Zone MN Research Articles

Equidae in the Ngorora Formation, Kenya, and the first appearance of the family in East Africa

Several papers published during the past two decades have denied the existence of equids in the type section of the Ngorora Formation, Tugen Hills, Kenya, despite their discovery there prior to 1975. A long term result of this omission is that the family is generally viewed as having arrived in East Africa as late as Zone MN 11 (between 9.0 and 8.5 Ma), well after its appearance in Europe and North Africa in MN 9 (ca 11 Ma). However, recent surveys in the type area of the Ngorora Formation confirm that the family is present in Member E in sediments deposited about 10.5 – 11 Ma. There was thus no significant offset in the arrival times of equids in Africa and Asia (Indian Subcontinent included).

Revision of Plioperdix (Aves: Phasianidae) from the Plio-Pleistocene of Ukraine

Remains of small phasianid birds from several Pliocene and Pleistocene localities in the Northern Black Sea Region and Eastern Europe (Ukraine, Moldova, Poland, Czech Republic, and Hungary) are traditionally, based on similar proportions, assigned to Plioperdix pontica (Tugarinov, 1940). Our study of the bone material from Ukraine has shown that they in fact belong to several taxa of Galliformes. The remains from the localities of the Kuchurganian faunal assemblage (MN 14) can be attributed to Eurobambusicola turolicus Zelenkov, 2016, and supposedly to “Plioperdix” hungarica (Janossy, 1991). Plioperdix pontica is characterized by morphological similarity to modern Coturnix and is represented mainly by bone remains from the Odessa catacombs locality (upper part of Zone MN 15) and several localities of Zone MN 16, including Rebielice Krolewskie-2 (Poland). In the Middle Villafranchian localities (for example, Kotlovina; as well as Etulia-3, Moldova; Zone MN 17) remains of another unnamed form, which reliably differs from P. pontica in most skeletal elements, prevail. Previous descriptions and diagnoses of Plioperdix pontica, which were based on mixed bone materials of various taxa, are revised. Problems of the taxonomy of small Neogene–Pleistocene phasianids from the Northern Black Sea region and Eastern Europe are discussed.

Evolution of the carnivoran (Carnivora, Mammalia) guild structure across the Middle/Upper Miocene boundary in Germany

We analyse the evolution of carnivoran guilds (body mass, locomotor pattern, and diet preference) across the Middle to Upper Miocene boundary based on a comparison of the carnivoran fauna from Steinheim (Mammal Neogene zone MN 7/8; Servallian to early Tortonian), and from the Eppelsheim Formation (Mammal Neogene zone MN 9/10; mid-Tortonian), Germany. Results reveal a massive faunal turnover between these two communties due to taxonomic differences up to the family level. Guild structures of both carnivoran faunas were similar, implying that Late Miocene taxa replaced Middle Miocene taxa in their respective niches rather than new ecological strategies being added to the guild. This is not surprising, as (1) the majority of Late Miocene taxa were derived from European Middle Miocene ancestors and mostly share their paleoecology, (2) of the few undisputed Late Miocene immigrant taxa (Eomellivora, Simocyon, Sivaonyx), only Eomellivora adds new ecological strategies to the guild, and (3) both faunas occupied the same kind of partly open woodland paleoenvironment. Our paper supports previous studies, suggesting that ecological diversity remains stable across the Middle to Upper Miocene boundary and that similar environments produce similar carnivoran guild structures irrespective of taxonomical composition.

Early Miocene land and freshwater gastropods from the karst fissure filling Tomerdingen 1 (southern Germany)

The mollusc fauna recovered from the fissure filling Tomerdingen 1 (southern Germany, 11 km NW Ulm) consists of six species of freshwater and land gastropods which are revised and figured. All except Triptychia tomerdingensis n. sp. (Clausilioidea, Filholididae) were already known from the Ulm Beds and Ehingen Beds in the area. The mammals of Tomerdingen 1 have been assigned to the early part of mammal zone MN 1; it is assumed that the molluscs, which occurred in a different, mammal-free rock matrix, have a similar age. The faunal assemblage of Tomerdingen 1 represents a new local mollusc assemblage zone, characterized by the presence of Triptychia tomerdingensis n. sp. Ties of the mollusc assemblages of the Ulm Beds and underlying Ehingen Beds with the mammal biozonation are discussed. The Tomerdingen assemblage is overlain by the Eggingen assemblage which is associated with mammal subzone MN 2a, possibly extending into late MN 1, and includes the majority of recorded mollusc occurrences; Tomerdingen is preceded by the Ehingen assemblage, from which no mammal evidence is known.

Finds of Ruminants and New Data on the Stratigraphy of the Late Miocene Locality of Fortep’yanka 2 (Northwest Caucasus, Adygea Republic)

New finds of fossil remains of ruminants of genera Euprox Stehlin, 1928 (Dicrocerini, Muntiacinae, Cervidae) and Protragocerus Deperet, 1887 (Boselaphini, Bovinae, Bovidae) and the faunal analysis clarify the age of the terrestrial fauna from the Fortep’yanka River composite section. We show that the fauna corresponds to the early Vallesian, mammal zone MN 9 of Europe and belongs to the first half of the Tortonian, upper Sarmatian (Khersonian regional stage) of the Eastern Paratethys.

Revision of the plant assemblage of Steinheim am Albuch (Baden- Württemberg, Germany, middle Miocene, reference locality of Mammal Neogene Zone MN 7)

Revision of the plant assemblage of Steinheim am Albuch (Baden- Württemberg, Germany, middle Miocene, reference locality of Mammal Neogene Zone MN 7)

The Carnivora (Mammalia) from the middle Miocene locality of Gra\u010danica (Bugojno Basin, Gornji Vakuf, Bosnia and Herzegovina)

The Carnivora (Mammalia) yielded in the coal mine Gračanica in Bosnia and Herzegovina are composed of the caniform families Amphicyonidae (Amphicyon giganteus), Ursidae (Hemicyon goeriachensis, Ursavus brevirhinus) and Mustelidae (indet.) and the feliform family Percrocutidae (Percrocuta miocenica). The site is of middle Miocene age and the biostratigraphical interpretation based on molluscs indicates Langhium, correlating Mammal Zone MN 5. The carnivore faunal assemblage suggests a possible assignement to MN 6 defined by the late occurrence of A. giganteus and the early occurrence of H. goeriachensis and P. miocenica. Despite the scarcity of remains belonging to the order Carnivora, the fossils suggest a diverse fauna including omnivores, mesocarnivores and hypercarnivores of a meat/bone diet as well as Carnivora of small (Mustelidae indet.) to large size (A. giganteus). Faunal similarities can be found with Prebreza (Serbia), Mordoğan, Çandır, Paşalar and Inönü (all Turkey), which are of comparable age. The absence of Felidae is worthy of remark, but could be explained by the general scarcity of carnivoran fossils. Gračanica records the most eastern European occurrence of H. goeriachensis and the first occurrence of A. giganteus outside central Europe except for Namibia (Africa). The Gračanica Carnivora fauna is mostly composed of European elements.

Miocene continental gastropods from Dischingen, Germany

Here is given an account, based on museum collections, of the fossil land and freshwater gastropods from Dischingen (Baden-Württemberg state, SW Germany). The fossiliferous outcrops belong to the Silvana Beds unit of the Upper Freshwater Molasse group, of late Early to early Middle Miocene age (Neogene European Land Mammal Zone MN 5). In total, 35 gastropod species were found (seven freshwater and 28 terrestrial), mainly belonging to Pulmonata, but also with representatives of Neritimorpha and Caenogastropoda. Seven species are reported here for the first time from Dischingen: Palaina diezi, Radix socialis, Granaria sp., Serrulina? sp., Discus pleuradrus, Punctum pumilio, and Oxyloma minima.

Technogenic loading of eastern industrial zone of Zhytomyr on vegetation of adjoining ecosystems

The results of investigations of the peculiarities of the heavy metals accumulation in soil and phytomass of wildlife vegetation from the territory exposed to the influence of the Eastern industrial zone in Zhytomyr are presented. The activity of the enterprises of the Eastern industrial zone leads to the inorganic dust entering the atmosphere, which includes toxic compounds and heavy metals that are transferred at considerable distances, settle and are accumulated in the components of the surrounding ecosystems. It has been determined that significant concentrations of Mn, Zn, Pb, Cu, Fe are accumulated in non-localized dust, which determines the elevated levels of these metals in the vegetation of ecosystems as well. The grass cover has accumulated more elements — dust components — in the south-eastern and southern areas, 2–4 times less — in the eastern and north-eastern areas. The accumulation peculiarities of two groups of metals in plant samples of the territory influenced by the enterprises zone of the Eastern industrial zone in Zhytomyr differ in the ability of air migration, depending on the dust fraction they belong to. The activity of the enterprises located in this zone causes the inorganic dust entering into the atmosphere, which includes toxic compounds and heavy metals. It has been found out that further from the Eastern industrial zone Mn, Zn and Fe are accumulated most in the above-ground phytomass. This is due to the high concentration of these elements in the fine dust fraction.

Cricetidae (Rodentia, Mammalia) from the early Miocene site of els Casots (Vallès-Penedès Basin, Catalonia)

Abstract Els Casots is an extremely rich early Miocene site located in the Vallès-Penedès Basin (Catalonia, Spain) that has provided both micro- and macrovertebrates. However, the small mammals have been poorly studied. In this work we describe the cricetid fauna from els Casots and provide further insights into the chronology of the site. The cricetids are very common and include the species Megacricetodon primitivus and Democricetodon hispanicus. A second, larger-sized Democricetodon species is also represented by just one molar. The presence of M. primitivus together with the eomyid Ligerimys ellipticus indicates a correlation to zone MN 4 and to the local zone C of the Calatayud-Montalbán Basin (Aragón, east-central Spain), the type area of the Aragonian mammal age. This is further supported by the presence of two different Democricetodon species. A correlation to the local subzones of that area is attempted, but unfortunately the cricetid succession is not the same in both basins. However, the fact that L. ellipticus is the only eomyid species present at els Casots would indicate that this site is somewhat younger than other MN 4 localities from the Vallès-Penedès, where this species coexists with its ancestor Ligerimys florancei.

Euleptes gallicaMüller (Squamata: Gekkota: Sphaerodactylidae) from the Lower Miocene of North-West Bohemia, Czech Republic

Gekkotan lizards are widely distributed in tropical regions and extend into more northern regions in Asia and Europe. Unfortunately, gekkotans lack significant fossil record and many aspects of their evolutionary biology are still poorly understood. Our study provides the first information about occurrence of this group in the Czech Republic. The fossil material comes from the Lower Miocene sediments (MN 3) of the locality Merkur-North. All the gekkonid bones can be assigned to the family Sphaerodactylidae and represent a single taxon, Euleptes gallica. This taxon was previously known only from the French locality Montaigu (zone MN 2), and thus our study extends its stratigraphic and geographic range.

A revision of chamaeleonids from the Lower Miocene of the Czech Republic with description of a new species of Chamaeleo (Squamata, Chamaeleonidae)

A revision of Chamaeleo caroliquarti Moody and Roček is presented. The comparisons of the holotypic left dentary with those of specimens subsequently assigned to C. caroliquarti and of the Recent species of Chamaeleo, Furcifer and Calumma is carried out. It is shown that the type dentaries of C. caroliquarti include two different morphotypes with the absence of unique features. Within the Recent chameleons, the exact determination of the individual species merely on the basis of the dentaries is impossible. The holotypic dentary of C. caroliquarti is basically identical with that of C. calyptratus. However, the same morphology of the dentary as present in C. caroliquarti is also present in other species of different genera such as Calumma globifer and Furcifer pardalis. The paratypic dentaries of C. caroliquarti have a different morphology to the holotype and are indistinguishable from that in the Recent C. chamaeleon. On the other hand, a new species of the genus Chamaeleo, C. andrusovi, is described on the basis of isolated cranial elements, which possess clear autapomorphic features. This material comes from the Lower Miocene (Ottnangian) zone MN 4 in the Dolnice locality of the Czech Republic, and it differs from Recent and fossil chameleons in the following combination of characters: (1) its typically developed strongly pustular ornamentation and its distribution on the external surfaces of the skull roofing bones; (2) the frontoparietal suture is digitiform with a well-developed, anteriorly directed mesial spine, and (3) the parietal bone narrows posteriorly at its midlength, it is not bowed dorsally and it does not contribute posteriorly to a dorsal sagittal crest. This new material expands our knowledge of the cranial anatomy of Lower Miocene chameleons.

Earliest world record of green lizards (Lacertilia, Lacertidae) from the Lower Miocene of Central Europe

The earliest world record of the green lizards, Lacerta viridis group, is described from the lower Miocene of Central Europe. The fossils come from greenish, calcareous marls and limnic clayey silts of the Ottnangian zone MN 4 of the Dolnice locality near Cheb in the Czech Republic. Sediments are interpreted as marginal, riparian facies. The material consists of isolated frontal bones of two different ontogenetic stages and one isolated fragment of parietal. Their morphology is identical to that of the extant members of the L. viridis group. However, the fossil material is much older than the previously described specimens of green lizards. Therefore, this finding extends our knowledge about the evolution and stratigraphic range of the group and about composition of the early Miocene herpetofauna in central Europe.

Structural characterization of terrestrial microbial Mn oxides from Pinal Creek, AZ

The microbial catalysis of Mn(II) oxidation is believed to be a dominant source of abundant sorption- and redox-active Mn oxides in marine, freshwater, and subsurface aquatic environments. In spite of their importance, environmental oxides of known biogenic origin have generally not been characterized in detail from a structural perspective. Hyporheic zone Mn oxide grain coatings at Pinal Creek, Arizona, a metals-contaminated stream, have been identified as being dominantly microbial in origin and are well studied from bulk chemistry and contaminant hydrology perspectives. This site thus presents an excellent opportunity to study the structures of terrestrial microbial Mn oxides in detail. XRD and EXAFS measurements performed in this study indicate that the hydrated Pinal Creek Mn oxide grain coatings are layer-type Mn oxides with dominantly hexagonal or pseudo-hexagonal layer symmetry. XRD and TEM measurements suggest the oxides to be nanoparticulate plates with average dimensions on the order of 11 nm thick × 35 nm diameter, but with individual particles exhibiting thickness as small as a single layer and sheets as wide as 500 nm. The hydrated oxides exhibit a 10-Å basal-plane spacing and turbostratic disorder. EXAFS analyses suggest the oxides contain layer Mn(IV) site vacancy defects, and layer Mn(III) is inferred to be present, as deduced from Jahn–Teller distortion of the local structure. The physical geometry and structural details of the coatings suggest formation within microbial biofilms. The biogenic Mn oxides are stable with respect to transformation into thermodynamically more stable phases over a time scale of at least 5 months. The nanoparticulate layered structural motif, also observed in pure culture laboratory studies, appears to be characteristic of biogenic Mn oxides and may explain the common occurrence of this mineral habit in soils and sediments.

Influence of sedimentation on enrichment of manganese and growth of ferromanganese micronodules, Bengal Fan, India

Based upon down core variations in O/Mn ratio in sediment and in micronodules, Mn content, organic carbon and abundance of micronodules in two box cores from high and low sedimentation regions of the Bay of Bengal, 0–20 and 0–40 cm levels were identified as “Mn oxidation zone” in the western and the eastern regions of the bay. Despite similarity in bottom water O 2 and organic carbon contents of the region, a higher abundance of micronodules down to the deeper levels was observed in the area of low sedimentation. But, in the upper surfaces increased enrichment of Mn was observed in core 1 located in the area of higher sediment accumulation. Rapid recycling of Mn (faster burial–transfer to Mn reduction zone–Mn dissolution and its upward diffusion–re-precipitation) increasing upward flux of Mn(II) and associated higher consumption of O 2 limits the width of Mn oxidation zone and appears to be responsible for enhanced enrichment of Mn in the area of high sedimentation. The results of the present study also suggest that though the availability of Mn controls the formation of micronodules, their resident time in Mn oxic zone regulates their growth and influences their morphology.

The ancestors of the lemmings (Lemmini, Arvicolinae, Cricetidae, Rodentia) in the early Pliocene of Wölfersheim near Frankfurt am Main; Germany

More than 1000 isolated molars of the advanced cricetids with high-crowned molars (the subfamilies Arvicolinae; the “microtoid” Baranomyinae, Prometheomyinae and Trilophomyinae) from the early Pliocene (MN 15b) in the lignite quarry “Romerstrase” at Wolfersheim in the Horloff Basin about 30 km north-east of Frankfurt am Main represent the following forms:Mimomys (Mimomys) hassiacusHeller 1936,Mimomys (Cseria) gracilisKretzoi 1969,Dolomys occitanus (Thaler 1956),Germanomys weileriHeller 1936,Baranomys longidens (Kowalski 1960),Baranomys kowalskii (Kretzoi 1962) andTrilophomys vandeweerdiBrandy 1979. Later, more extensive examinations revealed the unexpected record of two new forms with rooted molars which represent ancestral forms of two lemming tribes of the subfamily Arvicolinae, the Synaptomyini (Tobienia kretzoii n. g., n. sp.) and Lemmini (Lemmini n. g., n. sp.). The new genusTobienia shows close affinities to the extant North American genus of the Northern Bog LemmingMictomysTrue 1894, the history of which in North America is described in detail. The oldest record,Mictomys vetus (Wilson 1934), has rootless molars and is about 1.5 Ma younger than the fauna of Wolfersheim. The assemblage of both mastodontsAnancus arvernensis andMammut borsoni and a tapirTapirus arvernensis, together with the advanced cricetids supports a Late Ruscinian (mammalian zone MN 15b, i.e. approx. 4 Ma) age for the Wolfersheim fauna.

Artiodactyls From the Late Pliocene of Udunga, Western Trans-Baikal, Russia

ABSTRACT Seven species of artiodactyls from the Udunga locality in the Selenga basin, Trans-Baikal, Russia, are described: Capreolus constantini, sp. nov., Axis shansius, Orchonoceros gromovi, Alcinae gen. indet., Gazella sinensis, Antilospira zdanskyi, and Ovis sp. Capreolus constantini, the oldest known roe deer, is a possible descendant of Procapreolus wenzensis, which existed at the end of the early Pliocene (zone MN 15). The Udunga fauna is correlated with lower Villafranchian faunas (zone MN 16). The fauna existed on the southern border of the boreal forest at the boundary between the European-Siberian and Central Asian paleozoogeographic sub-areas after 3.5 million years ago.

Ranodon cf.Sibiriens (Amphibia, Caudata) from the upper pliocene of Southern Kazakhstan: The first fossil record of the family Hynobiidae

Remains of a hynobiid salamanderRanodon cf.Sibiriens are reported from the Upper Pliocene (Early Villafranchian, mammal zone MN 16) of the Zaili Alatau Range, southern Kazakhstan. Vertebrae and limb bones of this form do not differ from those of the RecentR. sibiricus. This is the first fossil record of a hynobiid salamander.

Fossil camels from the upper miocene of Europe: Implications for biogeography and faunal change

The discovery of fossil camels at two localities of upper Miocene age in Spain (Zone MN 13, c.7.5-6.5 Ma) providesimportant constraints on phylogenetic and palaeobiogeographic interpretations of Old World camels. The arrival of camels in Spain coincided in time with major faunal turnover events in the Old and New Worlds and with the Rhodanian tectogenic phase. The same period was also one of important climatic changes in various parts of the world, including India and East Africa. The faunal evidence suggests that the latest Miocene was a period of rather drastic adjustment to palaeozoogeographic boundaries, while the evidence for increased tectogenesis indicates a possible cause of this turbulent period in the history of the Earth's biosphere and atmosphere.

Magnetostratigraphic dating of the middle Miocene climate change in the continental deposits of the Aragonian type area in the Calatayud-Teruel basin (Central Spain)

The exceptionally dense mammalian faunal record of the Aragonian type area in Central Spain shows that an important climate change towards a cooler and more humid climate is recorded during the Neogene Mammal Zone MN 5 [1]. The magnetostratigraphic results from mammal-bearing middle Miocene continental sections in the Aragonian type area indicate that the onset of this climate change, at the MN 4/MN 5 boundary, occurs in the reversed chron C5ACr and has an age of 14.1 Ma, according to the geomagnetic polarity timescale (GPTS) of Cande and Kent [2]. This age is consistent with the age estimate of 14.1–14.05 Ma for the main increase in δ 18O in the marine record [3]. These independent obserbations of time-equivalent cooling in both continental and marine records confirm and accurately date a global cooling event in the middle Miocene. The age of 14.1 Ma for the MN 4/MN 5 boundary is significantly younger than previously recorded in continental timescales [4,5]. This results in a longer duration, by approximately 3 Myr, of the MN 4 zone, which is consistent with the many important faunal changes occurring in MN 4. Furthermore, the MN 5/MN 6 boundary occurs in chron C5ACn (13.8–13.9 Ma) and the MN 6/MN 7–8 boundary in the interval C5Ar.1n-C5Ar.3r (12.7–13.0 Ma).