The Antiquity of the Rhine River: Stratigraphic Coverage of the Dinotheriensande (Eppelsheim Formation) of the Mainz Basin (Germany)

Abstract

BackgroundMammalian fossils from the Eppelsheim Formation (Dinotheriensande) have been a benchmark for Neogene vertebrate palaeontology since 200 years. Worldwide famous sites like Eppelsheim serve as key localities for biochronologic, palaeobiologic, environmental, and mammal community studies. So far the formation is considered to be of early Late Miocene age (∼9.5 Ma, Vallesian), representing the oldest sediments of the Rhine River. The stratigraphic unity of the formation and of its fossil content was disputed at times, but persists unresolved.Principal FindingsHere we investigate a new fossil sample from Sprendlingen, composed by over 300 mammalian specimens and silicified wood. The mammals comprise entirely Middle Miocene species, like cervids Dicrocerus elegans, Paradicrocerus elegantulus, and deinotheres Deinotherium bavaricum and D. levius. A stratigraphic evaluation of Miocene Central European deer and deinothere species proof the stratigraphic inhomogenity of the sample, and suggest late Middle Miocene (∼12.5 Ma) reworking of early Middle Miocene (∼15 Ma) sediments. This results agree with taxonomic and palaeoclimatic analysis of plant fossils from above and within the mammalian assemblage. Based on the new fossil sample and published data three biochronologic levels within the Dinotheriensand fauna can be differentiated, corresponding to early Middle Miocene (late Orleanian to early Astaracian), late Middle Miocene (late Astaracian), and early Late Miocene (Vallesian) ages.Conclusions/SignificanceThis study documents complex faunal mixing of classical Dinotheriensand fauna, covering at least six million years, during a time of low subsidence in the Mainz Basin and shifts back the origination of the Rhine River by some five million years. Our results have severe implications for biostratigraphy and palaeobiology of the Middle to Late Miocene. They suggest that turnover events may be obliterated and challenge the proposed ‘supersaturated’ biodiversity, caused by Middle Miocene superstites, of Vallesian ecosystems in Central Europe.

Opportunistic Feeding Strategy for the Earliest Old World Hypsodont Equids: Evidence from Stable Isotope and Dental Wear Proxies

“…These fluvial sediments of the Eppelsheim Formation [25], [26], traditionally known as “Dinotheriensande”, have yielded many localities mainly placed stratigraphically within the Vallesian Land Mammal Age in the lower part of MN 9, the age of which is approximately 11.5 to 9.5 Ma [27], [28], [29]. However, in addition to Late Miocene (Vallesian) taxa the Dinotheriensand Fauna also contains early and late Middle Miocene mammal faunas [30]. Here, the focus is on Eppelsheim, situated 30 km south of the city of Mainz, which has provided the richest assemblage of mammalian remains among the Dinotheriensande complex [31], [32].…”

A gastropod-based biogeographic scheme for the European Neogene freshwater systems

“…Due to the superior sampling density of extant faunas their model has a much higher resolution. The ecoregions mainly correspond to large drainage systems which are mostly unknown for the fossil record, severely hampering a sound comparison (exceptions to this are provided by key studies on palaeo-drainage patterns, like Böhme et al, 2012). Moreover, we lack information about the North European faunas because of poor preservation.…”

Origination of antlerogenesis

“…The first antler morphotypes were small, simply forked or multi‐pointed, sitting on long pedicles protruding from the part of the frontals which formed the orbit roof and always co‐existing with enlarged upper canines in males (Gentry, ; Rössner, ; Azanza, ; Azanza et al, ). Most recent sources of the chronological occurrence of early fossil cervids include Gentry (), Gentry et al (), Azanza (), and Böhme et al () for Europe, as well as Vislobokova () for Asia. The oldest known cervids, as defined by the presence of antler‐like branched frontal protuberances, have been found in the early Miocene (Land Mammal Zone MN3, ∼19.5 to 17.2 mya; Hilgen et al, ).…”

“…The oldest known cervids, as defined by the presence of antler‐like branched frontal protuberances, have been found in the early Miocene (Land Mammal Zone MN3, ∼19.5 to 17.2 mya; Hilgen et al, ). They include Procervulus Gaudry, from Spain, France, and Germany, Acteocemas Ginsburg, from France and Ligeromeryx Azanza and Ginsburg, from France (Ginsburg, ; Azanza, ; Gentry, ; Rössner, ; Azanza and Ginsburg, ; Rössner, ; Gentry et al, ; Azanza, ; Ginsburg et al, ; Aguilar et al, ; Böhme et al, ). There are three morphotypes of early antlers: Procervulus with dichotomously forked antlers (Rössner, ), Ligeromeryx with multi‐pointed, crown‐like antlers (Azanza and Ginsburg, ), and Lagomeryx and Paradicrocerus with coronate, shaft‐less antlers (Azanza and Ginsburg, ).…”

“…Because of unresolved taxonomic discussions, Heteroprox is used in this study instead of the proposed senior synonym Procervulus ; see synonymized use in Van der Made () and discussion in Rössner (). In addition, Paradicrocerus is used instead of the junior synonym Stehlinoceros (excluded from Stephanocemas by Azanza and Menendez ; see also Böhme et al, ).…”