Paterimitra pyramidalis from South Australia: scleritome, shell structure and evolution of a lower Cambrian stem group brachiopod. (8th October 2013)

• Record Type: Journal Article
• Authors: Larsson, Cecilia M.; Skovsted, Christian B.; Brock, Glenn A.; Balthasar, Uwe; Topper, Timothy P.; Holmer, Lars E.; Lane, Phil
• Is Part Of: Palaeontology. Volume 57:Part 2(2014:Mar.)
• Page Start: 417
• Page End: 446
• Publication Date: 2013-10-08
• Subjects: Paleontology -- Periodicals; 560
• DOI: 10.1111/pala.12072
• Languages: English
• ISSNs: 0031-0239

Abstract

<abstract abstract-type="main" id="pala12072-abs-0001"> <title>Abstract</title> <p>The tommotiid <italic>Paterimitra pyramidalis</italic> Laurie, 1986, is redescribed based on well‐preserved material from the lower Cambrian Wilkawillina, Wirrapowie and Ajax limestones of the Flinders Ranges, South Australia. The material shows that the scleritome of <italic>Paterimitra pyramidalis</italic> includes three sclerite morphotypes (S1, S2 and L). Detailed shell microstructure studies show striking similarities with both the paterinid brachiopod <italic>Askepasma toddense</italic> and the tommotiid <italic>Eccentrotheca helenia</italic>, which strengthens the suggested evolutionary link between tommotiids and brachiopods. Based on the partly articulated specimens and similarities in shell microstructure and sclerite morphology with <italic>Eccentrotheca</italic>, <italic> Paterimitra pyramidalis</italic> is reconstructed as a tube‐dwelling, epifaunal, sessile, filter‐feeder with an organic pedicle‐like attachment structure. The proposed reconstruction of the scleritome comprises a basal unit composed of one S1 and one S2 sclerite, as well as an unresolved number of L sclerites lining a coniform tubular structure.</p> </abstract>