Mockina slovakensis,thought to have evolved from Epigondolella praeslovakensis,is an important species of the Norian(Upper Triassic),generally considered as the representative of the uppermost Alaunian to upper Sevati...Mockina slovakensis,thought to have evolved from Epigondolella praeslovakensis,is an important species of the Norian(Upper Triassic),generally considered as the representative of the uppermost Alaunian to upper Sevatian in the Tethys.The previous description of M.slovakensis was incomplete,thus has led to some misidentifications.We thus update the description of M.slovakensis and discuss its comparisons and occurrence based on the new conodont investigations in Dolomia di Forni and the data from previous literatures.The conodont assemblage in the succession of Dolomia di Forni is dominated by M.slovakensis,along with rare M.postera and E.praeslovakensis.We described two morphotypes of M.slovakensis(morphotypes A and B),on the basis of shape of the lateral profile.These two morphotypes can also be observed in the E.praeslovakensis.Moreover,M.slovakensis is usually documented as almost monospecific conodont association in intraplatform basins,thus its paleogeographic implications are also discussed.展开更多
Almost all aspects of conodont research rely on a sound taxonomy based on comparative analysis.This is founded on hypotheses of homology which ultimately rest on knowledge of the location of elements in the apparatus....Almost all aspects of conodont research rely on a sound taxonomy based on comparative analysis.This is founded on hypotheses of homology which ultimately rest on knowledge of the location of elements in the apparatus.Natural assemblages—fossils that preserve the articulated remains of the conodont skeletal apparatus—provide our only direct evidence for element location,but very few are known from the Late Triassic.Here we describe fused clusters(natural assemblages)from the late Norian limestone beds of the Nanshuba Formation in Baoshan,Yunnan Province,southwestern China.Recurrent arrangements and juxtaposition of S and M elements in multiple clusters reveal the composition of the apparatus of Mockina and,probably,Parvigondolella.They indicate that these taxa had a standard 15 elements ozarkodinid apparatus,and provide new insights into the morphology of the elements occupying the P2,M and S locations of the apparatus.The apparatus comprised a single alate(hibbardelliform)S0 element,paired breviform digyrate(grodelliform)S1 and(enantiognathiform)S2 elements,paired bipennate(hindeodelliform)S3 and S4 elements,paired breviform digyrate(cypridodellifrom)M elements,paired,modified-angulate P2 elements(with reduced or lacking‘posterior’process)and segminiplanate(mockiniform and parvigondolelliform)P1 elements.Our results will allow testing of the hypothesis that Mockina,Parvigondolella and Misikella—critical taxa in Late Triassic biostratigraphy—are closely related and possessed morphologically similar elements in homologous locations.展开更多
基金supported by the National Natural Science Foundation of China(Nos.41830320,45172002,41661134047)。
文摘Mockina slovakensis,thought to have evolved from Epigondolella praeslovakensis,is an important species of the Norian(Upper Triassic),generally considered as the representative of the uppermost Alaunian to upper Sevatian in the Tethys.The previous description of M.slovakensis was incomplete,thus has led to some misidentifications.We thus update the description of M.slovakensis and discuss its comparisons and occurrence based on the new conodont investigations in Dolomia di Forni and the data from previous literatures.The conodont assemblage in the succession of Dolomia di Forni is dominated by M.slovakensis,along with rare M.postera and E.praeslovakensis.We described two morphotypes of M.slovakensis(morphotypes A and B),on the basis of shape of the lateral profile.These two morphotypes can also be observed in the E.praeslovakensis.Moreover,M.slovakensis is usually documented as almost monospecific conodont association in intraplatform basins,thus its paleogeographic implications are also discussed.
基金supported by the National Natural Sciences Foundation of China(Nos.41830320,41972033,41572324)。
文摘Almost all aspects of conodont research rely on a sound taxonomy based on comparative analysis.This is founded on hypotheses of homology which ultimately rest on knowledge of the location of elements in the apparatus.Natural assemblages—fossils that preserve the articulated remains of the conodont skeletal apparatus—provide our only direct evidence for element location,but very few are known from the Late Triassic.Here we describe fused clusters(natural assemblages)from the late Norian limestone beds of the Nanshuba Formation in Baoshan,Yunnan Province,southwestern China.Recurrent arrangements and juxtaposition of S and M elements in multiple clusters reveal the composition of the apparatus of Mockina and,probably,Parvigondolella.They indicate that these taxa had a standard 15 elements ozarkodinid apparatus,and provide new insights into the morphology of the elements occupying the P2,M and S locations of the apparatus.The apparatus comprised a single alate(hibbardelliform)S0 element,paired breviform digyrate(grodelliform)S1 and(enantiognathiform)S2 elements,paired bipennate(hindeodelliform)S3 and S4 elements,paired breviform digyrate(cypridodellifrom)M elements,paired,modified-angulate P2 elements(with reduced or lacking‘posterior’process)and segminiplanate(mockiniform and parvigondolelliform)P1 elements.Our results will allow testing of the hypothesis that Mockina,Parvigondolella and Misikella—critical taxa in Late Triassic biostratigraphy—are closely related and possessed morphologically similar elements in homologous locations.
