Thomas A. Neubauer | Bayerische Staatssammlung für Paläontologie und Geologie (original) (raw)

Papers by Thomas A. Neubauer

The present paper details a very diverse non-marine gastropod fauna retrieved from Caspian Pleist... more The present paper details a very diverse non-marine gastropod fauna retrieved from Caspian Pleistocene deposits along the Volga River north of Astrakhan (Russia). During time of deposition (early Late Pleistocene, late Khazarian regional substage), the area was situated in shallow water of the greatly expanded Caspian Sea. The fauna contains 24 species, of which 16 are endemic to the Pontocaspian region and 15 to the Caspian Sea. The majority of the species (13) belongs to the Pyrgulinae (Hydrobiidae), a group famous for its huge morphological variability in the Pontocaspian region. The phenotypic diversity has led to an inflation of genus and species names in the literature. New concepts are proposed for many of the genera and species found in the present material, with implications for the systematics and taxonomy of the entire Pontocaspian gastropod fauna. Laevicaspia vinarskii sp. n. is described as a new species. This contribution is considered a first step in revising the Pontocaspian gastropod fauna.

We describe an early middle Miocene (late Langhian) terrestrial mollusc fauna from Nowa Wieś Król... more We describe an early middle Miocene (late Langhian) terrestrial mollusc fauna from Nowa Wieś Królewska at Opole in Silesia (Poland). This survey is based on the rich collection stored in the Natural History Museum in Vienna and represents the first revision of this classical fauna. The assemblage is extraordinarily diverse and comprises 82 gastropod species and one bivalve species. About 56% of the taxa are known so far only from Nowa Wieś Królewska, emphasizing the preeminent position of this fauna within the European Neogene. The fauna reveals taxonomic affinities with early and early middle Miocene faunas. Stratigraphic overlap of several species and genera would suggest a correlation with the mammal biozone MN 5; integrating mammal data, however, indicates correlation with the biozone MN 6. This discrepancy is explained best by the lack of other adequately revised European MN 6 mollusc faunas. Consequently, the fauna from Nowa Wieś Królewska is proposed here as type of a MN 6 mollusc fauna in Central Europe. As such, this fauna represents the best-documented terrestrial mollusc fauna from the late Miocene Climate Optimum. Semi-quantitative abundance data of the terrestrial gastropods suggests the presence of ephemeral ponds and fens that formed on Cret-aceous limestones, surrounded by forested environments with leaf litter and dead wood. Occidentina gen. nov., Mennoia gen. nov., Neubertella gen. nov. and Eurocystina gen. nov. are described as new genera. Martinietta kadolskyi sp. nov., Carychium stworzewiczae sp. nov., Gastrocopta (Albinula) polonica sp. nov., Leiostyla piserai sp. nov., Vertigo antipygmaea sp. nov., Mennoia sculpturata sp. nov., Neubertella pulchra sp. nov., Aegopinella depressula sp. nov., Eurocystina nordsiecki sp. nov. and Vitrea angustaeumbilicata sp. nov. are introduced as new species. •

Hydrocarbon exploration in the Bernhardsthal and Bernhardsthal-Sued oil fields documents an up to... more Hydrocarbon exploration in the Bernhardsthal and Bernhardsthal-Sued oil fields documents an up to 2000 m thick succession of middle and upper Badenian deposits in this part of the northern Vienna Basin (Austria). Based on palaeontological analyses of core-samples, well-log data and seismic surveys we propose an integrated stratigraphy and describe the depositional environments. As the middle/late Badenian boundary is correlated with the Langhian/Serravallian boundary, the cores capture the crucial phase of the Middle Miocene Climate Transition. The middle Badenian starts with a major transgression leading to outer neritic to upper bathyal conditions in the northern Vienna Basin, indicated by Bathysiphon-assemblages and glass-sponges. A strong palaeo-relief and rapid synsedimentary subsidence accentuated sedimentation during this phase. The middle/late Badenian boundary coincides with a major drop of relative sea level by about 200 m, resulting in a rapid shift from deeper marine depositional environments to coastal and freshwater swamps. In coeval marine settings, a more than 100 m thick unit of anhydrite-bearing clay formed. This is the first evidence of evaporite precipitation during the Badenian Salinity Crisis in the Vienna Basin. Shallow lagoonal environments with diverse and fully marine mollusc and fish assemblages were established during the subsequent late Badenian re-flooding. In composition, the mollusc fauna differs considerably from older ones and is characterized by the sudden appearance of species with eastern Paratethyan affinities.

The genus Galactochilus Sandberger has been treated as a typical fossil representative of helicoi... more The genus Galactochilus Sandberger has been treated as a typical fossil representative of helicoid land snails in Europe ever since its first description. Several authors have discussed the systematic relationships of the taxon, but all of them overlooked that the type species of the genus is a recent species from the Caribbean. In order to clarify their taxonomic and systematic identity, we reexamined the species formerly assigned to Galactochilus. Oligocene species, here assigned to the genus Galactochiloides Wenz, can be distinguished from Miocene representatives by differences in teleoconch surface ornamentation. For the latter we introduce the new genus Agalactochilus, with the late Miocene Helix leobersdorfensis Troll as type species. Because of the morphological and, apparently, phylogenetic distinctness of the two genera within the Helicoidea, we propose a new subfamilial taxon, the Galactochiloidini n.trib., which we tentatively rank within the Helicidae: Ariantinae.

The age of the Hudi Chert fauna is highly controversial and crucial for the reconstruction of the... more The age of the Hudi Chert fauna is highly controversial and crucial for the reconstruction of the geological history of the Nile valley. Herein, six species of Ampullariidae (Gastropoda) are described from the Hudi Chert Formation in the Republic of the Sudan, documenting that alleged relations of the Hudi Chert fauna with Oligocene faunas from Egypt turned out to be based on misidentifications. Although an Oligocene age cannot be excluded, we propose an Eocene age for the Hudi Chert fauna based on the known stratigraphic range of the newly established genus Sudanistes. A Neogene age is clearly excluded based on the presence of the exclusively Palaeogene genus Pseudoceratodus. The Hudi Chert ampullariids lived in an extensive freshwater system of swamps and ponds, whereas riverine conditions and deep lake setting are unlikely depositional environments. Pila busserti Harzhauser & Neubauer is described as a new species and Sudanistes Harzhauser & Neubauer is introduced as a new genus.

The Lesvos Petrified Forest (western Lesvos, Greece) has long been famous for its plant fossils. ... more The Lesvos Petrified Forest (western Lesvos, Greece) has long been famous for its plant fossils. Recently, one proboscidean (from the Gavathas locality) and seven micromammalian species (from the Lapsarna locality) were described; these were the first animals to be found in the Early Miocene subtropical forest. For the first time, a fauna of gastropods and ectothermic vertebrates from the Lapsarna locality is now available. This fauna derives from lacustrine sediments under the pyroclastic material that contains the petrified plants. Based on fragmented mollusc remains, isolated fish pharyngeal teeth and utricular otoliths (lapilli), fragmented amphibian vertebrae and a tooth-bearing element, and reptile fragmented dentaries, teeth, osteoderms and vertebrae, the presence of eight freshwater and three terrestrial gastropod species, three freshwater cyprinid species, and two amphibian and five reptile taxa has been confirmed. Stratigraphical and radiometric data suggest an age older than 18.4 ± 0.5 Ma (latest Early Miocene), in good agreement with the faunal composition. This paper is the first report of the concurrent presence of three cyprinid fish species in a Greek Early Miocene locality, as well as the first documentation of an Early Miocene proteid amphibian in southeastern Europe. The present findings represent one of the best-documented Early Miocene gastropod and fish faunas in the Aegean/southern Balkans, thus adding to our knowledge of Early Miocene amphibians and reptiles from that region and providing valuable information on the local subtropical ecosystem.

Large, sinistrally coiled gastropod species have been reported under the genus name Kosovia Atana... more Large, sinistrally coiled gastropod species have been reported under the genus name Kosovia Atanacković, 1959 from middle and late Miocene palaeolakes of central Serbia and Kosovo. Despite several papers dealing with the taxonomy and evolution of this genus, its systematic position and possible ancestry have been unresolved. Previously, it has been suggested that it may be a member of the Viviparidae, Lymnaeidae or Planorbidae, but without morphological criteria to support these assertions. In order to elucidate the systematic position of the genus, we investigated type material of the type species Kosovia matejici Pavlović, 1931, which is the oldest representative and is restricted to middle Miocene deposits of central Serbia. Embryonic shell characters support membership of the Planorbidae. Based on the congruence of all evaluated morphological characteristics, we attribute the species to the genus Bulinus, which makes Kosovia a junior subjective synonym of Bulinus. We discuss potential ancestry of the oldest representative and relationships among the species previously attributed to Kosovia. Our study emphasizes the importance of SEM-based examination of the protoconch to clarify the systematic position of problematic freshwater gastropods, especially when molecular data are absent.

Central Asia is a key area to study the impact of Cenozoic climate cooling on continental ecosyst... more Central Asia is a key area to study the impact of Cenozoic climate cooling on continental ecosystems. One of the best places to search for rather continuous paleontological records is the Valley of Lakes in Mongolia with its outstandingly fossil-rich Oligocene and Miocene terrestrial sediments. Here, we investigate the response by mammal communities during the early stage of Earth's icehouse climate in Central Asia. Based on statistical analyses of occurrence and abundance data of 18608 specimens representing 175 mammal species and geochemical (carbon isotopes) and geophysical (magnetic susceptibility) data we link shifts in diversities with major climatic variations. Our data document for the first time that the post-Eocene aridification of Central Asia happened in several steps, was interrupted by short episodes of increased precipitation, and was not a gradual process. We show that the timing of the major turnovers in Oligocene mammal communities is tightly linked with global climate events rather than slow tectonics processes. The most severe decline of up 48% of total diversity is related to aridification during the maximum of the Late Oligocene Warming at 25 Ma. Its magnitude was distinctly larger than the community turnover linked to the mid-Oligocene Glacial Maximum.

Geometric morphometrics offer effective methods to obtain information about shape and shape varia... more Geometric morphometrics offer effective methods to obtain information about shape and shape variability. In ostracodology, landmark-based methods are, however, not well established. To test the applicability of geometric morphometric analyses for ostracods, we investigated shape variation among recent and fossil populations of the genus Cytheridella using a combination of landmarks and semilandmarks. The study focuses on the species' intra-specific morphological variability on a supra-regional scale, comparing living populations from Florida, Yucatán, Colombia and Brazil. We performed Generalized least-squares Pro-crustes Analysis on 508 adult and juvenile specimens (valves) including stages A-1 to A-4. The analyses show that the primary pattern in shape variation is ontogenetic allometry, supporting a clear separation of adults and juveniles. Shape changes are relatively small during ontogeny from A-4 to A-1. Greatest modification of valve shape occurs during the last molt phase. Insufficient differentiation of sexes is caused by females with less developed brood pouches. Disentangling size-and non-size-dependent shape changes reveals regional differences between populations of the species C. ilosvayi and supports its taxonomic distinction from a fossil relative (C. danielopoli). The distribution of regional morphotypes of C. ilosvayi in Florida, Mexico, and Brazil are congruent with fly ways of water birds.

Conodonts are a clade of chordates and are valuable indicator fossils for biostratigraphy. The se... more Conodonts are a clade of chordates and are valuable indicator fossils for biostratigraphy. The segmini-planate (neogondolelliform) conodonts represent a major morphological group ranging from upper Carboniferous to Upper Triassic marine sediments. However, the morphological similarity of segminiplanate P 1 elements generates problems for taxonomy, especially in the Permian and Triassic clades. This paper represents the first study of morphological variation in Triassic segminiplanate conodonts using a geometric morphometric approach. The laminar microstructures observed in conodont cross-sections indicate that, within our analysed specimens, smaller conodonts with fewer laminae are generally from an earlier ontogenetic stage while larger conodonts with more laminae are from a later stage of onto-geny. Using linear regressions between relative warp scores from both upper and lateral views and conodont length, we demonstrate strongly allometric growth patterns for the species Paragondolella bifurcata Budurov & Stefanov. Our results indicate that the species-group taxon Pg. praeszaboi bystrickyi (Kovacs et al.) is an early growth stage of Pg. bifurcata and thus synonymous. We suggest that the allometry of con-odonts should be considered seriously, especially when there are numerous transitional morphologies between large-and small-sized conodonts. Reconstructing the ontogenetic series and using larger-sized conodonts within the numerous transitional morphologies in the population of a rock sample for the definition of new species are suggested for future studies.

In this paper, we describe a non-marine mollusk fauna deriving from late middle Miocene (late Ser... more In this paper, we describe a non-marine mollusk fauna deriving from late middle Miocene (late Serravallian; Sarmatian) deposits of western Serbia. The assemblage encompasses a diverse land snail fauna with twenty-four species, along with four species of freshwater pulmonate gastropods and one bivalve species. While the aquatic snails are ubiquitous elements in Europe during the middle Miocene, the terrestrial gastropod fauna, consisting of both common and rare species, offers the first comprehensive insight into land snail diversity on the Balkan Peninsula during that time and permits conclusions on regional biogeography. The fauna shows high affinities to the middle Miocene faunas of central Europe and shares only few elements with western and eastern European and Anatolian assemblages. Ecologically, the freshwater mollusks point to a standing or slowing moving, probably highly vegetated, lacustrine environment. The land snails indicate the presence of humid forests around Lake Vračević, which is in line with current climatic reconstruction for the Sarmatian of southeastern Europe. ?Vertigo vracevicensis Neubauer & Harzhauser sp. nov. and Pisidium mionicense Neubauer, Harzhauser & Mandic sp. nov. are introduced as new species. Discus costatus (Gottschick, 1911) is shown to be a junior objective synonym of Discus solarioides (Sandberger, 1872). •

Aim To investigate shell size variation among gastropod faunas of fossil and recent long-lived Eu... more Aim To investigate shell size variation among gastropod faunas of fossil and recent long-lived European lakes and discuss potential underlying processes.
Location Twenty-three long-lived lakes of the Miocene to Recent of Europe.
Methods Based on a dataset of 1412 species of both fossil and extant lacustrine gastropods, we assessed differences in shell size in terms of characteristics of the faunas (species richness, degree of endemism, differences in family composition) and the lakes (surface area, latitude and longitude of lake centroid, distance to closest neighbouring lake) using multiple and linear regression models. Because of a strong species–area relationship, we used resampling to determine whether any observed correlation is driven by that relationship.
Results The regression models indicated size range expansion rather than unidirectional increase or decrease as the dominant pattern of size evolution. The multiple regression models for size range and maximum and minimum size were statistically significant, while the model with mean size was not. Individual contributions and linear regressions indicated species richness and lake surface area as best predictors for size changes. Resampling analysis revealed no significant effects of species richness on the observed patterns. The correlations are comparable across families of different size classes, suggesting a general pattern.
Main conclusions Among the chosen variables, species richness and lake surface area are the most robust predictors of shell size in long-lived lake gastropods. Although the most outstanding and attractive examples for size evolution in lacustrine gastropods come from lakes with extensive durations, shell size appears to be independent of the duration of the lake as well as longevity of a species. The analogue of long-lived lakes as ‘evolutionary islands’ does not hold for developments of shell size because different sets of parameters predict size changes.

This contribution constitutes a taxonomic and systematic revision of the lacustrine gastropod fau... more This contribution constitutes a taxonomic and systematic revision of the lacustrine gastropod fauna of the locality Džepi in the Prozor Basin (Bosnia and Herzegovina). 15 gastropod species were detected in the course of the present study, belonging to the families Neritidae, Melanopsidae, Hydrobiidae, Pachychilidae and Planorbidae. The fauna revealed a high degree of endemism (66.6%) and low biogeographic relationships to coeval middle Miocene faunas of the Dinaride Lake System (DLS; maximum of shared species 14.3%). None of the species has been documented from outside the DLS. The generic composition with abundant melanopsids and hydrobiids but rare pulmonates is typical among DLS faunas and characteristic of shallow long-lived lakes. Since a large part of the type material of former investigations is lost, we designate five neotypes to settle the taxonomic status of the respective species. In addition, five lectotypes are defined from existing syntype series. Based on the occurrence of the biostratigraphical marker species Illyricocongeria cf. aletici (Brusina, 1907) (Bivalvia: Dreissenidae) and faunal similarities to the Kupres Basin the deposits are classified into the early Langhian (ca 15.3-15.0 Ma). Illyricella gen. nov. and Illyricella dzepiensis gen. nov. sp. nov. (Truncatelloidea: Hydrobiidae) are introduced as new, endemic taxa.

This nomenclator provides details on all published names in the family-, genus-, and species-grou... more This nomenclator provides details on all published names in the family-, genus-, and species-group, as well as for a few infrasubspecific names introduced for, or attributed to, the family Melanopsidae. It includes nomenclaturally valid names, as well as junior homonyms, junior objective synonyms, nomina nuda, common incorrect subsequent spellings, and as far as possible discussion on the current status in taxonomy. The catalogue encompasses three family-group names, 79 genus-group names, and 1381 species-group names. All of them are given in their original combination and spelling (except mandatory corrections requested by the Code), along with their original source. For each family- and genus-group name, the original classification and the type genus and type species, respectively, are given. Data provided for species-group taxa are type locality, type horizon (for fossil taxa), and type specimens, as far as available.

MolluscaBase, which will be a Global Species Database covering all marine, freshwater and terrest... more MolluscaBase, which will be a Global Species Database covering all marine, freshwater and terrestrial molluscs, recent and fossil, was launched on February 6-7, 2014 at the Flanders Marine Institute (VLIZ) at Ostende, host institute of the World Register of Marine Species (WoRMS). Currently, the WoRMS database contains more than 44,000 valid, verified species names of Recent marine Mollusca, which are estimated to represent approximately 95% of all valid species. Beyond catching up with the missing 5%, and keeping up with the yearly established new species, the molluscan component of WoRMS shall be expanded to contain freshwater and terrestrial Mollusca, estimated on ca 28,000 valid species. Adding the aspect of time to the current database, and acknowledging the fossil record as the source of extant diversity, it has been agreed that the list should be extended to include all fossil mollusc taxa. A solid estimate of the number of fossil mollusc species is not available yet. Mollusc...

We present the first analysis of population structure and cohort distribution in a fossil oyster ... more We present the first analysis of population structure and cohort distribution in a fossil oyster shell bed based on 1121 shells of the giant oyster Crassostrea gryphoides (von Schlotheim, 1813). Data derive from terrestrial laser scanning of a Lower Miocene shell bed covering 459 m 2. Within two transects, individual shells were manually outlined on a digital surface model and cross-checked based on high-resolution orthophotos, resulting in accurate information on center line length and area of exposed shell surface. A growth model was calculated, revealing this species as the fastest growing and largest Crassostrea known so far. Non-normal distribution of size, area and age data hints at the presence of at least four distinct recruitment cohorts. The rapid decline of frequency amplitudes with age is interpreted to be a function of mortality and shell loss. The calculated shell half-lives range around a few years, indicating that oyster reefs were geologically short-lived structures, which could have been fully degraded on a decadal scale. Crassostrea gryphoides reefs were widespread and common along the Miocene circum-Tethyan coasts. Given its enormous growth performance of ∼ 150 g carbonate per year this species has been an important carbonate producer in es-tuarine settings. Yet, the rapid shell loss impeded the formation of stable structures comparable to coral reefs.

We investigate the distributions of representatives of the family Melanopsidae (Gastropoda: Caeno... more We investigate the distributions of representatives of the family Melanopsidae (Gastropoda: Caenogastropoda: Cerithioidea) from the late Cretaceous to present-day. The present contribution discusses and partly revises former schemes of melanopsid dispersal during the Cenozoic, all of which were based on outdated stratigraphic and tectonic concepts as well as an incompletely considered fossil record. Conflating a comprehensive and stratigraphically well-constrained fossil record, modern paleogeographical reconstructions and contemporary climate data, our goal is to present a thorough model of melanopsid distribution and its changes over the Cenozoic as well as its paleogeographical and climatic constraints. The family Melanopsidae evolved about 90 Ma ago in the late Turonian from brackish cerithioidean ancestors. Cretaceous and Paleogene species occur in marginal marine to brackish environments along the shores of the Tethys and Paratethys seas. The extant clades of Melanopsis likely derive from the evolution of freshwater Melanopsis on the Balkan Peninsula back in the late early Miocene. Up to the Pliocene, freshwater species spread toward southwestern and southeastern Europe and successively replaced brackish-water representatives, paralleling a general decline of latter systems during the late Cenozoic. The southwards expansion of Melanopsis and its simultaneous retreat from northern latitudes resulted in the disjunct distribution pattern observed today.

The genus Holandriana first appeared in northern Italy in the late early Miocene. The genera Microcolpia and Esperiana both first occurred in the late Miocene and likely derive from brackish-water Melanopsis species native to peri-Paratethyan lakes. The present-day biogeographic isolation of the three latter genera and Melanopsis roots in the climatic deterioration and the disappearance of major lake systems in southeastern Europe. While thermophilous Melanopsis retreated to the warm, dry climates of the Mediterranean and Middle East, Holandriana, Microcolpia and Esperiana adapted to the seasonal, cold-temperate climate of southeastern and eastern Europe and some species became restricted to thermal springs.

Lake Pannon constituted the biggest hotspot of biodiversity in the late Cenozoic of Europe, compr... more Lake Pannon constituted the biggest hotspot of biodiversity in the late Cenozoic of Europe, comprising a total diversity of almost 600 gastropod species. The gastropod fauna of this huge brackish system, which existed over about seven million years from the late Miocene to earliest Pliocene within the Pannonian Basin System, has been well documented by a great many of taxonomic works. In contrast, the faunal development within the lake has not been properly addressed from a statistical point of view. The present investigation demonstrates that species were not homogeneously distributed across space and time, generating uneven and temporally shifting patterns of species richness and degree of point endemism across the lake. The faunal compositions of the time intervals analyzed were highly different, contrasting simple species accumulation as suggested by the overall numbers. Shifting patterns of local diversity within the lake reflect changing paleo-shorelines, resulting from prograding river systems entering and successively diminishing the lake surface area. As mainly herbivorous grazers and predominantly shallow-water inhabitants, the gastropods traced the moving shelf margins and vegetation belts accordingly, producing the observed diversity shifts. In addition, each time interval is characterized by a high degree of provincialism, which is considered to reflect high habitat diversity. This claim is supported by the complex subaqueous topography and the presence of extensive delta plains produced by the incoming river systems. A potential driver for provincialism might be the adaptation of species to distinct water depths (and related parameters). Finally, the notable differences among the faunal compositions of the upper Pannonian strata and the succeeding lower Viviparus beds, especially regarding family-level, indicate an environmental turnover at the transition. Brackish-water species are mostly replaced by typical freshwater elements, indicating strong fluvial influence. Based on our results and latest stratigraphic data, we conclude that the Viviparus beds were deposited in a different environment, replacing Lake Pannon in the southern Pannonian Basin in the Early Pliocene.