Oligocene Of Europe Research Articles

Petrology of the 31.6 Ma Central Rhodope Perelik monotonous intermediate ignimbrite eruption

Volcanism during the Priabonian–Oligocene times (35–27 Ma) in the Rhodope Massif produced large volume of shoshonitic and calcalkaline lavas and three large volume silicic ignimbrites and fallout deposits. The youngest of these ignimbrites, named here as Perelik ignimbrite (PI), consists of three areas, previously described as three separate ignimbrite units, namely Bratsigovo-Dospat, Perelik and Kotili-Vitina. The ~300 m thick ignimbrites cover an area of 700 km2, 220 km2 and 350 km2, respectively. Our study demonstrates that these ignimbrites have identical ages of ~31.6 Ma and mineral and chemical compositions and are parts of a single large eruption. Based on these data, we suggest that the original areal coverage was much larger, possibly 3000 km2, with magma volume of ~1000 km3. These results classify the Perelik eruption as one of the largest European Oligocene supereruptions These ignimbrites have notably high phenocrystal content (40–50%) and are a relatively homogeneous chemical composition, which are characteristics features of the ‘monotonous intermediate’ ignimbrites. Here, we provide petrographic observations, and chemical and isotopic (Sr, Nd) analyses to explain the P-T conditions of crystallization of these ignimbrites.

First report of the genus Eggysodon from Asia

ABSTRACT We described a new pair of incomplete mandibles from the Qingshuiying locality, Northwest China, and referred it to Eggysodon, E. lingwuensis sp. nov. The new species has a typical mosaic assemblage of features: dp1 (or p1) is present at adult stage, but the symphysis is posteriorly elongated and the diastema distance between the canine and dp1 (or p1) is further shortened. In terms of the evolutionary stage, E. lingwuensis sp. nov. is more advanced than E. osborni, but comparable to that of E. gaudryi. Together with other mammals from the Qingshuiying locality, we suggested that the strata-produced new material was deposited during the Early Oligocene. On the other hand, the continental fauna exchange during the Palaeogene between Europe and Asia had very scarce records. Eggysodon has four species from the Oligocene of Europe. This record definitely confirmed that there is a migration route between Central Europe and East Asia during the Early Oligocene.

Hogs, hippos or bears? Paleodiet of European Oligocene anthracotheres and entelodonts

Anthracotheres and entelodonts are large mammals with peculiar morphological characteristics that combine plesiomorphic and derived features. The unusual anatomy of anthracotheres shows a morphological resemblance to pigs and hippos and their bunoselenodont low-crowned molars have been interpreted as an adaptation to frugivorous/folivorous diets. Entelodonts share cranial and dental similarities to pigs and carnivores, and this has been interpreted as an adaption to opportunistic omnivore diets, hunting/scavenging, or bone-crushing (cf. hyenas). The objective of the present study is to use dental microwear analysis to test these assumptions and to infer the diet of anthracotheres and entelodonts. Dental microwear was quantified on the upper and lower molars using a stereomicroscope. To assess the dietary traits of the fossil samples, the results were compared to a dataset of extant large mammals covering ten dietary categories. The microwear features indicate different diets for Anthracotherium sp. and Entelodon magnus. Our sample of entelodonts shows an omnivorous diet similar to that of the wild boar, and it probably varied considerably between seasons. The anthracotheres we analysed were opportunistic browsing, frugivore, and grazing herbivores. During the Oligocene, these two taxa occupied ecological niches characterised by a large diversity of food resources. The results of the study offer further insights into the characteristics of the digestive system in fossil artiodactyls. The large dataset used in this research opens new perspectives for the dietary reconstruction of poorly known mammal taxa by considering a wide range of diets.

The oldest articulated ranid from Europe: a Pelophylax specimen from the lowest Oligocene of Chartres-de-Bretagne (N.W. France)

ABSTRACT Ranids represent an important part of the extant anuran diversity of Europe. One of the best-known genera is Pelophylax (green-water frog). This genus is considered to have arrived in Europe during the Eocene/Oligocene transition, with numerous occurrences of the genus throughout European Oligocene sites. Unfortunately, most of the specimens are isolated bones, hampering our understanding of the diversity and evolution of the genus during this time. We here present the description of an incomplete but articulated anuran skeleton from the lowest Oligocene of Chartres-de-Bretagne (western France). This specimen, missing its head, preserves almost all postcranial bones articulated and skin impressions. The osteological description allows to assign this specimen to Pelophylax kl. esculentus, making it one of the oldest known occurrences of the genus. We also suggest that specimens assigned to the late Oligocene “Rana” aquensis should be referred to the genus Pelophylax. The presence of a Pelophylax in western Europe during the early Oligocene indicates that the genus had already spread throughout Europe, no later than 5 Ma after its emergence in the eastern part of the continent. It suggests that Pelophylax benefitted from the extinction of ranoids during the “Grande Coupure.”

Comparative anatomy of the passerine carpometacarpus helps illuminate the early fossil record of crown Passeriformes.

The hyper-diverse clade Passeriformes (crown group passerines) comprises over half of extant bird diversity, yet disproportionately few studies have targeted passerine comparative anatomy on a broad phylogenetic scale. This general lack of research attention hinders efforts to interpret the passerine fossil record and obscures patterns of morphological evolution across one of the most diverse clades of extant vertebrates. Numerous potentially important crown passeriform fossils have proven challenging to place phylogenetically, due in part to a paucity of phylogenetically informative characters from across the passerine skeleton. Here, we present a detailed analysis of the morphology of extant passerine carpometacarpi, which are relatively abundant components of the passerine fossil record. We sampled >70% of extant family-level passerine clades (132 extant species) as well as several fossils from the Oligocene of Europe and scored them for 54 phylogenetically informative carpometacarpus characters optimised on a recently published phylogenomic scaffold. We document a considerable amount of previously undescribed morphological variation among passerine carpometacarpi, and, despite high levels of homoplasy, our results support the presence of representatives of both crown Passeri and crown Tyranni in Europe during the Oligocene.

New pollen genera and species from the Oligocene of northern Spain and a systematic, biostratigraphic and biogeographic re-evaluation of coeval taxa

The deposits of the As Pontes Basin in north-west Spain yield extraordinarily well-preserved microfloral assemblages that have unmatched diversity within the European Oligocene. The comprehensive examination of 300 miospore taxa has led to the discovery of two new fossil pollen genera, Eucommiopsispollenites gen. nov. and Pistaciapollenites gen. nov., as well as seven new species: Eucommiopsispollenites compactus sp. nov., Eucommiopsispollenites gracilis sp. nov., Nymphaeapollenites asponticus sp. nov., Nymphaeapollenites perforatus sp. nov., Pistaciapollenites heteroporatus sp. nov., Punctilongisulcites cryptornatus sp. nov. and Symplocoipollenites diktyotos sp. nov. Moreover, the botanical affinity and geographic distribution of 13 additional species of particular interest are discussed in detail, because these are either recorded for the first time anywhere within the Paleogene (Lythraceaepollenites bavaricus, Myrtaceidites myrtiformis, Punctilongisulcites punctiechinatus, Rhuspollenites ornatus and Vitispollenites tener), in the Iberian Peninsula (Aglaoreidia pristina, Diospyrospollenites ovalis, Pseudospinaepollis pseudospinosus, Reevesiapollis reticulatus and Tricolporopollenites vancampoae), or are studied for the first time using scanning electron microscopy (SEM) (Pentapollenites regulatius, Polycolpites helmstedtensis and Triporopollenites robustus). SEM analysis has enabled the conclusive botanical assignment of two species: Polycolpites helmstedtensis, with affinity to the extant tropical genus Eriandra, and Triporopollenites robustus, related to Myricaceae. In view of these affinities, new combinations are proposed accordingly: Polygalacidites helmstedtensis comb. nov. and Myricipites robustus comb. nov. The results of this study carry significant biostratigraphic and palaeobiogeographic implications at a regional and wider, continental scale. Firstly, the similarities of the As Pontes microflora with other Oligocene assemblages located various thousands of kilometres apart indicates the spread of a relatively homogenous broadleaved evergreen flora in Europe and allows for the recognition of Myricipites robustus and the genus Pentapollenites as key biostratigraphic index taxa across the continent. Secondly, the last occurrence datums of thermophilous taxa that became extinct in the Eocene in more northern latitudes indicates that the Iberian Peninsula functioned as a refuge area for thermic vegetation at least since the early Oligocene. http://zoobank.org/urn:lsid:zoobank.org:pub:16AFE374-A8B4-4CE9-B5B4-31807E2A6962

A tiny, long-legged raptor from the early Oligocene of Poland may be the earliest bird-eating diurnal bird of prey

We report a small hawk-like diurnal bird from the early Oligocene (30–31 million years ago) of Poland. Aviraptor longicrus, n. gen. et sp. is of a size comparable with the smallest extant Accipitridae. The new species is characterized by very long legs, which, together with the small size, suggest an avivorous (bird-eating) feeding behavior. Overall, the new species resembles extant sparrowhawks (Accipiter spp.) in the length proportions of the major limb bones, even though some features indicate that it convergently acquired an Accipiter-like morphology. Most specialized avivores amongst extant accipitrids belong to the taxon Accipiter and predominantly predate small forest passerines; the smallest Accipiter species also hunts hummingbirds. Occurrence of a possibly avivorous raptor in the early Oligocene of Europe is particularly notable because A. longicrus coexisted with the earliest Northern Hemispheric passerines and modern-type hummingbirds. We therefore hypothesize that the diversification of these birds towards the early Oligocene may have triggered the evolution of small-sized avivorous raptors, and the new fossil may exemplify one of the earliest examples of avian predator/prey coevolution.

An early Oligocene stem Galbulae (jacamars and puffbirds) from southern France, and the position of the Paleogene family Sylphornithidae

AbstractTogether, puffbirds (Bucconidae) and jacamars (Galbulidae) form the suborder Galbulae, sister group of all other Piciformes. Hitherto, the Galbulae had no ascertained pre-Pleistocene fossil record, and all previous alleged candidates have been refuted, except possibly the Sylphornithidae. Here we describe a wing of a tiny fossil bird from the early Oligocene of the Luberon region (southern France), which we assign to the Galbulae, as a new genus and species. Several characters, especially of the ulna and wing phalanx 1 of digit II, exclude the Passeriformes and Zygodactylidae, and indicate a representative of the Piciformes. Among Piciformes, absence of papillae remigales caudales and several characters of the wing phalanx 1 of digit II make it possible to assign the fossil to the Galbulae, and exclude all other clades. The fossil Sylphornithidae, with the carpometacarpus of Sylphornis being available, show some similarity with the Luberon fossil. The combination of features of the wing elements leads to the placement of the new fossil as stem Galbulae, and tentatively within the family Sylphornithidae. As such, it fills a gap and permits to better assign the whole enigmatic tiny sylphornithids, otherwise essentially known from leg bones. This yields the first firm pre-Pleistocene fossil record for the Galbulae. Today, both the Bucconidae and Galbulidae live exclusively in tropical America. The presence of stem Galbulae in the Oligocene of Europe, and probably the late Eocene, is a new example of a present-day Neotropical clade that had stem representatives in the Paleogene of Europe.

A review of Oligocene and early Miocene European Cricetidae (Mammalia)

The aim of this paper is to analyze the contents of several genera of European Oligocene and early Miocene Cricetidae, their distinguishing characters, and their stratigraphic distribution. The genera discussed are Atavocricetodon, Eucricetodon, Pseudocricetodon, and Allocricetodon. Several groups are distinguished within the genus Eucricetodon and any of these may constitute a separate (sub)genus. Our results also suggest that Atavocricetodon and Eucricetodon should be retained as separated genera. We restrict our analysis to the European forms because we don’t know the Asiatic species

The Oligocene and Miocene fossil lizards (Reptilia, Squamata) of Central Mongolia

Lizard material from the early Oligocene and early and late Miocene of the Valley of Lakes, Central Mongolia is described. Besides the Oligocene fossorial squamate published elsewere, the material can be allocated to several major clades: Agamidae, Lacertidae and Anguidae (Glyptosaurinae). The presence of PseudotinosaurusAlifanov, 1991 in early and late Rupelian localities shows that this taxon has a continuous history in this area from the Eocene to the Oligocene. The same is true for the clade Glyptosaurinae, represented by isolated osteoderms in the early Oligocene locality Hsanda Gol. This might suggest that the Eocene-Oligocene transition did not have such a strong or rapid impact in East Asia, in contrast to the Grande Coupure in Europe, at least among some lizard clades. The early Oligocene (early Rupelian) lacertids from Taatsiin Gol, Hsanda Gol and Tatal Gol represent one of the oldest evidences of Asiatic dispersal of this clade. It might reflect the dispersal pathways after closure of the Turgai Strait between Europe and Asia. Some of the material closely resembles the common European Oligocene taxon Lacerta s.l. filholiAugé, 1988. In the early Miocene locality Olon Ovoony Khurem, two clades can be recognized – Lacertidae and a scincoid with a specialized dentition (family indeterminate). The clade Lacertidae forms a dominant component of the late Miocene lizard fossils in Mongolia. The material from the locality Builstyn Khudag shows differences compared to the early Miocene lacertids and represents the oldest evidence of the tribe Eremiadini in this area.

Nomenclatural novelties in the fossil genus Spinopalmoxylon (Arecaceae) from the Central European Oligocene and Miocene: A whole-plant concept for Spinopalmoxylon daemonorops

Abstract The fossil genus Spinopalmoxylon from the Central European Oligocene and Miocene comprises three species: S. daemonorops, S. parvifructum sp. nov. and S. cicatricosum sp. nov. Here the species S. daemonorops is amended and its name is proposed as nomen conservandum against S. teutonicum. A series of synonyms is provided. In addition, two new species are described from late Oligocene deposits of Niederpleis: S. parvifructum sp. nov. (pistillate inflorescence, fruits, and seeds) and S. cicatricosum sp. nov. (staminate inflorescence and pollen). These three Spinopalmoxylon species together are proposed as a whole plant. Floras with the Spinopalmoxylon palm reflect the vegetation of the near-shore fluvial floodplain and back-swamp environments of the late Oligocene (Chattian) Köln Formation (Clay 1) and early Miocene (Burdigalian) Ville Formation (Seam 6A) in the northern foreland of the Siebengebirge Volcanic Field near Bonn, at the southeastern margin of the Lower Rhine Basin.

A primitive honey bee from the Middle Miocene deposits of southeastern Yunnan, China (Hymenoptera, Apidae).

While fossils of honey bees (Apini: Apis Linnaeus) are comparatively abundant in European Oligocene and Miocene deposits, the available material from Asia is scant and represented by only a handful of localities. It is therefore significant to report a new deposit with a fossil honey bee from southern China. Apis (Synapis) dalica Engel & Wappler, sp. n., is described and figured from Middle Miocene sediments of Maguan County, southeastern Yunnan Province, China. This is the first fossil bee from the Cenozoic of southern China, and is distinguished from its close congeners present at the slightly older locality of Shanwang, Shandong in northeastern China. The species can be distinguished on the basis of wing venation differences from other Miocene Apis.

A new species of Zelkova (Ulmaceae, Ulmoideae) with leaves and fruits from the Oligocene of South China and its biogeographical implications

A new fossil species of Zelkova is described from the Oligocene Ningming Formation of Guangxi, South China. Zelkova ningmingensis sp. nov. is characterized by leaves with craspedodromous venation pattern and drupaceous fruit type. The new species possesses elliptical to ovate leaves, bearing 7–12 pairs of secondary and simple toothed margin, as well as epidermal cells with straight or rounded anticlinal walls. The species is compared with extant and other fossil species hitherto reported of the genus. It is most similar to the living Zelkova schneideriana in the leaf gross morphology and epidermal characters, which may be suggested to be the ancestral type of Zelkova schneideriana. The discovery of Zelkova ningmingensis sp. nov. in Guangxi indicates that Zelkova has already existed in southern China as early as the Oligocene. In combination with Zelkova material from the Oligocene of Europe, it can be inferred that Eurasian Zelkova had begun to diversify by at least the Oligocene. Because China is the biodiversity centre of modern Zelkova, the fossil herein provides new insights into Zelkova biogeography.

The new rare record of the late Oligocene lizards and amphisbaenians from Germany and its impact on our knowledge of the European terminal Palaeogene

There have been only a few studies on squamates from the late Oligocene of Europe, resulting in significant gaps in our knowledge of the reptile faunas from the latest Paleogene. Here, we report on new late Oligocene fossil material from two German localities, Herrlingen 11 (MP 28) and Herrlingen 9 (MP 29). The material can be assigned to the following major clades: Iguanidae, Gekkota, Lacertidae, Amphisbaenia, and Anguimorpha. The iguanid material shows that this clade was much more widely distributed in the Oligocene of Europe than previously thought, and also represents the youngest known record of this clade for Eurasia and Africa, with the exception of Madagascar. Although very fragmentary, the gekkotan material appears to be more similar to early Miocene forms such as Euleptes or Gerandogekko, rather than to early Oligocene taxa like Cadurcogekko, as indicated by the small size and morphology. The resemblance of the gekkotan fossils to Miocene forms suggests potential faunal turnover prior to the Paleogene–Neogene transition. The amphisbaenian material is represented by several types; the first can be allocated to Blanidae based on tooth count and the presence of a small 4th and an enlarged 3rd tooth, which is a derived feature. The second type is attributed to Palaeoblanus. Other cranial material is assigned to Amphisbaenia indet. The lacertid material consists of several amblyodont forms such as Dracaenosaurus, Pseudeumeces and Mediolacerta, as typically seen in other Oligocene deposits from Europe, but also includes non-ambylodont taxa such as Plesiolacerta and an undetermined lacertid. Especially common among the material are anguimorphs, which are here represented by Ophisaurus and a form that appears identical to the French Oligocene taxon described as coderetensis. Reinvestigation of the European Oligocene Dopasia (=Ophisaurus) shows that the taxa described as D. frayssensis and D. coderetensis are markedly different from the members of the clade Ophisaurus in the morphology of the posterior dentary region and that those taxa cannot be allocated to this genus. For this reason, we erected a new generic name: Ophisauromimus gen. nov. The composition of the Herrlingen fauna shows an interesting mix of ancient Paleogene and more modern Neogene faunal elements, while overall bearing many similarities to contemporaneous faunas from France.

A new genus for ‘Testudo’ gigas, the largest European Paleogene testudinid

ABSTRACTA new genus, Taraschelon, is proposed here for the largest tortoise known in the European Paleogene record. Its type and only known species, ‘Testudo’ gigas, was described in the first half of the 19th century. It comes from the French locality of Bournoncle-Saint-Pierre, in Auvergne (Haute-Loire). Extremely limited and partially incorrect information about this species has hitherto been available. Detailed study confirms the validity of this species and for the first time allows for a diagnosis. Taraschelon is the first genus of tortoise identified in the European Oligocene record, and one of the few genera known from the Paleogene of this continent. Comparison of Taraschelon with other primitive European forms shows an important diversity of Testudinidae in the Paleogene of this continent.http://zoobank.org/urn:lsid:zoobank.org:pub:EC5F5D27-243C-4C33-A99E-98B5762267A1Citation for this article: Pérez-García, A. 2015. A new genus for ‘Testudo’ gigas, the largest European Paleogene testudinid. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2015.1030024.

Milk tooth morphology of small-sized Hyaenodon (Hyaenodontidae, Mammalia) from the European Oligocene – evidence of a Hyaenodon lineage in Europe

Milk tooth morphology of small-sized Hyaenodon (Hyaenodontidae, Mammalia) from the European Oligocene – evidence of a Hyaenodon lineage in Europe

Oligocene killifishes (Teleostei: Cyprinodontiformes) from southern France: relationships, taxonomic position, and evidence of internal fertilization

Phylogenetic relationships of five species of Prolebias from the Oligocene of southern France (P. aymardi, P. cephalotes, P. delphinensis, P. meridionalis, and P. stenoura) were examined under an analysis comprising 36 terminal taxa, representing all the main lineages of the order Cyprinodontiformes. It indicated Prolebias as a polyphyletic group, supporting Prolebias stenoura, the type species of the genus, as a valenciid monotypic lineage. Prolebias aymardi and P. delphinensis comprise a new valenciid genus, Francolebias, gen. nov., diagnosed by a unique morphology of pelvic bone, anterior proximal radials of the dorsal fin and anal fins, and hemal spines in putative males. The apomorphic specialized morphology of the anal fin and adjacent vertebrae is interpreted as evidence of an internal fertilization reproductive mode. Prolebias meridionalis is designated as the type species of a new monotypic cyprinodontid genus, Eurolebias, gen. nov., hypothesized to be the sister group to a clade comprising all other cyprinodontids, which is diagnosed by the apomorphic morphology of jaws, parhypural, and absence of parietals. Close relationships between P. cephalotes, P. egeranus from the lower Miocene of Czech Republic, and recent species of the poeciliid genus Pantanodon are corroborated on the basis of the apomorphic morphology of the dentary, pharyngobranchials, pelvic bone, and pelvic-fin rays, justifying the transference of those two species to the latter genus. The present study indicates that the European Oligocene fauna of cyprinodontiform fishes was greatly diversified when compared to its present poor fauna, comprising lineages now extinct or restricted to other continents.

Presence of iguanid lizards in the European Oligocene Lazarus taxa and fossil abundance

Abstract During the Eocene, iguanid lizards were a diverse and widespread group in Europe. Prior to this study, no iguanid was known in Europe after the Eocene-Oligocene boundary. Some specimens from the locality of Pech-du-Fraysse (late Oligocene, MP28, France, Phosphorites du Quercy) are described. They belong to the Iguanidae, more precisely to the genus Geiseltaliellus, demonstrating that iguanid lizards survived the Eocene-Oligocene extinctions in Europe, only to disappear in the aftermath, certainly during the latest Oligocene. Thus, Geiseltaliellus is recognized as a Lazarus taxa. Explanations pertaining to the Lazarus effect are examined.

Anatomy of the coracoid and diversity of the Procellariiformes (Aves) in the Oligocene of Europe

Abstract: Two European species of the Diomedeoididae, an extinct family of procellariiform (tube‐nose) birds, have hitherto been distinguished primarily by size of their limb bones. Here, we describe an Early Oligocene (Rupelian) procellariifom coracoid that in all probability represents the larger species, Diomedeoides lipsiensis, and compare it to the coracoids of smaller diomedeoidids and extant procellariiforms. Using multivariate (Principal Component Analysis) and univariate analyses, we demonstrate that nearly all measurements are heavily size dependent, which makes the proportions and some other shape characters of little use as phylogenetic markers. Among eight measurements, the coracoid corpus width shows the highest correlation (higher than corpus depth) with body mass, permitting a precise calculation of over twofold difference in body mass between D. lipsiensis and smaller species. Among 16 qualitative characters analysed, the majority proved too variable to be used as markers of interfamily relationships and only 2–3, the ventral intermuscular line, sternocoracoid articulation (divided vs. undivided), and, with reservations, epimarginal crest vary consistently between the families. By far the most variable is the acrocoracoid process that tends to be deeper (more elongate dorsoventrally) in larger petrels but not in the albatrosses. However, the detailed shapes of the acrocoracoid heads are highly genus specific and suggest a genus‐level diversity among the Diomedeoididae from the Oligocene of Europe. The common features of the diomedeoidid coracoids are best interpreted as plesiomorphies, which accounts for some similarities to the Oceanitinae (that are probably basal among the crown‐group procellariiforms). The evidence from the coracoid is consistent with a stem‐group position of the Diomedeoididae as previously proposed by others. We emphasize the need of a group‐specific character analysis, primarily of allometries and levels of character variation, prior to a phylogenetic reconstruction.

Early Eocene frogs from Vastan Lignite Mine, Gujarat, India

The Ypresian Cambay Shale Formation of Vastan Lignite Mine in Gujarat, western India, has yielded a rich vertebrate fauna, including the earliest modern mammals of the Indian subcontinent. Here we describe its assemblage of four frogs, including two new genera and species, based on numerous, diverse and well-preserved ilia and vertebrae. An abundant frog, Eobarbourula delfinoi gen. and sp. nov., with a particular vertebral articulation similar to a zygosphene-zygantrum complex, represents the oldest record of the Bombinatoridae and might have been capable of displaying the Unken reflex. The large non-fossorial pelobatid Eopelobates, known from complete skeletons from the Eocene and Oligocene of Europe, is also identified at Vastan based on a single nearly complete ilium. An abundant “ranid” and a possible rhacophorid Indorana prasadi gen. and sp. nov. represent the earliest records of both families. The Vastan pelobatids and ranids confirm an early worldwide distribution of these families, and the bombina...