Phylogenetic hypotheses of the relationships of arthropods to Precambrian and Cambrian problematic fossil taxa

Systematic Biology

Volumn 45, Issue 2, 1996, Pages 190-216

  Waggoner, Benjamin M ^a  

^a UNIVERSITY OF CALIFORNIA   (United States)

Author keywords

Arthropod; Cambrian; Ediacara fauna; Lobopod; Precambrian; Problematica; Vendian

Indexed keywords

EID: 0040062088     PISSN: 10635157     EISSN: None     Source Type: Journal    
DOI: 10.2307/2413615     Document Type: Article

References (140)

1. ALLISON, P. A., AND D. E. G. BRIGGS. 1991. The taphonomy of soft-bodied animals. Pages 120-140 in The process of fossilization (S. K. Donovan, ed.). Columbia Univ. Press, New York.
2. ANDERSON, C. 1993. Classification of organisms: Living and fossil. BioSystems 31:99-109.
3. AVEROF, M., AND M. AKAM. 1995. Insect-crustacean relationships: Insights from comparative developmental and molecular studies. Philos. Trans. R. Soc. Lond. B Biol. Sci. 347:293-303.
4. BACKELJAU, T., B. WINNEPENNINCKX, AND L. DE BRUYN. 1993. Cladistic analysis of metazoan relationships: A reappraisal. Cladistics 9:167-181.
5. BALLARD, J. W. O., G. J. OLSEN, D. P. FAITH, W. A. ODGERS, D. M. ROWELL, AND P. W. ATKINSON. 1992. Evidence from 12S ribosomal RNA sequences that onychophorans are modified arthropods. Science 258: 1345-1348.
6. BARSKOV, I. S., AND A. Y. ZHURAVLEV. 1988. Mjagkotelye organizmy kembrija Sibirskoj platformy. [Soft-bodied organisms of the Cambrian of the Siberian platform.] Paleontol. Zh. 1988:3-9.
7. BEALL, J. S. 1991. The Tully Monster and a new approach to analyzing problematica. Pages 217-186 in The early evolution of metazoa and the significance of problematic taxa (A. M. Simonetta and. S. Conway Morris, eds.). Cambridge Univ. Press, Cambridge, England.
8. BEKLEMISHEV, V. N. 1969. Principles of comparative anatomy of invertebrates, Volume 1. Promorphology (J. M. MacLennan, transl.; Z. Kabata, ed.). Univ. Chicago Press, Chicago.
9. BENGTSON, S. 1986 Introduction: The problem of the Problematica. Pages 3-11 in Problematic fossil taxa (A. Hoffman and M. H. Nitecki, eds.). Oxford Univ. Press/Clarendon Press, Oxford, England.
10. BENGTSON, S. 1991. Oddballs from the Cambrian start to get even. Nature 351:184-185.
11. BERGSTRÖM, J. 1986. Opabinia and Anomalocaris, unique Cambrian 'arthropods.' Lethaia 19:241-246.
12. BERGSTRÖM, J. 1987. The Cambrian Opabinia and Anomalocaris. Lethaia 20:187-188.
13. BERGSTRÖM, J. 1989. The origin of animal phyla and the new phylum Procoelomata. Lethaia 22:259-269.
14. BERGSTRÖM, J. 1991. Metazoan evolution around the Precambrian-Cambrian transition. Pages 25-34 in The early evolution of Metazoa and the significance of problematic taxa (A. M. Simonetta and S. Conway Morris, eds.). Cambridge Univ. Press, Cambridge, England.
15. BERGSTRÖM, J. 1992. The oldest arthropods and the origin of the Crustacea. Acta Zool. 73:287-291.
16. BIRKET-SMITH, S. J. R. 1981. A reconstruction of the preCambrian Spriggina. Zool. Jahrb. Anat. 105:237-258.
17. BOUSFIELD, E. L. 1995. A contribution to the natural classification of Lower and Middle Cambrian arthropods: Food gathering and feeding mechanisms. Amphipacifica 2:3-34.
18. BREMER, K. 1994. Branch support and tree stability. Cladistics 10:295-304.
19. BRIGGS, D. E. G., D. H. ERWIN, AND F. J. COLLIER. 1994. The fossils of the Burgess Shale. Smithsonian Institution Press, Washington, D.C.
20. BRIGGS, D. E. G., AND R. A. FORTEY. 1992. The Early Cambrian radiation of arthropods. Pages 335-373 in The origin and early evolution of the Metazoa (J. H. Lipps and P. W. Signor, eds.). Plenum, New York.
21. BRIGGS, D. E. G., R. A FORTEY, AND M. A. WILLS. 1992. Morphological disparity in the Cambrian. Science 256:1670-1673.
22. BRIGGS, D. E. G., AND H. B. WHITTINGTON. 1987. The affinities of the Cambrian animals Anomalocaris and Opabinia. Lethaia 20:185-186.
23. BROCK, G. A., AND B. J. COOPER. 1993. Shelly fossils from the Early Cambrian (Toyonian) Wirrealpa, Aroona Creek, and Ramsay limestones of South Australia. J. Paleontol. 67:758-787.
24. BUDD, G. 1993. A Cambrian gilled lobopod from Greenland. Nature 364:709-711.
25. BUSS, L. W., AND A. SEILACHER. 1994. The phylum Vendobionta: Sister group of the Eumetazoa? Paleobiology 20:1-4.
26. BUTTERFIELD, N. J. 1990a. A Carboniferous analogue of 'Peytoia' and a possible taxonomic affiliation for 'Anomalocaris.' Geol. Soc. Am. Abstr. Progr. 22(7):A35.
27. BUTTERFIELD, N. J. 1990b. A reassessment of the enigmatic Burgess Shale fossil Wiwaxia corrugata (Matthew) and its relationship to the polychaete Canadia spinosa Walcott. Paleobiology 16:287-303.
28. CARPENTER, F. M. 1992. Treatise on invertebrate paleontology, Part R. Arthropoda 4, Volume 3. Superclass Hexapoda. Geological Society of America and Univ. Kansas Press, Lawrence.
29. CHEN, J.-Y., L. RAMSKOLD, AND G.-Q. ZHOU. 1994. Evidence for monophyly and arthropod affinity of Cambrian giant predators. Science 264:1304-1308.
30. CONWAY MORRIS, S. 1977. Fossil priapulid worms. Spec. Pap. Palaeontol. 20:1-95.
31. CONWAY MORRIS, S. 1993a. Ediacaran-like fossils in Cambrian Burgess Shale-type faunas of North America. Palaeontology 36:593-635.
32. CONWAY MORRIS, S. 1993b. The fossil record and the early evolution of the Metazoa. Nature 361:219-225.
33. CONWAY MORRIS, S., AND J. S. PEEL. 1995. Articulated halkieriids from the Lower Cambrian of north Greenland and their role in early protostome evolution. Philos. Trans. R. Soc. Lond. B 347:305-358.
34. CUTLER, B. 1980. Arthropod cuticle features and arthropod monophyly. Experientia 36:953.
35. DELLE CAVE, L., AND A. M. SIMONETTA. 1991. Early Palaeozoic arthropods and problems of arthropod phylogeny; with some notes on taxa of doubtful affinities. Pages 189-244 in The early evolution of Metazoa and the significance of problematic taxa (A. M. Simonetta and S. Conway Morris, eds.). Cambridge Univ. Press, Cambridge, England.
36. DE QUEIROZ, K., AND J. GAUTHIER. 1992. Phylogenetic taxonomy. Annu. Rev. Ecol. Syst. 23:449-480.
37. DEWEL, R. A., D. R. NELSON, AND W. C. DEWEL. 1993. Tardigrada. Pages 142-181 in Microscopic anatomy of invertebrates, Volume 12. Onychophora, Chilopoda, and lesser Protostomata (F. W. Harrison and M. E. Rice, eds.). Wiley-Liss, New York.
38. DONOGHUE, M. J., J. A. DOYLE, J. GAUTHIER, A. G. KLUGE, AND T. ROWE. 1989. The importance of fossils in phylogeny reconstruction. Annu. Rev. Ecol. Syst. 20: 431-460.
39. DZIK, J. 1991. Is fossil evidence consistent with traditional views of the early metazoan phylogeny? Pages 47-56 in The early evolution of Metazoa and the significance of problematic taxa (A. M. Simonetta and S. Conway Morris, eds.). Cambridge Univ. Press, Cambridge, England.
40. DZIK, J. 1993. Early metazoan evolution and the meaning of its fossil record. Evol. Biol. 27:339-386.
41. DZIK, J., AND G. KRUMBIEGEL. 1989. The oldest 'onychophoran' Xenusion: A link connecting phyla? Lethaia 22:169-182.
42. EERNISSE, D. J., J. S. ALBERT, AND F. E. ANDERSON. 1992. Annelida and Arthropoda are not sister taxa: A phylogenetic analysis of spiralian metazoan morphology. Syst. Biol. 41:305-330.
43. ERWIN, D. H. 1991. Metazoan phylogeny and the Cambrian radiation. Trends Ecol. Evol. 6:131-135
44. FAHRENBACH, W. H. 1994. Microscopic anatomy of Pycnogonida. I. Cuticle, epidermis, and muscle. J. Morphol. 222:33-48.
45. FAUCHALD, K. 1977. The polychaete worms: Definitions and keys to the orders, families and genera. Natural History Museum of Los Angeles County, Los Angeles, California.
46. FEDONKIN, M. A. 1985a. Besskeletnaja fauna venda: Promorfologicheskij analiz. Pages 10-69 in Vendskaja sistema, tom 1 (B. S. Sokolov and A. B. Iwanowski, eds.). Nauka, Moscow, Russia.
47. FEDONKIN, M. A. 1985b. Sistematicheskoe opisanie vendskikh metazoa. Pages 70-106 in Vendskaja sistema, tom 1 (B. S. Sokolov and A. B. Iwanowski, eds.). Nauka, Moscow, Russia.
48. FEDONKIN, M. A. 1985c. Paleoikhnologiya vendskikh metazoa. Pages 112-117 in Vendskaja sistema, tom 1 (B. S. Sokolov and A. B. Iwanowski, eds.). Nauka, Moscow, Russia.
49. FEDONKIN, M. A. 1992. Vendian faunas and the early evolution of Metazoa. Pages 87-129 in Origin and early evolution of the Metazoa (J. H. Lipps and P. W. Signor, eds.). Plenum, New York.
50. FELITSYN, S. B., A. V. SOCHAVA, P. A. VAGANOV, AND V. A. MEIER. 1989. Iridievaja anomalija na rubezhe vymiranija ediakarskoj fauny. [Iridium anomaly at the extinction boundary of the Ediacaran fauna.] Dokl. Akad. Nauk SSSR 308:1200-1202.
51. FORTEY, R. A., AND J. N. THERON. 1994. A new Ordovician arthropod, Soomaspis, and the agnostid problem. Palaeontology 37:841-861.
52. FRYER, G. 1992. The origin of the Crustacea. Acta Zool. 73:273-286.
53. GEHLING, J. 1987. Earliest known echinoderm - A new Ediacaran fossil from the Pound Subgroup of South Australia. Alcheringa 11:337-345.
54. GEHLING, J. 1991. The case for Ediacaran fossil roots to the metazoan tree. Mem. Geol. Soc. India 20:181-223.
55. GEHLING, J. 1993. The earliest known poriferans: Bath Tub sponges from the Ediacara fauna of south Australia. PaleoBios 14(4):S6-S7.
56. GIBBS, P. E., AND E. B. CUTLER. 1987. A classification of the phylum Sipuncula. Bull. Br. Mus. Nat. Hist. Zool. 52:43-58.
57. GLAESSNER, M. F. 1979. Precambrian. Pages A79-A118 in Treatise on invertebrate paleontology, Part A. Introduction (R. A. Robison and C. Teichert, eds.). Geological Society of America and Univ. Kansas Press, Lawrence.
58. GLAESSNER, M. F. 1984. The dawn of animal life. Cambridge Univ. Press, Cambridge, England.
59. GOULD, S. J. 1989. Wonderful life. Norton, New York.
60. HALL, B. K. 1992. Evolutionary developmental biology. Chapman and Hall, London.
61. HASZPRUNAR, G., R. M. RIEGER, AND P. SCHUCHERT. 1991. Extant 'Problematica' within or near the Metazoa. Pages 99-106 in The early evolution of Metazoa and the significance of problematic taxa (A. M. Simonetta and S. Conway Morris, eds.). Cambridge Univ. Press, Cambridge, England.
62. HEDGPETH, J. W. 1955. Pycnogonida. Pages P163-P170 in Treatise on invertebrate paleontology, Part P. Arthropoda 2 (R. C. Moore, ed.). Geological Society of America and Univ. Kansas Press, Lawrence.
63. HIGGINS, R. P., V. STÖRCH, AND T. C. SHIRLEY. 1993. Scanning and transmission electron microscopical observations on the larvae of Priapulus caudatus (Priapulida). Acta Zool. 74:301-319.
64. HOU X. AND J. BERGSTRÖM. 1994. Palaeoscolecid worms may be nematomorphs rather than annelids. Lethaia 27:11-17.
65. HOU X. AND J. BERGSTRÖM. 1995. Cambrian lobopodians - Ancestors of extant onychophorans? Zool. J. Linn. Soc. 114:3-19.
66. HOU X., L. RAMSKOLD, AND J. BERGSTRÖM. 1991. Composition and preservation of the Chengjiang fauna - A Lower Cambrian soft-bodied biota. Zool. Scr. 20: 395-411.
67. HUELSENBECK, J. P. 1991. When are fossils better than extant taxa in phylogenetic analysis? Syst. Zool. 40: 458-469.
68. HYMAN, L. H. 1951. The invertebrates, Volume III. Acanthocephala, Aschelminthes, and Entoprocta, the pseudocoelomate Bilateria. McGraw-Hill, New York.
69. HYMAN, L. H. 1967. The invertebrates, Volume VI. Mollusca I. McGraw-Hill, New York.
70. JACOBS, D. K. 1992. Two applications of developmental genetics to paleontology: Segmentation genes in molluscs and preoral appendages in taxa of uncertain affinity. Paleontol. Soc. Spec. Publ. 6:145. (Abstr.)
71. JENKINS, R. J. F. 1989. The "supposed terminal Precambrian extinction event" in relation to the Cnidaria. Mem. Assoc. Australasian Palaeontol. 8:307-317.
72. JENKINS, R. J. F. 1992. Functional and ecological aspects of Ediacarian assemblages. Pages 131-176 in Origin and early evolution of the Metazoa (J. H. Lipps and P. W. Signor, eds.). Plenum, New York.
73. KINCHIN, I. M. 1994. The biology of tardigrades. Portland, London.
74. KLASSEN, G. J., R. D. MOOI, AND A. LOCKE. 1991. Consistency indices and random data. Syst. Zool. 40:446-457.
75. KRISTENSEN, R. M., AND R. P. HIGGINS. 1991. Kinorhyncha. Pages 377-404 in Microscopic anatomy of invertebrates, Volume 4. Aschelminthes (F. W. Harrison and E. E. Ruppert, eds.). Wiley-Liss, New York.
76. KUKALOVA-PECK, J. 1991. Fossil history and the evolution of hexapod structures. Pages 141-179 in The insects of Australia, Volume 1. (I. D. Naumann, ed.). Cornell Univ. Press, Ithaca, New York.
77. LAKE, J. A. 1990. Origin of the Metazoa. Proc. Natl. Acad. Sci. USA 87:763-766.
78. LANG, K. 1963. The relation between the Kinorhyncha and Priapulida and their connection with the Aschelminthes. Pages 256-262 in The lower Metazoa: Comparative biology and phylogeny (E. C. Dougherty, Z. N. Brown, E. D. Hanson, and W. D. Hartman, eds.). Univ. California Press, Berkeley.
79. LAUTERBACH, K.-E. 1978. Gedanken zur Evolution der Euarthropoden-Extremitàt. Zool. Jahrb. Anat. 99:64-92.
80. LAVALLARD, R., AND S. CAMPIGLIA. 1973. Contribution a la biologie de Peripatus acacioi Marcus et Marcus (Onychophora, Peripatidae). I. Pourcentage des sexes et variations du nombre des lobopods dans une echantillonage de plusiers centaines d'individus. Bol. Zool. Biol. Mar. NS 30:483-498.
81. MADDISON, W. P., AND D. R. MADDISON. 1992. MacClade, version 3.01. Sinauer, Sunderland, Massachusetts.
82. MALAKHOV, V. V. 1994. Nematodes: Structure, development, classification, and phylogeny. Smithsonian Institution Press, Washington, D.C.
83. MANTON, S. M., AND D. T. ANDERSON. 1979. Polyphyly and the evolution of arthropods. Pages 269-321 in The origin of major invertebrate groups (M. R. House, ed.). Syst. Assoc. Spec. Vol. 12. Academic Press, London.
84. MCMENAMIN, M. A. S. 1986. The Garden of Ediacara. Palaios 1:178-182.
85. MCMENAMIN, M. A. S., AND D. L. S. MCMENAMIN. 1990. the emergence of animals: The Cambrian breakthrough. Columbia Univ. Press, New York.
86. MCSHEA, D. W. 1993. Arguments, tests, and the Burgess Shale - A commentary on the debate. Paleobiology 19:399-402.
87. MONJE-NAJERA, J. 1995. Phylogeny, biogeography and reproductive trends in the Onychophora. Zool. J. Linn. Soc. 114:21-60.
88. MÜLLER, K. J., AND I. HINZ-SCHALLREUTER. 1993. Palaeoscolecid worms from the Middle Cambrian of Australia. Palaeontology 36:549-592.
89. MÜLLER, K. J., D. WALOSSEK, AND A. ZAKHAROV. 1995. 'Orsten' type phosphatized soft-integument preservation and a new record from the Middle Cambrian Kuonamka Formation in Siberia. Neus Jahrb. Geol. Paläontol. Abh. 197:101-118.
90. NEBELSICK, M. 1993. Introvert, mouth cone, and nervous system of Echinoderes capitatus (Kinorhyncha, Cyclorhagida) and implications for the phylogenetic relationships of Kinorhyncha. Zoomorphology 113: 211-232.
91. NIELSEN, C. 1995. Animal evolution: Interrelationships of the living phyla. Oxford Univ. Press, Oxford, England.
92. PAULUS, H. F. 1979. Eye structure and the monophyly of the Arthropoda. Pages 299-383 in Arthropod phylogeny (A. P. Gupta, ed.). Van Nostrand Reinhold, New York.
93. PICKERILL, R. K. 1982. Cambrian medusoids from the St. John Group, southern New Brunswick. Curr. Res. B Geol. Surv. Can. 82-18:71-76.
94. PIRRUS, E. 1992. Freshening of the late Vendian basin on the East European craton. Proc. Estonian Acad. Sci. Geol. 41:115-123.
95. PLATNICK, N. I., C. E. GRISWOLD, AND J. A. CODDINGTON. 1991. On missing entries in cladistic analysis. Cladistics 7:337-343.
96. RAFF, R. A., C. R. MARSHALL, AND J. M. TURBEVILLE. 1994. Using DNA sequences to unravel the Cambrian radiation of the animal phyla. Annu. Rev. Ecol. Syst. 25:351-375.
97. RAMSKOLD, L. 1992 Homologies in Cambrian Onychophora. Lethaia 25:443-460.
98. REMANE, A. 1963. The systematic position and phylogeny of the pseudocoelomates. Pages 247-255 in The lower Metazoa: Comparative biology and phylogeny (E. C. Dougherty, Z. N. Brown, E. D. Hanson, and W. D. Hartman, eds.). Univ. California Press, Berkeley.
99. RETALLACK, G. J. 1994. Were the Ediacaran fossils lichens? Paleobiology 20:523-544.
100. ROBISON, R. A. 1985 Affinities of Aysheaia (Onychophora), with description of a new Cambrian species. J. Paleontol. 59:226-235.
101. ROBISON, R. A. 1991. Middle Cambrian biotic diversity: Examples from four Utah Lagerstätten. Pages 77-98 in The early evolution of Metazoa and the significance of problematic taxa (A. M. Simonetta and S. Conway Morris, eds.). Cambridge Univ. Press, Cambridge, England.
102. RUPPERT, E. E. 1991. Introduction to the aschelminth phyla: A consideration of mesoderm, body cavities, and cuticle. Pages 1-17 in Microscopic anatomy of invertebrates, Volume 4. Aschelminthes (F. W. Harrison and E. E. Ruppert, eds.). Wiley-Liss, New York.
103. SANDERSON, M. J., AND M. J. DONOGHUE. 1989. Patterns of variation in levels of homoplasy. Evolution 43: 1781-1795.
104. SCHRAM, F. R. 1981. The fossil record and evolution of Crustacea. Pages 93-147 in The biology of Crustacea, Volume 1. Systematics, the fossil record, and biogeography (L. G. Abele, ed.). Academic Press, New York.
105. SCHRAM, F. R. 1991. Cladistic analysis of metazoan phyla and the placement of fossil problematica. Pages 35-46 in The early evolution of Metazoa and the significance of problematic taxa (A. M. Simonetta and S. Conway Morris, eds.). Cambridge Univ. Press, Cambridge, England.
106. SCHRAM, F. R., AND W. N. ELLIS. 1994. Metazoan relationships: A rebuttal. Cladistics 10:331-337.
107. SEILACHER, A. 1989. Vendozoa: Organismic construction in the Proterozoic biosphere. Lethaia 22:229-239.
108. SEILACHER, A. 1992. Vendobionta and Psammocorallia: Lost constructions of Precambrian evolution. J. Geol. Soc. Lond. 149:607-613.
109. SHAROV, A. G. 1966. Basic arthropodan stock: With special reference to insects. Pergamon, Oxford, England.
110. SIMONETTA, A. M. 1970. Studies of non-trilobite arthropods of the Burgess Shale (Middle Cambrian). Palaeontogr. Ital. 66:35-45.
111. SIMONETTA, A. M. 1988. Is Nectocaris pteryx a chordate? Boll. Zool. 55:63-68.
112. SIMONETTA, A. M. 1990. On the significance of ecotones in evolution and on the significance of morphological differences in primitive taxa: Reflections and hypotheses. Boll. Zool. 57:325-330.
113. SIMONETTA, A. M., AND E. INSOM. 1993. New animals from the Burgess Shale (Middle Cambrian) and their possible significance for understanding of the Bilateria. Boll. Zool. 60:97-107.
114. SMITH, A. B. 1994. Systematics and the fossil record: Documenting evolutionary patterns. Blackwell Scientific, London.
115. SOKOLOV, B. S. 1968. Vendian and Early Cambrian sabelliditida (Pogonophora) of the USSR. Proc. IPU Int. Geol. Congr. 23:79-86.
116. STÖRCH, V. 1991. Priapulida. Pages 333-350 in Microscopic anatomy of invertebrates, Volume 4. Aschelminthes (F. W. Harrison and E. E. Ruppert, eds.). Wiley-Liss, New York.
117. STÖRCH, V., R. P. HIGGINS, AND M. P. MORSE. 1989. Ultrastructure of the body wall of Meiopriapulus fijiensis (Priapulida). Trans. Am. Microsc. Soc. 108:319-331.
118. STÜRMER, W., F. SCHAARSCHMIDT, AND H.-G. MITTMEYER. 1980. Versteinertes Leben im Röntgenlicht. Kleine Senckenberg-Reihe 11:1-80.
119. SWOFFORD, D. L. 1993. PAUP: Phylogenetic analysis using parsimony, version 3.1.1. Illinois Natural History Survey, Champaign.
120. TARLO, L. B. H. 1967. Xenusion - Onychophoran or coelenterate? Mercian Geol. 2:97-99.
121. THOMPSON, I., AND D. S. JONES. 1980. A possible onychophoran from the Middle Pennsylvanian Mazon Creek beds of northern Illinois. J. Paleontol. 54:588-596.
122. TURBEVILLE, J. M., D. M. PFEIFER, K. G. FIELD, AND R. A. RAFF. 1991. The phylogenetic status of arthropods, as inferred from 18S rRNA sequences. Mol. Biol. Evol. 8:669-686.
123. VALENTINE, J. W. 1973. Coelomate superphyla. Syst. Zool. 22:97-102.
124. VALENTINE, J. W. 1989. Bilaterians of the Precambrian-Cambrian transition and the annelid-arthropod relationship. Proc. Natl. Acad. Sci. USA 86:2272-2275.
125. VALENTINE, J. W. 1991. The sequence of body plans and locomotory systems during the Precambrian-Cambrian transition. Pages 389-397 in Constructional morphology and evolution (N. Schmidt-Kittle and K. Vogel, eds.). Springer-Verlag, Berlin.
126. VALENTINE, J. W. 1994 Late Precambrian bilaterians: Grades and clades. Proc. Natl. Acad. Sci. USA 91: 6751-6757.
127. VALENTINE, J. W., AND C. A. CAMPBELL. 1975. Genetic regulation and the fossil record. Am. Sci. 63:673-680.
128. VAN DER LAND, J., AND A. NØRREVANG. 1985. Affinities and intraphyletic relationships of the Priapulida. Pages 261-273 in The origins and relationships of lower invertebrates (S. Conway Morris, J. D. George, R. Gibson, and H. M. Platt, eds.). Syst. Assoc. Spec. Vol. 28. Clarendon Press, Oxford, England.
129. WAGELE, J. W., AND G. STANJEK. 1995. Arthropod phylogeny inferred from partial 12S rRNA revisited: Monophyly of the Tracheata depends on sequence alignment. J. Zool. Syst. Evol. Res. 33:75-80.
130. WAGELE, J. W., AND R. WETZEL. 1994. Nucleic acid sequence data are not per se reliable for influence of phytogenies. J. Nat. Hist. 28:749-761.
131. WAGGONER, B. M. 1995. Ediacaran lichens: A critique. Paleobiology 21:393-397.
132. WAGGONER, B. M., AND A. G. COLLINS. 1995. A new chondrophorine (Cnidaria, Hydrozoa) from the Cadiz Formation (Middle Cambrian) of California. Paläontol. Z. 69:7-16.
133. WHEELER, W. C., P. CARTWRIGHT, AND C. Y. HAYASHI. 1993. Arthropod phylogeny: A combined approach. Cladistics 9:1-39.
134. WHITTINGTON, H. B., AND D. E. G. BRIGGS. 1985. The largest Cambrian animal, Anomalocaris, Burgess Shale, British Columbia. Philos. Trans. R. Soc. Lond. B Biol. Sci. 309:569-609.
135. WILLMER, P. 1990. Invertebrate relationships: Patterns in animal evolution. Cambridge Univ. Press, Cambridge, England.
136. WILLS, M. A., D. E. G. BRIGGS, AND R. A. FORTEY. 1994. Disparity as an evolutionary index: A comparison of Cambrian and Recent arthropods. Paleobiology 20: 93-130.
137. WINNEPENNINCKX, B., T. BACKELJAU, AND R. DE WÄCHTER. 1995. Phylogeny of protostome worms derived from 18S rRNA sequences. Mol. Biol. Evol. 12:641-649.
138. WINNEPENNINCKX, B., T. BACKELJAU, Y. VAN DE PEER, AND R. DE WACHTER. 1992. Structure of the small ribosomal subunit RNA of the pulmonate snail, Limicolaria kambeul, and phylogenetic analysis of the Metazoa. FEBS Lett. 309:123-126.
139. YOCHELSON, E. L. 1991. Problematica/incertae sedis. Pages 287-296 in The early evolution of Metazoa and the significance of problematic taxa (A. M. Simonetta and S. Conway Morris, eds.). Cambridge Univ. Press, Cambridge, England.
140. ZHURAVLEV, A. Y. 1993. Were Ediacaran Vendobionta multicellulars? Neues Jahrb. Geol. Paläontol. Abh. 190:299-314.