Reinforcing the idea of an early dispersal of Hippopotamus amphibius in Europe: Restoration and multidisciplinary study of the skull from the Middle Pleistocene of Cava Montanari (Rome, central Italy)

Abstract

A skull of Hippopotamus recovered from the area of Tor di Quinto, within the urban area of Rome (central Italy) is here redescribed. Despite being one of the most complete specimens of hippopotamuses of the European Pleistocene, the Tor di Quinto skull did not attract much research interest, due to long-standing uncertainties on its provenance. This work begun in 2021, when the skull was restored, within a large renovation project on the vertebrate exposed at the Earth Science University Museum of Sapienza University of Rome. Original sediments were found inside the cranial and mandible cavities during the restoration work, which were sampled for petrographic analyses. By combining a review of the old paleontological, archeological and geological literature published during the 19th and 20th century on the Rome basin and the correlation of these new sedimentological and petrographic information with the lithostratigraphic and synthemic units of the national geological cartography, we clarify that the Hippopotamus skull was most likely to have been collected from a quarry called Cava Montanari, from a formation dated between 560 and 460 ka. Morphological and biometric analyses clearly support an attribution of the Cava Montanari specimen to the extant species Hippopotamus amphibius. The reassessment of the stratigraphic and geological data on Cava Montanari implies that the studied specimen is the earliest confirmed occurrence of Hippopotamus amphibius in the European fossil record.

The Middle Pleistocene Hippopotamus from Malagrotta (Latium, Italy): New Data and Future Perspectives

“…The LAD age of 0.45 Ma proposed for H. antiquus based on the evidence from Portugal is in agreement also with its presence in the roughly contemporaneous locality Marathousa-2 of the Megalopolis Basin of Greece, which again acted as a glacial refugium for several animals, including hippopotamuses [18]. Hippopotamus amphibius probably arrived in Europe during the Middle Pleistocene, and it persisted until the Late Pleistocene [13,16,19]. It should be noted that during Pleistocene another disputed species, H. tiberinus, has been described from different localities of Europe by Mazza [20,21].…”

“…However, a more precise age constrain of 535-500 ka was established by Marra et al [27] based on the fact that the sedimentary succession cropping out at Cava Nera Montanari (also known as Cava Nera Molinario) is firmly correlated with the MIS 13 aggradational succession (Valle Giulia Formation [38]), due to the intercalation of the Tufo del Palatino pyroclastic-flow deposit. As it has been verified for the site of Malagrotta (see Section Geological Setting and references therein), most of the fossil remains stored in the different repositories in Rome (see, for example, the material from Ponte Milvio, and the several attempts to stratigraphically locate the fossil remains from the urban area of Rome such as Di Stefano et al [62]; Marra et al [27]; Mecozzi et al [19]) are catalogued according to the site of collection, without regard to the complex stratigraphic setting of each location. Evidently, at the beginning of the 20th century, there was no awareness about the wide time interval that the so-called "Tiber terraces" (i.e., the fluvial-lacustrine deposits outcropping along the flanks of the Tiber Valley and its tributaries in Rome) span.…”

“…Hippopotamids during the Middle Pleistocene in Europe are poorly represented, and the dispersal of H. amphibius is unclear. Recently, Mecozzi et al [19] re-described a skull of a hippopotamid (MPUR/V 149) collected from the area of Rome, previously attributed to H. amphibius ( [13,29] and references therein). The exact location of the remains is unknown, but through an analysis of the sediment recovered from the skull, Mecozzi et al [19] concluded that most likely it was collected from Cava Nera Montanari, dated between 560 and 460 ka.…”

“…Recently, Mecozzi et al [19] re-described a skull of a hippopotamid (MPUR/V 149) collected from the area of Rome, previously attributed to H. amphibius ( [13,29] and references therein). The exact location of the remains is unknown, but through an analysis of the sediment recovered from the skull, Mecozzi et al [19] concluded that most likely it was collected from Cava Nera Montanari, dated between 560 and 460 ka. However, a more precise age constrain of 535-500 ka was established by Marra et al [27] based on the fact that the sedimentary succession cropping out at Cava Nera Montanari (also known as Cava Nera Molinario) is firmly correlated with the MIS 13 aggradational succession (Valle Giulia Formation [38]), due to the intercalation of the Tufo del Palatino pyroclastic-flow deposit.…”

A taphonomic and spatial distribution study of the new levels of the middle Pleistocene site of Notarchirico (670–695 ka, Venosa, Basilicata, Italy)

“…No carnivoran remains have been found so far, unlike at other sites such as Barranc de la Boella or Isernia La Pineta (Pineda et al, 2017a, b;2020), although their role as modification agents is attested through some tooth marks identified in level I1. The absence of remains is, not conclusive, considering the low density at which most carnivoran species are documented at Isernia La Pineta and others non-anthropic early Middle Pleistocene sites of the Italian Peninsula (i.e., Mecozzi et al, 2021b;Strani et al, 2022). The lithic component and micro-wear traces indicate domestic activities, in addition to possible meat procurement and we can consider Notarchirico as a favourable "foraging site" in an auspicious, attractive and rich environment.…”