4 research outputs found
Fossil molluscs from the Middle Miocene of Öhningen, southwestern Germany
Herein, we revise an extensive set of mollusc fossils from the Upper Freshwater Molasse
deposits of Öhningen palaeolake (SW Germany; Middle Miocene, MN7). Based on material housed in
paleontological collections in Europe and North America, we present the first thorough systematic account
of the phylum from this historic locality. A total of ten species were identified from Öhningen: three
freshwater gastropods (Lymnaea dilatata Noulet, 1854, Gyraulus cf. applanatus (Thomä), Planorbarius mantelli
(Dunker)), two terrestrial gastropods (Granaria cf. schuebleri (Klein), Palaeotachea sylvestrina (Schlotheim)),
and five bivalves (Anodonta splendens Goldfuss, A. lavateri (Münster), Pseudunio flabellatus (Goldfuss),
“Dreissena” sp., Pisidium escheri (Mayer-Eymar, 1865)). Three freshwater and five terrestrial gastropod genera
mentioned in older literature could not be found in the available material. Ours is the first report of a
Dreissenidae from Öhningen
A Review of the Paleobiology of Some Neogene Sharks and the Fossil Records of Extant Shark Species
In recent years, new findings and new methods (stable isotopes of oxygen, zinc, and nitrogen; 2D and 3D modeling; and geometric morphometric analyses of the teeth) have enhanced our knowledge of the Neogene shark fauna and its paleobiology. Several papers deal with the large Otodus (Megaselachus) species, including the construction of a 3D model, as well as insights into its lifestyle and diet. In addition, the skeletal remains of Carcharias gustrowensis, Carcharodon hastalis, and Keasius parvus and a natural tooth set of Carcharodon hubbelli have been described in the last 13 years, and the dentition of the Neogene species Carcharoides catticus, Megachasma applegatei, and Parotodus benedenii has been reconstructed. Stable isotope analyses of the teeth from the Neogene species of Araloselachus, Carcharias, Carcharodon, Galeocerdo, Hemipristris, and Mitsukurina have given insights into the trophic positions of these genera during the Neogene, and shark teeth preserved near the skeletal remains of prey animals (mammals) and shark bite traces on these remains provide direct evidence of trophic interactions. The tooth shape, fossil locality, and paleoenvironment have been used to better understand the taxa Carcharhinus dicelmai, Megalolamna paradoxodon, Pachyscyllium dachiardii, and P. distans. Among extant species, Galeorhinus galeus can be traced back to the Eocene. Alopias superciliosus, Rhincodon typus, and possibly A. vulpinus can be traced back to the Oligocene. Species present by the Miocene include Alopias vulpinus, Carcharhinus amblyrhynchoides, C. amblyrhynchos, C. albimarginatus, C. amboinensis, C. brachyurus, C. brevipinna, C. falciformis, C. glaucus, C. leucas, C. limbatus, C. longimanus, C. macloti, C. obscurus, C. perezi, C. sealei, Centrophorus granulosus, Cetorhinus maximus, Dalatias licha, Deania calcea, Galeocerdo cuvier, Glyphis glyphis, Heptranchias perlo, Isurus paucus, Lamna nasus, Negaprion brevirostris, Odontaspis ferox, Pseudocarcharias kamoharai, Sphyrna media, S. mokarran, and possibly Carcharodon carcharias. First appearing in the Pliocene are Scymnodon ringens, Somniosus rostratus, and Zameus squamulosus. For some extant species (Carcharias taurus, Hexanchus griseus, Isurus oxyrinchus, Notorynchus cepedianus, and Sphyrna zygaena), it is not clear whether the assigned Neogene teeth represent the same species. The application of new methods to more fossil shark taxa, a detailed search for shark fossils, and better knowledge of the dentition of extant species (especially those with minute-sized teeth) will further enhance our knowledge of the evolution and paleobiology of sharks
Turritelline mass accumulations from the Lower Miocene of southern Germany: implications for tidal currents and nutrient transport within the North Alpine Foreland Basin
The mass occurrence of turritelline gastropod shells from the Lower Miocene of southern Germany allows for detailed studies of their palaeoecology, transport mechanisms, preservation potentials and the reconstruction of nutrient regimes. Changes in the fabric of the gastropod‐dominated beds are used to reconstruct a generally deepening environment corresponding to the Lower Miocene transgression within the Upper Molasse Sea of the North Alpine Foreland Basin. The sedimentary succession ranges from chaotically arranged, densely packed and near‐shore transported; wave‐influenced deposits showing bimodal shell orientations; more widely dispersed shells showing a uni‐directional orientation; and dispersed shells showing diverse orientations. The shells often show damage to the apex and aperture though it is not clear whether this is due to predation events, pagurisation or abrasion due to transport. An outstanding feature is the replacement of aragonite shells by calcite leading to internal vugs as well as modulating the outer shell surface morphology. The high density of turritelline gastropods indicates a nutrient‐rich palaeoenvironment at the northern edge of the Molasse Sea.Gesellschaft zur Förderung des Naturkundemuseums Stuttgar