Angiolini, Lucia and Crippa, Gaia and Azmy, Karem and Capitani, Giancarlo and Confalonieri, Giorgia and Della Porta, Giovanna and Griesshaber, Erika and Harper, David A. T. and Leng, Melanie J. and Nolan, Leah and Orlandi, Marco and Posenato, Renato and Schmahl, Wolfgang W. and Banks, Vanessa J. and Stephenson, Michael H. (2019) 'The giants of the phylum Brachiopoda : a matter of diet?', Palaeontology., 62 (6). pp. 889-917.
The species of the brachiopod Gigantoproductus are giants within the Palaeozoic sedentary benthos. This presents a dilemma as living brachiopods have low‐energy lifestyles. Although brachiopod metabolic rates were probably higher during the Palaeozoic than today, the massive size reached by species of Gigantoproductus is nevertheless unusual. By examining the diet of Gigantoproductus species from the Visean (Mississippian, Carboniferous) of Derbyshire (UK), we seek to understand the mechanisms that enabled those low‐metabolism brachiopod species to become giants. Were they suspension feeders, similar to all other brachiopods, or did endosymbiosis provide a lifestyle that allowed them to have higher metabolic rates and become giants? We suggest that the answer to this conundrum may be solved by the identification of the biogeochemical signatures of symbionts, through combined analyses of the carbon and nitrogen‐isotopic compositions of the occluded organic matrix within their calcite shells. The shells are formed of substructured columnar units that are remarkably long and a few hundreds of microns wide, deemed to be mostly pristine based on multiple analyses (petrography, cathodoluminescence (CL), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM)); they contain occluded organic fractions detected by TEM, nuclear magnetic resonance (NMR) and gas chromatography mass spectrometry (GC‐MS) analyses. We conclude that the gigantic size reached by the species of Gigantoproductus is probably the result of a mixotroph lifestyle, by which they could rely on the energy and nutrients derived both from photosymbiotic microbes and from filtered particulate food.
|Full text:||(AM) Accepted Manuscript|
Download PDF (7653Kb)
|Publisher Web site:||https://doi.org/10.1111/pala.12433|
|Publisher statement:||This is the peer reviewed version of the following article: Angiolini, Lucia, Crippa, Gaia, Azmy, Karem, Capitani, Giancarlo, Confalonieri, Giorgia, Della Porta, Giovanna, Griesshaber, Erika, Harper, David A. T., Leng, Melanie J., Nolan, Leah, Orlandi, Marco, Posenato, Renato, Schmahl, Wolfgang W., Banks, Vanessa J. & Stephenson, Michael H. (2019). The giants of the phylum Brachiopoda: a matter of diet? Palaeontology 62(6): 889-917 which has been published in final form at https://doi.org/10.5061/dryad.m42t6tm. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.|
|Date accepted:||19 February 2019|
|Date deposited:||25 June 2019|
|Date of first online publication:||10 June 2019|
|Date first made open access:||10 June 2020|
Save or Share this output
|Look up in GoogleScholar|