578 research outputs found

    The occurrence of the coronuloid barnacle Chelonibia Leach, 1817 as an encruster on mammalian bone in the central Mediterranean Sea

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    Među kornjačama i kitovima (Coronuloidea: Chelonibiidae, Coronulidae, † Emersoniidae i Platylepadidae), pripadnici vrste Chelonibia testudinaria (Linnaeus, 1758) poznati su kao epizoični brumbuljci koji se mogu pričvrstiti na prilično širok spektar podloga (prvenstveno na kornjače, rakove i velike vodene sisavce koji se hrane biljkama iz reda Sirenia). Trenutno su prepoznate tri živa morfija C. testudinaria; od njih, manje specifična za domaćina je morph patula, koja također prikazuje izuzetno jednostavnu, nespecijaliziranu arhitekturu ljuske. U ovom radu izvještavamo o nekoliko ljuski helonibiida, koje se odnose na morfe patule C. testudinaria, koja inkrustira lopaticu kitova sakupljenu s dna Jadranskog mora prema Salentu (regija Apulia, jugoistočna Italija) i okvirno upućenu na Tursiops truncatus (Montagu, 1821). Ovo je jedan od rijetkih zapisa u svijetu o brumbuljku iz nežive podloge, a i kao drugi slučaj inkrustriranja na kosti sisavca. Takva neobična pojava potom se ukratko raspravlja u širem kontekstu komensalizma brumbuljaka i supstrata staništa.Among the turtle and whale barnacles (Coronuloidea: Chelonibiidae, Coronulidae, †Emersoniidae and Platylepadidae), the members of the chelonibiid species Chelonibia testudinaria (Linnaeus, 1758) are known as epizoic barnacles that can attach to a rather wide spectrum of substrates (primarily sea turtles, crabs and sirenians). At present, three living morphs of C. testudinaria have been recognised; of these, the less host-specific is the patula morph, which also displays a remarkably simple, unspecialised shell architecture. Here we report on several chelonibiid shells, referred to the patula morph of C. testudinaria, encrusting a cetacean scapula collected from the floor of the Adriatic Sea facing Salento (Apulia Region, southeastern Italy) and tentatively referred to Tursiops truncatus (Montagu, 1821). This is one of the few records worldwide of a coronuloid barnacle from an inanimate substrate, as well as the second as an encruster on mammalian bone. Such an unusual occurrence is then briefly discussed in the broader framework of the coronuloid commensalism and substrate habits

    <i>Caviziphius altirostris</i>, a new beaked whale from the Miocene southern North Sea basin

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    An odontocete cranium from Miocene deposits in northern Belgium is examined and referred to Caviziphius altirostris, a new genus and species of beaked whale. In the general architecture of its vertex and closed mesorostral canal, Caviziphius resembles the fossil genera Ziphirostrum and Choneziphius, but differs from all known ziphiids by a very deep excavated prenarial basin with a semicircular outline in lateral view. This peculiar cranial architecture of Caviziphius might indicate an advanced and efficient mechanism of sound production in this fossil ziphiid

    A new record of Physeteroidea from the upper Miocene of the Pietra leccese (southern Italy): Systematics, paleoecology and taphonomy of a fossil macroraptorial sperm whale

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    We report on a partial skeleton of sperm whale (Cetacea, Odontoceti, Physeteroidea) from the Pietra leccese, a Miocene limestone widely exposed in the Salento Peninsula (southern Italy). This specimen was found in Tortonian strata cropping out at the Cisterna quarry, not far from the holotype of the stem physeteroid Zygophyster varolai. The presence of a deep and rectilinear groove medial to the tympanosquamosal recess of the squamosal, the bowed mandibles, and some dental features suggest that this specimen belongs to a still undescribed new genus and species of macroraptorial sperm whale that displays some affinities with the late Miocene Acrophyseter from Peru. Nevertheless, due to the incompleteness and poor preservation state of the skull, we abstain from creating a new taxon. The teeth exhibit both apical wear and deep occlusal facets, and three teeth even lost their crowns. These dental modifications suggest that the studied specimen used a raptorial feeding strategy for preying upon food items such as large-sized bony fishes or diminutive marine mammals. The bones are mostly disarticulated and broken, and some of them preserve traces hinting at the action of macro-scavengers, possibly including both sharks and bony fishes. Furthermore, the skull is pervasively encrusted by oysters, which suggests that it laid on the seafloor for a long time before being buried. This find provides new clues about the composition of the Miocene vertebrate assemblage of the Pietra leccese and indicates that various macroraptorial sperm whale species inhabited the Mediterranean Basin during the Tortonian

    Paleoecology and paleobiogeography of fossil mollusks from Isabela

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    Design and advancement status of the Beam Expander Testing X-ray facility (BEaTriX)

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    The BEaTriX (Beam Expander Testing X-ray facility) project is an X-ray apparatus under construction at INAF/OAB to generate a broad (200 x 60 mm2), uniform and low-divergent X-ray beam within a small lab (6 x 15 m2). BEaTriX will consist of an X-ray source in the focus a grazing incidence paraboloidal mirror to obtain a parallel beam, followed by a crystal monochromation system and by an asymmetrically-cut diffracting crystal to perform the beam expansion to the desired size. Once completed, BEaTriX will be used to directly perform the quality control of focusing modules of large X-ray optics such as those for the ATHENA X-ray observatory, based on either Silicon Pore Optics (baseline) or Slumped Glass Optics (alternative), and will thereby enable a direct quality control of angular resolution and effective area on a number of mirror modules in a short time, in full X-ray illumination and without being affected by the finite distance of the X-ray source. However, since the individual mirror modules for ATHENA will have an optical quality of 3-4 arcsec HEW or better, BEaTriX is required to produce a broad beam with divergence below 1-2 arcsec, and sufficient flux to quickly characterize the PSF of the module without being significantly affected by statistical uncertainties. Therefore, the optical components of BEaTriX have to be selected and/or manufactured with excellent optical properties in order to guarantee the final performance of the system. In this paper we report the final design of the facility and a detailed performance simulation.Comment: Accepted paper, pre-print version. The finally published manuscript can be downloaded from http://dx.doi.org/10.1117/12.223895

    Trace fossils on a trace fossil: A vertebrate-bitten vertebrate coprolite from the miocene of Italy

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    Despite their long history of discoveries and research, of all the vertebrate coprolites currently known worldwide, only a very few have been explicitly recognised as exhibiting bite marks by other vertebrates. These rare specimens represent “compound ichnofossils”, i.e., trace fossils (the lithifie faeces) on which other trace fossils (the tooth incisions) are present. Here we report on an unusual large-sized coprolite from the Miocene “Pietra leccese” formation of southern Italy that displays several superficia bite marks. This specimen is described, f gured, and chemically characterised by means of hand-held energy dispersive X-ray f uorescence – the firs application of this method to the analysis of a vertebrate coprolite. Based on its size, morphology, structure, and major-element composition, the Pietra leccese coprolite is here identifie as the fossilised excreta of a large carnivorous vertebrate, possibly a shark, whereas the tooth incisions are attributed to the biting action of indeterminate f sh, likely including both bony and cartilaginous fish Biting seemingly occurred prior to the eventual deposition of the scat at the seafl or (i.e., when it was still in the water column) and probably ref ects unintentional snagging or aborted exploratory coprophagy aimed at testing the palatability of the faeces. In conclusion, the highly idiosyncratic specimen described in this paper represents a significa t addition to the overly scanty record of vertebrate-bitten vertebrate coprolites and provides an unusual window on the ecological interactions between marine vertebrates in the Miocene central Mediterranean ecosystems witnessed by the remarkable fossil assemblage of the Pietra leccese

    Just a different place to graze? An unusual occurrence of the echinoid feeding trace Gnathichnus pentax on a marine vertebrate coprolite (Miocene, Italy) and its palaeoethological implications

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    Faeces produced by marine vertebrates and macro-invertebrates contain sufficient organic matter to represent a usable food source for a wide array of macroscopic animals. In some extant marine environments, coprophagy even represents a crucial trophic interaction in food webs. In ancient ecosystems, coprophagy by macroscopic animals is occasionally exemplified by coprolites that exhibit biting traces or burrows. Here, we report Gnathichnus pentax on an exquisitely preserved vertebrate-bitten vertebrate coprolite from the marine calcareous deposits of the Pietra leccese (Miocene, southern Italy). This unusual occurrence is interpreted as evidence of the feeding activity of a regular echi-noid; in particular, it may represent either exploratory coprophagy or the browsing of an algal (microbial) film that locally developed on the exterior of the faeces. Strengthening the former interpretation, the development of microbial communities on submerged faeces often leads to their destruction; furthermore, some extant Antarctic echinoderms are well known to ordinarily feed on vertebrate faeces, and coprophagy is believed to be fairly widespread among sea urchins. Supporting the algal browsing hypothesis, in turn, only a limited area of the external surface of the faeces was subject to grazing, and the resulting trace is neatly defined, which suggest that the feeding sea urchin targeted a precise location on the dung's exterior when the latter was already rather firm. To our knowledge, the G. pentax specimen studied here represents the first published record of this ichnotaxon on a coprolite

    The shark-toothed dolphin Squalodon (Cetacea: Odontoceti) from the remarkable Montagna della Majella marine vertebrate assemblage (Bolognano formation, Central Italy)

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    The extinct family Squalodontidae consists of heterodont, medium-sized odontocetes, featuring a long rostrum that houses large, procumbent incisors and heavily ornamented postcanine teeth carrying accessory denticles, hence their vernacular name, "shark-toothed dolphins". These longirostri-ne toothed whales are often seen as bridging the anatomical gap between archaic Oligocene odontocetes and their late Miocene to Holocene relatives. Possibly among the major marine predators of their time, the shark-toothed dolphins are important components of several lower Miocene marine-mammal assemblages from the North Atlantic and Mediterranean/Paratethysian realms. In the present work, a partial skull of Squalodontidae is described from the strata of the Bolognano Formation cropping out in the northeastern sector of the Montagna della Majella massif (Abruzzo, central Italy), which has previously yielded a rich lower Miocene marine-vertebrate assemblage, including eleven taxa of elasmobranchs as well as subordinate teleosts and very fragmentary remains of marine reptiles and mammals. The specimen consists of the anterodorsal portion of a rostrum, preserving parts of both pre-maxillae and left maxilla, and the anteriormost seven upper left teeth. This partial skull is here identified as belonging to the genus Squalodon, whose presence in the Montagna della Majella vertebrate assemblage had already been tentatively proposed on the basis of two fragmentary teeth. The paleontological significance of this find is discussed in the broader framework of the Euromediterranean record of Squalodon

    <i>Koristocetus pescei</i> gen. et sp. nov., a diminutive sperm whale (Cetacea: Odontoceti: Kogiidae) from the late Miocene of Peru

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    Among odontocetes, members of the family Kogiidae (pygmy and dwarf sperm whales) are known as small-sized and in many respects enigmatic relatives of the great sperm whale Physeter macrocephalus. Most of the still scanty fossil record of Kogiidae is represented by isolated skulls and ear bones from Neogene deposits of the Northern Hemisphere, with the significant exception of Scaphokogia, a highly autapomorphic genus from late Miocene deposits of the Pisco Formation exposed along the southern coast of Peru. Here we report on a new fossil kogiid from Aguada de Lomas, a site where the late Miocene beds of the Pisco Formation are exposed. This specimen consists of an almost complete cranium representing a new taxon of Kogiidae: Koristocetus pescei gen. et sp. nov. Koristocetus mainly differs from extant Kogia spp. by displaying a larger temporal fossa and well-individualized dental alveoli on the upper jaws. Coupled with a relatively elongated rostrum, these characters suggest that Koristocetus retained some degree of raptorial feeding abilities, contrasting with the strong suction feeding specialization seen in Recent kogiids. Our phylogenetic analysis recognizes Koristocetus as the earliest branching member of the subfamily Kogiinae. Interestingly, Koristocetus shared the southern coast of present-day Peru with members of the genus Scaphokogia, whose unique convex rostrum and unusual neurocranial morphology seemingly indicate a peculiar foraging specialization that has still to be understood. In conclusion, Koristocetus evokes a long history of high diversity, morphological disparity, and sympatric habits in fossil kogiids, thus suggesting that our comprehension of the evolutionary history of pygmy and dwarf sperm whales is still far from being exhaustive
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