ABSTRACT Ambergrisichnus alleronae igen. et isp. nov. from early Pleistocene clay marine deposits... more ABSTRACT Ambergrisichnus alleronae igen. et isp. nov. from early Pleistocene clay marine deposits of Umbria, central Italy is here described, and attributed to cololites (evisceralites) of sperm whales. This interpretation is supported by the following characteristics that are frequently identified in modern ambergris including: internal organization of concentric structures, external shape with converging striae and bulges (rognons), and inclusions of squid beaks. These cololites were deposited in a relatively deep (100-150 m) marine environment, and the large number of structures in a restricted area is plausibly ascribed to multiple death events of sperm whales. The description of A. alleronae igen. et isp. nov. is held by analysis of the taphonomic processes that took place after the sperm whale carcasses reached the seabed and led to fossilization. The analysis of benthic micro- and macrofauna found close to the studied structures provides supplementary data, which support the reconstruction of palaeoecological and palaeoenvironmental conditions comparable with those of the whale fall communities. This work increases knowledge of vertebrate coprolites. Moreover, this new information provides the data about the frequency of sperm whales in the Tyrrhenian Sea during the early Pleistocene, and raises new questions about the causes of this anomalous accumulation.
Bollettino della Società Paleontologica Italiana, 2011
ABSTRACT-Findings of isolated wood clasts (wood branches and/or portions of a tree trunk) in Earl... more ABSTRACT-Findings of isolated wood clasts (wood branches and/or portions of a tree trunk) in Early Pleistocene deposits within the “Chiani-Tevere” depositional cycle (Orvieto area, central Italy) are described. The specimens show pervasive borings developed parallel to the wood fibers, assigned here to Teredolites longissimus Kelly & Bromley, 1984 and doubtfully to T. clavatus Leymerie, 1842. Oriented thin section analyses of the grouped or isolated Teredolites specimens have shown that the borings vary in shape and diameter ...
Recenti ricerche geologiche sul Quaternario dell'Umbria occidentale hanno apportato nuovi dat... more Recenti ricerche geologiche sul Quaternario dell'Umbria occidentale hanno apportato nuovi dati, sedimentologici e stra-tigrafici, che hanno permesso di ricostruire il paleoambiente nell'area di Orvieto (Umbria). Lo scenario proposto vede la presenza di un ambiente marino costiero, con coste articolate in spiagge e falesie rocciose, influenzato dalla presenza di delta fluviali, che si stava trasformando in un’area continentale. A partire da circa 3 milioni di anni fa, durante il Pliocene, il mare lambiva la catena Amerina e tale situazione rimase pressoché invariata, nell'area orvietana, per tutto il Pleistocene inferiore. Tra il Pliocene e il Pleistocene inferiore, l’area orvietana era un ampio golfo, isolato rispetto alle foci dei principali fiumi, ricevendo apporti locali da corsi d’acqua secondari. La sedimentazione marina proseguì fino a circa 1.2 Ma, ma tali depositi oggi sono presenti solo in aree circoscritte nei dintorni di Orvieto. I depositi sovrastanti quelli ...
Recenti ricerche geologiche sul Quaternario dell'Umbria occidentale hanno apportato nuovi dat... more Recenti ricerche geologiche sul Quaternario dell'Umbria occidentale hanno apportato nuovi dati, sedimentologici e stra-tigrafici, che hanno permesso di ricostruire il paleoambiente nell'area di Orvieto (Umbria). Lo scenario proposto vede la presenza di un ambiente marino costiero, con coste articolate in spiagge e falesie rocciose, influenzato dalla presenza di delta fluviali, che si stava trasformando in un’area continentale. A partire da circa 3 milioni di anni fa, durante il Pliocene, il mare lambiva la catena Amerina e tale situazione rimase pressoché invariata, nell'area orvietana, per tutto il Pleistocene inferiore. Tra il Pliocene e il Pleistocene inferiore, l’area orvietana era un ampio golfo, isolato rispetto alle foci dei principali fiumi, ricevendo apporti locali da corsi d’acqua secondari. La sedimentazione marina proseguì fino a circa 1.2 Ma, ma tali depositi oggi sono presenti solo in aree circoscritte nei dintorni di Orvieto. I depositi sovrastanti quelli ...
Bollettino della Società Paleontologica Italiana, 2011
ABSTRACT-Findings of isolated wood clasts (wood branches and/or portions of a tree trunk) in Earl... more ABSTRACT-Findings of isolated wood clasts (wood branches and/or portions of a tree trunk) in Early Pleistocene deposits within the “Chiani-Tevere” depositional cycle (Orvieto area, central Italy) are described. The specimens show pervasive borings developed parallel to the wood fibers, assigned here to Teredolites longissimus Kelly & Bromley, 1984 and doubtfully to T. clavatus Leymerie, 1842. Oriented thin section analyses of the grouped or isolated Teredolites specimens have shown that the borings vary in shape and diameter ...
An integrated taphonomical, ichnological and sedimentological analysis has been carried out on th... more An integrated taphonomical, ichnological and sedimentological analysis has been carried out on the Albian deposits of the Sierra Helada section (Province of Alicante, southeastern Spain). This allowed recognition and detailed characterization of the shallowing-and coarsening-upward sequences present in these deposits. Twenty sequences were detected throughout the section. They contain the following, from bottom to top: (1) the bottom of the sequence characterized by very fine-grained marls rich in echinoid tests and echinoid trace fossils with very little evidence of physical reworking—it records a distal platform, low-energy environment; (2) marls inter-bedded with fine-grained calcarenites, rich in large Thalassinoides and slightly reworked echinoid tests, with common bioclast-armored tubes (Ereipichnus geladensis), recording low-energy background conditions but increasing energy of the sedimentary events, (3) coarse-grained calcarenites rich in different types of small to large Thalassinoides and E. geladensis horizons, showing the intense and frequent action of storms and directed currents on the seafloor, and (4) coarse-grained, cross-bedded calcarenites, rich in Ophiomorpha nodosa, deposited under high-energy background conditions in the shallowest part of the sequence, recording the presence of shifting dunes in the inner platform. Occasionally, also the record of a rapid transgression has been pointed out through the presence of condensed tapho-and sedimentary facies and mixed ichnocoenoses at the top of the sequence just after an erosive surface. The defined ichnoceonoses and their distribution throughout the sequence reflect the shifting from a distal expression of the Cruziana Ichnofacies to the shallower archetypal Cruziana Ichnofacies and finally to the high-energy, shallow-water Skolithos Ichnofacies. The distribution of taphofacies and ichnocoenoses and development of the sequences all through the section show a general transgression followed by a regressive phase, which fit with the third-order curves described for the area on the basis of pure sedimentological analysis in previous studies (Castro et al., 2008).
ABSTRACT Ambergrisichnus alleronae igen. et isp. nov. from early Pleistocene clay marine deposits... more ABSTRACT Ambergrisichnus alleronae igen. et isp. nov. from early Pleistocene clay marine deposits of Umbria, central Italy is here described, and attributed to cololites (evisceralites) of sperm whales. This interpretation is supported by the following characteristics that are frequently identified in modern ambergris including: internal organization of concentric structures, external shape with converging striae and bulges (rognons), and inclusions of squid beaks. These cololites were deposited in a relatively deep (100-150 m) marine environment, and the large number of structures in a restricted area is plausibly ascribed to multiple death events of sperm whales. The description of A. alleronae igen. et isp. nov. is held by analysis of the taphonomic processes that took place after the sperm whale carcasses reached the seabed and led to fossilization. The analysis of benthic micro- and macrofauna found close to the studied structures provides supplementary data, which support the reconstruction of palaeoecological and palaeoenvironmental conditions comparable with those of the whale fall communities. This work increases knowledge of vertebrate coprolites. Moreover, this new information provides the data about the frequency of sperm whales in the Tyrrhenian Sea during the early Pleistocene, and raises new questions about the causes of this anomalous accumulation.
Bollettino della Società Paleontologica Italiana, 2011
ABSTRACT-Findings of isolated wood clasts (wood branches and/or portions of a tree trunk) in Earl... more ABSTRACT-Findings of isolated wood clasts (wood branches and/or portions of a tree trunk) in Early Pleistocene deposits within the “Chiani-Tevere” depositional cycle (Orvieto area, central Italy) are described. The specimens show pervasive borings developed parallel to the wood fibers, assigned here to Teredolites longissimus Kelly & Bromley, 1984 and doubtfully to T. clavatus Leymerie, 1842. Oriented thin section analyses of the grouped or isolated Teredolites specimens have shown that the borings vary in shape and diameter ...
Recenti ricerche geologiche sul Quaternario dell'Umbria occidentale hanno apportato nuovi dat... more Recenti ricerche geologiche sul Quaternario dell'Umbria occidentale hanno apportato nuovi dati, sedimentologici e stra-tigrafici, che hanno permesso di ricostruire il paleoambiente nell'area di Orvieto (Umbria). Lo scenario proposto vede la presenza di un ambiente marino costiero, con coste articolate in spiagge e falesie rocciose, influenzato dalla presenza di delta fluviali, che si stava trasformando in un’area continentale. A partire da circa 3 milioni di anni fa, durante il Pliocene, il mare lambiva la catena Amerina e tale situazione rimase pressoché invariata, nell'area orvietana, per tutto il Pleistocene inferiore. Tra il Pliocene e il Pleistocene inferiore, l’area orvietana era un ampio golfo, isolato rispetto alle foci dei principali fiumi, ricevendo apporti locali da corsi d’acqua secondari. La sedimentazione marina proseguì fino a circa 1.2 Ma, ma tali depositi oggi sono presenti solo in aree circoscritte nei dintorni di Orvieto. I depositi sovrastanti quelli ...
Recenti ricerche geologiche sul Quaternario dell'Umbria occidentale hanno apportato nuovi dat... more Recenti ricerche geologiche sul Quaternario dell'Umbria occidentale hanno apportato nuovi dati, sedimentologici e stra-tigrafici, che hanno permesso di ricostruire il paleoambiente nell'area di Orvieto (Umbria). Lo scenario proposto vede la presenza di un ambiente marino costiero, con coste articolate in spiagge e falesie rocciose, influenzato dalla presenza di delta fluviali, che si stava trasformando in un’area continentale. A partire da circa 3 milioni di anni fa, durante il Pliocene, il mare lambiva la catena Amerina e tale situazione rimase pressoché invariata, nell'area orvietana, per tutto il Pleistocene inferiore. Tra il Pliocene e il Pleistocene inferiore, l’area orvietana era un ampio golfo, isolato rispetto alle foci dei principali fiumi, ricevendo apporti locali da corsi d’acqua secondari. La sedimentazione marina proseguì fino a circa 1.2 Ma, ma tali depositi oggi sono presenti solo in aree circoscritte nei dintorni di Orvieto. I depositi sovrastanti quelli ...
Bollettino della Società Paleontologica Italiana, 2011
ABSTRACT-Findings of isolated wood clasts (wood branches and/or portions of a tree trunk) in Earl... more ABSTRACT-Findings of isolated wood clasts (wood branches and/or portions of a tree trunk) in Early Pleistocene deposits within the “Chiani-Tevere” depositional cycle (Orvieto area, central Italy) are described. The specimens show pervasive borings developed parallel to the wood fibers, assigned here to Teredolites longissimus Kelly & Bromley, 1984 and doubtfully to T. clavatus Leymerie, 1842. Oriented thin section analyses of the grouped or isolated Teredolites specimens have shown that the borings vary in shape and diameter ...
An integrated taphonomical, ichnological and sedimentological analysis has been carried out on th... more An integrated taphonomical, ichnological and sedimentological analysis has been carried out on the Albian deposits of the Sierra Helada section (Province of Alicante, southeastern Spain). This allowed recognition and detailed characterization of the shallowing-and coarsening-upward sequences present in these deposits. Twenty sequences were detected throughout the section. They contain the following, from bottom to top: (1) the bottom of the sequence characterized by very fine-grained marls rich in echinoid tests and echinoid trace fossils with very little evidence of physical reworking—it records a distal platform, low-energy environment; (2) marls inter-bedded with fine-grained calcarenites, rich in large Thalassinoides and slightly reworked echinoid tests, with common bioclast-armored tubes (Ereipichnus geladensis), recording low-energy background conditions but increasing energy of the sedimentary events, (3) coarse-grained calcarenites rich in different types of small to large Thalassinoides and E. geladensis horizons, showing the intense and frequent action of storms and directed currents on the seafloor, and (4) coarse-grained, cross-bedded calcarenites, rich in Ophiomorpha nodosa, deposited under high-energy background conditions in the shallowest part of the sequence, recording the presence of shifting dunes in the inner platform. Occasionally, also the record of a rapid transgression has been pointed out through the presence of condensed tapho-and sedimentary facies and mixed ichnocoenoses at the top of the sequence just after an erosive surface. The defined ichnoceonoses and their distribution throughout the sequence reflect the shifting from a distal expression of the Cruziana Ichnofacies to the shallower archetypal Cruziana Ichnofacies and finally to the high-energy, shallow-water Skolithos Ichnofacies. The distribution of taphofacies and ichnocoenoses and development of the sequences all through the section show a general transgression followed by a regressive phase, which fit with the third-order curves described for the area on the basis of pure sedimentological analysis in previous studies (Castro et al., 2008).
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