Umberto Nicosia

Triassic Footprints from Lerici (La Spezia, Northern Italy)

A reptile footprint fauna was recovered at Lerici, near La Spezia (northern Apennines, Italy) from Triassic sediments, belonging to the upper portion of the Montemarcello Formation. These sediments, of Mid to Late Triassic age, were deposited on a flood plain, during an early stage of rifting. The footprint-bearing levels are Carnian in age and the ichnofauna is unexpectedly diverse, including two chirotherian- and three dinosaur-related forms; consequently our findings are among the more ancient records of a true dinosaur-based ichnocoenosis. Due to the emerging complexity of systematic and stratigraphical problems, we restrict this paper to the description of a new prosauropod-related ichnotaxon named Evazoum siriguii igen. et isp. nov. In attempting to include this ichnotaxon into a convincing systematic framework we were obliged to examine the present confused situation of some different ichnotaxa. The conclusion of this attempt was that an integrated study is urgently needed to shed light on the systematics of quite a large number of prosauropod-related ichnotaxa.

Dinosaur Tracks as Paleogeographic Constraints: New Scenarios for the Cretaceous Geography of the Periadriatic Region

A really unexpected finding of sauropod and theropod footprints in southern Latium raises to four the number of the trampled levels recognized in central and southern Italy. After the recent findings in Latest Jurassic and Early, mid and Late Cretaceous carbonate platform deposits of the Periadriatic region, dinosaur footprints seem to provide very important paleogeographic constraints for reconstructing the geodynamic history of the Mediterranean area. The presence of a varied ichnoassociation makes acceptance of the current paleogeographic models concerning the relative and absolute position of the Laziale-Abruzzese-Campano and of Apulian-Dinaric domains during the Late Cretaceous more and more problematic. Dinosaur footprints, combined with other paleontological data, demonstrate that these areas were never completely pulled apart by deep seaways, while frequent or continuous links between them, and to southern and northern mainlands, probably persisted. These data also allowed us to improve our understanding of the timing of the Mesozoic plate motion in this segment of the Western Tethys.

Re-Examination of Some Large Early Mesozoic Tetrapod Footprints from the African Collection of Paul Ellenberger

The Late Triassic—Early Jurassic ichnofauna described mainly by Paul Ellenberger from southern Africa (Lesotho) is a valuable window on first phases of dinosaur diversification. Unfortunately, the present taxonomic status of several forms from that ichnofauna is unclear. The revision of this material has been frequently invoked and partially done without reaching many definitive results. Due to the enormous amount of data, a global revision seems at present impossible and must be accomplished in smaller steps. A small number of Ellenbergers ichnogenera including Tetrasauropus, Pseudotetrasauropus, Pentasauropus, Paratetrasauropus, Sauropodopus and Deuterosauropodopus, which different authors have ascribed to basal sauropodomorphs, are here revised in a consistent manner and their attribution to osteological clades is considered. Tetrasauropus and Pseudotetrasauropus are here validated as the only ichnotaxa related to sauropodomorphs. Pentasauropus is retained as valid, and a therapsid trackmaker is suggested. Paratetrasauropus and Sauropodopus are also validated and ascribed to non-dinosaurian trackmakers, and Deuterosauropodopus is synonymized with Sauropodopus.

Permian tetrapod footprintsfrom W Orobic Basin (Northern Italy). Biochronological and evolutionary remarks

Abstract Numerous tetrapod footprints have been found in the Permian deposits of the Western Orobic Prealps(Upper Gerola Valley, Sondrio and Lecco Provinces, Lombardy, Italy). The footprints come from the uppermost levels of the Collio Fm. and are ascribed to Amphisauropus latus Haubold 1970, A. imminutus Haubold 1970, Dromopus lacertoides ( Geinitz 1861) and Varanopus curvidactylus Moodie 1929. The association is closely comparable to the association known from the lower portion of the Collio Fm. cropping out within the Collio Basin, in the Brescia region and to the similar and coeval Early Permian associations of Central Europe and North America.

Jurassic Dinosaur Footprints from Southern Italy: Footprints as Indicators of Constraints in Paleogeographic Interpretation

Abstract Three loose blocks, rich in dinosaur footprints, were found in a small pier at Mattinata (Gargano Promontory, Foggia, Italy), most probably quarried from the Upper Jurassic Sannicandro Formation. All of the footprints in the blocks are ascribed to medium-sized theropod trackmakers. Recent track discoveries from both the Early Cretaceous San Giovanni Rotondo Limestone and the Late Cretaceous Altamura Limestone, as well as this new discovery, reveal the consistency of terrestrial associations along the southern margin of the Tethys Ocean in the peri-Mediterranean area at the end of Jurassic through Cretaceous times. The presence of these dinosaur-track-rich levels within marine sediments of the Apulia Platform underlines the relevance of dinosaur footprints as a means of constraining paleogeographic reconstructions.

A huge caseid pelycosaur from north−western Sardinia and its bearing on European Permian stratigraphy and palaeobiogeography

Skeletal remains, some loose on the surface and others still embedded, have been recovered from the uppermost part of an outcrop of the Permian Cala del Vino Formation located near Torre del Porticciolo (Alghero, Nurra, NW Sardinia). Taphonomic analysis suggests that all the elements pertain to a single individual; ongoing studies indicate the fossil represents a large caseid close (or referable) to Cotylorhynchus; otherwise restricted to a narrow geographic and stratigraphic zone of the central USA. The new finding, the first of a caseid in Italy and one of few in Europe, enlarges the known distribution of the family and provides a significant and key chronostratigraphic constraint for the continental succession of this area and, in turn, helps establish a stratigraphic framework for the Permian units cropping out in Italy and southern France.

Alierasaurus ronchii, gen. et sp. nov., a caseid from the Permian of Sardinia, Italy

ABSTRACT A giant caseid, Alierasaurus ronchii, gen. et sp. nov., is herein described, based on a partial postcranial skeleton collected from the Permian Cala del Vino Formation (Alghero, Nurra, northwest Sardinia). Despite the highly conservative morphology of ribs and vertebral material, typical of caseids, the very well-preserved foot elements show highly autapomorphic features, warranting assignment of the specimen to a new genus. In particular, the fourth metatarsal is not short and massive, as in other large caseids, and shows a distinct axial region. Finally, the claw-shaped ungual phalanges are autapomorphic in being proportionately very short, with a strong double ventral flexor tubercle positioned very close to the proximal phalangeal rim, and a distal end that is not spatulate, but rather subtriangular in transverse section. Principal component and reduced major axis slope analyses, performed on 10 caseid specimens, suggest that the observed changes in overall shape of metatarsal IV were mainly linked to the enormous body size reached by the Sardinian specimen.

Dimetropus osageorum n. isp. from the Early Permian of Oklahoma (USA): A Trace and its Trackmaker

A new ichnospecies is named as Dimetropus osageorum n. isp. within the ichnogenus Dimetropus Romer and Price, 1940. The new ichnotaxon comes from the Lower Permian Midco Member of the Wellington Formation, cropping out near Perry, Noble Co. (Oklahoma, USA), and differs from congeneric ichnospecies in the apparent heteropody and in the proportionally shorter digits. The characters of the new ichnotaxon, together with comparative analysis of footprints and of known skeletal remains, suggest referral of the trackmaker to the Caseidae, although edaphosaurid affinities cannot be excluded. Tracks referred to Dimetropus exhibit wide variation, and their respective trackmakers may be ascribed to an accordingly wide range of different zoological taxa among non-therapsid Synapsida and not only to Sphenacodontidae as has been generally believed. At the same time, the process of attributing ichnotaxa, on the basis of well preserved tracks and by comparison with known skeletal remains, is validated.

NEW ABELISAURID MATERIAL FROM THE UPPER CRETACEOUS (CENOMANIAN) OF MOROCCO

Fragmentary cranial bones of dinosaur origin have been recently recovered from the Kem Kem beds (Upper Cretaceous, Cenomanian) of Morocco. They include two incompletely preserved maxillary bones evidencing diagnostic features of abelisaurid theropods. These new finds provide further evidence of Abelisauridae in the Late Cretaceous of Morocco.

Elongated theropod tracks from the Cretaceous Apenninic Carbonate Platform of southern Latium (central Italy)

New dinosaur footprints were recently discovered in southern Latium (Italy). The tracks all appear slightly differently preserved and are characterized by elongated metatarsal impressions, recording the complex locomotor behaviour of a medium-sized theropod. The spatial distribution and the features of the footprints indicate that the trackmaker adopted a “crouched” position as part of an activity as well as a resting phase suggested by sub-parallel, calcigrade tracks. These new data once again highlight the great potential of ichnological evidence in the study of the biology and behaviour of extinct tetrapods. Paolo Citton. Dipartimento di Scienze della Terra, “Sapienza” Università di Roma, Piazzale Aldo Moro 5, 00185, Rome, Italy. paolo.citton@uniroma1.it Umberto Nicosia. Dipartimento di Scienze della Terra, “Sapienza” Università di Roma, Piazzale Aldo Moro 5, 00185, Rome, Italy. umberto.nicosia@uniroma1.it Iacopo Nicolosi. Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143 Roma, Italy. iacopo.nicolosi@ingv.it Roberto Carluccio. Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143 Roma, Italy. roberto.carluccio@ingv.it Marco Romano. Dipartimento di Scienze della Terra, “Sapienza” Università di Roma, Piazzale Aldo Moro 5, 00185, Rome, Italy; Sam Noble Museum, 2401 Chautauqua Ave., Norman, Oklahoma 73072, USA. marco.romano@uniroma1.it (corresponding author)