An exceptionally well-preserved new acanthothoracid (placoderm fish) presenting complete endocranium and skull roof, from Saudi Arabia (Qasr Limestone Member, Jauf Formation), Early Devonian in age, is described as Arabosteus variabilis n. gen., n. sp. Compared to other Acanthothoraci, the new taxon exhibits a skull roof variable in its dermal plate distribution (e.g., a supernumerary plate: the posterior central plate) and sensory line pattern. Even the different specimens of this taxon show such variability between them. Arabosteus variabilis n. gen., n. sp. enlarges the scope of our knowledge of Acanthothoraci and Placodermi in general. Traditionally, the Arthrodira, one of the historically earliest described groups, provide the standard reference model for the placoderm skull roof pattern. The interpretation of the acanthothoracid skull roof pattern of the Saudi taxon from an arthrodiran model and the establishment of homologies is impossible to resolve unless based on prior assumptions (e.g., hypothesis of fragmentation or fusion for the paranuchal plate complex). The lateral line system of A. variabilis n. gen., n. sp. is unstable (e.g., presence or absence of the postmarginal sensory line canal) making it ambiguous to define bone homology and terminology. Consequently spatial distribution of skull roof plates has been retained for such a task with a minimal reference to the instable features of the sensory line groove distribution.

Two fossil-bearing levels at Griesbeckerzell (the central part of the North Alpine Foreland Basin; Early Badenian, Mittlere Serie of the Upper Freshwater Molasse) have produced a rich reptile fauna that includes a large number of snakes, i.e. Grisbeckerzell lb (OSM E, 15.0–14.9 Ma): Boidae: Python sp.; Colubridae: “Coluber” cf. caspioides; Vipendae: Vipera sp. (“oriental vipers” group) or Daboia sp.; Griesbeckerzell la (beginning of unit OSM F, 14.77 Ma): Boidae: Bavarioboa aff. hermi, cf. Bavarioboa sp., Python sp.; Colubridae: “Coluber” cf. caspioides, Coluber hungaricus, “Coluber” sp., Texasophis cf. meint, Natrix sp.; Elapidae: Micrurus cf. gallicus; Viperidae: Vipera sp. (“Oriental vipers” group), Vipera sp. (“European vipers” group; “Vipera aspis complex”). The Miocene Climatic Optimum (MCO) is documented in central Europe by the presence of highly thermophilous reptile taxa, including Python sp., which is the most thermophilous reptile known from the European Neogene. The presence of Python sp. in Griesbeckerzell 1 a pushes up the last appearance date (LAD) of this large Booidea in central Europe into the early Middle Miocene. The dramatic decrease in temperatures after 14.0 Ma (i.e. below 16°C in mean annual air temperature) was most probably responsible for the extinction of the European non-Erycinae Booidea, regardless of food competition. The genus Bavarioboa (Bavarioboa aff. hermi) and possibly “Coluber” caspioides (“Coluber” cf. caspioides) both have their LADs in Griesbeckerzell la; Coluber hungaricus probably represents the earliest appearance (FAD) of this colubrid snake. Palaeoclimatic analyses of the herpetofauna indicate for both Griesbeckerzell levels humid conditions of between 750 and 1 025 mm mean annual precipitation. Temperature estimates combined with palaeobotanical data indicate a warm, subtropical climate with mean annual temperatures of 18.6 to 20.8°C, cold month temperatures with 12.6 to 13.3°C, and warm month temperatures with 25.1 to 28.1°C.

Geraads D., Spassov N., Hristova L., Markov G. N. & Tzankov T. 2011. — Upper Miocene mammals from Strumyani, South-Western Bulgaria. Geodiversitas 33 (3): 451–484.

The localities of Strumyani in the Struma valley (South-Western Bulgaria) yield a rich assemblage of large mammals, including more than 20 species, hipparions and rhinos being especially well represented. Many species are commonly found in the Balkano-Iranian province, but there are also some rarely found taxa, such as Tapirus Brünnich, 1771, Dorcatherium Kaup, 1833, and a cervid that looks different from other contemporaneous finds. The instantaneous nature of the deposition shows that the association of taxa with likely diverse ecological requirements reflects a truly mosaic environment. The close similarity of the faunal association with that of Pikermi implies a similar middle Turolian age, although some differences suggest that Strumyani is earlier than this Greek locality. The issue of the age of Turolian sites of the Balkans is discussed.

Paleoenvironmental variations that occurred in Italy from the Middle Pliocene to the Late Pleistocene are described. The number of large mammal species seems increased moderately, especially from the Galerian to the Late Aurelian biochronological units. On the contrary, the paleobotanical data show a decrease of the forest cover from the Middle Pliocene to the late Early Pleistocene and an increase of lands occupied by prairies and steppes. This change is also supported by the appearance of hypsodont taxa among mammals. The distribution of mammal faunas between the Adriatic and Tyrrhenian sides of Central Italy, during the Middle and Late Pleistocene, seems not to be influenced by climatic and environment differences. When the Adriatic data are more complete, it is possible, in fact, to observe a trend that is fairly close to that of the Tyrrhenian. The majority of megaherbivorous taxa has an Asian origin, and it can be hypothesized that in the interglacial phases, the Tosco-Emilian Apennines allowed the taxa coming from the northeast to enter and spread out into the more diversified Tyrrhenian side, whereas during the glacial periods the narrow Ligurian corridor were followed. This research supports the role of the Italian Peninsula as a refuge area for continental Europe; this particular condition permits the Italian mammal faunas to develop endemic lineage (such as Elephas antiquus italicus Osborn, 1931, Cervus elaphus rianensis Leonardi & Petronio, 1974, C. e. aretinus Azzaroli, 1947, etc.). At last, biodiversity sharply dropped during the last 30 000 years, probably due to the anthropic activities and the strong climatic cooling of the last pleniglacial.

A new species of Equus, E. (Sussemionus) ovodovi n. sp., was excavated in Proskuriakova Cave (Khakassia, Southwestern Siberia) in deposits carbon dated at 40 000 BP. This slender, middle-sized equid was first considered as related to E. hydruntinus Stehlin & Graziosi, 1935 but biomolecular analyses showed that it actually belonged to a group hitherto unknown of Equus. Indeed, a more detailed study of the fossils evidenced features characteristic of the subgenus Sussemionus Eisenmann, 2010, common during the middle Pleistocene but supposed extinct after. The current article describes this new species.