NEW REMAINS OF CASATIA THERMOPHILA (CETACEA, MONODONTIDAE) FROM THE LOWER PLIOCENE MARINE VERTEBRATE-BEARING LOCALITY OF ARCILLE (TUSCANY, ITALY)

An incomplete cranium, three cervicals (including the axis) and two likely lumbars of a monodontid cetacean are here described from lower Pliocene (ca. 5.1–4.5 Ma) marine sandstones cropping out at Arcille (Grosseto Province, Tuscany, Italy). This fossil find comes from the same locality as the holotype of Casatia thermophila, which it resembles in terms of overall size and cranial morphology, and especially, by displaying a similarly depressed portion of the dorsal surface of the premaxillae anterior to the premaxillary sac fossae and medial to the anteromedial sulci. Our new find is thus assigned to C. thermophila, and significant anatomical parts that are missing in the holotype are described in order to improve the diagnosis of this monodontid species. Some dentigerous fragments of the maxillae hint at a homodont and polydont dentition, which in turn suggests a ram prey capture method that differs from the highly derived suction method that is proper of extant monodontids. This second find of C. thermophila from the warm-water Arcille palaeoenvironment lends further support to the hypothesis that monodontids once thrived in tropical and subtropical habitats

A revision of Stenopterygius (Ichthyosauria: Thunnosauria) in Italian museum collections

Natural history museum collections are invaluable resources for scientific research, providing material for many fields, and notably for palaeontology. Over the last two centuries, many relevant vertebrate fossils have been discovered, gathered, and traded all over Europe, sometimes without being subsequently published or described. This is also the case for ichthyosaur fossils of the genus Stenopterygius, a high number of which were found in near Holzmaden (SW Germany), in lower Toarcian rocks of the Posidonia Shale Formation. From the mid-19th century onwards, these fossils made their way into palaeontological collections all over the world, including Italian museums. Stenopterygius is one of the most studied ichthyosaur taxa in literature. Research on Stenopterygius ranges from its trophic niche to ontogenesis, biological responses to environmental stress and soft tissue histology (from cells structures to skin pigmentation). Even though the role of Stenopterygius as a model organism for marine vertebrate palaeontology is well established, difficulties nonetheless exist regarding the taxonomy and systematics of this genus, with four valid species being currently differentiated using a linear morphometric approach. Here, we provide new data on 19 Stenopterygius specimens from five Italian museum collections: Pisa, Milano, Napoli, Padova and Bologna. Out of these specimens, four belong to S. triscissus (a relatively rare species), and ten are juveniles (an underrepresented ontogenetic group). Additionally, CT scans were performed on two historical Stenopterygius specimens stored at the Museo di Storia Naturale dell’Università di Pisa, providing images of skeletal parts that are still embedded in rock, which may prove crucial for the species-level identification, as well as for detecting the presence of associated macrofaun

Comparative analysis of digital models from 3D photogrammetry and structured light scanning for the study of tetrapod tracks

The present work aims at analyzing the acquisition capacity of different digital reconstruction techniques for three-dimensional models, in the frame of the study of the remarkable Middle Triassic (Ladinic) tetrapod ichnoassemblage from the Quarziti del Monte Serra Formation (Monti Pisani, Tuscany, central Italy). Tracks stored in different Italian museum collections were processed and analyzed through two different digital acquisition methodologies, namely, digital photogrammetry and structured light scanning (with the EinScan Pro HD scanner model, capable of a maximum resolution of 0.2 mm) to evaluate which of these techniques is most suitable for the study of small- to medium-sized tetrapod tracks. Two models were created for each sample, one for each acquisition methodology. These models were processed using the software Meshmixer, Meshlab and CloudCompare, to locate any possible error in the mesh, correct them and compare the models with each other in terms of quality and graphical rendering, respectively. The RStudio software was also used to verify and control, by using statistical tests, the normal distribution of the data, as well as to further process them. We noticed that the average number of triangles is higher for the meshes obtained via photogrammetry; likewise, the values of the metric “Per Face Quality according to triangle shape and aspect ratio – Mean ratio of triangle”, available on Meshlab and used here to evaluate the quality of a mesh, is higher. Photogrammetry is thus preferable in the study of centimetric tracks as it allows for very high levels of mesh detail. That said, more experience and a deeper understanding of the acquisition process by the operator are needed for fruitfully exploiting the full potentialities of photogrammetr

Remarkable multicuspid teeth in a new elusive skate (Chondrichthyes, Rajiformes) from the Mediterranean Pliocene

AbstractHere we report on four highly peculiar skate teeth from Arcille and Certaldo, two Pliocene localities of Tuscany (central Italy). While being attributable to Rajiformes and somewhat reminiscent ofDipturusandRostroraja, these specimens display an unusual multicuspid tooth design that does not match any extinct or extant skate taxon known to date. The studied teeth are thus referred to a new genus and species of Rajiformes,Nebriimimus wardigen. et sp. nov., which is here tentatively assigned to the family Rajidae. Based on pronounced morphological similarities between the rather large-sized teeth of the latter and those of extant nurse sharks, we hypothesise thatN. wardimight have been capable of actively foraging upon relatively large food items compared to other rays. This extinct skate species was likely not a common component of the Pliocene Tuscan marine vertebrate assemblages. The palaeoenvironmental scenarios thatN. wardiinhabited were marginal-marine and open shelf settings characterised by tropical climate conditions. AsN. wardiis currently known only from lower to mid-Pliocene deposits of the Mediterranean Basin, it is tempting to speculate that its speciation dates back to an earliest Pliocene phase of diversification that also contributed to the emergence of the Mediterranean endemic stock of extant skate species

A new platyrostrine sperm whale from the Early Miocene of the southeastern Pacific (East Pisco Basin, Peru) supports affinities with the southwestern Atlantic cetacean fauna

Contrasting with their suction feeding modern relatives in the families Kogiidae and Physeteridae, Miocene physeteroids display a broad range of feeding strategies. Despite the continuous improvements of the fossil record, the transition from the earliest sperm whales to suction feeding forms as well as the once prominent macroraptorial forms remains poorly understood. In the present work, we investigate a partial sperm whale skull from Lower Miocene (Burdigalian) strata of the Chilcatay Formation of the East Pisco Basin, along the southern coast of Peru. Based on this specimen, we describe a new species in the genus Diaphorocetus Ameghino, 1894, which was previously known only by the holotype of Diaphorocetus poucheti (Moreno, 1892) from a roughly synchronous unit in Patagonia (Argentina). Differing from the latter in its smaller cranial dimensions, higher tooth count, and minor differences in the position of facial foramina, the new species Diaphorocetus ortegai n. sp. confirms a key character of D. poucheti, the marked dorsoventral flattening of the maxillary portion of the rostrum. Such cranial proportions suggest that, compared to other physeteroids, D. poucheti and D. ortegai n. sp. were more efficient at performing fast lateral sweeps of their rostra to capture small- to medium-sized prey items with their proportionally small teeth. Recovered as stem physeteroids in our phylogenetic analysis, these sister species contribute to the ecomorphological disparity of sperm whales during the Early Miocene, but without displaying any of the cranial and dental changes occurring in later, macroraptorial and suction feeding sperm whales. The description of a new species of Diaphorocetus from southern Peru increases the similarities between the toothed whale faunas from the local Chilcatay Formation and the Gaiman and Monte Leon formations of Argentinian Patagonia, pointing not only to dispersal routes between the southeastern Pacific and southwestern Atlantic during the Burdigalian, but also to relatively similar ecological settings along the coasts of Peru and Patagonia at that time

The combination of transcriptomics and informatics identifies pathways targeted by miR-204 during neurogenesis and axon guidance

Vertebrate organogenesis is critically sensitive to gene dosage and even subtle variations in the expression levels of key genes may result in a variety of tissue anomalies. MicroRNAs (miRNAs) are fundamental regulators of gene expression and their role in vertebrate tissue patterning is just beginning to be elucidated. To gain further insight into this issue, we analysed the transcriptomic consequences of manipulating the expression of miR-204 in the Medaka fish model system. We used RNA-Seq and an innovative bioinformatics approach, which combines conventional differential expression analysis with the behavior expected by miR-204 targets after its overexpression and knockdown. With this approach combined with a correlative analysis of the putative targets, we identified a wider set of miR-204 target genes belonging to different pathways. Together, these approaches confirmed that miR-204 has a key role in eye development and further highlighted its putative function in neural differentiation processes, including axon guidance as supported by in vivo functional studies. Together, our results demonstrate the advantage of integrating next-generation sequencing and bioinformatics approaches to investigate miRNA biology and provide new important information on the role of miRNAs in the control of axon guidance and more broadly in nervous system development. \uc2\ua9 The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research

Gli elasmobranchi del Pliocene inferiore di Arcille (Campagnatico, Grosseto): significato paleoecologico e paleoambientale.

Da quasi due secoli, le successioni marine plioceniche della Toscana sono luogo di importanti ritrovamenti di resti fossili di elasmobranchi. Nel passato, tali fossili sono stati raccolti per formare importanti collezioni, spesso oggetto di studio da parte di illustri paleontologi. A seguito dell'affermarsi dei moderni standard di ricerca paleontologica, tuttavia, queste collezioni storiche hanno perso parte della loro rilevanza scientifica a causa delle molte incertezze riguardanti la contestualizzazione geografica e stratigrafica del materiale di cui esse si compongono. Si è resa pertanto necessaria la raccolta di nuovo materiale con un approccio metodologico più rigoroso che permetta di valorizzare meglio, dal punto di vista scientifico, questo importante patrimonio paleontologico del territorio toscano. La presente tesi consiste nello studio stratigraficamente informato della fauna ad elasmobranchi rinvenuta nelle sabbie zancleane esposte presso Arcille (Campagnatico, GR) al fine di ricostruire il contesto paleobiologico e paleoambientale che caratterizzava le coste toscane durante il Pliocene inferiore. I sedimenti esposti ad Arcille si depositarono intorno a 5,1–4,5 Ma all'interno del bacino di Baccinello-Cinigiano e testimoniano contesti deposizionali di delta sommerso e di piattaforma. Tra i siti a vertebrati del Pliocene toscano, Arcille riveste una particolare importanza, in quanto sede del rinvenimento di numerosi scheletri del sirenio dugongide †Metaxytherium subapenninum e dell'olotipo del monodontide arcaico †Casatia thermophila e di due scheletri di marlin (Makaira sp.). L’associazione ad elasmobranchi di Arcille, ricostruita sulla base di oltre 300 denti e spine dermiche, comprende 24 specie distribuite in 13 famiglie (Hexanchidae, Squatinidae, Carcharhinidae, Scyliorhinidae, Triakidae, Cetorhinidae, Alopiidae, Lamnidae, Odontaspididae, Dasyatidae, Myliobatidae, Rajidae e Rhinobatidae) in 7 ordini e 3 superordini. Di particolare interesse risulta l'identificazione di taxa quali Negaprion brevirostris, †Pachyscyllium dachiardii e †Megascyliorhinus miocaenicus, il cui record fossile nel Mediterraneo post-miocenico è estremamente frammentario, e il cui rinvenimento ad Arcille rappresenta un importate dato a sostegno della permanenza di elementi di derivazione miocenica e tetidea a seguito della Crisi di Salinità del Messiniano. Accanto a tale associazione ad elasmobranchi, l'attività di tesi ha portato al rinvenimento di un elevato numero di denti di pesci ossei (labridi, sparidi e sfirenidi) e di una nutrita malacofauna che comprende †Callista italica e †Pelecyora gigas, due veneridi estinti tipici delle associazioni di piattaforma del Pliocene inferiore del Mediterraneo. Sulla base dell'associazione studiata è possibile delineare un quadro paleoecologico dell'area di Arcille durante lo Zancleano. La presenza dello squalo leuca (Carcharhinus leucas) e del pesce vescovo (Aetomylaeus bovinus) suggerisce un paleoambiente marino di acque poco profonde, prossimo alla foce di un fiume, mentre lo squalo capopiatto (Hexanchus griseus), lo squalo volpe (Alopias superciliosus) e marlin indicano forti connessioni con ambienti di mare aperto ed acque profonde. Inoltre, la presenza dello squalo leuca e dello squalo limone (Negaprion brevirostris) – specie che oggi abitano le coste dell'Africa occidentale – indica condizioni paleoclimatiche francamente tropicali. A sostegno di questa interpretazione, la condrofauna ivi descritta prende posto accanto a resti di invertebrati e vertebrati marini di acque basse e calde, quali ad esempio †Metaxytherium subapenninum, forma tropicale e costiero-estuarina che condivideva le preferenze ambientali dei sireni attuali

3D technologies and virtual reality for the study and museum valorisation of marine vertebrate fossils from the Pliocene of Tuscany

Riassunto: L'avvento delle tecnologie tridimensionali (3D) ha rivoluzionato le scienze naturali e gli studi sul patrimonio culturale, offrendo metodologie come la scansione superficiale, l'acquisizione fotogrammetrica, la modellazione e la scultura 3D. Queste tecnologie consentono di generare modelli digitali 3D di oggetti con precisione straordinaria, fornendo dati utili a molteplici scopi, dalla ricerca scientifica alla valorizzazione del patrimonio culturale. La paleontologia è stata una delle prime discipline a sfruttare le potenzialità delle tecnologie 3D, dando vita alla "Paleontologia Virtuale", che consente lo studio dei fossili attraverso tecniche digitali interattive senza danneggiare i reperti. Questo approccio permette di visualizzare parti difficilmente documentabili, come endocrani di vertebrati o porzioni interne dei gusci degli invertebrati. Oltre alla paleontologia, anche altre discipline come zoologia, botanica, archeologia e geologia hanno adottato queste tecnologie. Il presente lavoro di tesi si concentra sull'integrazione delle moderne tecniche di digitalizzazione 3D nella ricerca e nella valorizzazione della ricca associazione fossile a vertebrati marini del Pliocene della Toscana. Le principali tecnologie impiegate includono la scansione a luce strutturata e la fotogrammetria digitale, che consentono di generare modelli tridimensionali fedeli agli originali. Questi modelli possono essere elaborati con software di grafica 3D per condurre analisi dettagliate, apportare modifiche e generare simulazioni virtuali e rendering. L'analisi è stata condotta su tre cave della Toscana, rappresentative dei numerosi siti paleontologici pliocenici della regione. I reperti fossili recuperati hanno incluso fossili di elasmobranchi, cetacei e altri vertebrati marini, fornendo importanti informazioni sulla biodiversità e l'ecologia del Mar Mediterraneo durante il Pliocene. Inoltre, sono stati condotti studi tafonomici e paleoecologici, che hanno rivelato tracce di interazioni trofiche tra predatori e prede nel record fossile. Sono state proposte iniziative di valorizzazione e conservazione dei siti fossiliferi, con l'obiettivo di promuovere la sensibilizzazione ambientale e il turismo scientifico-naturalistico. Le tecnologie 3D sono state applicate anche nel campo della museologia, con progetti di musealizzazione digitale che consentono la visualizzazione e la diffusione online di modelli 3D di reperti fossili. In conclusione, l'applicazione delle tecniche 3D alla paleontologia mira a valorizzare, conservare e condividere il materiale fossile, contribuendo alla comprensione del passato e al progresso scientifico verso il futuro. Abstract: Three-dimensional (3D) technologies have revolutionized natural sciences and cultural heritage studies, offering methodologies such as surface scanning, digital photogrammetry, 3D modeling, and sculpting. These techniques facilitate the creation of highly accurate 3D digital models useful for scientific research, knowledge dissemination, and cultural heritage preservation. Paleontology was among the first disciplines to embrace these technologies, giving rise to Virtual Paleontology, which enables the study of fossils through interactive digital techniques, avoiding damage to delicate specimens. Beyond paleontology, 3D technologies have been widely adopted across various fields including zoology, botany, archaeology, and geology. This thesis focuses on integrating modern 3D digitization techniques into scientific research, particularly in the valorization of marine vertebrate fossils from Pliocene paleontological sites in Tuscany. Utilizing structured light scanning and digital photogrammetry, the study proposes valorization programs for quarry environments, recognizing their significance in scientific research and education. The structured light scanning method involves projecting light patterns onto objects to capture their detailed shapes, while digital photogrammetry combines 2D images to create 3D models. These technologies enable detailed analysis and virtual simulations, enhancing geosites and promoting geotourism. Excavation campaigns have yielded numerous fossils from analyzed quarries, with detailed systematic, paleoecological, and taphonomic studies conducted on many specimens. Studies from La Serra quarry revealed a diverse elasmobranch assemblage, including significant finds like a stingray caudal spine, providing insights into Mediterranean biodiversity during the Pliocene. The Arcille quarry yielded the discovery of Casatia thermophila, an ancient cetacean species, along with other unique finds like multicuspid teeth and the presence of the black-tip shark, Carcharhinus limbatus. Additional fossiliferous sites near Certaldo village and Monterotondo Marittimo provided further evidence of trophic interactions and significant paleontological material. A valorization project aimed at protecting and promoting these sites through geoconservation and geotourism initiatives was outlined, highlighting the importance of utilizing innovative dissemination tools like 3D technologies. The application of 3D technologies extends to museology, with a digital musealization project undertaken at the Natural History Museum of the University of Pisa. This project involved creating 3D models of cetacean specimens, facilitating their visualization and dissemination online. In conclusion, the application of 3D techniques to paleontology and related fields aims to enhance the valorization, preservation, and sharing of fossil material. By embracing these technologies, the scientific community continues to evolve, bridging the past with the future

A SECOND SPECIMEN OF THE ARCHAIC MEDITERRANEAN MONODONTID CETACEAN CASATIA THERMOPHILA FROM THE ZANCLEAN DEPOSITS OF ARCILLE (TUSCANY, ITALY)

The white whale Delphinapterus leucas (also known as the beluga) and the narwhal Monodon monoceros are the only extant members of the family Monodontidae (Cetacea, Odontoceti, Delphinoidea). These two species are exclusive of Arctic and subarctic cold waters. They are well known as iconic cetaceans by virtue of a white skin color (in case of D. leucas) and a spiraled tusk (in case of M. monoceros). Differing from other groups of odontocetes cetaceans, the monodontids are known as fossils from just a handful of specimens. Only four species have been described in literature, all being known by the sole holotype, namely: Bohaskaia monodontoides, Denebola brachycephala, Haborodelphis japonicus and Casatia thermophila. In particular, C. thermophila is the only fossil monodontid to have ever been found in the whole Mediterranean basin. Here we describe a second specimen of C. thermophila, from its lower Pliocene type locality of Arcille (Grosseto Province, Tuscany, central Italy). The new find consists of three cervicals (including the axis) and two lumbars. This fossil resembles the holotype in terms of overall size and cranial morphology, and especially, by displaying a similarly depressed portion of the dorsal surface of the premaxillae anterior to the premaxillary sac fossae and medial to the anteromedial sulci. Our new find is thus assigned to C. thermophila, and significant anatomical parts that are missing in the holotype are described in order to improve the diagnosis of this monodontid species. Several dentigerous fragments of the maxillae hint at a homodont and polydont dentition, which in turn suggests a ram prey capture method that differs from the highly derived suction method that is proper of extant monodontids. This second specimen of C. thermophila from the warm-water Arcille palaeoenvironment lends further support to the hypothesis that monodontids once thrived in tropical and subtropical habitats