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P aterimitra pyramidalis from S outh A ustralia: scleritome, shell structure and evolution of a lower C ambrian stem group brachiopod
Author(s) -
Larsson Cecilia M.,
Skovsted Christian B.,
Brock Glenn A.,
Balthasar Uwe,
Topper Timothy P.,
Holmer Lars E.
Publication year - 2014
Publication title -
palaeontology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.69
H-Index - 63
eISSN - 1475-4983
pISSN - 0031-0239
DOI - 10.1111/pala.12072
Subject(s) - shell (structure) , biology , chemistry , engineering , civil engineering
The tommotiid P aterimitra pyramidalis Laurie, 1986, is redescribed based on well‐preserved material from the lower C ambrian W ilkawillina, W irrapowie and A jax limestones of the F linders R anges, S outh A ustralia. The material shows that the scleritome of P aterimitra pyramidalis includes three sclerite morphotypes (S1, S2 and L). Detailed shell microstructure studies show striking similarities with both the paterinid brachiopod A skepasma toddense and the tommotiid E ccentrotheca helenia , 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 E ccentrotheca , P aterimitra pyramidalis 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.