UPPER TRIASSIC AMBER FROM THE DOLOMITES (NORTHERN ITALY).A PALEOCLIMATIC INDICATOR?

Amber in Triassic deposits in the Dolomites is demonstrated for the first time. The amber-bearing deposits belong to the middle part of the Dürrenstein Formation, referred to uppermost Julian (Lower Carnian, about 225 My). Chemico-physical features of amber, which occurs as small yellow to reddish droplets, have been determined. Infrared (IR) spectroscopy shows typical bands of fossil resins; the "fingerprint" region of the spectrum presents a unique pattern that cannot be referred to any other known fossil resin. Palynological investigation of amber-bearing layers shows a large prevalence of bisaccates and circumpolles. Particularly, the taeniate bisaccates are frequent (41%) and suggest a correlation with the amber-producing species. Amber production and preservation is possibly related to a humid climatic event.&nbsp

Megaspores from the Lower Jurassic (Pliensbachian) Rotzo Formation (Monti Lessini, northern Italy) and their palaeoenvironmental implications

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AMBER DROPLETS IN THE SOUTHERN ALPS (NE ITALY): A LINK BETWEEN THEIR OCCURRENCES AND MAIN HUMID EPISODES IN THE TRIASSIC

The Anisian amber from the “Voltzia beds” of the Recoaro area, produced by Voltzia recubariensis, represents the most ancient Triassic amber known so far. The discovery of amber in the Anisian localities of Kühwiesenkopf/Monte Prà della Vacca and Piz da Peres, in the Dolomites area, fills a gap in the amber fossil record and gives an important contribution to the knowledge of Triassic amber. The finding of amber droplets, both dispersed in the sediment and anatomically connected to shoot fragments of V. recubariensis, demonstrates that during the Anisian this species was a major resin-producer and that the favorable conditions for the preservation of resin and plant remains were present at regional scale. The contribution of Voltziales to Middle Triassic resin production in Northern Italy is also testified by the Ladinian amber from the “Wengener Schichten” of Wengen/La Valle, produced by Voltzia ladinica, whereas the Late Triassic amber was mainly produced by cheirolepidiaceous conifers. The finding of organic body trapped in the amber of Kühwiesenkopf/Monte Prà dalla Vacca is noteworthy, although difficult to interpret, and shows once again its capability to entrap and preserve witnesses of past life. Moreover, the correspondence between the Triassic amber occurrences and regional/global scale humid shifts, suggests a cause-and-effect relationship, in which the rise of amber production/preservation potential is related to climate/environmental changes, particularly in marginal marine/costal environments

MIDDLE TRIASSIC AMBER ASSOCIATED WITH VOLTZIALEAN CONIFERS FROM THE SOUTHERN ALPS OF ITALY

Amber from the Carnian succession of the Dolomites and Julian Alps (northeastern Italy) represents one of the most ancient and quantitatively substantial Triassic fossil resin records in the world. So far, the Carnian appeared to be the only Triassic stage with findings of amber remains. However, the recent reappraisal of historical collections of plant fossils led to the discovery of even older Triassic amber, found on a rock slab from the “Voltzia beds” of the Recoaro area (Anisian) and on a sample from the “Wengener Schichten” of Wengen/La Valle (Ladinian), respectively. Both specimens are associated with conifer shoots of Voltziales. To date, they are the oldest known Triassic fossil resins, demonstrating that the preservation of amber was not restricted to the sediments deposited during the Carnian as suggested before. These finds contribute to partially fill the gap in the amber record between the Carboniferous and Upper Triassic

A microworld in Triassic amber

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A MONOTYPIC STAND OF NEOCALAMITES IRANENSIS N. SP. FROM THE CARNIAN PLUVIAL EPISODE (LATE TRIASSIC) OF THE AGHDARBAND AREA, NE IRAN (TURAN PLATE)

The Aghdarband Basin in the Kopeh-Dagh Range (NE Iran) is one of the most important areas for unraveling the evolution of the Turan plate (southern margin of Eurasia) during the last phase of the closure of the Paleotethys and to reconstruct the history of the Cimmerian blocks just before their collision with Eurasia during the early Late Triassic. The youngest sediments affected by the Early Cimmerian orogeny are those of the Upper Triassic Miankuhi Formation, which covers unconformably the Upper Triassic (lower Carnian) marine beds of the Sina Formation by an interval of continental facies including local conglomerates, cross-bedded sandstones, mudstone layers, silty shales, an up to one-meter thick coal layer with plant remains, and shales. The plant assemblages represent a relatively wide variety of different forms (sphenophytes, ginkgophytes, conifers, and incertis sedis), documenting wetlands with lush vegetation typical of warm and humid environments. In this study, we describe a plant fossil assemblage from the base of the Miankuhi Fm., dominated by roots and vegetative organs of Neocalamites iranensis n. sp., with few plant fossils of uncertain botanical affinity. Palynological investigations of the basal part of the Miankuhi Formation confirm a latest early Carnian to late Carnian age for this interval and reveal, for the first time, a clear link between this plant-bearing bed, and a time of global environmental changes, the Carnian Pluvial Episode. This is the first report of the Carnian Pluvial Episode in the Turan plate (southern margin of Eurasia) and Iran

Nuovi dati stratigrafici sull’ambra di Castelvecchio di Prignano (MO)

L’ambra dell’Appennino settentrionale è nota nel Bolognese fin dal XVII secolo (Masini, 1650; Boccone, 1684). La prima segnalazione dal Modenese risale a Strobel (1886), che parla di ambra da “Sassuolo nella provincia di Modena”; l’età di tale ambra rimane però indefinita. Skalski & Veggiani (1990), nella loro rassegna di ambre della Sicilia e dell’Appennino settentrionale, attribuiscono l’ambra del Bolognese (Scanello vicino a Loiano, provincia di Bologna) alla Formazione di Ranzano (o Loiano? L’equivalenza tra le due formazioni dichiarata dagli autori non è valida), assegnandole all’Oligocene inferiore. L’ambra del Modenese, più precisamente localizzata da Skalski & Veggiani (1990) nelle “Castelvecchio sandstones” (sic), vicino a Prignano (MO), viene dagli stessi autori attribuita alla Formazione di Ranzano e quindi datata anch’essa all’Oligocene inferiore. Angelini & Bellintani (2005), nella loro rassegna sulle ambre di provenienza archeologica dell’Italia settentrionale, hanno analizzato con metodi spettroscopici ambre di Scanello Bolognese (BO) e di Castelvecchio di Prignano (MO), evidenziando una marcata differenza tra i campioni provenienti dal Bolognese e dal Modenese. Inoltre, l’attribuzione dell’ambra di Castelvecchio all’Oligocene non è sostenuta da alcun dato diretto, se si esclude una possibile somiglianza litologica tra gli strati campionati e quelli della Formazione di Ranzano. In sintesi, l’attribuzione di un’età oligocenica all’ambra proveniente da Castelvecchio di Prignano risulta quantomeno dubbia. Un affioramento contenente ambra da questa località del Modenese è stato recentemente localizzato con precisione, misurato e campionato. L’esposizione comprende circa 5 m di successione, costituita da arenarie più o meno calcaree intercalate a livelli siltitici e argillosi variamente bioturbati. All’interno dei livelli arenitici (di solito nella loro parte superiore) si trovano livelli ricchi di frustoli vegetali, contenenti ambra e pezzi di carbone. L’ambra si presenta in frammenti e gocce, generalmente di colore rosso molto scuro, di dimensioni che vanno da 0,5 cm fino a oltre 6-7 cm. Al momento non sono state osservate inclusioni animali, soltanto alcuni minuscoli frammenti carboniosi che rendono scuro il colore della resina fossile. Sull’ambra è stata effettuata l’analisi agli infrarossi a trasformata di Fourier (FTIR). Per chiarire il contesto stratigrafico della resina fossile di Castelvecchio, sono stati raccolti campioni per lo studio del plancton calcareo, che ha consentito di attribuire i livelli fossiliferi alla parte superiore del Maastrichtiano. Questo dato diretto ha permesso, per la prima volta, di far risalire un’ambra dell’Appennino settentrionale al Cretaceo, diversamente da quanto finora riportato in letteratura. Bibliografia: Angelini I. & Bellintani P. (2005). Archaeological ambers from Northern Italy: an FTIR-DRIFT study of provenance by comparison with the geological amber database. Archaeometry, 47: 441-454. Boccone P. (1684). Osservazioni naturali ove si contengono Materie Medico-Fisiche, e di Botanica, Produzioni Naturali, Fosfori diversi, Fuochi sotterranei d’Italia, et altre curiosità. Manolessi Stamp., Bologna, p. 156-157. Masini A. (1650). Bologna perlustrata. Zenero, Bologna, p. 180. Skalski A.W. & Veggiani A. (1990). Fossil Resin in Sicily and the Northern Apennines: Geology and Organic content. Prace Muzeum Ziemi, 41: 37-49. Strobel P. (1886). L’ambra padana. Bullettino di Paletnologia Italiana, 12: 42-49

Morphology and paleobiology of the Late Cretaceous large-sized shark Cretodus crassidens (Dixon, 1850) (Neoselachii; Lamniformes)

The definition of the Cretaceous shark genus Cretodus Sokolov, 1965 is primarily based on isolated teeth. This genus includes five species. Among these, Cretodus houghtonorum Shimada and Everhart, 2019 is the only species based on a partially preserved skeleton. Here, the taxonomic attribution of a virtually complete skeleton of Cretodus from the Turonian of northeastern Italy is discussed, together with a few specimens from the Turonian of England. One of the latter is investigated through micropaleontological analysis to determine its stratigraphic position. The material is referred to Cretodus crassidens (Dixon, 1850), the diagnosis of which is emended herein. The dentition is tentatively reconstructed, exhibiting strong similarities with congeneric species, although it differs in having strong vertical folds on the main cusp labial face, a mesiodistally broad tooth aspect, weak and well-spaced 'costulae' at crown base, and a different dental formula in the number of parasymphyseal and lateral rows. Some tooth malformations are interpreted as feeding-related or senile characters. The Italian specimen suggests that Cretodus crassidens had a wide and laterally expanded mouth and head, a stout body, and attained a gigantic size. Cretodus crassidens was a moderate-speed swimming shark ecologically like the extant tiger shark Galeocerdo cuvier (Péron and Lesueur in Lesueur, 1822). The age estimate from vertebral-band counting suggests that the Italian individual was at least 23 years old and the growth model indicates a longevity of 64 years and a maximum attainable total length of 9-11 m. Cretodus crassidens occurs both in Boreal and Tethyan domains, implying a broad paleobiogeographic distribution and a preference toward offshore settings

Paleobotanical assemblage from the Lower Jurassic amber bearing levels from the Rotzo Formation, Monti Lessini (Venetian Prealps, Northern Italy)

The Rotzo Formation flower Jurassic) is famous for its fossiliferous content, includ- ing plant fossils that have been collected and studied since the XIX century. The For- mation is composed of bioclastic limestones and marls, deposited from shallow ma- rine to lagoonal environments in the tropical zone. Of particular interest is the recent discovery of fossil resin [amberJ in the Bellori section [Lessini Mountains, Verona). This section is about 20 m thick and composed mostly of marine limestones. The limestone is well stratified, with beds of 10 cm to more than one metre thickness. In- tercalated in the limestones are clayey levels 3 to 40 cm thick sometimes yielding well-visible coal and charcoal fragments. The amber was found as millimetre-sized fragments in two clayey levels intercalated in the limestones. It is blackish to red-brownish in colour and can be subdivided, ac- cording to its size and shape, into droplets and tubular-shaped structures about 10-15 pm in diameter. The palynological assemblages from the two clayey levels yielding the amber contain abundant Classopollis and trilete spores, Classopolliswas produced by cheirolepidiaceous conifers that were probably well adapted to both wet and dry climates in a coastal area. The trilete spores in the plant assemblage are more diversified and be- long to sphenophytes, horsetails, lyCophytes and ferns. The dominance [more than 50%) of trilete spores (e.g., Deltoidospora) suggests abundant freshwater, corre- sponding to a general humid climate. A nearby marsh environment is inferred by the presence of freshwater algae such as Botryococcus and Pseudoschizaea; the latter is reported for the first time from the Lower furassic. Some clayey levels yielded many very well-preserved cuticle fragments. They are gen- erally thich with a high number of slightly sunken stomata complexes on both sides of the leaves. These cuticles are currently under study: preliminary data suggest that most cuticles belong to Pagiophyllum cf. rotzoanum, a cheirolepidiaceous conifer, but the diversity in the cuticle assemblage is high. The exceptional preservation of the cu- ticles and other palynomorphs suggests negligible transport after shielding from the parent plants, and sedimentation taking place in calm water, free from wave action and surface disturbance, as well as sedimentation in low-oxygen conditions. Some of the clayey levels yielded also numerous pieces of charcoal with well-preserved vascu- lar tissues. Sedimentological and palynological analyses suggest for the amber-bearing clayey levels a lagoonal palaeoenvironment with humid climate, comparable to the present- day Taxodium swamp or cypress swamp and a bahamian-type marine environment, with the additional influence of monsoonal climate as in modern southern Asia