Evolutionary Process from Mockina bidentata to Parvigondolella andrusovi: Evidence from the Pizzo Mondello Section, Sicily, Italy
Yixing Du, Tetsuji Onoue, Viktor Karádi, Ian S. Williams, Manuel Rigo
Journal of Earth Science ›› 2021, Vol. 32 ›› Issue (3) : 667-676.
Evolutionary Process from Mockina bidentata to Parvigondolella andrusovi: Evidence from the Pizzo Mondello Section, Sicily, Italy
During their last phase of evolution, the pectiniform conodont elements manifested an evident trend of simplification and miniaturization. This phase started from the late Norian (Sevatian) in the Late Triassic and the evolutionary process of genus Mockina to Parvigondolella, in particular between Mockina bidentata and Parvigondolella andrusovi, is one of the most significant examples. Parvigondolella has been reported worldwide since it was first described in the early 1970s. However, it has recently been suggested that genus Parvigondolella is an ecostratigraphic morphotype of genus Mockina, and thus a phenotype controlled by the environmental conditions, and not an independent taxon. In the Pizzo Mondello Section (Sicily, Italy), transitional forms between M. bidentata and P. andrusovi have been found at different evolutionary stages. We have investigated the oceanic conditions at the time by using redox-sensitive elements (Mn, Fe, V, Cr, and Ni) and seawater temperatures from biogenetic δ18Ophos to understand the possible environmental influences on the phylogenetic evolution between Mockina and Parvigondolella. The geochemical and isotope analyses indicate that the redox condition and temperature were stable during the evolution of genus Parvigondolella in Pizzo Mondello, confirming that genus Parvigondolella is a real taxon and not a phenotype. A new conodont species named Parvigondolella ciarapicae n. sp. is described here for the first time.
conodont / Late Triassic / evolution / oxygen isotope / geochemistry
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Krystyn, L., Bouquerel, H., Kuerschner, W., et al., 2007a. Proposal for a Candidate GSSP for the Base of the Rhaetian Stage. In: Lucas, S. G., Spielmann, J. A., eds., The Global Triassic. New Mexico Museum of Natural History and Science Bulletin, 41: 189–199
|
|
|
|
|
|
|
|
|
|
|
Moix, P., Kozur, H. W., Stampfli, G. M., et al., 2007. New Paleontological, Biostratigraphic and Paleogeographic Results from the Triassic of the Mersin Mélange, SE Turkey. In: Lucas, S. G., Spielmann, J. A., eds., The Global Triassic. New Mexico Museum of Natural History and Science Bullettin, 41: 282–311
|
|
|
|
|
|
|
Orchard, M. J., 2018. The Lower-Middle Norian (Upper Triassic) Boundary: New Conodont Taxa and a Refined Biozonation. In: Over, D. J., Henderson, C. M., eds., Conodont Studies Dedicated to the Careers and Contributions of Anita Harris, Glen Merrill, Carl Rexroad, Walter Sweet, and Bruce Wardlaw. Bulletins of American Paleontology, 395/396: 165–193. https://doi.org/10.32857/bap.2018.395.12
|
|
Orchard, M. J., Whalen, P. A., Carter, E. S., et al., 2007b. Latest Triassic Conodonts and Radiolarian-Bearing Successions in Baja California Sur. In: Lucas, S. G., Spielmann, J. A., eds., The Global Triassic. New Mexico Museum of Natural History and Science Bulletin, 41: 355–365
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