39 research outputs found
A PLIOSAURID TOOTH FROM THE ARGILLE VARICOLORI FORMATION NEAR CASTELVECCHIO DI PRIGNANO (MODENA PROVINCE, NORTHERN ITALY)
The first discovery of a Cretaceous pliosaurid tooth in Italy is reported. It comes from the Cenomanian-lower Campanian Argille Varicolori Formation near Castelvecchio di Prignano (Modena Province, northern Italy). Excepting this new specimen, Italy's only reported pliosaurid is a humerus from the Upper Cretaceous of Zavattarello near Pavia. The tooth morphology allows it to be ascribed to Polyptychodon interruptus Owen, 1841, a species only reported thus far from northern-central Europe (England, Germany, and the Czech Republic). This suggests the presence of marine reptile remains in the northern Apennines may have been underestimated.
A PLIOSAURID TOOTH FROM THE ARGILLE VARICOLORI FORMATION NEAR CASTELVECCHIO DI PRIGNANO (MODENA PROVINCE, NORTHERN ITALY)
The first discovery of a Cretaceous pliosaurid tooth in Italy is reported. It comes from the Cenomanian-lower Campanian Argille Varicolori Formation near Castelvecchio di Prignano (Modena Province, northern Italy). Excepting this new specimen, Italy's only reported pliosaurid is a humerus from the Upper Cretaceous of Zavattarello near Pavia. The tooth morphology allows it to be ascribed to Polyptychodon interruptus Owen, 1841, a species only reported thus far from northern-central Europe (England, Germany, and the Czech Republic). This suggests the presence of marine reptile remains in the northern Apennines may have been underestimated.
HIGH CORAL DIVERSITY IS COUPLED WITH REEF-BUILDING CAPACITY DURING THE LATE OLIGOCENE WARMING EVENT (CASTRO LIMESTONE, SALENTO PENINSULA, S ITALY)
The Oligocene, well known as the apex of Cenozoic reef growth, is a crucial period of time to investigate the mutual relationship between coral reef construction and coral diversity and their link with palaeoclimate and palaeoenvironmental changes. Here we provide a complete characterization of the Upper Oligocene reef complex of the Castro Limestone (Salento Peninsula, S Italy), which is one of the best-preserved Oligocene coral reefs of the Mediterranean region. By combining facies analysis with the first detailed characterization of its coral fauna, we show that the Castro Limestone has both a rich scleractinian coral fauna (25 genera and 41 species) and a large reef volume, and it represents a luxuriant fringing reef formed within the euphotic zone in clear water conditions facing the open sea. The coral fauna differs both in its composition and in its proportions among reef palaeoenvironments, ranging from the shallow back reef to the fore reef slope, and its stratigraphic and palaeogeographic distribution testifies to the persistence of a cosmopolitan Tethyan fauna in Oligocene time, with the Mediterranean and Indo-Pacific provinces being more closely connected than the Mediterranean and the Caribbean. The age of the Castro Limestone is here reassigned to the middle-late Chattian, which coincides with the Late Oligocene Warming Event (LOWE) when atmospheric CO2 values declined. We suggest that the strong reef-building capacity of the Castro Limestone, coupled with high coral diversity, was not hampered by warming conditions but most probably promoted by the reduced pCO2 and a suitable local/regional physiographic setting
Evolution of western Tethyan involute Heterostegina from late Bartonian to the end-Priabonian
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High coral diversity is coupled with reef-building capacity during the Late Oligocene Warming Event (Castro Limestone, Salento Peninsula, S Italy)
The Oligocene, well known as the apex of Cenozoic reef growth, is a crucial period of time to investigate the mutual relationship between coral reef construction and coral diversity and their link with palaeoclimate and palaeoenvironmental changes. Here we provide a complete characterization of the upper Oligocene reef complex of the Castro Limestone (Salento Peninsula, S Italy), which is one of the best-preserved Oligocene coral reefs of the Mediterranean region. By combining facies analysis with the first detailed characterization of its coral fauna, we show that the Castro Limestone has both a rich scleractinian coral fauna (25 genera and 41 species) and a large reef volume, and it represents a luxuriant fringing reef formed within the euphotic zone in clear water conditions facing the open sea. The coral fauna differs both in its composition and in its proportions among reef palaeoenvironments, ranging from the shallow back reef to the fore reef slope, and its stratigraphic and palaeogeographic distribution testifies to the persistence of a cosmopolitan Tethyan fauna in Oligocene time, with the Mediterranean and Indo-Pacific provinces being more closely connected than the Mediterranean and the Caribbean. The age of the Castro Limestone is here reassigned to the middle-late Chattian, which coincides with the Late Oligocene Warming Event (LOWE) when atmospheric CO2 values declined. We suggest that the strong reef-building capacity of the Castro Limestone, coupled with high coral diversity, was not hampered by warming conditions but most probably promoted by the reduced pCO2 and a suitable local/regional physiographic setting
Proposal for the Global Boundary Stratotype Section and Point (GSSP) for the Priabonian Stage (Eocene) at the Alano section (Italy)
The base of the Priabonian Stage is one of two stage boundaries in the Paleogene that remains to be formalized. The Alano section (NE Italy) was elected by consensus as a suitable candidate for the base of the Priabonian during the Priabonian Working Group meeting held in Alano di Piave in June 2012. Further detailed research on the section is now followed by a formal proposal, which identifies the base of a prominent crystal tuff layer, the Tiziano bed, at meter 63.57 of the Alano section, as a suitable candidate for the Priabonian Stage. The choice of the Tiziano bed is appropriate from the historical point of view and several bio-magnetostratigraphic events are available to approximate this chronostratigraphic boundary and guarantee a high degree of correlatability over wide geographic areas. Events which approximate the base of the Priabonian Stage in the Alano section are the successive extinction of large acarininids and Morozovelloides (planktonic foraminifera), the Base of common and continuous Cribrocentrum erbae and the Top of Chiasmolithus grandis (nannofossils), as well as the Base of Subchron C17n.2n and the Base of Chron C17n (magnetostratigraphy). Cyclostratigraphic analysis of the Bartonian-Priabonian transition of the Alano section as well as radioisotopic data of the Tiziano tuff layer provide an absolute age (37.710 – 37.762 Ma, respectively) of this bed and, consequently, of the base of the Priabonian Stage
New mosasaurs from Northern Italy.
A series of mosasaur specimens has been discovered in northern Italy thanks to the quarrying operations in the local Upper Cretaceous limestones. These carbonate rocks belong to the Scaglia Rossa Veneta Formation and in particular to a unit informally referred to as the “Lastame”. The Lastame is a lithotype loosely dated to the uppermost Turonian-lowermost Santonian (Lozar and Grosso, 1997), however, a recent analysis of the rocky matrix of one of the mosasaurs (MPPS-IGVR 42224) allowed us to date the specimen more precisely to the early Santonian.So far five mosasaur specimens (NHMV-V7481, MPPS-IGVR 45301, MPPS-IGVR 42224, MPPS-IGVR 45299 and THF-IGVR 64108) have been recovered from quarries located north of Verona: NHMV-V7481 is represented only by isolated skull bones, including the two maxillary bones, the left dentary, the frontal, and the posterior end of the left mandibular ramus; MPPS-IGVR 42224 is a well preserved but fragmentary skull represented by two complete mandibular rami, the left maxilla, the right jugal, the two quadrates, one cervical vertebra, and a series of uncertainly identified bony fragments. The left quadrate of MPPS-IGVR 42224 has been prepared free of the matrix and compares closely with the quadrate of Russellosaurus coheni (Polcyn and Bell, 2005); MPPS-IGVR 45301 consists of an incomplete skull and some postcranial material, which unfortunately is poorly preserved. However, on the basis of the similar anatomy of some skull bones and the identical marginal dentition, it is possible to conclude that it very probably belongs to the same species of MPPS-IGVR 42224; MPPS IGVR 45299 is represented only by a poorly preserved series of vertebrae belonging to the dorsal and proximal caudal regions. However, the size and morphology of the preserved elements show a clear resemblance to the vertebrae belonging to MPPS-IGVR 45301. Adding all available data together (morphology, identical locality and horizon) we consider these last three specimens to be congeners, if not conspecific; THF-IGVR 64108 is the most recently found mosasaur of the series, and consists of an almost complete skull (inclusive of jaws, braincase, squamosals, pterygoids, ectopterygoids, and quadrates) and about half of the vertebral column exposed in ventral view.These mosasaurs have some anatomical characters in common with Russellosaurus coheni, but the presence of some distinctive features suggests placement in a new genus and possibly two distinct species. A preliminary phylogenetic analysis of the Mosasauroidea based on a modified version of the data matrix published by Caldwell and Palci (2007) places these new mosasaurs in a clade that is in the sister group to the Plioplatecarpinae and Tylosaurinae.ReferencesCALDWELL M.W., & PALCI A. (2007). A new basal mosasauroid from the Cenomanian (U. Cretaceous) of Slovenia with a review of mosasauroid phylogeny and evolution. Journal of Vertebrate Paleontology 27: 863–880.LOZAR F., & GROSSO F. (1997). Biostratigrafia della successione cretacica del margine dei Lessini occidentali (Provincia di Verona, Italia). Bollettino del Museo Regionale di Scienze Naturali, Torino 15: 111–136.POLCYN M. J., & BELL G.L.Jr. (2005). Russellosaurus coheni n. gen., n. sp., a 92 million-year-old mosasaur from Texas (USA), and the definition of the parafamily Russellosaurina. Netherlands Journal of Geosciences 84: 321–333
EOCENE STALKED CRINOIDS IN THE GENUS ISSELICRINUS (ECHINODERMATA, CRINOIDEA, ISOCRINIDA) FROM NORTHEASTERN ITALY
Long fragments of isocrinid stalks belonging to the stalked crinoid genus Isselicrinus (Isocrinida, Isselicrininae) were found at Cambrigar, near Ferrara di Monte Baldo (Verona province, northeastern Italy) in the strata called “Harpactocarcinus punctulatus and Pentacrinus diaboli horizon”, traditionally ascribed to the lower Eocene (Ypresian). Morphometric analysis of this material allowed us to identify two distinct species filtering their food at different levels of the water column. The first species, characterized by a mostly pentagonal stalk section, is ascribable to Isselicrinus diaboli (Bayan), a taxon frequently cited from the lower Eocene of northeastern Italy but until now poorly known. The other species has a marked star-shaped stalk section presenting a combination of pedomorphic characters and is ascribed to the new taxon Isselicrinus baldoensis n. sp. A detailed analysis of numerous columnals and pluricolumnals of Isselicrinus diaboli from the type-locality of San Pancrazio near Mossano (Berici Hills, Vicenza province, northeastern Italy) allowed us to propose a revised and more complete diagnosis of this taxon. The particular burial conditions and the ecology of these two species are discussed as well as a reappraisal of the age of the “Harpactocarcinus punctulatus and Pentacrinus diaboli horizon”. Based on new calcareous nannofossil data, and confirmed by the larger foraminiferal assemblages, the isocrinids from Cambrigar are firmly assigned to the Lutetian (middle Eocene). Calcareous nannofossils identified in the matrix of historical hand specimens from the classical locality of San Pancrazio indicate a similar age