. Comparative ultrastructure of the gastrotrich pharynx and the evolution of myoepithelial foreguts in Aschelminthes. Zoomorphology 99: 181220.Google Scholar
Salvini-Plawen, L. V. 1974. Zur Morphologie und Systematiek der Priapulida: Chaetostephanus praeposteriens, der Vertreter einer neuen Ordnung Seticoronaria. Zeitschrift für Zoologische Systematik und Evolutionsforschung 12: 3154.Google Scholar
Schram, F. R. 1973. Pseudocoelomates and a nemertine from the Illinois Pennsylvanian. Journal of Paleontology 47: 985989.Google Scholar
Shapeero, W. L. 1961. Phylogeny of the Priapulida. Science 133: 879880.Google Scholar
Smith, A. B. 1994. Systematics and the fossil record: documenting evolutionary patterns. Blackwell Scientific, Oxford.Google Scholar
Sneath, P. H. A. and Sokal, R. R. 1973. Numerical taxonomy. W. H. Freeman, San Francisco.Google Scholar
Storch, V. and Alberti, G. 1985. Ultrastructural investigation of the integument of Tubiluchus philippinensis (Priapulida, Tubiluchidae). Zoologica Scripta 14: 265272.Google Scholar
Storch, V., Higgins, R. P., and Morse, M. P. 1989a. Internal anatomy of Meiopriapulus fijiensis (Priapulida). Transactions of the American Microscopical Society 108: 245261.Google Scholar
Storch, V. 1989b. The ultrastructure of the body wall of Meiopriapulus fijiensis (Priapulida). Transactions of the American Microscopical Society 108: 319331.Google Scholar
Storch, V., Higgins, R. P., and Rumohr, H. 1990. Ultrastructure of introvert and pharynx of Halicryptus spinulosus (Priapulida). Journal of Morphology 206: 163171.Google Scholar
Storch, V., Higgins, R. P., Anderson, P., and Svavarsson, J. 1995. Scanning and transmission electron microscopic analysis of the introvert of Priapulus australis and Priapulopsis bicaudatus (Priapulida). Invertebrate Biology 114: 6472.Google Scholar
Sun, W. G. and Hou, X. G. 1987. Early Cambrian worms from the Chengjiang, Yunnan, China: Maotianshania gen. nov. Acta Palaeontologica Sinica 26: 303305.Google Scholar
Swofford, D. L. 1993. PAUP: Phylogenetic Analysis Using Parsimony, Version 3.1.1. Computer program distributed by the Smithsonian Institution, Washington, D.C.Google Scholar
Valentine, J. W. 1973. Evolutionary paleoecology of the marine biosphere. Prentice Hall, Englewood Cliffs, N.J.Google Scholar
Waggoner, B. M. 1996. Phylogenetic hypotheses of the relationships of arthropods to Precambrian and Cambrian problematic fossil taxa. Systematic Biology 45: 190222.Google Scholar
Wagner, P. J. 1995. Testing evolutionary constraint hypotheses with early Paleozoic gastropods. Paleobiology 21: 248272.Google Scholar
Walcott, C. D. 1911. Middle Cambrian annelids. Cambrian geology and paleontology. II. Smithsonian Miscellaneous Collections 57: 109144. Washington, D. C.Google Scholar
Warwick, R. 1991. Are loriciferans neotenic priapulids? Psammonalia. 89: 34.Google Scholar
Whittard, W. F. 1953. Palaeoscolex piscatorum gen et sp. nov., a worm from the Tremadocian of Shropshire. Quarterly Journal of the Geological Society of London 109: 125135.Google Scholar
Wills, M. A. 1993. Miscellanea. Pp. 555560. Benton, M. J.The fossil record 2. Chapman and Hall, London.Google Scholar
Wills, M. A. 1996. Classification of the arthropod Fuxianhuia. Science 272: 746748.Google Scholar
Wills, M. A., Briggs, D. E. G., and Fortey, R. A. 1994. Disparity as an evolutionary index. A comparison of Cambrian and Recent arthropods. Paleobiology 20: 93130.Google Scholar
Wills, M. A., Briggs, D. E. G., Fortey, R. A., and Wilkinson, M. 1995. The significance of fossils in understanding arthropod evolution. Verhandlungen der Deutschen Zoologischen Gesellschaft 57: 1333.Google Scholar
Wills, M. A., Briggs, D. E. G., Fortey, R. A., Wilkinson, M., and Sneath, P. H. A. 1998. An arthropod phylogeny based on fossil and Recent taxa. Pp. 33105. Edgecombe, G. E.Arthropod fossils and phylogeny Columbia University Press, New York (in press).Google Scholar
Winnepenninckx, B., Backeljau, T., Mackey, L. Y., Brooks, J. M., de Wachter, R., Kumar, S., and Garey, J. R. 1995. 18S rRNA data indicate that aschelminthes are polyphyletic in origin and consist of at least three distinct clades. Molecular Biology and Evolution 12: 11321137.Google Scholar
Wolter, K. 1987. Submikroskopische Strukturen von Priapulida der mediterranen Meiofauna. Dissertation, Universität Wien, Vienna.Google Scholar