One of the most significant global climatic events in the Cenozoic was the transition from greenhouse to icehouse conditions in Antarctica. Tectonic evolution of the region and gradual cooling at the end of Eocene led to the first appearance of ice sheets at the Eocene/Oligocene boundary (ca. 34 Ma). Here we report geological record of mountain glaciers that preceded major ice sheet formation in Antarctica. A terrestrial- valley-type tillite up to 65 metres thick was revealed between two basaltic lava sequences in the Eocene- Oligocene Point Thomas Formation at Hervé Cove - Breccia Crag in Admiralty Bay- King George Island- South Shetland Islands. K-Ar dating of the lavas suggests the age of the glaciation at 45-41 Ma (Middle Eocene). It is the oldest Cenozoic record of alpine glaciers in West Antarctica- providing insight into the onset of glaciation of the Antarctic Peninsula and South Shetland Islands.
Contrary to insects, snails only rarely become embedded in amber. Snail inclusions dealt with in this paper come from Baltic amber: five represent species described at the end of the 19th c., whose status has now been revised, two are of uncertain position, one is a Leiostyla - a genus not previosly found in amber, and one - Propupa hoffeinsorum gen. and sp. nov., with its unique apertural barriers - may prove an important link in further studies on the origin, evolution and distribution of pupilloids. Reasons for the rarity of snail inclusions and geographical affinities of the Baltic amber snails are discussed. A catalogue of Baltic amber snails is provided.
A new species of the genus Cheilotrichia Rossi, 1848 (Diptera: Limoniidae) from Bitterfeld amber is described. Bitterfeld amber (Saxonian amber) is contemporaneous with the Baltic amber deposited in Gdańsk Amber Bay area. The representatives of the same species are often found among inclusions of Bitterfeld and Baltic amber but the species described herein Cheiliotrichia (Empeda) weitschati sp. nov. have been found only in Bitterfeld amber.
The conflicting views of Rovno amber being allochthonous, having been transported to the Pripyat area during the Eocene from the north across the sea and thus deriving from the same region as Baltic amber versus suggested local origins within the Ukrainian Crystalline Shield must have been tested by a comparison of inclusions of the Rovno and other ambers. The study of Rovno ants confirms Rovno amber being autochthonous.
Helmeted frogs with co−ossified skulls (Thaumastosaurus) were previously known in Europe only in the Eocene on the basis of Thaumastosaurus bottii from southwestern France and Thaumastosaurus wardi from coastal southern England. We describe Thaumastosaurus sulcatus, that differs from these species in having a different dermal sculpture pattern and tooth morphology. We suggest that the auburn colored tooth crown tips in T. sulcatus, as in some other vertebrates, reflect extra hardness for protection against tooth wear. Autochthonous Thaumastosaurus species in southern England support the concept that southern England and southwestern France were distinct faunal provinces in the Late Eocene.
We review an ungulate mammalian fauna of the Eocene Pondaung Formation, central Myanmar, and herein describe new dental specimens. The taxa newly recognized in the Pondaung Formation are two indeterminate bunodont artiodactyls, two small “eomoropid” perissodactyls (Eomoropussp. cf. E. minimus and an indeterminate “eomoropid”), and a new deperetellid perissodactyl genus, Bahinolophus, which is established for Deperetella birmanica from the Pondaung Formation. The Pondaung ungulate fauna consists of 29 species (14 families and 18 genera): one species of an indeterminate small ungulate, 12 species (six genera in six families) of artiodactyls, and 16 species (11 genera in seven families) of perissodactyls. Although both Pondaung artiodactyls and perissodactyls are abundant and taxonomically diverse, the former are less diversified in generic numbers than the latter, but are nearly equal to the latter in abundance. Anthracotheriid artiodactyls and brontotheriid and amynodontid perissodactyls are the most abundant elements in the fauna. The estimated paleoecologies of the included taxa, the geologic and geographic evidence, and cenogram analysis suggest that the paleoenvironment of the Pondaung fauna was forested/woodland vegetation with humid/subhumid moisture and large rivers, which were located not far from the eastern Tethyan Sea. The age of the Pondaung fauna is independently correlated with the latest middle Eocene only on the basis of the stratigraphic, microfossil, and radiometric evidence, yielding a result consistent with mammalian faunal correlations. On the other hand, the Pondaung fauna includes many artiodactyl taxa compared to other middle Eocene faunas of East Asia and shows relatively high endemism at the generic level, implying that the Pondaung fauna is not formally included in the Eocene Asian Land Mammal “Ages” system.
Georges Cuvier (1798) established the classical concept of Edentata which included sloths, anteaters, armadillos, aardvarks, and pangolins. With the growing body of comparative morphological data becoming available during the nineteenth century, it was evident that Cuvier's “Edentata” was an artificial group (e.g., Huxley 1872). In his classical textbook, Weber (1904) excluded aardvarks and pangolins from the Edentata and put them in separate orders, Tubulidentata and Pholidota. Later on, fossil taxa were repeatedly added to and removed from Edentata, such as various xenarthran groups, taeniodonts, palaeanodonts, and gondwanatheres, but the South American Xenarthra always was considered as their core group. Even the living order Pholidota has been cited again as ?Edentata incertae sedis many years after Weber’s work (Romer 1966). The validity and extent of a higher taxon Edentata are still in dispute. In this discussion, the Middle Eocene pholidotan Eomanis and the putative xenarthran Eurotamandua from Grube Messel near Darmstadt (Germany) play an important role (Storch 1978, 1981, 2003; Rose and Emry 1993; Gaudin and Branham 1998; Rose 1999). Eomanis krebsi and Eurotamandua joresi have been subject to some discussion regarding their taxonomic distinction. It has been suggested that the only specimen known of Eo. krebsi might actually be a juvenile representative of the senior species E. joresi. A reexamination of the type specimen of Eo. krebsi has yielded some new observations regarding the identity of some of its ankle elements. An element that was previously identified as a navicular, is here reidentified as a partial distal tibia, whereas a partially exposed calcaneus had gone unnoticed. These two elements display several differences in morphology between Eo. krebsi and E. joresi, indicating that these are in fact distinct species.
Spider wasps had long been proposed to originate in the Late Cretaceous based on the Burmese amber fossil Bryopompilus interfector. We performed a morphological examination of this fossil and determined that it does not belong to Pompilidae or any other described hymenopteran family. Instead, we place it in the new family Bryopompilidae. The oldest verifiable member of the Pompilidae is from Baltic amber, which suggests that the crown group of the family probably originated in the Eocene, not in the Late Cretaceous as previously proposed. The origin of spider wasps appears to be correlated with an increase in spider familial diversity in the Cenozoic. We also add two genera to the extinct pompilid fauna: Tainopompilus Rodriguez and Pitts gen. nov. and Paleogenia Waichert and Pitts gen. nov., and describe three new species of fossil spider wasps: Anoplius planeta Rodriguez and Pitts sp. nov., from Dominican amber (Burdigalian to Langhian); Paleogenia wahisi Waichert and Pitts sp. nov., from Baltic amber (Lutetian to Priabonian); and Tainopompilus argentum Rodriguez and Pitts sp. nov., from Dominican amber (Chattian to Langhian).
The male subimago of Analetris secundus sp. nov. is described and illustrated from the Eocene Baltic amber. A new species presents the first fossil representative of the previously monotypie genus Analetris Edmunds, 1972. The extant species Analetris eximia Edmunds, 1972 is known from the Northwestern of the North America. Critical characters distinguishing these both species are discussed.
The new genera and species of the new fossil tribe Protodikraneurini trib. nov. of leafhoppers (Cicadellidae: Typhlocybinae) are described. The new genera and species are: Protodikraneura gen. nov. with Protodikraneura cephalica sp. nov. and Protodikraneura nasti sp. nov., Stareono mirabilis gen. nov. and sp. nov. The keys to recently recognized tribes of Typhlocybinae is given. Taxonomie position of Protodikraneurini as well as extant tribes of Typhlocybinae is discussed. Some other fossils formerly believed to be representatives of Typhlocybinae and their placement is also discussed. "Typhlocyba" bremi Heer, 1855 is excluded from Typhlocybinae.
Asida groehni sp. nov. (Coleoptera, Tenebrionidae, Asidini) is described from Eocene Baltic amber from the Kaliningrad Region (Russia). This is the first fossil species belonging to the genus Asida Latreille, 1802 and only the eighth described darkling beetle species from Eocene Baltic amber. This species helps support the hypothesis that the climate in this part of Europe was warmer during Eocene, as no Asida species are currently present in the Baltic area due to not appropriate climate. This new fossil species is similar to modern Asida species in the subgenus Planasida Escalera, 1907, which occur in the Iberian Peninsula and the Maghreb, but it differs from all known Asida in pronotal sculpturing and pilosity, and by its yellow brown shiny cuticle, well visible on the pronotal disc. Despite species-level differences, the new extinct species appears to fit easily within the extant genus Asida.
A new neotenic salamander, Seminobatrachus boltyschkensis gen. et sp. nov., is described based on 14 skeletons of late Paleocene–early Eocene age preserved on drill core slabs from the Cherkassy Region, central Ukraine. The new taxon is diagnosed by the following unique combination of characters: dorsal process of premaxilla posteriorly elongate and overlaps frontal; maxilla greatly reduced in size; parietal–squamosal contact absent; vomerine tooth row long and parallel to maxillary arcade; pterygoid has long anterior process; quadrate ossified; marginal and palatal teeth pedicellate; trunk vertebrae amphicoelous, each having a subcentral keel, anterior basapophysis, and spinal nerve foramina; ribs bicipital; carpals and tarsals unossified; and phalangeal formulae of 2−2−3−2 and 2−2−3−4−2 for manus and pes, respectively. Phylogenetic analysis nests S. boltyschkensis within Urodela (i.e., crown−clade salamanders), but its exact phylogenetic position is equivocal, resolving in one of three ways: (1) in an unresolved trichotomy with Salamandra and (Ambystomatidae + (Dicamptodon + Rhyacotriton)) (results obtained in NONA v. 2.0, with the WINCLADA v. 1.00.08 interface; the parsimony ratchet (island hopper) algorithm), (2) as a sister taxon of (Salamandra + (Ambystomatidae + (Dicamptodon + Rhyacotriton))) clade (results obtained in TNT v. 1.1; the implicit enumeration search algorithm) or (3) as a sister taxon of Ambystomatidae (results obtained in PAUP v. 4.0b10; the branch−and−bound search algorithm).
“Miacid” carnivorans comprise one of the modern mammal groups appearing around the Palaeocene–Eocene Thermal Maximum (PETM) in the Northern Hemisphere. Here we describe a new very small “miacid” carnivoran from the earliest Eocene of Dormaal, Belgium, that shares a particular dental morphology with the species “Miacis” winkleri and “Miacis” rosei from the early Eocene of North America. The three species present very gracile and sharp teeth, and are hereby placed in the new genus Gracilocyon. Comparative dental analysis of Gracilocyon with other early “miacids” contributes to better resolve the polarity of dental characters and indicates that this genus is one of the most primitive members of the family. Diversity of early modern carnivorans is greater than previously considered and early “miacids” seem to have dispersed into North America from two different geographic origins.
The lacustrine oil shales of the Coal Creek Member of the Kishenehn Formation in northwestern Montana comprise a relatively unstudied middle Eocene fossil insect locality. Herein, we detail the stratigraphic position of the fossiliferous unit, describe the insect fauna of the Coal Creek locality and document its bias towards very small but remarkably preserved insects. In addition, the depositional environment is examined and the mineral constituents of the laminations that comprise the varves of the Kishenehn oil shale are defined. Fifteen orders of insects have been recorded with the majority of all insects identified as aquatic with the families Chironomidae (Diptera) and Corixidae (Hemiptera) dominant. The presence of small aquatic insects, many of which are immature, the intact nature of >90% of the fossil insects and the presence of Daphnia ephippia, all indicate that the depositional environment was the shallow margin of a large freshwater lake. The fossil insects occur within fossilized microbial mat layers that comprise the bedding planes of the oil shale. Unlike the fossiliferous shales of the Florissant and Okanagan Highlands, the mats are not a product of diatomaceous algae nor are diatom frustules a component of the sediments or the varve structure. Instead, the varves are composed of very fine eolian siliciclastic silt grains overlaid with non-diatomaceous, possibly cyanobacteria-derived microbial mats which contain distinct traces of polyaromatic hydrocarbons. A distinct third layer composed of essentially pure calcite is present in the shale of some exposures and is presumably derived from the seasonal warming-induced precipitation of carbonate from the lake's waters. The Coal Creek locality presents a unique opportunity to study both very small middle Eocene insects not often preserved as compression fossils in most Konservat-Lagerstätte and the processes that led to their preservation.
A new species of the genus Dicranomyia Stephens, 1829 (Diptera: Limoniidae) from Baltic amber (Eocene) is described. The characteristic feature distinguishing a new species, D. gorskii sp. nov. is the presence of the surprisingly strong and elongate spine on rostral prolongation of ventral gonostylus. The morphological features of the new species are briefly discussed. New replacement name Dicranomyia alexandri nom. nov. for Dicranomyia nagellata (Alexander, 1931) is proposed to avoid with Dicranomyia nagellata Edwards, 1928.
The pelecypod assemblage from Upper Eocene sandy deposits of the vicinity of Siemień and Luszawa (eastern part of the Polish Lowlands) consists of 23 species. The majority of the species are typical of the Bartonian.
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