Enamel thickness per masticatory phases (ETMP): A new approach to assess the relationship between macrowear and enamel thickness in the human lower first molar

Many anthropological studies have examined the functional implications of enamel thickness in human dental crowns. Despite limitations, Enamel thickness (ET) values are still used to infer taxonomic attribution in the genus Homo, and to identify mechanisms of functional adaptation against macrowear. However, only a few studies have tried to describe the possible relationship between ET and dental wear patterns in permanent lower first molars (M1) aiming to observe whether an adaptive response to the environmental and cultural context is detectable. The present work aims to investigate a possible signal of ET adaptive response in M1 (wear stage 3; Molnar, 1971) belonging to individuals who lived between the Neolithic (early 6th millennium BCE) and the Bronze Age (second half of the 2nd millennium BCE) in Croatia to identify any signal of change in dental tissue proportions based on archaeologically documented shifts in population structure and subsistence strategies. In order to do so, we explored 3D Average Enamel Thickness (AET) of the entire crown and wear pattern distribution among individuals and across chronological groups. We then described a new method called “Enamel Thickness per Masticatory Phases” (ETMP) involving the creation of virtual sections cutting enamel and coronal dentine in three parts based on masticatory phases, and explored the distribution of 3D AET accordingly. Finally, we performed geometric morphometric analysis on dental crown to ascertain possible morphological differences between Neolithic, Eneolithic, and Bronze Age groups. Results show that Bronze Age individuals differ from previous groups due to 1) higher values of ET in both the entire crown and specifically in the buccal area, 2) to an extensive wear pattern localized on the buccal side, and 3) to the distal extension of the hypoconid together with an extended mesio-distal shape of the crown. These patterns may represent an adaptive response of dental tissue to varying functional demands (e.g. archaeologically documented dietary shift). The study of ETMP therefore offers a more nuanced method, in addition to morphology and macrowear analysis, to document biocultural processes of change over time in archaeological populations through dental tissues

Primi risultati di un’analisi multidisciplinare di un femore umano associato ai livelli del Musteriano finale (Foyer B) della Grotta del Principe di Monaco (Ventimiglia, IM, Italia).

Durante le campagne di scavo condotte tra il 1895 e il 1902, nella Grotta del Principe di Monaco (Ventimiglia, Imperia, Italia) venne alla luce un frammento di osso lungo (PM-F-3034) dai livelli tardo-musteriani della stratigrafia (Foyer B), attribuiti al MIS4. Questo reperto è rimasto per molto tempo conservato e non identificato nel Museo di Antropologia preistorica del Principato di Monaco, fino alla sua “riscoperta” da parte del Dr. Abdelkader Moussous, durante l’analisi dei resti di grandi mammiferi delle Grotte dei Balzi Rossi, nell’ambito della sua tesi di dottorato (2014); il reperto venne già allora riconosciuto come un resto umano. Al fine di identificarne la corretta determinazione anatomica, l’appartenenza tassonomica e, di conseguenza, comprenderne la relazione con il contesto musteriano associato, si è proceduto all’acquisizione tramite tomografia computerizzata ospedaliera (TC) con conseguenti elaborazioni digitali. Le analisi hanno evidenziato una forte alterazione corticale causata da particolari processi tafonomici avvenuti nel corso del tempo. L’elaborazione virtuale della diafisi umana, riconosciuta come femore (PM-F-3034), ha permesso di condurre analisi morfometriche non invasive (diametri antero-posteriori e medio-laterali, lunghezza biomeccanica, area midollare e corticale, indice pilastrico) (Caffarone, 2020), volte a identificare l’attribuzione tassonomica di questo individuo. Inoltre, considerando la posizione stratigrafica e lo stato di conservazione del resto umano, si è deciso di procedere con l’attribuzione cronologica al radiocarbonio (14C), previo rilevamento di collagene tramite analisi microspettroscopica NIR (microNIR) (Catelli et al., 2020). Contrariamente a quanto ci si poteva aspettare, i valori ottenuti attraverso le analisi virtuali attribuiscono il femore a un individuo appartenente a Homo sapiens, esito confermato anche dall’analisi al 14C che lo colloca cronologicamente nel XV secolo. Questi risultati sottolineano la complessità stratigrafica della Grotta del Principe di Monaco, evidenziando occupazioni diacroniche sin da periodi relativamente recenti. In conclusione, questo studio ha dimostrato che l’analisi antropologica dei resti fossili, unitamente all’analisi al 14C, è fondamentale per una corretta attribuzione crono-tassonomica, compensando le incertezze e le alterazioni indotte durante l’attività di scavo, oltre a quelle prodotte da processi diagenetici che possono aver generato un parziale rimescolamento sedimentario.During the excavation campaigns occurred between 1895 and 1902, a fragment of a long bone (PM-F-3034) was discovered in the late Mousterian levels of the stratigraphy (Foyer B), attributed to MIS4, in the Prince of Monaco’s Cave (Ventimiglia, Imperia, Italy). This find remained for a long time stored but unidentified in the Museum of Prehistoric Anthropology of the Principality of Monaco until its “rediscovery” by Dr. Abdelkader Moussous, during the analysis of large mammal remains from the Balzi Rossi caves, as part of his PhD thesis (2014); in this circumstance the fragment was recognized as a human remain. In order to identify its correct anatomical determination, its taxonomy and, consequently, to understand its relationship with the associated Mousterian context, it was acquired by hospital computed tomography (CT) with subsequent digital processing. The analysis showed a strong cortical alteration, caused by taphonomic processes that occurred over time. Virtual processing of the human diaphysis, recognized as a femur (PM-F-3034), allowed to conduct non-invasive morphometric analyses (antero-posterior and medio-lateral diameters, biomechanical length, medullary and cortical area, pilastric index) (Caffarone, 2020) aimed to identify the taxonomic attribution of this individual. Furthermore, considering the stratigraphic position and the state of preservation of the human remain, it was decided to proceed with 14C chronological attribution, preceded by the collagen detection by microspectroscopic NIR (microNIR) analysis (Catelli et al., 2020). Contrary to what might have been expected, the values obtained through the virtual analysis attribute the femur to Homo sapiens and it is also confirmed by 14C, that place the human bone chronologically in the 15th century. These results underline the stratigraphic complexity of the Prince of Monaco’s Cave and highlighting diachronic occupations since relatively recent periods. In conclusion, this study has shown that the anthropological analysis of fossil remains, along with 14C, is fundamental for a correct chrono-taxonomic attribution, compensating for the uncertainties and alterations induced during excavation activities, as well as those produced by diagenetic processes that may have generated a partial sedimentary mixing

A late Neanderthal tooth from northeastern Italy

The site of Riparo Broion (Vicenza, northeastern Italy) preserves a stratigraphic sequence documenting the Middle-to-Upper Paleolithic transition, in particular the final Mousterian and the Uluzzian cultures. In 2018, a human tooth was retrieved from a late Mousterian level, representing the first human remain ever found from this rock shelter (Riparo Broion 1). Here, we provide the morphological description and taxonomic assessment of Riparo Broion 1 with the support of classic and virtual morphology, 2D and 3D analysis of the topography of enamel thickness, and DNA analysis. The tooth is an exfoliated right upper deciduous canine, and its general morphology and enamel thickness distribution support attribution to a Neanderthal child. Correspondingly, the mitochondrial DNA sequence from Riparo Broion 1 falls within the known genetic variation of Late Pleistocene Neanderthals, in accordance with newly obtained radiocarbon dates that point to approximately 48 ka cal BP as the most likely minimum age for this specimen. The present work describes novel and direct evidence of the late Neanderthal occupation in northern Italy that preceded the marked cultural and technological shift documented by the Uluzzian layers in the archaeological sequence at Riparo Broion. Here, we provide a new full morphological, morphometric, and taxonomic analysis of Riparo Broion 1, in addition to generating the wider reference sample of Neanderthal and modern human upper deciduous canines. This research contributes to increasing the sample of fossil remains from Italy, as well as the number of currently available upper deciduous canines, which are presently poorly documented in the scientific literature

Exploring late Paleolithic and Mesolithic diet in the Eastern Alpine region of Italy through multiple proxies

© 2020 The Authors. American Journal of Physical Anthropology published by Wiley Periodicals LLC. Objectives: The analysis of prehistoric human dietary habits is key for understanding the effects of paleoenvironmental changes on the evolution of cultural and social human behaviors. In this study, we compare results from zooarchaeological, stable isotope and dental calculus analyses as well as lower second molar macrowear patterns to gain a broader understanding of the diet of three individuals who lived between the end of the Late Pleistocene and the Early Holocene (ca., 17–8 ky cal BP) in the Eastern Alpine region of Italy. Materials and methods: We analyze individuals buried at the sites of Riparo Tagliente (Verona), Riparo Villabruna, and Mondeval de Sora (Belluno). The three burials provide a unique dataset for diachronically exploring the influence of climatic changes on human subsistence strategies. Results: Isotopic results indicate that all individuals likely relied on both terrestrial and freshwater animal proteins. Even though dental calculus analysis was, in part, hindered by the amount of mineral deposit available on the teeth, tooth macrowear study suggests that the dietary habits of the individuals included plant foods. Moreover, differences in macrowear patterns of lower second molars have been documented between Neanderthals and modern humans in the present sample, due to a prevalence of Buccal wear among the former as opposed to higher values of Lingual wear in modern human teeth. Discussion: Isotopic analyses have emphasized the contribution of animal proteins in the diet of the three foragers from the Eastern Alpine region. The possible intake of carbohydrate-rich plant foods, suggested by the retrieval of plant remains in dental calculus, is supported by the signal of macrowear analysis. Moreover, the latter method indicates that the distribution of macrowear in lower second molars (M2s) allows us to discriminate between Neanderthals and modern humans within the present reference sample. Overall, our results show these three prehistoric hunter-gatherers were well adapted to the environment in which they lived exploiting many natural resources