Nacholapithecus skeleton from the Middle Miocene of Kenya

An almost entire skeleton of a male individual of Nacholapithecus kerioi (KNM-BG 35250) was discovered from Middle Miocene (approximately 15 Ma) sediments at Nachola, northern Kenya. N. kerioi exhibits a shared derived subnasal morphology with living apes. In many postcranial features, such as articular shape, as well as the number of the lumbar vertebrae, N. kerioi resembles Proconsul heseloni and/or P. nyanzae, and lacks suspensory specializations characteristic of living apes. Similarly, N. kerioi shares some postcranial characters with Kenyapithecus spp. However, despite the resemblance, N. kerioi and Proconsul spp. are quite different in their body proportions and some joint morphologies. N. kerioi has proportionally large forelimb bones and long pedal digits compared to its hindlimb bones and lumbar vertebrae. Its distinctive body proportions suggest that N. kerioi was more derived for forelimb dominated arboreal activities than P. nyanzae and P. heseloni. On the other hand, it exhibits a mixture of derived and primitive cranio-dental and postcranial features relative to the contemporaneous Kenyapithecus and Early MioceneMorotopithecus. While the phylogenetic position of N. kerioi is unsettled, it seems necessary to posit parallel evolution of cranio-dental and/or postcranial features in fossil and living apes.     

New Catarrhine fossils from Moroto II, Early Middle Miocene (ca 17.5 Ma) Uganda

During the 1998–2003 field seasons of the Uganda Palaeontology Expedition, dental remains of three catarrhine species were recovered from Moroto II, Uganda. Micromammals from the locality indicate a late Early Miocene to basal Middle Miocene (ca 17.5–17 Ma) age, younger than Rusinga (17.8 Ma), but similar in age to Buluk (17.2 Ma) and Kalodirr (17.2 Ma). This paper describes and interprets new catarrhines from the site, one of which is a victoriapithecid monkey, the second a new genus and species of small-bodied ape, and the third a large hominoid. A fourth species collected in the 1960's is attibuted to Afropithecus turkanensis. To cite this article: M. Pickford et al., C. R. Palevol 2 (2003).     

Gradual evolution in the African hunting dog lineage Systematic implications

The hunting dog, Lycaon pictus, is one of the most representative species of the extant African fauna and one of the most efficient predators in the World. This species is actually a relict within Sub-Saharan Africa, but its lineage is well recorded in Eurasia during the Pliocene, and in Eurasia and Africa during the Early Pleistocene, while its record during the Middle Pleistocene is not well documented. Though postcranial skeletal remains dating from the Early Pleistocene show a tetradactyl forelimb, a characteristic feature of the extant lycaon, unique among canids, the upper and lower dentitions show gradual evolution from a primitive morphology in the Late Pliocene specimens to the highly specialized trenchant carnassials of the extant predatory species. We propose a new systematics for the lineage, grouping all the forms within the genus Lycaon. To cite this article: B. Martínez-Navarro, L. Rook, C. R. Palevol 2 (2003).     

New observations on the Late Miocene–Early Pliocene Lutrinae (Mustelidae: Carnivora,Mammalia) from the Middle Awash,Afar Rift,Ethiopia

New observations on the Late Miocene and Earliest Pliocene mustelids from the Middle Awash of Ethiopia are presented. The Middle Awash study area samples the last six million years of African vertebrate evolutionary history. Its Latest Miocene (Asa Koma Member of the Adu-Asa Formation, 5.54–5.77 Ma) and Earliest Pliocene (Kuseralee and Gawto Members of the Sagantole Formation, 5.2 and 4.85 Ma, respectively) deposits sample a number of large and small carnivore taxa among which mustelids are numerically abundant. Among the known Late Miocene and Early Pliocene mustelid genera, the Middle Awash Late Miocene documents the earliest Mellivora in eastern Africa and its likely first appearance in Africa, a new species of Plesiogulo, and a species of Vishnuonyx. The latter possibly represents the last appearance of this genus in Africa. Torolutra ougandensis is known from both the Late Miocene and Early Pliocene deposits of the Middle Awash. The genus Sivaonyx is represented by at least two species: S. ekecaman and S. aff. S. soriae. Most of the lutrine genera documented in the Middle Awash Late Miocene/Early Pliocene are also documented in contemporaneous sites of eastern Africa. The new observations presented here show that mustelids were more diverse in the Middle Awash Late Miocene and Early Pliocene than previously documented.     

Taxonomic attribution of the La Grive hominoid teeth

The two hominoid teeth—a central upper incisor (NMB G.a.9.) and an upper molar (FSL 213981)—from the Middle Miocene site of La Grive‐Saint‐Alban (France) have been traditionally attributed to Dryopithecus fontani (Hominidae: Dryopithecinae). However, during the last decade discoveries in the Vallès‐Penedès Basin (Spain) have shown that several hominoid genera were present in Western Europe during the late Middle Miocene. As a result, the attribution of the dryopithecine teeth from La Grive is not as straightforward as previously thought. In fact, similarities with the upper incisor of Pierolapithecus have led to suggestions that either the latter taxon is present at La Grive, or that it is a junior synonym of Dryopithecus. Here, we re‐describe the La Grive teeth and critically revise their taxonomic assignment based on metrical and morphological comparisons with other Middle to Late Miocene hominoids from Europe and Turkey, with particular emphasis on those from the Vallès‐Penedès Basin. Our results suggest that the I¹ differs in several respects from those of Pierolapithecus and Hispanopithecus, so that an attribution to either Dryopithecus or Anoiapithecus (for which this tooth is unknown) seems more likely. The molar, in turn, most likely corresponds to the M¹ of a female individual. Compared to other Middle Miocene taxa, its occlusal morphology enables its distinction from Pierolapithecus, whereas relative crown height agrees well with Dryopithecus. Therefore, based on available evidence, we support the traditional attribution of the La Grive hominoid to D. fontani. Am J Phys Anthropol 151:558–565, 2013. © 2013 Wiley Periodicals, Inc.     

The oldest Eurasian hominoid.

Engelswies is an early Miocene vertebrate locality in southern Germany with a rich assemblage of terrestrial mammals, invertebrates and fossil plants. It is dated to 16.5-17.0 Ma based on magnetostratigraphy, biostratigraphy and lithostratigraphy, and includes among the faunal remains a hominoid upper molar fragment, the oldest hominoid so far identified from Europe. The evidence from Engelswies suggests that hominoids arrived in Eurasia about 17 Ma, roughly contemporaneously with pliopithecoids and Deinotherium, and before the last marine transgression to isolate Eurasia from Africa. Thick enamel and low dentine penetrance may have been key adaptations that contributed to the success of hominoids of dentally modern aspect in western Eurasia and ultimately to their ability to spread to eastern Eurasia and Africa in the middle and late Miocene.     

Small mammal (rodents and lagomorphs) European biogeography from the Late Oligocene to the mid Pliocene

Aim To analyse the fossil species assemblages of rodents and lagomorphs from the European Neogene in order to assess what factors control small mammal biogeography at a deep‐time evolutionary time‐scale. Location Western Europe: 626 fossil‐bearing localities located within 31 regions and distributed among 18 successive biochronological units ranging from c. 27 Ma (million years ago; Late Oligocene) to c. 3 Ma (mid Pliocene). Methods Taxonomically homogenized pooled regional assemblages are compared using the Raup and Crick index of faunal similarity; then, the inferred similarity matrices are visualized as neighbour‐joining trees and by projecting the statistically significant interregional similarities and dissimilarities onto palaeogeographical maps. The inferred biogeographical patterns are analysed and discussed in the light of known palaeogeographical and palaeoclimatic events. Results Successive time intervals with distinct biogeographical contexts are identified. Prior to c. 18 Ma (Late Oligocene and Early Miocene), a relative faunal homogeneity (high interregional connectivity) is observed all over Europe, a time when major geographical barriers and a weak climatic gradient are known. Then, from the beginning of the Middle Miocene onwards, the biogeography is marked by a significant decrease in interregional faunal affinities which matches a drastic global climatic degradation and leads, in the Late Miocene (c. 11 Ma), to a marked latitudinal pattern of small mammal distribution. In spite of a short rehomogenization around the Miocene/Pliocene boundary (6–4 Ma), the biogeography of small mammals in the mid Pliocene (c. 3 Ma) finally closely reflects the extant situation. Main conclusions The resulting biogeographical evolutionary scheme indicates that the extant endemic situation has deep historical roots corresponding to global tectonic and climatic events acting as primary drivers of long‐term changes. The correlation of biogeographical events with climatic changes emphasizes the prevalent role of the climate over geography in generating heterogeneous biogeographical patterns at the continental scale.     

Parallel evolution in the hominoid trunk and forelimb

The evolutionary history of the living hominoids has remained elusive despite years of exploration and the discovery of numerous Miocene fossil ape species. Part of the difficulty can be attributed to the changing nature of our views about the course of hominoid evolution. In the 1950s and 1960s, individual Miocene taxa were commonly viewed as the direct ancestors of specific living ape species, suggesting an early divergence of the modern lineages.^1–5 However, in most cases, the Miocene forms were essentially “dental apes,” resembling extant species in dental and a few cranial features, but possessing more primitive postcranial features that suggested arboreal quadrupedalism rather than suspensory habits. With the introduction of molecular methods of phylogenetic reconstruction and the increasing use of cladistic analysis, it has become apparent that the radiation leading to the modern hominoids was somewhat more recent than had been believed, and that most of the Miocene hominoid species had little to do with the evolutionary history of the living apes. © 1998 Wiley-Liss, Inc.     

First hominoid from the Late Miocene of the Irrawaddy Formation (Myanmar)

For over a century, a Neogene fossil mammal fauna has been known in the Irrawaddy Formation in central Myanmar. Unfortunately, the lack of accurately located fossiliferous sites and the absence of hominoid fossils have impeded paleontological studies. Here we describe the first hominoid found in Myanmar together with a Hipparion (s.l.) associated mammal fauna from Irrawaddy Formation deposits dated between 10.4 and 8.8 Ma by biochronology and magnetostratigraphy. This hominoid documents a new species of Khoratpithecus, increasing thereby the Miocene diversity of southern Asian hominoids. The composition of the associated fauna as well as stable isotope data on Hipparion (s.l.) indicate that it inhabited an evergreen forest in a C3-plant environment. Our results enlighten that late Miocene hominoids were more regionally diversified than other large mammals, pointing towards regionally-bounded evolution of the representatives of this group in Southeast Asia. The Irrawaddy Formation, with its extensive outcrops and long temporal range, has a great potential for improving our knowledge of hominoid evolution in Asia.     

Bio-magnetostratigraphy and environment of the oldest Eurasian hominoid from the Early Miocene of Engelswies (Germany)

The paleobiogeography of hominoids exhibits a puzzling pattern of migrations between and within Africa and Eurasia. A precise dating of hominoid-bearing localities is therefore essential to reveal the timing, direction and possible causes of dispersals. Here, we present a bio-magnetostratigraphic analysis of the section of Engelswies (Southern Germany, Upper Freshwater Molasse, North Alpine Foreland Basin) where the oldest Eurasian hominoid was found. Our paleomagnetic results reveal a very short normal and a reverse magnetic polarity for the entire section. The polarity record is correlated to the Astronomical Tuned Neogene Time Scale using an integrated stratigraphic approach. This approach follows the chronostratigraphic framework for the Upper Freshwater Molasse, which combines magnetostratigraphy with biostratigraphic, lithostratigraphic and ⁴⁰Ar/³⁹Ar dating results. According to this outcome, the reverse polarity of the Engelswies section most likely correlates to magnetochron C5Cr. The origin of the short normal polarity remains enigmatic. The magnetostratigraphic calibration and the evolutionary level of the Engelswies small mammal fauna suggest an age of 17.1-17.0 Ma (Early Karpatian, Early Miocene) for the oldest Eurasian hominoid, and roughly confirm the estimates of Heizmann and Begun (2001). The estimated age suggests that the first hominoids in Eurasia are contemporaneous with Afro-Arabian afropithecins, and dispersal may have been facilitated by intra-Burdigalian (∼18-17 Ma) sea-level low stands and the beginning of the Miocene Climate Optimum. The paleoclimatic and environmental reconstruction of the Engelswies locality indicates a lakeshore environment near dense subtropical rain forest vegetation, where paratropical temperatures (mean annual temperature around 20 °C) and humid conditions (mean annual precipitation > 1.100 mm) prevailed.     

The Miocene floras of Iceland and their significance for late Cainozoic North Atlantic biogeography

A large number of plant macrofossils from several Middle to Upper Miocene localities from Iceland have been studied. The fossil material includes four ferns and fern allies, seven conifers, and about 40 species of flowering plants. Betula islandica and Salix gruberi are described as new species. Coniferous twigs previously ascribed to the genus Sequoia are shown to belong to Cryptomeria based on macro‐morphological and epidermal features. Fossil plants from Iceland are compared with coeval fossil taxa from Europe and North America and with living plants. The main finding is that the Miocene flora of Iceland belongs to a widespread Neogene northern hemispheric floral type including plants whose representatives are restricted to East Asia, North America and to western Eurasia at the present time. Previously inferred conspicuous similarities to North American modern equivalents appear to be misleading. The type of vegetation in four plant‐bearing sedimentary formations from the late Mid Miocene to Late Miocene, the 12 Ma Brjánslækur‐Seljá Formation, the 10 Ma Tröllatunga‐Gautshamar Formation, the 9–8 Ma Skarðsströnd‐Mókollsdalur Formation, and the 7–6 Ma Hreðavatn‐Stafholt Formation, corresponds to a humid temperate broadleaved (deciduous)–coniferous mixed forest dominated by Betulaceae, Fagaceae and Acer. Changes in species composition in the sedimentary formations reflect a shift from warm temperate (Cfa climate) to cool temperate (Cfb climate) conditions from the late Mid Miocene to the latest Miocene. This shift was connected to repeated phases of extinction and colonization. Specifically, one set of thermophilic taxa including Magnolia, Liriodendron, Sassafras and Comptonia went extinct between 12 and 10 Ma, and appears to have been replaced by another set of thermophilic taxa in the 10 Ma formation (Juglandaceae aff. Pterocarya/Cyclocarya, Rhododendron ponticum type). The 9–8 and 7–6 Ma formations are characterized by taxa that migrated to Iceland from Europe, such as Fagus gussonii, Betula cristata and Pterocarya fraxinifolia type. Although there is convincing evidence that plants colonized Iceland both from North America and Europe until 12 Ma, migration in the younger formations (9–8, 7–6 Ma) is suggested to have occurred mainly from Europe. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society, 2005, 149 , 369–417.     

Earliest colobine skeletons from Nakali,Kenya

Old World monkeys represent one of the most successful adaptive radiations of modern primates, but a sparse fossil record has limited our knowledge about the early evolution of this clade. We report the discovery of two partial skeletons of an early colobine monkey (Microcolobus) from the Nakali Formation (9.8–9.9 Ma) in Kenya that share postcranial synapomorphies with extant colobines in relation to arboreality such as mediolaterally wide distal humeral joint, globular humeral capitulum, distinctly angled zona conoidea, reduced medial trochlear keel, long medial epicondyle with weak retroflexion, narrow and tall olecranon, posteriorly dislocated fovea on the radial head, low projection of the femoral greater trochanter, wide talar head with a greater rotation, and proximodistally short cuboid and ectocuneiform. Microcolobus in Nakali clearly differs from the stem cercopithecoid Victoriapithecus regarding these features, as Victoriapithecus is postcranially similar to extant small‐sized terrestrial cercopithecines. However, degeneration of the thumb, a hallmark of modern colobines, is not observed, suggesting that this was a late event in colobine evolution. This discovery contradicts the prevailing hypothesis that the forest invasion by cercopithecids first occurred in the Plio‐Pleistocene, and shows that this event occurred by the late Miocene at a time when ape diversity declined. Am J Phys Anthropol 143:365‐382, 2010. © 2010 Wiley‐Liss, Inc.     

On the adaptive pattern of "Ramapithecus".

A reconstruction of the adaptive pattern of the Miocene hominoid "Ramapithecus," supported by comparative data and morphological comparisons, is presented. It is based upon the completely known dentition, inferior portion of the face, and on the paleoecology and geographic distribution of "Ramapithecus" bearing deposits. The known adaptive and morphological patterns of the "Ramapithecus" species are almost indistinguishable from those of the contemporary species of Sivapithecus, which has taxonomic priority. The "Ramapithecus" species are therefore referred to Sivapithecus, a dryopithecine genus which apparently radiated throughout Eurasia and Africa during the Middle Miocene.     

Palaeoenvironments and the origin of hominid bipedalism

Abstract

It has long been accepted that hominids emerged during the Pliocene in a savannah environment in which a terrestrial quadruped gradually developed bipedal adaptations. However, data from the Late Miocene (i.e. 7–7.5 Ma), including detailed palaeontological and biogeochemical studies, suggest that our earliest Upper Miocene ancestors inhabited well-wooded to forested environments where they could have spent a certain amount of time in the trees. A plausible type of ecosystem in which upright posture and bipedal locomotion could have emerged is represented by Miombo Woodland, in which vertical arboreal supports predominate and trees are separated from each other by gaps. Subsequently hominids dispersed into the Savannah as accomplished bipeds, but retained the ability to climb trees. This scenario is compatible with the postcranial anatomy of Australopithecus, including its femoral elongation, body proportions, manual precision grip (also present in 6-million-year-old Orrorin) and a non-prehensile hallux.     

Additional specimens of Hyracoidea (Mammalia) from the Early and Middle Miocene of Kenya

We describe unpublished material of the poorly known hyracoid, Brachyhyrax aequatorialis from the Early Miocene of Songhor and Koru, Kenya, on the basis of specimens stored in the Community Museums of Kenya, the National Museums of Kenya and the Natural History Museum, London. As a result, we added 17 specimens to the hypodigm of this species which was previously known from only seven specimens. In addition, we describe further material of another hyracoid, Afrohyrax championi, from the Early Miocene of Mfwangano and the Middle Miocene of Kipsaraman. The chronological distributions of the two hyracoids do not overlap. Brachyhyrax appears to have lived in forest environments, a suggestion supported by its brachyodont dentition and the associated molluscan fauna, whereas Afrohyrax seems to have lived in more open wooded habitats which agree with its slightly more hypsodont dentition and the cursorial postcranial skeleton as well as with the land snails that occur with it.     

Knee function through finite element analysis and the role of Miocene hominoids in our understanding of the origin of antipronograde behaviours: the Pierolapithecus catalaunicus patella as a case study

Although extensive research has been carried out in recent years on the origin and evolution of human bipedalism, a full understanding of this question is far from settled. Miocene hominoids are key to a better understanding of the locomotor types observed in living apes and humans. Pierolapithecus catalaunicus, an extinct stem great ape from the middle Miocene (c. 12.0 Ma) of the Vallès-Penedès Basin (north-eastern Iberian Peninsula), is the first undoubted hominoid with an orthograde (erect) body plan. Its locomotor repertoire included above-branch quadrupedalism and other antipronograde behaviours. Elucidating the adaptive features present in the Pierolapithecus skeleton and its associated biomechanics helps us to better understand the origin of hominoid orthogrady. This work represents a new biomechanical perspective on Pierolapithecus locomotion, by studying its patella and comparing it with those drawn from a large sample of extant anthropoids. This is the first time that the biomechanical patellar performance in living non-human anthropoids and a stem hominid has been studied using finite element analysis (FEA). Differences in stress distribution are found depending on body plan and the presence/absence of a distal apex, probably due to dissimilar biomechanical performances. Pierolapithecus’ biomechanical response mainly resembles that of great apes, suggesting a similar knee joint use in mechanical terms. These results underpin previous studies on Pierolapithecus, favouring the idea that a relevant degree of some antipronograde behaviour may have made up part of its locomotor repertoire. Moreover, our results corroborate the presence of modern great ape-like knee biomechanical performances back in the Miocene.     

Neogene planktonic foraminiferal biostratigraphy and evolution: Equatorial to subantarctic, South Pacific

Detailed planktonic foraminiferal zonations have been established for the Neogene (Latest Oligocene through present) in six DSDP sites in the South Pacific ranging from equatorial to subantarctic latitudes (48°S). Two basic zonal schemes are readily recognized: tropical and temperate. The tropical zonation is best developed in DSDP Site 289 and the temperate zonation in Sites 206, 207A and 284. Tropical and temperate zonations can be linked by a warm subtropical scheme in Site 208, because this sequence includes a mixture of tropical and temperate elements. A site located close to the Subantarctic Convergence (Site 281) contains a zonation largely of temperate character, but the present of cooler elements and some differences in biostratigraphic ranges have required a slightly different biostratigraphic scheme.Although two broad schemes are recognized, none of the biostratigraphic sequences are identical between any of the sites. This reflects differences in biogeography, evolution and diachronous extinction at various latitudes during the entire Neogene. Diachronism in biostratigraphic ranges continue to create difficulties in correlation across such wide latitudes.Our detailed work has required the establishment of new biostratigraphic zonations in certain parts of the Neogene sequence and modifications in some other parts. Otherwise, previously established schemes are followed as closely as possible. In the temperate region, a new zonation has been established for the Early Miocene to early Middle Miocene. For the remainder of the Neogene the zonation of Kennett (1973) has been largely used. The tropical zonation of Blow (1969) is employed in the equatorial Site 289, but with further subdivisions for Zones N4 and N17. For areas intermediate between tropical and temperate latitudes (Site 208), a modified Early Miocene zonation is established based on changes in tropical and temperate elements.The zonal schemes are established on taxa that exhibit both diachronous and isochronous ranges across the latitudes. Zones that are at least partly diachronous include the Globigerinoides trilobus and Globorotalia miozea Zones of Early Miocene age; perhaps the Globorotalia mayeri Zone (its base) of the Middle Miocene; the Globorotalia conomiozea Zone of the Late Miocene; and the Globorotalia crassaformis Zone of the Early Pliocene.A large number of datum levels are recognized based on first evolutionary appearances or extinctions. The most widely applicable datums are as follows: latest Oligocene — Globigerinoides F.A.; Early Miocene — Globoquadrina dehiscens, F.A., Globorotalia kugleri L.A., Catapsydrax dissimilis L.A. and Praeorbulina glomerosa F.A.; Middle Miocene — Orbulina suturalis F.A., Globorotalia peripheroacuta F.A., Fohsella lineage L.A., Globorotalia mayeri L.A.; Late Miocene — “Neogloboquadrina” continuosa L.A., Globoquadrina dehiscens L.A., Globorotalia cibaoensis F.A.; Early Pliocene — Globorotalia puncticulata F.A., Globorotalia margaritae F.A.; Early Pleistocene — Globorotalia truncatulinoides F.A. A number of other datums are identified which assist with correlation over more restricted latitudinal ranges.The evolution of most Neogene planktonic foraminifera is now well established for a wide range of water masses. Evolutionary lineages are primarily centered in the temperate and tropical regions. Tropical lineages have recently been reviewed by Srinivasan and Kennett (1981) and are not discussed in detail here. However, Sphaeroidinellopsis seminulina is now considered to have evolved directly into S. paenedehiscens during the Late Miocene and S. subdehiscens Blow is considered to be junior synonym of S. seminulina.A new evolutionary lineage is recognized in the warm subtropics (Site 208) whereby Globigerina woodi woodi gave rise to Globigerinoides subquadratus via Globigerina brazieri. The discovery of this lineage clearly demonstrates that Globigerinoides is a polyphyletic “genus”. Another major phylogenetic lineage is recognized within the temperate globorotaliids of Early Miocene age as follows: “N.” continuosa → Globorotalia zealandica incognita → G. zealandica zelandica → G. praescitula → G. miozea. Although parts of this lineage have been recognized earlier, the entire phylogeny has previously been underscribed.A new Early to Middle Miocene lineage is recognized in the subantarctic to temperate areas which involve a transition from Globorotalia praescitula to G. challengeri n. sp. via intermediate forms.Two major Neogene globorotaliid lineages — the Menardella of the tropics and Middle Miocene to Recent forms of Globoconella of the temperate areas — are both considered to have evolved from Globorotalia praescitula beginning in the Early Miocene. This evolution initially was restricted to temperate areas but has since separated into distinctly tropical and temperate phylogenetic elements.     

A new Miocene fauna of snakes from eastern Siberia,Russia.: Was the snake fauna largely homogenous in Eurasia during the Miocene?

Togay, a locality from Ol’khon Island, Baykal Lake, Russia, has yielded a fauna of snakes of Late Middle or early Late Miocene age. It is located in a broad area from which no Neogene snake has been reported; therefore, it represents an important landmark. The fauna includes a non-erycine boid, two or three colubrids, a viperid of the ‘oriental complex’ of Vipera, and perhaps another viperid. This assemblage is astonishingly reminiscent of the snake faunas from the late Early and early Middle Miocene from western and central Europe, it being understood that Miocene faunas are practically unknown in the geographically intermediary area. It may be entertained whether a homogenous snake fauna inhabited Eurasia (except the southern part of the continent) during the Miocene.