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Leanchoilia guts and the interpretation of three-dimensional structures in Burgess Shale-type fossils
Published online by Cambridge University Press: 08 February 2016
Abstract
The Burgess Shale arthropod Leanchoilia superlata Walcott 1912, commonly preserves a three-dimensional axial structure generally interpreted as gut contents. Thin-section examination shows this instead to be phosphatized biserially repeated midgut glands, including exceptional preservation of subcellular features. The preferential mineralization of these structures is related to their unusually high chemical reactivity and probably to an internal source of phosphate. Sub-millimetric lineations previously interpreted as annular musculature are in fact planar, sometimes radially arranged, subdivisions of these glands. Ventral rows of isolated phosphate patches appear to represent the same tissue.
In extant arthropods, extensively developed midgut glands are related to a rich but infrequent diet with a primary function in storage. Their conspicuous occurrence in unambiguous fossil predators such as Sidneyia and Laggania (Anomalocaris) suggests they served a similar role in the Cambrian; by extension, their conspicuous occurrence in Leanchoilia suggests it was a predator or scavenger.
Phosphatized midguts with a structure essentially indistinguishable from that of Leanchoilia are also found in Burgess Shale Odaraia, Canadaspis, Perspicaris, Sidneyia, Anomalocaris, and Opabinia. All are characterized by a distinctive sub-millimetric arrangement of planar elements that is not found in extant arthropods or trilobites, suggesting they diverged before the last common ancestor of extant forms; i.e., they represent stem-group arthropods.
Three-dimensionally preserved guts are widely preserved in the Lower Cambrian Chengjiang biota but, unlike those in the Burgess Shale, appear to be filled with sediment. Although generally interpreted as evidence of deposit feeding, the form of these structures points to early permineralization of (sediment-free) midgut glands that were subsequently altered to clay minerals. There is no evidence of deposit feeding in the Chengjiang; indeed, there is a case to be made for deposit feeding not being generally exploited generally until after the Cambrian.
Fossils with three-dimensionally preserved axes from the Lower Cambrian Sirius Passet biota have been interpreted as lobopodians; however, most of the putative lobopodian features find alternative interpretations as aspects of Leanchoilia-type midgut glands. Although Kerygmachela is reliably identified as a stem-group arthropod, its phylogenetic position remains unresolved owing to the non-preservation of critical external features and to the plesiomorphic nature of its Leanchoilia-type midgut.
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Literature Cited
Babcock, L. E., and Chang, W. T. 1997. Comparative taphonomy of two nonmineralized arthropods: Naraoia (Nektaspida; Early Cambrian, Chengjiang Biota, China) and Limulus (Xiphosurida; Holocene, Atlantic Ocean). Bulletin of the National Museum of Natural Science 10:233–250.Google Scholar
Bengtson, S., and Zhao, Y. 1997. Fossilized metazoan embryos from the earliest Cambrian. Science 277:1645–1648.CrossRefGoogle Scholar
Bergström, J. 1986. Opabinia and Anomalocaris, unique Cambrian ‘arthropods.’ Lethaia 19:241–246.CrossRefGoogle Scholar
Bergström, J. 2001. Chengjiang. Pp. 337–340in Briggs, D. E. G. and Crowther, P. R., eds. Palaeobiology II: a synthesis. Blackwell Scientific, Oxford.CrossRefGoogle Scholar
Briggs, D. E. G. 1977. Bivalved arthropods from the Cambrian Burgess Shale of British Columbia. Palaeontology 20:67–72.Google Scholar
Briggs, D. E. G. 1978. The morphology, mode of life, and affinities of Canadaspis perfecta (Crustacea: Phyllocarida), Middle Cambrian, Burgess Shale, British Columbia. Philosophical Transactions of the Royal Society of London B 281:439–487.Google Scholar
Briggs, D. E. G. 1981. The arthropod Odaraia alata Walcott, Middle Cambrian, Burgess Shale, British Columbia. Philosophical Transactions of the Royal Society of London B 291:541–582.Google Scholar
Briggs, D. E. G., and Collins, D. 1999. The arthropod Alalcomenaeus cambricus Simonetta, from the Middle Cambrian Burgess Shale of British Columbia. Palaeontology 42:953–977.CrossRefGoogle Scholar
Briggs, D. E. G., and Kear, A. J. 1994. Decay and mineralization of shrimps. Palaios 9:431–456.CrossRefGoogle Scholar
Briggs, D. E. G., and Nedin, C. 1997. The taphonomy and affinities of the problematic fossil Myoscolex from the Lower Cambrian Emu Bay Shale of South Australia. Journal of Paleontology 71:22–32.CrossRefGoogle Scholar
Briggs, D. E. G., and Whittington, H. B. 1985. Modes of life of arthropods from the Burgess Shale, British Columbia. Transactions of the Royal Society of Edinburgh 76:149–160.CrossRefGoogle Scholar
Bruton, D. L. 1981. The arthropod Sidneyia inexpectans, Middle Cambrian Burgess Shale, British Columbia. Philosophical Transactions of the Royal Society of London B 295:619–653.Google Scholar
Bruton, D. L., and Whittington, H. B. 1983. Emeraldella and Leanchoilia, two arthropods from the Burgess Shale, British Columbia. Philosophical Transactions of the Royal Society of London B 300:553–585.Google Scholar
Budd, G. E. 1996. The morphology of Opabinia regalis and the reconstruction of the arthropod stem group. Lethaia 29:1–14.CrossRefGoogle Scholar
Budd, G. E. 1997. Stem group arthropods from the Lower Cambrian Sirius Passet fauna of North Greenland. In Fortey, R. A. and Thomas, R. H., eds. Arthropod relationships. Systematics Association Special Volume 55:125–138. Chapman and Hall, London.Google Scholar
Budd, G. E. 1998. Arthropod body-plan evolution in the Cambrian with an example from anomalocaridid muscle. Lethaia 31:197–210.CrossRefGoogle Scholar
Budd, G. E. 1999 (for 1998). The morphology and phylogenetic significance of Kerygmachela kierkegaardi Budd (Buen Formation, Lower Cambrian, N Greenland). Transactions of the Royal Society of Edinburgh: Earth Sciences 89:249–290.CrossRefGoogle Scholar
Butterfield, N. J. 1990. Organic preservation of non-mineralizing organisms and the taphonomy of the Burgess Shale. Paleobiology 16:272–286.CrossRefGoogle Scholar
Butterfield, N. J. 1995. Secular distribution of Burgess Shale-type preservation. Lethaia 28:1–13.CrossRefGoogle Scholar
Butterfield, N. J. 1996. Fossil preservation in the Burgess Shale: reply. Lethaia 29:109–112.CrossRefGoogle Scholar
Butterfield, N. J. 2000. Cambrian food webs. Pp. 40–43in Briggs, D. E. G. and Crowther, P., eds. Palaeobiology II: a synthesis. Blackwell Scientific, Oxford.Google Scholar
Chatterton, B. D. E., Johanson, Z., and Sutherland, G. 1994. Form of the trilobite digestive system: alimentary structures in Pterocephalia. Journal of Paleontology 68:294–305.CrossRefGoogle Scholar
Chen, J., and Li, C., 1997. Early Cambrian chordate from Chengjiang, China. Bulletin of National Museum of Natural Science 10:257–273.Google Scholar
Chen, J., and Zhou, G., 1997. Biology of the Chengjiang fauna. Bulletin of National Museum of Natural Science 10:11–105.Google Scholar
Chen, J., Ramsköld, L., and Zhou, G.-Q., 1994. Evidence for monophyly and arthropod affinity of Cambrian giant predators. Science 264:1304–1308.CrossRefGoogle ScholarPubMed
Chen, J.-Y., Zhou, G.-Q., and Ramsköld, L. 1995. A new Early Cambrian onychophoran-like animal, Paucipodia gen. nov., from the Chengjiang fauna, China. Transactions of the Royal Society of Edinburgh, Earth Sciences 85:275–282.Google Scholar
Chen, J.-Y., Edgecomb, G. D., and Ramsköld, L. 1997. Morphological and ecological disparity in naraoiids (Arthropoda) from the Early Cambrian Chengjiang fauna, China. Records of the Australian Museum 49:1–24.CrossRefGoogle Scholar
Chen, J.-Y., Huang, D.-Y., and Li, C.-W., 1999. An early Cambrian craniate-like chordate. Nature 402:518–522.CrossRefGoogle Scholar
Collins, D. 1996. The “evolution” of Anomalocaris and its classification in the arthropod class Dinocarida (nov.) and order Radiodonta (nov.). Journal of Paleontology 70:280–293.CrossRefGoogle Scholar
Conway Morris, S. 1986. The community structure of the Middle Cambrian Phyllopod Bed (Burgess Shale). Palaeontology 29:423–467.Google Scholar
Fahrenbach, W. H. 1999. Merostomata. Pp. 21–115in Harrison, F. W. and Foelix, R. F., eds. Microscopic anatomy of invertebrates, Vol. 8A. Chelicerate Arthropoda. Wiley-Liss, New York.Google Scholar
Farley, R. D. 1999. Scorpiones. Pp. 117–222in Harrison, F. W. and Foelix, R. F., eds. Microscopic anatomy of invertebrates, Vol. 8A. Chelicerate Arthropoda. Wiley-Liss, New York.Google Scholar
Felgenhauer, B. E., Abele, L. G., and Felder, D. L. 1992. Remipedia. Pp. 225–247in Harrison, F. W. and Humes, A. G., eds. Microscopic anatomy of invertebrates, Vol. 9. Crustacea. Wiley-Liss, New York.Google Scholar
Fortey, R. A., and Owens, R. M. 1999. Feeding habits in trilobites. Palaeontology 42:429–465.CrossRefGoogle Scholar
Gabbott, S. 1998. Taphonomy of the Ordovician Soom Shale Lagerstätte: an example of soft tissue preservation in clay minerals. Palaeontology 41:631–667.Google Scholar
Garcia-Bellido Capdevila, D., and Conway Morris, S. 1999. New fossil worms from the Lower Cambrian of the Kinzers Formation, Pennsylvania, with some comments on Burgess Shale-type preservation. Journal of Paleontology 73:394–402.CrossRefGoogle Scholar
Hou, X.-G. 1999. New rare bivalved arthropods from the Lower Cambrian Chengjiang fauna, Yunnan, China. Journal of Paleontology 73:102–116.Google Scholar
Hou, X., and Bergström, J. 1997. Arthropods of the Lower Cambrian Chengjiang fauna, southwest China. Fossils and Strata 45:1–116.Google Scholar
Hughes, C. P. 1975. Redescription of Burgessia bella from the Middle Cambrian Burgess Shale, British Columbia. Fossils and Strata 4:415–435.CrossRefGoogle Scholar
Icely, J. D., and Nott, J. A. 1992. Digestion and absorption: digestive system and associated organs. Pp. 147–201in Harrison, F. W. and Humes, A. G., eds. Microscopic anatomy of invertebrates, Vol. 10. Decapod crustacea. Wiley-Liss, New York.Google Scholar
Ivantsov, A. Yu. 1999. Trilobite-like arthropod from the Lower Cambrian of the Siberian Platform. Acta Palaeontologica Polonica 44:455–466.Google Scholar
Jell, P. A. 1978. Trilobite respiration and genal caeca. Alcheringa 2:251–260.CrossRefGoogle Scholar
Jumars, P. A. 1993. Gourmands of mud: diet selection in marine deposit feeders. Pp. 124–156in Hughes, R. N., ed. Diet selection: an interdisciplinary approach to foraging behaviour. Blackwell Scientific, Oxford.Google Scholar
Jumars, P. A., Mayer, L. M., Deming, J. W., Baross, J. A., and Wheatcroft, R. A. 1990. Deep-sea deposit-feeding strategies suggested by environmental and feeding constraints. Philosophical Transactions of the Royal Society of London A 331:85–101.Google Scholar
Lopez, G. R., and Levinton, J. S. 1987. Ecology of deposit-feeding animals in marine sediments. Quarterly Review of Biology 62:235–260.CrossRefGoogle Scholar
Luo, H., Hu, S., Chen, L., Zhang, S., and Tao, Y. 1999. Early Cambrian Chengjiang fauna from Kunming region, China. Yunnan Science and Technology Press, Kunming, China.Google Scholar
Martill, D. M. 1990. Macromolecular resolution of fossilized muscle tissue from an elopomorph fish. Nature 346:171–172.CrossRefGoogle Scholar
Müller, K. J. 1983. Crustacea with preserved soft parts from the Upper Cambrian of Sweden. Lethaia 16:93–109.CrossRefGoogle Scholar
Orr, P. J., Briggs, D. E. G., and Kearns, S. L. 1998. Cambrian Burgess Shale animals replicated in clay minerals. Science 281:1173–1175.CrossRefGoogle ScholarPubMed
Penry, D. L. 2000. Digestive kinematics of suspension-feeding bivalves: modelling and measuring particle-processing in the gut of Potamocorbula amurensis. Marine Ecology Progress Series 197:181–192.CrossRefGoogle Scholar
Penry, D. L., and Jumars, P. A. 1987. Modelling animal guts as chemical reactors. American Naturalist 129:69–96.CrossRefGoogle Scholar
Penry, D. L., and Jumars, P. A. 1990. Gut architecture, digestive constraints and feeding ecology of deposit-feeding and carnivorous polychaetes. Oecologia 82:1–11.CrossRefGoogle ScholarPubMed
Plante, C., Jumars, P. A., and Baross, J. A. 1990. Digestive associations between marine detritivores and bacteria. Annual Review of Ecology and Systematics 21:93–127.CrossRefGoogle Scholar
Ramsköld, L., Junyuan, Chen, Edgecombe, G. D., and Quiqing, Zhou. 1996. Preservational folds simulating tergite junctions in tegopeltid and naraoiid arthropods. Lethaia 29:15–20.CrossRefGoogle Scholar
Raymond, P. E. 1935. Leanchoilia and other mid-Cambrian Arthropoda. Bulletin of the Museum of Comparative Zoology at Harvard College 76:205–230.Google Scholar
Senowbari-Daryan, B., and Bernecker, M. 2000. Crustacean microcoprolites from the Upper Triassic, Oman. Bollettino della Società Paleontologica Italiana 39:13–20.Google Scholar
Shu, D., Zhang, X., and Chen, L. 1996. Reinterpretation of Yunnanozoon as the earliest known hemichordate. Nature 380:428–430.CrossRefGoogle Scholar
Shu, D.-G., Luo, H.-L., Conway Morris, S., Zhang, X.-L., Hu, S.-X., Chen, L., Han, J., Zhu, M., Li, Y., and Chen, L.-Z. 1999. Lower Cambrian vertebrates from South China. Nature 402:42–46.CrossRefGoogle Scholar
Sibly, R. M. 1981. Strategies of digestion and defecation. Pp. 109–139in Townsend, C. R. and Calow, P., eds. Physiological ecology. Blackwell Scientific, Oxford.Google Scholar
Simonetta, A. 1970. Studies on non trilobite arthropods of the Burgess Shale. Palaeontographica Italica 66(new series Vol. 36):35–45.Google Scholar
van Weel, P. B. 1974. Hepatopancreas? Comparative Biochemistry and Physiology 47A:1–9.Google Scholar
Vermeij, G. J., and Lindberg, D. R. 2000. Delayed herbivory and the assembly of marine benthic ecosystems. Paleobiology 26:419–430.2.0.CO;2>CrossRefGoogle Scholar
Walcott, C. D. 1912. Cambrian geology and paleontology II, No. 6. Middle Cambrian Branchiopoda, Malacostraca, Trilobita, and Merostomata. Smithsonian Miscellaneous Collections 57:145–229.Google Scholar
Walossek, D. 1999. On the Cambrian diversity of Crustacea. Pp. 3–27in Schram, F. R. and von Vaupel Klein, J. C., eds. Crustaceans and the biodiversity crisis, Vol. 1. Brill, Leiden.CrossRefGoogle Scholar
Whittington, H. B. 1974. Yohoia Walcott and Plenocaris n. gen., arthropods from the Burgess Shale, Middle Cambrian, British Columbia. Geological Survey of Canada Bulletin 231.Google Scholar
Whittington, H. B. 1975. The enigmatic animal Opabinia regalis, Middle Cambrian, Burgess Shale, British Columbia. Philosophical Transactions of the Royal Society of London B 271:1–43.Google Scholar
Whittington, H. B. 1977. The Middle Cambrian trilobite Naraoia, Burgess Shale, British Columbia. Philosophical Transactions of the Royal Society of London B 280:409–443.Google Scholar
Whittington, H. B. 1978. The lobopod animal Aysheaia pedunculata Walcott, Middle Cambrian, Burgess Shale, British Columbia. Philosophical Transactions of the Royal Society of London B 284:165–197.Google Scholar
Whittington, H. B. 1980. Exoskeleton, moult stage, appendage morphology and habits of the Middle Cambrian trilobite Olenoides serratus. Palaeontology 23:171–204.Google Scholar
Whittington, H. B., and Briggs, D. E. G. 1985. The largest Cambrian animal, Anomalocaris, Burgess Shale, British Columbia. Philosophical Transactions of the Royal Society of London B 309:569–609.Google Scholar
Wilby, P. R., and Briggs, D. E. G. 1997. Taxonomic trends in the resolution of detail preserved in fossil phosphatized soft tissues. Geobios 20:493–502.CrossRefGoogle Scholar
Wilby, P. R., and Martill, D. M. 1992. Fossil fish stomachs: a microenvironment for exceptional preservation. Historical Biology 6:25–36.CrossRefGoogle Scholar
Wills, M. A., Briggs, D. E. G., and Fortey, R. A. 1997. Evolutionary correlates of arthropod tagmosis: scrambled legs. In Fortey, R. A. and Thomas, R. H., eds. Arthropod relationships. Systematics Association Special Volume 55:57–65. Chapman and Hall, London.Google Scholar
Xiao, S., Zhang, Y., and Knoll, A. H. 1998. Three-dimensional preservation of algae and animal embryos in a Neoproterozoic phosphorite. Nature 391:553–558.CrossRefGoogle Scholar