The fossiliferous sediments of the Lower Xianshuihe Formation at Lanzhou are among the few important Early Oligocene mammalbearing localities in China. Previous studies have revealed a diversified local fauna, including the presence of the paraceratheriid Paraceratherium huangheense that is restricted to the late Early Oligocene Lanzhou Basin. However, fossils of P. huangheense were poorly documented, with only mandibular and dental materials available. The newly discovered postcranial skeletal elements provide supplementary morphological features of P. huangheense and allow for a detailed comparison with other large-sized paraceratheres. Nevertheless, additional cranial and postcranial fossils are needed for identifiable traits at the species level. The improvement of climatic and ecological conditions - characterized by a temperate semi-arid climate and expansion of open woodlands - during the Early Oligocene in Lanzhou likely played a significant role in the distribution of giant rhinos.

Eocene climate cooling, driven by the falling pCO2 and tectonic changes in the Southern Ocean, impacted marine ecosystems. Sharks in high-latitude oceans, sensitive to these changes, offer insights into both environmental shifts and biological responses, yet few paleoecological studies exist. The Middle-to-Late Eocene units on Seymour Island, Antarctica, provide a rich, diverse fossil record, including sharks. We analyzed the oxygen isotope composition of phosphate from shark tooth bioapatite (δ18Op) and compared our results to co-occurring bivalves and predictions from an isotope-enabled global climate model to investigate habitat use and environmental conditions. Bulk δ18Op values (mean 22.0 ± 1.3‰) show no significant changes through the Eocene. Furthermore, the variation in bulk δ18Op values often exceeds that in simulated seasonal and regional values. Pelagic and benthic sharks exhibit similar δ18Op values across units but are offset relative to bivalve and modeled values. Some taxa suggest movements into warmer or more brackish waters (e.g., Striatolamia, Carcharias) or deeper, colder waters (e.g., Pristiophorus). Taxa like Raja and Squalus display no shift, tracking local conditions in Seymour Island. The lack of difference in δ18Op values between pelagic and benthic sharks in the Late Eocene could suggest a poorly stratified water column, inconsistent with a fully opened Drake Passage. Our findings demonstrate that shark tooth bioapatite tracks the preferred habitat conditions for individual taxa rather than recording environmental conditions where they are found. A lack of secular variation in δ18Op values says more about species ecology than the absence of regional or global environmental changes.

The Hambach lignite mine in northwestern Germany is a renowned fossil locality, which has yielded remains of several vertebrates dated back to the Middle Miocene and the Late Pliocene. Among these is a recently-described and peculiar proteid urodele, Euronecturus grogu, currently known only from the Middle Miocene level in Hambach. Here, we provide detailed descriptions and identifications of the remaining fossil amphibians (both urodeles and anurans) from the Hambach mine, in total identifying at indet., Pelobatidae indet., Hyla sp., Pelophylax sp., Rana sp.) and at least nine Late Ranidae indet.). The high diversity of amphibians in both Miocene and Pliocene levels at Hambach supports a very humid climate persisting in the area for most of the Neogene, possibly originating a refugium for these animals in northwestern Europe that persisted until the Late Pliocene (and possibly even the Early Pleistocene). Urodeles such as Palaeoproteus and Mioproteus and anurans such as Latonia, the palaeobatrachids, and possibly Eopelobates are all significant occurrences in such a northern latitude at the end of the Pliocene, a period when southward withdrawal of thermophilic animals as well as the first effects of a deteriorizing climate ultimately leading to the Quaternary glaciation had already started in the European continent.

Ctenodactylid rodents prospered during the Paleogene in East and Central Asia, and due to their high diversification, they are important for biostratigraphic correlations. Here, we present new and diverse material from the late early Oligocene Nanpoping mammal fauna of the Lower Member of the Xianshuihe Formation from the Lanzhou Basin, Central China. Nine species -Tataromys plicidens, Tataromys sigmodon, Tataromys minor, Yindirtemys ulantatalensis, Yindirtemys shevyrevae, Alashania tengkoliensis, Karakoromys decessus, ?Euryodontomys ampliatus and Helanshania deserta -were recognized and described here in detail, the latter five species for the first time from early Oligocene Nanpoping fauna of the Lanzhou Basin. For the Lanzhou Basin, ctenodactylids show the maximum richness in the early Oligocene and have a comparatively high diversity compared with other contemporaneous faunas until the abrupt decline at the late Oligocene, with only Yindirtemys left. Ctenodactylid diversification in the early Oligocene may be related to the semi-arid climate with episodes of higher precipitation, and the following niche partitioning.

Glirid dental material is described from the Middle Miocene channel fill of the Hambach open-cast lignite mine in northwestern Germany. The fauna Hambach 6C shows a high diversity with seven species in six genera: Glirudinus undosus, Muscardinus thaleri, Muscardinus sansaniensis, Miodyromys aegercii, Paraglirulus werenfelsi, Microdyromys koenigswaldi, and Paraglis astaracensis, which are characteristic taxa in Middle Miocene European localities. Regarding the faunal composition and high diversity, the Hambach 6C assemblage is closest to that of the MN 5 locality Schonenberg in southern Germany, but also shares many taxa with late Middle Miocene faunas. The species richness of glirids, combined with other vertebrate remains in Hambach 6C indicates a warm, humid forested environment during the Mid-Miocene Climate Optimum (MCO).

Melissiodon is a rare cricetid with a long stratigraphic range, present from the Oligocene until the Miocene, only found in western and central Europe except some specimens recovered in Anatolia. What makes Melissiodon special is its unique dental and mandible morphology that has led to many questions regarding its relationship to other cricetid genera and its type of diet. In this work, we have studied new material attributed to Melissiodon from the German localities Echzell (MN4) and Petersbuch (MN3 and MN4), and from the French locality Beaulieu (MN3). Moreover, we compared these specimens with the already published material from other localities across western and central Europe during the early Miocene (MN3 and MN4). In conclusion, the studied specimens and the comparison with other material from different European localities allow us to ascribe this new material as Melissiodon dominans, a widely dispersed species across Europe during the early Miocene 

We report about the Early Miocene Tagay fauna of Olkhon Island, the largest island of the Baikal Lake. The Tagay fauna is of high scientific importance because of the diversity of fishes, amphibians, lizards, snakes, turtles, manifold birds and mammals. The lithology, geochemistry and the fossil record along the Tagay-1 section allow reconstruction of various palaeoenvironments, i.e. open water, shallow lakes with adjacent wetlands, riverine woodlands, and also forested and dry habitats. The fossil record, lithology and geochemical sediment-analyses suggest a temperate palaeoclimate with short humid and dry periods. The small mammal record and the magnetic polarity pattern of the upper part of section Tagay-1 correlate with the subchrons C5Cn.2r – C5Cn.1r of Chron C5C and the late Burdigalian Stage of the Geologic Time Scale (GTS2000). The corresponding age range of the Tagay fauna is ~16.5 to ~16.3 Ma. 

The present study describes a rich amphibian and reptilian assemblage from the early Miocene locality Echzell, Germany. It consists of one allocaudate, five salamander, five frog, one gecko, chamaeleonids, anguine lizards, one lacertid, one skink and five snake taxa. The entire herpetofauna of Echzell is represented by genera and/or families very broadly known from the early Miocene of Europe. Contrary to other early Miocene herpetofaunas, the Echzell assemblage includes surprisingly only one form of crocodile-newts (Chelotriton). The Echzell Palaeobatrachus robustus represents the youngest record of the species and extends its stratigraphic range to the late early Miocene. Regarding chameleons, the frontal is partly preserved, but represents the first described frontal of the extinct species Chamaeleo andrusovi. The only anguine lizard that can be identified in the assemblage is represented by a new genus and species Smithosaurus echzellensis. Our phylogenetic analyses consistently recovered it as the sister taxon to either [Ophisauriscus quadrupes + Ophisaurus holeci] + [Anguis + Ophisaurus] (in the first analysis) or [Anguis + Ophisaurus] (in the second analysis). However, the results are based on limited fossil material – the parietal – and the support for the clade is very low. Thus, the interpretation of the Smithosaurus relationship among anguines needs to be taken with caution and has to be tested in further studies. Among snakes, Natrix longivertebrata represents the oldest record of the species and extends the stratigraphic range of this fossil snake back to the early Miocene. In addition, we provide here a broader comparison of the Echzell amphibian and reptilian assemblage with their European records for the MN3 and MN4 biostratigraphical units. Besides that, the entire herpetofauna of Echzell includes very broadly known early Miocene European forms. Remains of other groups of the same period such as Bufonidae, Hylidae, Pelodytidae, Amphisbaenia, Varanidae, Cordylidae, Pseudopus, are not found in the material available to us. We also conclude that the amphibian and reptilian fossil record across MN3–MN4 is significantly biased by taphonomic and/or environmental conditions. The amphibian and reptilian assemblage of Echzell is rich in forms living in humid and warm environments with forested areas, permanent water bodies and also some open habitats. The following climatic parameters can be reconstructed based on the herpetofauna: a mean annual temperature of 17.4–28.8 °C, minimal warm month temperature 18–28.3 °C, minimal cold month temperature 8–22.2 °C, and mean annual precipitation with a value of 791±254 mm.

New excavations in the Tagay locality have revealed the presence of Amphilagus plicadentis Erbajeva, 2013, which belongs to the palaeolagine Lagomorpha rather than leporids, previously referred to Procaprolagus sp. (Logachev et al., 1964). Herein, we report a comprehensive morphological description of this species and compare it with the other known species of the genus Amphilagus. The Tagay lagomorph is conspecific with the Early Miocene species Amphilagus plicadentis found at locality Unkheltseg (UNCH-A) (biozone D; Early Miocene) in the Valley of Lakes, Central Mongolia. The Tagay specimens suggest a more advanced evolutionary stage of A. plicadentis and an age around Early/Middle Miocene transition.

The collection of fossil Rodentia from the Miocene Tagay fauna comprises Aplodontidae, Mylagaulidae, Sciuridae, Gliridae, Castoridae, Eomyidae and Cricetodontinae. Represented by three taxa the Cricetodontinae dominate the rodent assemblage of the Tagay fauna. The fossils were collected by wet-screening of test samples along the section Tagay-1 at Tagay Bay of Olkhon Island. Here, we report on the medium-sized Democricetodon cf. lindsayi, the very small Democricetodon sp. and the large Gobicricetodon filippovi. The primitive dental pattern of D. cf. lindsayi and G. filippovi suggest archaic members of the genera, and an age around the Early/Middle Miocene transition.