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Embrithopoda is an extinct clade of herbivorous placental mammals belonging to the afrotherian subclade Paenungulata. Early in their evolutionary history, embrithopods colonized the insular terrane of Balkanatolia, presumably via dispersal across the Tethyan marine barrier that separated Africa from Eurasia during the early Cenozoic. Here we report new embrithopods from the early Eocene locality of Çamili Mezra, Çiçekdaği Basin, central Anatolia, which document the early co-occurrence of two sympatric species of embrithopods, including Crivadiatherium sevketseni sp. nov. and Crivadiatherium sahini sp. nov. The genus Crivadiatherium, otherwise known only from the late Eocene of Romania, is reported for the first time in Anatolia. Hypsamasia seni from the middle Eocene of north-central Anatolia is interpreted as a nomen dubium. Embrithopod specimens previously described as Palaeoamasia sp. nov. from the Eocene-Oligocene transition of the Boyabat Basin in northern Anatolia are identified as a new genus and species, Axainamasia sandersi. The embrithopod fauna of Çamili Mezra indicates that this clade experienced at least a modest adaptive radiation after successfully colonizing Balkanatolia. The Balkanatolian record of embrithopod evolution contrasts with the evolutionary history of this clade in its native Africa, where sympatric embrithopod taxa have never been documented. 

The Eocene-Oligocene transition marks a period of dramatic global climatic change correlated with pronounced mammalian faunal change. Fossil evidence is indispensable for studying the distribution of taxa through time, and determining how abiotic parameters shaped ancient biodiversity. Here we report ruminant artiodactyls and a new anthropoid primate from Süngülü, a locality in Eastern Anatolia that has yielded a diversified and largely endemic assemblage of rodents. Three taxa of ­ruminants are recognized, the tragulid Iberomeryx parvus Gabunia, 1964, a larger species of Iberomeryx Gabunia, 1964, and a bachitheriid referred to cf. Bachitherium sp. A lower molar is identified as the new eosimiid primate Sungulusimias unayae n. gen., n. sp., which is the first occurrence of Paleogene anthropoids in western Asia. The lower molar of Sungulusimias unayae n. gen., n. sp. is characterized by protoconid and metaconid closely spaced and of similar height and volume, paraconid cuspidate and nearly connate with metaconid, strong mesiobuccal cingulid, and entoconid without strong connection to hypoconulid via the postcristid. The composition of this assemblage together with rodents indicates a probable Latest Eocene age for Süngülü, although an early Oligocene age cannot be completely ruled out. The rodent fauna from Süngülü suggests that endemism persisted at the periphery of Balkanatolia until the latest Eocene while Eastern Anatolia was situated in a strategic corridor for faunal exchanges between eastern Asia, Indo-Pakistan and Europe. During the Eocene-Oligocene transition, Balkanatolia probably functioned as a “holding pen” where various taxa were confined for significant intervals of time before proceeding to colonize Western Europe at the Grande Coupure. 

Two new specimens of the anatoliadelphyid metatherian Orhaniyeia nauta are described from the middle Eocene Uzunçarşıdere Formation in the Orhaniye Basin, north-central Turkey. These specimens augment our knowledge of the dentition of this taxon, revealing that P3 and p3 of Orhaniyeia resemble those of its sister taxon Anatoliadelphys in being enlarged and highly inflated, suggesting that both taxa consumed a durophagous diet. The ancestral dental morphology of anatoliadelphyids likely approximated that of Orhaniyeia nauta, whereas the dentition of Anatoliadelphys is autapomorphous. A phylogenetic analysis incorporating the new data for Orhaniyeia reconstructs anatoliadelphyids as nested among a diverse, but generally poorly documented, assemblage of early Paleogene bunodont Gondwanan marsupials that are typically allied with polydolopimorphians. Alternative phylogenetic reconstructions based on Anatoliadelphys alone have suggested either peradectid or protodidelphid affinities for anatoliadelphyids, but these hypotheses are not supported by the new data from Orhaniyeia. Anatoliadelphyids likely colonized Balkanatolia from the south (Africa/Arabia), even though there is no current fossil record indicating that this Gondwanan bunodont marsupial clade ever inhabited Africa/Arabia. The durophagous diet of Orhaniyeia was probably eclectic, but with an emphasis on gastropods. A similar dietary reconstruction has been proposed for the Australian Miocene marsupial Malleodectes, the dentition of which is remarkably convergent with that of Orhaniyeia. Orhaniyeia and Anatoliadelphys appear to have exploited distinct ecological niches, because the autapomorphous dentition of Anatoliadelphys includes multiple specializations for enhanced carnivory. The colonization of Balkanatolia by anatoliadelphyids instigated a small endemic radiation, a pattern that was replicated by multiple other Balkanatolian mammal clades. 

Abstract The Ancestral Rocky Mountains system consists of a series of basement-cored uplifts and associated sedimentary basins that formed in southwestern Laurentia during Early Pennsylvanian–middle Permian time. This system was originally recognized by aprons of coarse, arkosic sandstone and conglomerate within the Paradox, Eagle, and Denver Basins, which surround the Front Range and Uncompahgre basement uplifts. However, substantial portions of Ancestral Rocky Mountain–adjacent basins are filled with carbonate or fine-grained quartzose material that is distinct from proximal arkosic rocks, and detrital zircon data from basins adjacent to the Ancestral Rocky Mountains have been interpreted to indicate that a substantial proportion of their clastic sediment was sourced from the Appalachian and/or Arctic orogenic belts and transported over long distances across Laurentia into Ancestral Rocky Mountain basins. In this study, we present new U-Pb detrital zircon data from 72 samples from strata within the Denver Basin, Eagle Basin, Paradox Basin, northern Arizona shelf, Pedregosa Basin, and Keeler–Lone Pine Basin spanning ∼50 m.y. and compare these to published data from 241 samples from across Laurentia. Traditional visual comparison and inverse modeling methods map sediment transport pathways within the Ancestral Rocky Mountains system and indicate that proximal basins were filled with detritus eroded from nearby basement uplifts, whereas distal portions of these basins were filled with a mix of local sediment and sediment derived from marginal Laurentian sources including the Arctic Ellesmerian orogen and possibly the northern Appalachian orogen. This sediment was transported to southwestern Laurentia via a ca. 2,000-km-long longshore and aeolian system analogous to the modern Namibian coast. Deformation of the Ancestral Rocky Mountains slowed in Permian time, reducing basinal accommodation and allowing marginal clastic sources to overwhelm the system.