The operculum and mode of life of the lower Cambrian hyolith Cupitheca from South Australia and North China

The operculum of the problematic tubular fossil Cupitheca holocyclata Bengtson in Bengtson et al., (1990) is described for the first time based on collections from South Australia and North China. The phosphatized sub-circular operculum exhibits well defined cardinal processes and a narrow cardinal...

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Bibliographic Details
Published in:Palaeogeography, Palaeoclimatology, Palaeoecology
Main Authors: Skovsted, Christian B., Pan, Bing, Topper, Timothy P., Betts, Marissa J., Li, Guoxiang, Brock, Glenn A.
Format: Report
Language:English
Published: ELSEVIER SCIENCE BV 2016
Subjects:
Operculum
Lower Cambrian
South Australia
North China
Hyolitha
Orthothecida
SMALL SHELLY FOSSILS
BRACHIOPOD PHYLOGENY
EARLIEST ONTOGENY
GREENLAND
SIBERIA
ECOLOGY
Physical Geography
Geology
Paleontology
Geography
Physical
Geosciences
Multidisciplinary
Greenland
Siberia
Online Access:http://ir.nigpas.ac.cn/handle/332004/21439
https://doi.org/10.1016/j.palaeo.2015.11.042
Description
Summary:The operculum of the problematic tubular fossil Cupitheca holocyclata Bengtson in Bengtson et al., (1990) is described for the first time based on collections from South Australia and North China. The phosphatized sub-circular operculum exhibits well defined cardinal processes and a narrow cardinal shield unequivocally demonstrating that Cupitheca is a hyolith, probably an orthothecid. C. holocyclata has an almost global distribution in Cambrian Stages 3-4. The apical structure of the operculum is an elevated, disc-shaped platform with a concave base and a marginal rim that could represent the scar of a specialized larval attachment structure, perhaps anchoring the larval hyolith to a sediment grain, algae or other benthic substrate. Cupitheca probably had a pelagic larval stage and settled on the seafloor by attachment of the apical disc to suitable substrates before developing a free-living benthic adult lifestyle. This contrasting mode of life compared to other hyolith genera suggests that the group had already evolved a range of distinct lifestyles in the Cambrian, providing significant clues into their ecology and distribution. (C) 2015 Elsevier B.V. All rights reserved.

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