We propose the definition of Atlantic pre-glacial Pliocene Molluscan Units and a critical compari... more We propose the definition of Atlantic pre-glacial Pliocene Molluscan Units and a critical comparison with the Mediterranean Pliocene Molluscan Units (MPMU1) of Raffi & Monegatti (1993). Our aim is to outline the extent and boundaries of the pre-glacial climatic zone (in the sense of Hall, 1964) by means of molluscan proxy data. This approach enables to demonstrate that the latitudes between 38° and 40° both through the pre-glacial Pliocene, before 3.0 Ma, and at the Present-day, mark the transition between two different climatic marine zones. These latitudes marked the boundary between the tropical and subtropical zones in the pre-glacial Pliocene, whereas they correspond to the subtropical-warm temperate transition in the Present-day. A similar pattern is recognizable at about Latitude 50° North which in the present-day approximates the boundary between the warm-cool temperate climatic zones and in the preglacial Pliocene marked the boundary between the subtropical-warm temperate z...
We propose the definition of Atlantic pre-glacial Pliocene Molluscan Units and a critical compari... more We propose the definition of Atlantic pre-glacial Pliocene Molluscan Units and a critical comparison with the Mediterranean Pliocene Molluscan Units (MPMU1) of Raffi & Monegatti (1993). Our aim is to outline the extent and boundaries of the pre-glacial climatic zone (in the sense of Hall, 1964) by means of molluscan proxy data. This approach enables to demonstrate that the lati-
... by the appearance of BGs and by the disappearance (already begun in the Piacenzian; see Raffi... more ... by the appearance of BGs and by the disappearance (already begun in the Piacenzian; see Raffi and Marasti, 1982) of warmwater taxa (Philippi, 1844; Doderlein, 1872; De Stefani, 1876, 1891 ... In: J. Murray and J. Hjort (Editors), The Depths of the Ocean, McMillan, London, pp. ...
Macro-benthic assemblages from the Lower to Middle Pleistocene of the Valle di Manche (VdM) secti... more Macro-benthic assemblages from the Lower to Middle Pleistocene of the Valle di Manche (VdM) section (Crotone Basin, Southern Italy) were used to assess the value of merging paleoecological quantitative patterns into a sequence stratigraphic framework. Two-way cluster and detrended correspondence (DCA) analyses were applied to the macrofossil data matrix comprising 22 samples, 157 species and 5761 specimens. Specifically, two-way cluster analysis allowed for the characterization of five shelf-related biofacies and four sub-biofacies along section. Biofacies change along the VdM generally supported previous sequence stratigraphic interpretations and suggests that faunal turnover is the result of habitat tracking. DCA stratigraphic curves (=DC1 sample scores), calibrated to the depth preferences of extant species, provided quantitative estimates of bathymetry and the assessment of related parameters (e.g., grain-size, sedimentation/turbidity). When plotted stratigraphically, calibrated DC1 scores highlight the magnitude of relative sea-level fluctuations at the scale of the section as well as individual sequences and systems tracts. Additionally, DCA-derived paleobathymetric trends track the oscillations of the δ 18 O record, indicative of global sea-level change. Based on this comparison, it is held that macro-benthic assemblages, once supported by a robust statistical interpretation, can be employed successfully as a proxy for δ 18 O, depicting the variability in local water depths. The potential of this approach is especially high for studies in shallow-water depositional settings where dependable δ 18 O data are typically difficult to obtain.
Page 1. Paleobiology, 11(4), 1985, pp. 368-388 Biogeographic patterns and Plio-Pleistocene extinc... more Page 1. Paleobiology, 11(4), 1985, pp. 368-388 Biogeographic patterns and Plio-Pleistocene extinction of Bivalvia in the Mediterranean and southern North Sea Sergio Raffi, Steven M. Stanley, and Raffaella Marasti Abstract ...
The biological impact of the Messinian Salinity Crisis (MSC) and its bearing on the Pliocene Medi... more The biological impact of the Messinian Salinity Crisis (MSC) and its bearing on the Pliocene Mediterranean marine molluscan fauna has been analyzed on the basis of the biogeographic and stratigraphic distributions of the taxa of 16 early Messinian outcrops. The extinction of the last paleoendemic Proto-Mediterranean taxa is historically significant but it appears to be numerically less important than the extinction of the Tortonian and Messinian neoendemic taxa. The available data suggest that the MSC caused a regional mass disappearance but only a limited number of extinctions. It is also emphasized that the Late Pliocene (Monegatti et al., 2002) extinctions were far heavier than those caused by the MSC. We suggest that the greatest Messinian extinctions were triggered, during the salinity crisis, in the Atlantic "sanctuary" by the Messinian glacial events TG22, TG20, TG14, and TG12, of , dated between 5.79 and 5.55 Ma by . A comparison between the Mediterranean Messinian and the Redonian molluscan faunas was also carried out. Finally, the possible latitudinal stability of the climatic thresholds, despite the shifting of the climatic zones throughout the Neogene along the European coast, is pointed out.
The mollusc disappearance-extinction events throughout the Mediterranean Pliocene suggest the def... more The mollusc disappearance-extinction events throughout the Mediterranean Pliocene suggest the definition of four faunistic units [Mediterranean Pliocene Molluscan Units (MPMUs)]. The bivalve taxonomic diversity, the paleobiogeographic significance and the chronological classification of each unit are analyzed in detail. The boundaries of the MPMUs approximate the major climatic changes of the Northern Hemisphere, respectively at 3.0, 2.5 and 2.1 Ma. On the whole, the molluscan fauna changes (356 species of shallow water bivalves have been considered ) record the transition from a tropical unit (MPMU1) to a biogeographic unit (MPMU4) comparable with that of the Recent Mediterranean.
The biological impact of the Messinian Salinity Crisis (MSC) and its bearing on the Pliocene Medi... more The biological impact of the Messinian Salinity Crisis (MSC) and its bearing on the Pliocene Mediterranean marine molluscan fauna has been analyzed on the basis of the biogeographic and stratigraphic distributions of the taxa of 16 early Messinian outcrops. The extinction of the last paleoendemic Proto-Mediterranean taxa is historically significant but it appears to be numerically less important than the extinction of the Tortonian and Messinian neoendemic taxa. The available data suggest that the MSC caused a regional mass disappearance but only a limited number of extinctions. It is also emphasized that the Late Pliocene (Monegatti et al., 2002) extinctions were far heavier than those caused by the MSC. We suggest that the greatest Messinian extinctions were triggered, during the salinity crisis, in the Atlantic "sanctuary" by the Messinian glacial events TG22, TG20, TG14, and TG12, of , dated between 5.79 and 5.55 Ma by . A comparison between the Mediterranean Messinian and the Redonian molluscan faunas was also carried out. Finally, the possible latitudinal stability of the climatic thresholds, despite the shifting of the climatic zones throughout the Neogene along the European coast, is pointed out.
We propose the definition of Atlantic pre-glacial Pliocene Molluscan Units and a critical compari... more We propose the definition of Atlantic pre-glacial Pliocene Molluscan Units and a critical comparison with the Mediterranean Pliocene Molluscan Units (MPMU1) of Raffi & Monegatti (1993). Our aim is to outline the extent and boundaries of the pre-glacial climatic zone (in the sense of Hall, 1964) by means of molluscan proxy data. This approach enables to demonstrate that the latitudes between 38° and 40° both through the pre-glacial Pliocene, before 3.0 Ma, and at the Present-day, mark the transition between two different climatic marine zones. These latitudes marked the boundary between the tropical and subtropical zones in the pre-glacial Pliocene, whereas they correspond to the subtropical-warm temperate transition in the Present-day. A similar pattern is recognizable at about Latitude 50° North which in the present-day approximates the boundary between the warm-cool temperate climatic zones and in the preglacial Pliocene marked the boundary between the subtropical-warm temperate z...
We propose the definition of Atlantic pre-glacial Pliocene Molluscan Units and a critical compari... more We propose the definition of Atlantic pre-glacial Pliocene Molluscan Units and a critical comparison with the Mediterranean Pliocene Molluscan Units (MPMU1) of Raffi & Monegatti (1993). Our aim is to outline the extent and boundaries of the pre-glacial climatic zone (in the sense of Hall, 1964) by means of molluscan proxy data. This approach enables to demonstrate that the lati-
... by the appearance of BGs and by the disappearance (already begun in the Piacenzian; see Raffi... more ... by the appearance of BGs and by the disappearance (already begun in the Piacenzian; see Raffi and Marasti, 1982) of warmwater taxa (Philippi, 1844; Doderlein, 1872; De Stefani, 1876, 1891 ... In: J. Murray and J. Hjort (Editors), The Depths of the Ocean, McMillan, London, pp. ...
Macro-benthic assemblages from the Lower to Middle Pleistocene of the Valle di Manche (VdM) secti... more Macro-benthic assemblages from the Lower to Middle Pleistocene of the Valle di Manche (VdM) section (Crotone Basin, Southern Italy) were used to assess the value of merging paleoecological quantitative patterns into a sequence stratigraphic framework. Two-way cluster and detrended correspondence (DCA) analyses were applied to the macrofossil data matrix comprising 22 samples, 157 species and 5761 specimens. Specifically, two-way cluster analysis allowed for the characterization of five shelf-related biofacies and four sub-biofacies along section. Biofacies change along the VdM generally supported previous sequence stratigraphic interpretations and suggests that faunal turnover is the result of habitat tracking. DCA stratigraphic curves (=DC1 sample scores), calibrated to the depth preferences of extant species, provided quantitative estimates of bathymetry and the assessment of related parameters (e.g., grain-size, sedimentation/turbidity). When plotted stratigraphically, calibrated DC1 scores highlight the magnitude of relative sea-level fluctuations at the scale of the section as well as individual sequences and systems tracts. Additionally, DCA-derived paleobathymetric trends track the oscillations of the δ 18 O record, indicative of global sea-level change. Based on this comparison, it is held that macro-benthic assemblages, once supported by a robust statistical interpretation, can be employed successfully as a proxy for δ 18 O, depicting the variability in local water depths. The potential of this approach is especially high for studies in shallow-water depositional settings where dependable δ 18 O data are typically difficult to obtain.
Page 1. Paleobiology, 11(4), 1985, pp. 368-388 Biogeographic patterns and Plio-Pleistocene extinc... more Page 1. Paleobiology, 11(4), 1985, pp. 368-388 Biogeographic patterns and Plio-Pleistocene extinction of Bivalvia in the Mediterranean and southern North Sea Sergio Raffi, Steven M. Stanley, and Raffaella Marasti Abstract ...
The biological impact of the Messinian Salinity Crisis (MSC) and its bearing on the Pliocene Medi... more The biological impact of the Messinian Salinity Crisis (MSC) and its bearing on the Pliocene Mediterranean marine molluscan fauna has been analyzed on the basis of the biogeographic and stratigraphic distributions of the taxa of 16 early Messinian outcrops. The extinction of the last paleoendemic Proto-Mediterranean taxa is historically significant but it appears to be numerically less important than the extinction of the Tortonian and Messinian neoendemic taxa. The available data suggest that the MSC caused a regional mass disappearance but only a limited number of extinctions. It is also emphasized that the Late Pliocene (Monegatti et al., 2002) extinctions were far heavier than those caused by the MSC. We suggest that the greatest Messinian extinctions were triggered, during the salinity crisis, in the Atlantic "sanctuary" by the Messinian glacial events TG22, TG20, TG14, and TG12, of , dated between 5.79 and 5.55 Ma by . A comparison between the Mediterranean Messinian and the Redonian molluscan faunas was also carried out. Finally, the possible latitudinal stability of the climatic thresholds, despite the shifting of the climatic zones throughout the Neogene along the European coast, is pointed out.
The mollusc disappearance-extinction events throughout the Mediterranean Pliocene suggest the def... more The mollusc disappearance-extinction events throughout the Mediterranean Pliocene suggest the definition of four faunistic units [Mediterranean Pliocene Molluscan Units (MPMUs)]. The bivalve taxonomic diversity, the paleobiogeographic significance and the chronological classification of each unit are analyzed in detail. The boundaries of the MPMUs approximate the major climatic changes of the Northern Hemisphere, respectively at 3.0, 2.5 and 2.1 Ma. On the whole, the molluscan fauna changes (356 species of shallow water bivalves have been considered ) record the transition from a tropical unit (MPMU1) to a biogeographic unit (MPMU4) comparable with that of the Recent Mediterranean.
The biological impact of the Messinian Salinity Crisis (MSC) and its bearing on the Pliocene Medi... more The biological impact of the Messinian Salinity Crisis (MSC) and its bearing on the Pliocene Mediterranean marine molluscan fauna has been analyzed on the basis of the biogeographic and stratigraphic distributions of the taxa of 16 early Messinian outcrops. The extinction of the last paleoendemic Proto-Mediterranean taxa is historically significant but it appears to be numerically less important than the extinction of the Tortonian and Messinian neoendemic taxa. The available data suggest that the MSC caused a regional mass disappearance but only a limited number of extinctions. It is also emphasized that the Late Pliocene (Monegatti et al., 2002) extinctions were far heavier than those caused by the MSC. We suggest that the greatest Messinian extinctions were triggered, during the salinity crisis, in the Atlantic "sanctuary" by the Messinian glacial events TG22, TG20, TG14, and TG12, of , dated between 5.79 and 5.55 Ma by . A comparison between the Mediterranean Messinian and the Redonian molluscan faunas was also carried out. Finally, the possible latitudinal stability of the climatic thresholds, despite the shifting of the climatic zones throughout the Neogene along the European coast, is pointed out.
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