Relazione fra impronte e trackmaker: validazione del potere di discriminazione di una sequenza di impronte

In questo lavoro si è cercato di massimizzare le potenzialità dell'Icnologia cercando di risolvere alcune problematiche esistenti. La prima problematica affrontata era legata all’inesistenza di una metodologia standardizzata per la misurazione dei parametri relativi a un’impronta di dinosauro. È stato definito un insieme di parametri codificato in forma geometrica, tramite il quale è stato redatto e proposto un manuale in cui è stata illustrata la metodologia di misurazione, sia in forma letterale sia grafica. Il potere descrittivo dell’insieme di parametri è stato verificato e validato con un’analisi dei gruppi, nonostante il processo di “geometrizzazione” faccia pensare a un’eccessiva semplificazione della morfologia delle orme. Successivamente si è cercato di comprendere in che misura le impronte di dinosauro siano legate all’organismo che le ha impresse. Lo strumento di indagine utilizzato è l’analisi filogenetica che ha permesso di mettere in parallelo e confrontare i risultati ottenuti con un albero filogenetico basato sui body fossils. Nonostante le orme fossili in esame siano diverse dai resti scheletrici, è stata seguita la prassi delle più comuni analisi filogenetiche. È stato, quindi, individuato un ingroup, definito un set di caratteri (suddiviso in stati evolutivi) e scelto un outgroup. Inoltre, per analizzare in maniera approfondita questa tematica, è stato necessario considerare anche le sequenze di impronte (piste o trackways), le quali rappresentano il movimento del trackmaker nel tempo e nello spazio. Ritenendo il presente la chiave per comprendere il passato, per valutare il grado di relazione che c’è fra una sequenza di impronte e le diverse modalità di deambulazione è stato condotto un esperimento, in cui è stato scelto come trackmaker l’uomo. La sperimentazione, oltre ad aver risolto il problema “paleoicnologico”, dati i materiali e i metodi utilizzati ha fornito lo spunto per intraprendere lo sviluppo di una nuova metodologia dell’Icnologia in un contesto diverso da quello paleontologico ovvero l’ambito forense. È stata quindi esaminata l’applicazione della nuova metodologia nell’ambito delle Geoscienze Forensi. L’applicazione di un approccio di tipo icnologico per lo studio di una sequenza di impronte rinvenute su una potenziale scena del crimine è stata vagliata in diverse situazioni operative, definendone, come per le impronte fossili, la procedura di caratterizzazione basata su un insieme di parametri definiti. L’analisi di una sequenza di impronte di calzature può essere di fatto considerato come un secondo caso studio. Questo ha ulteriormente messo in evidenza il “potere descrittivo” di un insieme di parametri e ha suggerito la possibilità di proporre un approccio di tipo icnologico per lo studio di piste trovate su una scena del crimine. Questa metodologia può rappresentare un nuovo orizzonte per l’Icnologia dei vertebrati permettendogli di avere un’identità propria all’interno delle Geoscienze Forensi

“…Every contact leaves a trace…”, Locard 1920

The adjective “forensic” placed next to a word indicating any branch of Science means apply scientific methods and techniques to the investigation of crime. Therefore, a variety of forensic specialists exist: anthropologists, biologists, entomologists, geologists and many others. In particular geologists are involved in investigations for everything related to Geosciences. Geosciences in Forensics have a relatively long but not well known history especially if we think to newborn areas of research such as Forensic Paleontology (sensu Sacchi & Nicosia, 2013). The interest is focused on Paleoichnology (branch of Paleontology developed essentially to study fossil footprints) in Forensics because gives well consolidated techniques to detect, recovery and analyze footwear impressions trackways (at least a sequence of three consecutive footprints). According to Locard’s Exchange Principle people involved in a crime could leave footwear impressions en route to, at, and exiting from the crime scene (Bodziak, 2000). The Principle, summarized in “every contact leaves a trace” and inferred from Edmond Locard’s perception that it is impossible for a criminal to act, especially considering the intensity of a crime, without leaving traces of his presence. This concept has to be kept in mind during every crime scene investigation; even more from an ichnological point of view because of footwear impressions evanescence. The right approach to inspect the place where the crime occurred should be with the expectation and awareness that it always could contain traces. All the previous researches were focused on the analysis of a single footprint (Forensic Podology) and most striking, without a real ichnological approach. The detection of a trackway on a crime scene expects the use of the same tools and analysis methods to those used for fossil trackways. Precisely for this, I want to prove that footwear impressions and trackways, analyzed with paleoichnological methodologies, can give distinctive information such as the locomotion type that is necessarily related to the trackmaker’s deambulation. Indeed, the attempt to extrapolate characters from trackways has been done based on the rationale that many characters of human locomotion derive from biomechanical constraints which are strongly related to the physical structure. The results suggest a very high possibility to discriminate the males from the females by their trackways as well a high possibility to recognize the trackways imprinted by the same individual

ICHNOLOGY ON THE CRIME SCENE

Among the Forensic Geosciences, Forensic Paleontology (sensu Sacchi & Nicosia 2013) could play an important role. It proved to be a very powerful tool in law enforcement activities and it’s frequently applied in criminology and criminalistics in leading countries such as United States, Canada, United Kingdom, and many others; unfortunately, in Italy, this is a newborn area of study and is still practically unknown. Among the branches of Forensic Paleontology, Ichnology, developed essentially to study fossil footprints (Paleoichnology), is to date the discipline that best suits the study of footwear impressions and trackways on a crime scene. It provides useful tools and techniques to detect, recover and examine this type of evidences. To maximize the power of Ichnology in law enforcement activities it will be necessary, in a short time, to perform a well settled procedure, in order to see its results accepted by the scientific-forensic community and thus formally admissible in Court

How phylogeny can be a tool for ichnosystematics?

The need to improve dinosaur tracks zoological attribution has led to experiment phylogenetic analysis as a tool in order to more closely parallelize ichnosystematics and bone based systematics. According to Carrano & Wilson (2001) a ...“trackmakers should be identified primarily by skeletal structures that are both preserved in the ichnofossils and synapomorphies of some body-fossil clade.”. Indeed this attempt to parallelize the ichnosystematics with the phylogeny of dinosauromorphs has been done based on the rationale that many characters of dinosaur locomotion derive from biomechanical constraints. The latter depend on osteological features related among them by ancestor/descendant relationships. These characters could, at least partially, have been recorded in well preserved footprints and trackways, allowing to attribute the ichnofossils to bone based groups on the basis of the analysis of phylogenetic characters. In this paper we support the proposal that well preserved and correctly described ichnotaxa might have a real phylogenetic value. Investigate to what extent a footprint can be considered as a delegated of an organism, is a key step to demonstrate the potential of dinosauromorphs Ichnology. The current and the future results open new perspectives to the Ichnology and could be very important in paleogeography studies. Reference Carrano M.T. & Wilson J.A. (2001). Taxon distributions and the tetrapod track record. Paleobiology, 27 (3): 564-582

THE FORGOTTEN ICHTHYOSAUR: REVALUATION OF THE FIRST OPHTHALMOSAURID SPECIMEN FROM THE UPPER JURASSIC OF THE MARCHE APENNINES (CENTRAL ITALY)

With the exception of the Triassic material of Monte San Giorgio, which is quite abundant and well-preserved, the Italian fossil record about ichthyosaurs for the remainder of the Mesozoic is very poor, and usually consists of few disarticulated elements. Lower Cretaceous remains have been described from the Northern Apennines, south of Modena and Bologna; another rostrum belonging to Platypterygius sp. has been recently reported from the Lessini Mts., near Verona; and a few vertebrae are reported from the Triassic of Sicily. In the summer of 1976, an ichthyosaur specimen was discovered in the locality of Camponocecchio, near Genga (Ancona, Marche, Italy) in an Upper Jurassic outcrop of the Marche Apennines. The specimen consists of a reasonably complete skeleton crushed on a slab, with a disarticulated skull, partially articulated vertebral column (from the atlas-axis to the tail bend, with few missing vertebrae), part of the pectoral girdles and some elements of the forelimbs. During the Late Jurassic, the Umbria-Marche area was occupied by a pelagic domain consisting of numerous structural highs and lows, as a result of the fragmentation and drowning of the pre-rifting Early Jurassic carbonate platform. The Genga ichthyosaur comes from the Calcari ad aptici e Saccocoma Formation (sensu Galluzzo & Santantonio, 2002), and thanks to the combination of the occurrence/lack of some micro- and macrofossils with biostratigraphic meaning, it has been possible to date the ichthyosaur-bearing level to the late Kimmeridgian – earliest Tithonian. The history of the Genga ichthyosaur has always been problematic, mainly because of the lack of attention that the authorities turn to paleontological findings: it took more than 20 years before the specimen could find a proper location, where it was finally prepared and where it is still exposed, in the Abbey of San Vittore di Genga. Since its discovery, few studies have focused on the Genga ichthyosaur (e. g. Fastelli & Nicosia, 1980; De Marinis & Nicosia, 2000), but never addressing its taxonomy and paleogeographical importance. This is the first time that this Mesozoic marine reptile is described and compared with other Late Jurassic and Early Cretaceous ichthyosaurs by including it in the most recent phylogenetic analysis of ophthalmosaurids

First occurrence of an ophthalmosaurid ichthyosaur in the Upper Jurassic of the Northern Apennines (Marche, Central Italy): stratigraphic setting

An ophthalmosaurid ichthyosaur was discovered in Upper Jurassic deposits of the Umbria-Marche sedimentary succession near Genga (Ancona, Marche, Italy). While other Mesozoic marine reptiles have been found at different stratigraphic intervals in Italy, this specimen represents the first ichthyosaur ever recorded from the Upper Jurassic of the Apennines. It consists of an almost complete skeleton preserved on a slab, with an articulated vertebral column, and disarticulated skull and pectoral girdle. This paper describes the stratigraphy of the ichthyosaur-bearing deposits. The Umbria-Marche sedimentary succession is characterized by Meso-Cenozoic pelagites and hemipelagites overlying Lower Jurassic shallow-water carbonates (Calcare Massiccio Fm.). The rifting stage, which affected the Western Tethys in the Early Jurassic, produced a complex submarine architecture, resulting in a mosaic of variable facies and thickness differences in the syn- and post-rift succession. Extension linked with opening of the Liguria - Piedmont Ocean dismembered and drowned a huge carbonate platform (Calcare Massiccio paleoplatform), and converted it into a system with small horsts-and-grabens/semigrabens, where pelagic deposits capped the shallow-water carbonates. The original Early Jurassic paleobathymetric differences were levelled by Early Cretaceous times. The basin-fill deposits onlapped the (mostly pre-rift) Calcare Massiccio facies, exposed at the footwall of Jurassic faults in the form of paleoescarpments, and buried the structural highs while their margins were largely inactive. The area in which the ichthyosaur was found was characterized by numerous structural highs (Mt. Murano, Mt. Revellone, Mt. Scoccioni and Mt. Valmontagnola), onlapped by the Jurassic - Early Cretaceous basin-fill units. In the Middle Jurassic, a huge block (about 0,7 km longer axis) of Calcare Massiccio - characterizing the Il Sassone sector - collapsed from the western escarpment of the Mt. Scoccioni or from the Mt. Revellone high, due to tectonic/gravitative instability. The olistolith was embedded in the “Calcari e marne a Posidonia” Fm. (late Toarcian-?late Bajocian), and subsequently was onlapped by the “Calcari Diasprigni” (?late Bajocian-early Kimmeridgian) and “Calcari ad aptici e Saccocoma” (Kimmeridgian p.p.-early Tithonian) Fms. Additional stratigraphic evidence for tectonic instability across the study area is found in the Middle Jurassic with gravity flow deposits, slumps and breccias bearing Calcare Massiccio clasts. The specimen was discovered in the Upper Jurassic deposits onlapping the Il Sassone mega-olistolith. It was embedded in green and reddish limestones and cherty-limestones referable to the “Calcari ad aptici e Saccocoma” Fm. The faunal assemblage includes belemnites (Duvalia spp.), aptychi (Laevaptychus sp., ?Laevilamellaptychus sp.), rhyncholites (Leptocheilus sp.), shark teeth (hexanchiforms), trace fossils (Thalassinoides sp., Chondrites sp.), radiolarians, calcisphaerulids and abundant Saccocoma tenella. These elements, coupled with the absence of S. vernioryi, Chitinoidella spp. and calpionellids, constrain the age of the ichthyosaur to the late Kimmeridgian - earliest Tithonian

The first ophthalmosaurid ichthyosaur from the Upper Jurassic of the Umbrian–Marchean Apennines (Marche, Central Italy)

The first ophthalmosaurid ichthyosaur from the Upper Jurassic deposits of the Central– Northern Apennines (Marche, Italy) is here described for the first time. The specimen is relatively complete and is referred to Gengasaurus nicosiai gen. et sp. nov. based on a unique combination of characters, including a peculiar condition of the preaxial accessory facet on the humerus. The faunal association of the ichthyosaur-bearing level indicates a late Kimmeridgian – earliest Tithonian age, and its finding contributes significantly to our knowledge of the diversity of Late Jurassic ichthyosaurs from the Western Tethys. Two shark teeth assigned to the order Hexanchiformes were also recovered in association with the ichthyosaur specimen, suggesting that scavenging of the carcass might have occurred. Gengasaurus can be referred to Ophthalmosauridae based on the reduced extracondylar area of the basioccipital, and the presence of a preaxial digit. It differs from Ophthalmosaurus spp. in several respects, including the shape of the posterior basisphenoid, the shape of the supraoccipital, the anteriorly deflected preaxial facet of the humerus, and a proximodistally shortened ulna. The new taxon actually shares diagnostic characters with both members of the two main lineages recovered in previous phylogenetic analyses,more nested within Ophthalmosauridae. The affinities of Gengasaurus to genera from both the northern and southern hemispheres also suggest that connectivity between pelagic habitats was high during the early Late Jurassic, allowing dispersal of some forms, followed by local, endemic divergence

Konservat-­‐Lagerstätten in the Upper Cretaceous of the Apulian Platform: preliminary report

An  extraordinarily  preserved  and  almost  complete  specimen  of  an  aquatic  lizard  (Squamata,  Pythonomorpha), showing preservation of soft tissues (mineralized scales and muscles), was recently  donated  to  the  Museum  of  Paleontology  of  the  “Sapienza”  University  of  Rome.  Unfortunately, the only information about the locality of provenance is based on an oral statement,  and  addresses  a  small  outcrop  of  limestone  close  to  the  town  of  Nardò  (Lecce,  Southern Italy). Considering the importance of the discovery, a preliminary study focused on the analysis of the embedding sediments was carried out to identify the lithostratigraphic unit of provenance and the age of the specimen. The  investigation  led  to  the  examination  of  a  well-­‐known  collection  of  vertebrate  fossils  housed at the Natural History Museum of Verona, excavated a few decades ago from some localities  in  the  Salento  Peninsula  (Apulian  Platform  Domain),  and  dating  back  to  the  Upper  Cretaceous. The exceptional conditions of preservation of this material and of the new specimen at  the  University  of  Rome,  suggests  that  a  new  study  of  the  Upper  Cretaceous  deposits  of  the  Apulian Platform cropping out in the Salento peninsula is needed. It would be particularly important  to  improve  the  stratigraphic  resolution  and  refine  the  palaeobiogeographical  reconstructions proposed to date. Material  referable  to  crinoids  and  other  echinoderms  is  also  well  known  from  the  same  deposits, but the material is poorly studied. The high concentration of very well preserved fossils (primarily fishes and echinoderms) in densely laminated mudstones was detected during a  preliminary  field  survey,  with  the  recognition  of  at  least  two  Upper  Cretaceous  fossiliferous  horizons, very rich both in terms of vertebrate and invertebrate remains. With  regard  to  the  Palaeomediterranean  domain,  a  palaeogeographical  gap  in  the  fossil  record is evident for the group of lizards to which the new specimen in Rome belongs: the Pythonomorpha.  Several  Late  Cretaceous  basal  pythonomorphs  from  both  the  Dalmatian  and  North African realms are abundantly described in the literature, and the presumed gap in the central area of the Palaeomediterraneum – occupied by the Apulian Platform – is most likely due to the lack of studies rather than the true lack of data. The  new  multidisciplinary  research  project  aims  to  understand  the  dispersal  routes  for  basal pythonomorph lizards and associated fossil remains in the Mediterranean area, with possible major implications in both stratigraphic, palaeobiogeographical and geodynamic fields

PRELIMINARY PALEONTOLOGICAL AND GEOLOGICAL NOTES ABOUT AN ABANDONED QUARRY NEAR MANDURIA (SALENTO PENINSULA, SOUTHERN ITALY)

A collection of fossil vertebrates from the Salento Peninsula (Italy), and housed at the Natural History Museum of Verona, prompted new fieldwork in the area. The attention was focused on the northern sector of the Salento Peninsula, and led to the study of an abandoned quarry near Manduria (Taranto, Italy). The preliminary results of this investigation are reported here. The original quarry operations had exposed about 8 meters of Upper Cretaceous “platten-kalke”-type deposits, containing interesting and quite peculiar palaeontological and geological features. A high-resolution litho-biostratigraphic analysis was performed. The lithotypes outcropping in the quarry are dominated by the cyclic alternation of: i) mm- to cm-thick, dome-shaped, cyanoalgal laminites, sometimes presenting mud-cracks; ii) “vuggy” layers made of prismatic-to-discoidal voids, related to evaporitic salts dissolution; and iii) pedogenetic horizons (terre rosse). The facies analysis suggests a supratidal depositional setting for these “fenestral” and laminated mudstones, under hypersaline evaporitic conditions. A unique, oligotypic, and mostly well-preserved thanatocoenosis characterizes the stratigraphic framework, adding further constraining information about the depositional environment. The macrofauna is strictly oligotypic, and is represented by articulated fish remains, coprolites, regular sea urchins and few specimens of Chondrodonta sp.; the echinoids and their spines are preserved as “phantoms”, since the original high-Mg calcite of the tests is not preserved, and the spines are always found disarticulated. The preferential orientation of the echinoid spines provides some evidence about the paleocurrents that affected the area. The microfauna is missing, possibly as a result of the extreme conditions of the depositional environment and/or because of postmortem dissolution. The colonization of supratidal environments by benthic organisms and fishes could be related to periodical and ephemeral flooding of the area by normal-salinity seawater

Kids geosciences labs: the experience of “Sabato al Museo” 2016

During the events “Sabato al Museo” (7th and 21th May 2016) and the European Night at the Museums (21th May 2016), organized by the Polo museale Sapienza (https://web.uniroma1.it/polomuseale/), the Italian Geological Society (SGI - http://www.socgeol.it/) designed and realized six laboratories for children. These were carried out at “Sapienza University of Rome” inside the MUST (University Museum of Earth Science) and the Museum of Anthropology. The main goal of these labs was to mediate the research activities performed by the Sapienza University in different fields of geosciences to an audience of children (from six to twelve years old). The laboratories were holded by selected experts in teaching and disseminating for children. The activities were organized in two phases. In the first phase (about 15 minutes), the operators introduced the audience in the topic of the laboratory by means of multimedia material, involving children with questions and discussions. In the second phase (about thirty minutes), the children carried out experimental activities using the proper scientific methodology. The SGI organized and realized the following laboratories: “Dinosaurs… even in Italy!” (in collaboration with MUSE – Science Museum of Trento); “Footprints”; “Microworlds” (a micropalentological laboratory); “Prey and predators” (in collaboration with PaleoFactory Lab – Sapienza University of Rome); “Discovering our history: apes, fossils and man” and “Ancient weapons”. About 800 children attended these laboratories. The feedback of the audience proved to be very positive, as testified by ex post questionnaires; they had indeed the opportunity to explore topics that commonly capture their imagination. We are deeply convinced that these activities can greatly contribute to expanding the cultural background of the younger generations, in particular the geosciences that unfortunately are still too neglected