Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

Journal of Paleontology

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (6) Citing Articles via Google Scholar Google Scholar Articles by JANUSSEN, D. Articles by MAOYAN, Z. Search for Related Content GeoRef GeoRef Citation

NEW WELL-PRESERVED SCLERITOMES OF CHANCELLORIDAE FROM THE EARLY CAMBRIAN YUANSHAN FORMATION (CHENGJIANG, CHINA) AND THE MIDDLE CAMBRIAN WHEELER SHALE (UTAH, USA) AND PALEOBIOLOGICAL IMPLICATIONS

¹ Forschungsinstitut und Naturmuseum Senckenberg, Senckenberganlage 25, 60325 Frankfurt am Main, Germany, djanussen{at}sng.uni-frankfurt.de
² Technische Universität Berlin, Sekr. ACK 14, 13355 Berlin, Germany, steishhb{at}mailszrz.zrz.tu-berlin.de,
³ Nanjing Institute of Geology and Palaeontology, Academia Sinica, Nanjing 210008, P. R. China, myzhu{at}nigpas.ac.cn

From the early Cambrian of Yunnan, China, new chancellorid scleritomes assigned to Allonnia junyuani new species are described and compared with scleritomes of Chancelloria eros Walcott, 1920 from the Middle Cambrian of Utah, USA and isolated phosphatized chancellorid sclerites from the Georgina Basin of North Australia. Characters of the entirely preserved chancellorids offer new insight into the paleobiology of Chancelloridae. An irregular thickening at the inferred base of the narrow body end of Chancelloria eros from Utah is interpreted as a root bulb that anchored the sessile animal in the soft bottom sediment. Sclerites show gradual increase in size from the narrower towards the broader upper end of the chancellorid body. A central "gastral" lumen was not directly observed in any of the investigated specimens, but the orientation of sclerites towards the outer body surface indicates that the fossils are secondarily flattened due to compaction and were originally hollow. Taphonomy of isolated chancellorid sclerites from the Georgina Basin, Australia, indicates a biomineralization very different from that of sponge spicules, including the spongin spiculoids of demospongid Keratosa. Allonnia junyuani from Chengjiang (Yunnan) exhibits a prominent epidermis, probably with stable epithelian cell-to-cell connections. This feature excludes a sponge affiliation of the Chancelloridae and points towards a systematic position of this group within the epithelian-bearing animals and thus well above the Porifera.

This article has been cited by other articles:

				E. A. Sperling, D. Pisani, and K. J. Peterson Poriferan paraphyly and its implications for Precambrian palaeobiology Geological Society, London, Special Publications, January 1, 2007; 286(1): 355 - 368. [Abstract] [Full Text] [PDF]

				R. D. RANDELL, B. S. LIEBERMAN, S. T. HASIOTIS, and M. C. POPE NEW CHANCELLORIIDS FROM THE EARLY CAMBRIAN SEKWI FORMATION WITH A COMMENT ON CHANCELLORIID AFFINITIES Journal of Paleontology, September 1, 2005; 79(5): 987 - 996. [Abstract] [Full Text] [PDF]

				J. P. Botting and N. J. Butterfield From The Cover: Reconstructing early sponge relationships by using the Burgess Shale fossil Eiffelia globosa, Walcott PNAS, February 1, 2005; 102(5): 1554 - 1559. [Abstract] [Full Text] [PDF]