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Dinosaur Footprints from Central and Southern Italy. International Symposium on Dinosaurs and other Vertebrates Palaeoichnology
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Early Triassic terrestrial tetrapod fauna. A review
No full textThe Permian-Triassic mass extinction (PTME, ca. 252 Mya) was one of the most severe biotic crises of the Phanerozoic, eliminating >90% of marine and terrestrial species. This was followed by a long period of recovery in the Early and Middle Triassic which revolutionised the structure of both marine and terrestrial ecosystems, triggering the new ecosystem structure of the Mesozoic and Cenozoic. Entire new clades emerged after the mass extinction, including decapods and marine reptiles in the oceans and new tetrapods on land. In both marine and terrestrial ecosystems, the recovery is interpreted as stepwise and slow, from a combination of continuing environmental perturbations and complex multilevel interaction between species in the new environments as ecosystems reconstructed themselves. Here, we present a review of Early Triassic terrestrial tetrapod faunas, geological formations and outcrops around the world, and provide a semi-quantitative analysis of a data set of Early Triassic terrestrial tetrapods. We identify a marked regionalisation of Early Triassic terrestrial tetrapods, with faunas varying in both taxonomic composition and relative abundance according to palaeolatitudinal belt. We reject the alleged uniformity of faunas around Pangaea suggested in the literature as a result of the hot-house climate. In addition, we can restrict the “tetrapod gap” of terrestrial life in the Early Triassic to palaeolatitudes between 15°N and about 31°S, in contrast to the earlier suggestion of total absence of tetrapod taxa between 30°N and 40°S. There was fairly strong provincialism following the PTME, according to cluster analysis of a taxon presence matrix, entirely consistent with Early Triassic palaeobiogeography. Unexpectedly, the overall pattern for Early Triassic terrestrial tetrapod faunas largely reflects that of the Late Permian, suggesting that the recovery faunas in the Early Triassic retained some kind of imprint of tetrapod distributions according to palaeogeography and palaeoclimate, despite the near-total extinction of life through the PTME
Theropod and sauropod footprints in the Early Cretaceous (Aptian) Apenninic Carbonate Platform (Esperia, Lazio, Central Italy): a further constraint on the palaeogeography of the Central-Mediterranean area.
No full textAvanzini A. & Petti F.M. (eds), Proceedings of the Ichnology session of Geoitalia 2007, VI Forum Italiano di Scienze della Terra Rimini - September 12-14, 2007
The Late Cretaceous dinosaur tracksite near Altamura (Bari, southern Italy). II - Apulosauripus federicianus new ichnogen. and new ichnosp.
No full textTetrapod footprints and associated biota: new evidences from the Upper Carboniferous of Southwestern Sardinia, Italy
No full textSeveral tetrapod footprints have been recently found in the U. Carboniferous fluvio-lacustrine
deposits of the San Giorgio Basin (Iglesias, SW Sardinia). They represent, together with the
ones figured by Fondi (1980), the earliest evidence of vertebrate tracks recorded in Italy. The
studied section, about 33 m thick, is located 2.5 km SSW of Iglesias and is entirely assigned to
the Westphalian-Stephanian. The specimens originate from the yellow-grey dolomitic siltstone
interval of the middle unit (unit B, Del Rio et al., 2002). The collected tetrapod footprints are
on eight slabs and are chiefly preserved as casts of three manus-pes couples and by other
isolated footprints which, for their different shape and size, are referable to three distinct
morphotypes that differ from those assigned to Salichnium (Saurichnites) heringi (Geinitz,
1885) by Fondi (1980). Additional ichnofossils are represented by tiny arthropod tracks and
trails. The biota is largely dominated by diversified plant remains and palynomophs, while
body fossils are represented by an exquisitely preserved Anthracomartid spider and a blattoid
wing. (Del Rio et al., 2002, and cited references). These findings add new data about the U.
Carboniferous of Sardinia and suggest an unexpected faunal diversity which may support more accurate age bracketing and correlations
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