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First record of Pliensbachian (Lower Jurassic) amber and associated palynoflora from the Monti Lessini (northern Italy)
Authors:Mirco Neri  Guido Roghi  Eugenio Ragazzi  Cesare Andrea Papazzoni
Institution:1. Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy;2. CNR Institute of Geosciences and Earth Resources (IGG-CNR), Via Gradenigo 6, 35131 Padova, Italy;3. Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Largo E. Meneghetti 2, 35131 Padova, Italy
Abstract:The fossil record of amber dates back to the Palaeozoic, but it is only since the Mesozoic that amber became relatively common, probably because of the spreading of resin-producing plants. In Italy, the oldest ambers come from the Middle and Upper Triassic of the Dolomites. Cretaceous ambers come from some Albian sites in the Dolomites and from the Coniacian–Santonian of Vernasso, Julian Prealps, northern Italy. Until now, no Jurassic sites with amber have been reported in Italy, and this “Jurassic gap” seems generalized, since there are only a few Jurassic ambers described all over the world. Here, we report the first finding of Lower Jurassic (Pliensbachian) amber from the Bellori locality (Grezzana, Verona Province, Northern Italy). The amber was found in two clayey-coal levels containing plant remains and cuticles, with subordinate bivalves, foraminifera and ostracods. Palynomorphs of the amber levels are dominated by levigate and ornamented spores (ferns) and Circumpolles (conifers). Foraminiferal linings and algal cysts are also present. The freshwater alga Pseudoschizaea is reported for the first time from the Lower Jurassic. The amber shows different kinds of preservation, some peculiar features probably connected with the plant structure, and colours ranging from light yellow to blackish red. Moreover, it includes millimetre-sized wood structures (“mummified wood”) and gas bubbles. Fourier-transform–Infrared, thermogravimetric and differential thermogravimetric analyses were carried out and resulted in a clear characterization of this amber with respect to all others known so far. These data, together with sedimentological observations and fossil content analysis, suggest a coastal palaeoenvironment under rather wet conditions, comparable with the present-day Everglades, with the addition of a monsoonal climate as in the modern southern Asia.
Keywords:Fossil resin  Rotzo Formation  Plant remains  Conifers  Pollens  Palaeoenvironment
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