Paleodays 2019 La Società Paleontologica Italiana a Benevento e Pietraroja Parte 2: Guida all’escursione XIX Riunione annuale SPI Ente GeoPaleontologico di Pietraroja (21)22-24(25) Maggio 2019 a cura di Rook L. & Pandolfi L. Paleodays 2019. La Società Paleontologica Italiana a Benevento e Pietraroja XIX Riunione annuale della Società Paleontologica Italiana Benevento/Pietraroja, (21)22-24(25) Maggio 2019 Comitato Organizzatore Ente GeoPaleontologico di Pietraroja: G. Santamaria, G. Festinese, P. Forte, G. Lioni, A.V. Maturo, R. Melillo, L. Prencipe, A. Torrillo, F.O. Amore, S. Foresta, C. Dal Sasso, V. Morra, L. Rook Comitato Scientifico F.O. Amore, L. Angiolini, A. Bartiromo, M. Bernardi, G. Carnevale, M. Cherin, M. Chiari, G. Crippa, C. Dal Sasso, A. Ferretti, E. Ghezzo, L. Jaselli, L. Pandolfi, P. Raia, L. Rook Con il supporto di Ente Geopaleontologico di Pietraroja Univeristà degli Studi del Sannio Dipartimento di Scienze e Tecnologie, Univeristà degli Studi del Sannio Dipartimento di Scienze della Terra, Università degli Studi di Firenze Confindustria, BN Provincia di Benevento Comune di Pietraroja, BN Con il patrocinio di Ministero dell’Ambiente e della Tutela del Territorio e del Mare MATTM Ministero per i Beni e le Attività Culturali MiBAC Istituto Superiore per la Protezione e la Ricerca Ambientale ISPRA Federculture Regione Campania Provincia di Benevento Comune di Pietraroja Parco regionale del Matese Museo Civico di Storia Naturale di Milano Società Geologica Italiana Università degli Studi di Firenze Università degli Studi del Sannio Università degli Studi di Napoli “Federico II” Università degli Studi di Napoli “Suor Orsola Benincasa” Università degli Studi di Napoli “L’Orientale” Università degli Studi della Campania Luigi Vanvittelli Progetto grafico logo di copertina M. Repola, R. D’Uva Rook L. & Pandolfi L. (a cura di) 2019. Paleodays 2019. La Società Paleontologica Italiana a Benevento e Pietraroja. Parte 2: Guida all’e- scursione della XIX Riunione annuale SPI (Società Paleontologica Italiana). 24 pp. Ente GeoPaleontologico di Pietraroja (Benevento). ISBN 979-12-200-4867-5 Paleodays 2019 - XIX Edizione delle Giornate di Paleontologia Benevento/Pietraroja (21)22-24(25) Maggio 2019 Scipionyx samniticus & Pietraroja Paleodays 2019 - XIX Edizione delle Giornate di Paleontologia Benevento/Pietraroja (21)22-24(25) Maggio 2019 Restoration of Scipionyx, according to the Milanese palaeoartist Davide Bonadonna. (© Davide Bonadonna) 4 Paleodays 2019 - XIX Edizione delle Giornate di Paleontologia Benevento/Pietraroja (21)22-24(25) Maggio 2019 Scipionyx samniticus Cristiano Dal Sasso & Simone Maganuco Scipionyx samniticus abruptly entered the limelight when, on the occasion of its formal naming, it made the cover of Nature (Dal Sasso & Signore, 1998), attracting not only the interest of palaeontologists but also popular imagination throughout the world. In fact, the Scipionyx fossil is a striking, articulated, juvenile coelurosaur with a unique combination of osteological characters and superbly fossilised soft tissues (Fig. 1). The latter render Scipionyx one of the best-preserved dinosaurs known, and a unique specimen within the fossil record of Mesozoic vertebrates. Scipionyx samniticus was the first dinosaur fossil body unearthed in Italy; thus, its discovery was a major event in the history of Italian palaeontology. The finding The story of the discovery of the Scipionyx fossil is original in itself (for a detailed account, see Dal Sasso, 2001, 2004). In the spring of 1981, Giovanni Todesco unearthed it at Le Cavere. The collector cleaned the fossil as well as he could and stored it in the basement of his house. It remained the- re until 1993, when Todesco showed it to professional pa- laeontologists, who identified the tiny reptile as a dinosaur. In accordance with Italian law, the specimen was handed over to the Superintendence of the site of provenance, and the popular magazine Oggi dubbed the dinosaur “Ciro” (a typical Neapolitan name). In 1994, the Museo di Storia Na- turale di Milano (MSNM) obtained permission to properly prepare and study the fossil. It was only during this prepa- ration work, that the extraordinary degree of preservation of the specimen’s soft tissue was fully realised. This later became the main focus of the paper published in Nature on its formal description (Dal Sasso & Signore, 1998), and, subsequently, of a detailed monograph (Dal Sasso & Maga- Fig. 1 - Overall view of the holotype (and only known specimen) of nuco, 2011), which is most complete publication existing Scipionyx samniticus. Most of the soft tissues are visible to the naked eye to date on Scipionyx samniticus. on account of their distinctive ochre colour. Other organic remains are preserved as thin films, that can be seen only under ultraviolet-induced Osteology, ontogenetic stage and phylogenetic rela- fluorescence. Scale bar = 2 cm. (After Dal Sasso & Maganuco, 2011. © tionships SABAP-CE-BN, centro operativo di Benevento, courtesy MIBAC. Photo The diagnosis of this taxon includes five premaxillary te- Roberto Appiani & Leonardo Vitola) eth, a sinusoidal ridge of the supratemporal fossa, a distally squared descending process of the squamosal, lower tooth row extending farther back than the upper row, and the absence of an external mandibular fenestra (Fig. 2). Among the relevant postcranial skeletal features are fan-shaped dorsal neural spines with beak-like ligament attachments, hair-like cervical ribs, dorsal ribs with cup-like sternal at- tachments, carpus composed of only two stacked, well-os- sified bones, manual digit III longer than digit I, a cranially notched iliac preacetabular blade and a distally squared ischial obturator process. The holotype (and only know specimen) of Scipionyx sam- niticus is clearly a very immature individual, probably less than three weeks old at the time of death. This is indicated by a long list of juvenile characters, such as the presen- ce of a frontoparietal fontanelle (Fig. 2), a short and deep antorbital region, tooth replacement not yet started, pe- culiar scarred bone surfaces, non-sutured girdle elements Fig. 2 - Skull and mandible of Scipionyx samniticus. The large circular and closure of the neurocentral sutures not yet started in orbits, the short snout, and the fronto-parietal fontanelle (i.e., the U-shaped gap on the cranial vault) point out to the very young age of any vertebra, and -last but not least- anterior abdominal the animal. (After Dal Sasso & Maganuco, 2011. © SABAP-CE-BN, centro displacement of the intestine, with an empty space in the operativo di Benevento, courtesy MIBAC. Photo Roberto Appiani) pelvic area suggesting the presence of a yolksac. 5 Paleodays 2019 - XIX Edizione delle Giornate di Paleontologia Benevento/Pietraroja (21)22-24(25) Maggio 2019 Fig. 3 - Map of the soft tissues preserved in the holotype of Scipionyx samniticus, obtained by combining observations under optical microscopy, ultraviolet light and scanning electron microscopy. (After Dal Sasso & Maganuco, 2011. © Museo di Storia Naturale di Milano. Drawing Marco Auditore) According to Dal Sasso & Maganuco (2011), the recon- structed total body length of the holotype of Scipionyx does not exceed 50 cm. After having re-articulated its elements and corrected for the deformation, the pel- vis of Scipionyx results comparatively slightly narrower mediolaterally than that of Mirischia, the three-dimen- sionally preserved pelvis of which has a width appro- ximately 30 mm wide across the sacrum (Martill et al., 2000). Comparison with usual body proportions of small extinct and extant coelurosaurs, including birds, permitted to tentatively estimate a weight in life of no more than 0.2 kg. Phylogenetic analysis of Coelurosauria (90 taxa, 360 characters), evaluating also the ontogeny-related cha- racters, identified Scipionyx as a basal member of a monophyletic Compsognathidae, which resulted to be more derived than Tyrannosauroidea (Dal Sasso & Ma- ganuco, 2011). Soft tissue anatomy and taphonomy Fig. 4 - The duodenal loop of the intestine of Scipionyx samniticus still pre- Scipionyx superbly preserves a unique variety of fossi- serves the circular folds of the mucosa (arrows). The iron-rich reddish halo to the right comes from the decay of the liver (After Dal Sasso & Maganuco, lised internal organs and soft tissues (Fig. 3), so that a 2011. © SABAP-CE-BN, centro operativo di Benevento, courtesy MIBAC. real paleo-autopsy has been possible (for a complete Photo Leonardo Vitola) account, see Dal Sasso & Maganuco, 2011). External 6 Paleodays 2019 - XIX Edizione delle Giornate di Paleontologia Benevento/Pietraroja (21)22-24(25) Maggio 2019 soft tissues are beautifully represented by the horny (keratinised) manual claws. The internal tissues in- clude axial ligaments, axial and appendicular arti- cular cartilage, neck muscles and connective tissue, part of the trachea, oesophageal remains, traces of the liver and other blood-rich organs, the entire intestine, mesenteric blood vessels, and pelvic and hind limb muscles. The intestine is the largest, most complete and most visible internal organ of Scipio- nyx (Fig. 4): its three-dimensional duodenal loops are lumpy and shiny, reminiscent of the aspect one would see after dissecting a modern animal; the jejunum shows a typical lower density of mucosal folds and garland-like coils in the dorsal portion of the abdomen; cranial to the pelvic girdle, a constric- tion possibly marks a ileorectal valve; the rectum makes the terminal enlarged tract of the