Gastropod Fauna Research Articles

Isolation and endemism in the subterranean aquatic snails of the genus Belgrandiella A. J. Wagner, 1928 (Caenogastropoda: Truncatelloidea: Hydrobiidae)

The Western Balkans hosts the richest subterranean aquatic gastropod fauna in the world. The main factors shaping intraspecies diversity are thought to be isolation and endemism. In the genus Belgrandiella, minute snails inhabiting subterranean waters and springs in Central Europe and Balkans, molecular studies have shown much fewer valid species than previously anticipated. The present study applies mitochondrial cytochrome c oxidase subunit I, histone 3, and RAPD analysis, to check the inter- and intraspecies genetic diversity in 36 Belgrandiella populations from caves, springs and interstitial aquifers. The level of gene flow is assessed to check if these snails form a widespread genetically uniform metapopulation or rather follow the highly endemic pattern. The studied populations have been assigned to six species. In the most widely distributed B. kusceri from 21 populations, 60 sequenced specimens represent 16 haplotypes. While the same haplotypes are present in distant populations, gene flow between the other populations is low. Nei distances for RAPD show no geographic pattern. The interspecies differences in COI evidently confirm the time of speciation in Pleistocene, before karstification, which rejects speciation within isolated caves. The pattern observed in Belgrandiella seems more similar to the one described in Montenegrospeum than in Kerkia.

Unusual shallow-water boreal gastropod species associations at the Northern part of Arctic archipelago Novaya Zemlya

The fauna of the Barents Sea is the richest compared to other Arctic seas and is represented by a mixture of Arctic and boreal species, the distribution of which is believed to be due to the temperature conditions. In this study, this hypothesis was tested using data on the species composition of gastropods in the northern part of Novaya Zemlya, one of the coldest regions in the Barents Sea. Species associations with the predominance of the boreal species Lacuna vincta (Montagu, 1803) were found in the studied area; additionally, the fauna of gastropods was generally more similar to that of the boreal regions (White Sea and the Murman Coast) than the Arctic (fjords of Svalbard, Matochkin Shar (Novaya Zemlya), Franz Josef Land). The results obtained do not agree with the assumption about the effect of the temperature being the main factor determining the distribution of benthic communities in the Barents Sea. Two alternative hypotheses are proposed: either the influence of the Novaya Zemlya current as a corridor for the dispersal of species; or the existence of a glacier refugium off the coast of Novaya Zemlya where the shallow-water fauna could have survived the last glaciation.

Late Jurassic (Upper Kimmeridgian) Heterobranchia (Gastropoda) of the coral-facies of Saal near Kelheim and the viciniy of Nattheim (Germany)

Forty gastropod species of the subclass Heterobranchia are described from the Upper Jurassic (Upper Kimmeridgian) reefal limestones of South Germany, including ten species in open nomenclature and further ten species of uncertain identity. Six species are new to science: Ceritella convexasp. nov., Nerinea donosasp. nov., Endoplocus acutussp. nov., Endoplocus inflatussp. nov., Pseudonerinea ? pseudomelaniformissp. nov., and Itieroptygmatis cylindratasp. nov. A lectotype is designated for Ptygmatis ? tornata (Quenstedt, 1852). With this final part of the study of the Late Jurassic gastropods from Saal and the Nattheim area, a total of 156 species have been reported. Of these species, 125 have been reported from Saal and 54 from the Nattheim area. Only 23 species occur in both Saal and the Nattheim area. The sample sizes (number of specimens) from Saal and the Nattheim area differ considerably and few species are shared. Diversity metrics suggest the same high diversity at both sites. The gastropod fauna from the Saal quarry has yielded particularly much new information – all new species are based on specimens from Saal. With 125 gastropod species from a single outcrop, the diversity at the Saal quarry is the highest from the Kimmeridgian worldwide. In total, up to 300 species of marine macro-invertebrates have been reported from this quarry, which is a very high point diversity. Gastropods are by far the most diverse group from Saal, which is a modern aspect of this fauna.

Latest Triassic (Sevatian–Rhaetian) reef carbonates from the Northern Calcareous Alps (Austria), their mollusc dwellers, and their fate at the end-Triassic extinction event

A reef-associated mollusc fauna (gastropods and bivalves) and its facies context are described from latest Triassic (Sevatian–Rhaetian) reef carbonates of Austria (Rötelwand reef at Gaissau and Gosaukamm near Hallstatt). The studied carbonates from the Rötelwand reef consist of mollusc-rich rudstones, partly boundstones, which contain branched corals (Cycliphyllia and Retiophylia, Pinacophyllum), whereas coralline sponges are absent. The rich foraminiferid fauna that is associated with the reef builders consists of 11 genera; eight of these genera became extinct until the end of the Rhaetian. Associated with small patch reefs was a rich mollusc fauna with 19 gastropod species and 8 epifaunal bivalve species. The gastropod fauna is dominated by Microschiza rhaetica, Trochotoma praecursor, and the large growing Purpuroidea moosleitneri. Six gastropod species are new to science: Angulomphalus senowbarii sp. nov., Stuorella zapfei sp. nov., Hologyra callosa sp. nov., Microschiza rhaetica sp. nov., Angularia corallina sp. nov., and Purpuroidea moosleitneri sp. nov. Four Triassic gastropod species are placed in other genera (new combinations): Tylotrochus diversicostatus Wolff, 1967 and Eucycloscala epitoniformis Nützel and Senowbari-Daryan, 1999 are placed in Sadkia, Praelittorina sepkoskii Nützel and Erwin, 2004 in Microschiza, and Purpuroidea? minioi Leonardi, 1935 in Angularia Koken, 1892. Reversal of precedence is proposed for Angularia Koken, 1892 (Gastropoda) and Angularia Busk, 1881 (Bryozoa) under ICZN Art. 23.9. Although reefs suffered a catastrophic decline at the end of the Triassic, most of the studied reef-associated bivalve and gastropod genera survived into the Jurassic, indicating a considerable ecological plasticity of these groups. Only 12 out of 47 reef-associated mollusc genera became extinct (25.5%). This observation is at variance with earlier suggestions that taxa that were associated with reefs and carbonate substrata had a significantly higher extinction risk than level-bottom dwellers. However, extinction at the species level appears more severe; only three bivalve species but no gastropod species recorded in this fauna have records from the Jurassic.

Contributions to the malacology of Malta, IV & V: Second European record of Paropeas achatinaceum (L. Pfeiffer, 1846) (Gastropoda, Achatinidae) and an annotated checklist of allochthonous non-marine gastropods

The first record in Malta, and the second record in Europe, of the tropical terrestrial gastropod Paropeas achatinaceum (L. Pfeiffer, 1846) is presented, with an annotated bibliography of the allochthonous (and non-marine) gastropod fauna hitherto recorded from the Maltese archipelago.

Catatan Biodiversitas Gastropoda pada Ekosistem Mangrove Desa Kramat Kecamatan Mananggu Kabupaten Boalemo, Provinsi Gorontalo

Anthropogenic actions that degrade mangroves in coastal areas are suspected to reduce the biodiversity of gastropod fauna in this region. The purpose of this research, conducted from July to October 2021, was to evaluate the number of species, dominance, and diversity of gastropods and the richness and similarity of gastropod communities in the coastal mangrove ecosystem in Kramat Village, Mananggu-Boalemo District. The survey method carried out by purposive sampling was on a 3-line transect as an observation station based on differences in the width of the mangrove belt. The study results recorded 14 species of gastropod members from 8 families at all stations. The highest presence was recorded in the family Potamidae, with members of Terebralia sulcata being the most abundant species at all stations. The unique environmental conditions in all stations are land conversion in the area behind the mangrove formation, and the substrate tends to be acidic (pH 6). This study indicates the complexity between stations as a habitat for live gastropods as epi and tree fauna in the mangrove community of Kramat Village .

A multi-proxy record of palaeoenvironmental and palaeoclimatic conditions during Plio-Pleistocene peat accumulation in the eastern flank of the Isparta Angle: A case study from the Şarkikaraağaç coalfield (Isparta, SW Central Anatolia)

The Şarkikaraağaç coalfield is located in the north-western part of the Lake Beyşehir Basin, which is the most significant graben area in the eastern flank of Isparta Angle, and hosts a 300-Mt coal resource. This study focuses on the first palaeoenvironmental and palaeoclimatic reconstruction of Pliocene and early Pleistocene coal-bearing sequences cored in the two coal exploration wells (SK-1 and SK-2) using coal petrography, mineralogy, faunal (ostracod and mollusk), and floral (palynology and diatom) data from four coal seams (from bottom to top: B, A, X-1, and X-0) with the variable total thickness (1 to 7 m). According to the palynological data, warm and humid climate conditions prevailed during the early Pliocene, and the precursor peats of seams A and B were mainly accumulated under limno-telmatic conditions, with high contributions of herbaceous peat-forming plants. Nevertheless, the co-occurrence of syngenetic carbonate minerals and framboidal pyrites along with calcareous fossil and diatom remains implies neutral to weakly alkaline conditions within palaeomires of these seams. Furthermore, ostracod and gastropod fauna from these seams might imply nutrient-rich shallow water conditions and spring support (e.g., karstic aquifer) into palaeomires. Thus, algal activity within the palaeomires was presumably high, and freshwater algae and diatoms were commonly identified in these seams.With the development of increased uplift ratio of central Taurides and climatic changes towards to late stages of Pliocene and particularly early Pleistocene, the common peat-forming plants within palaeomires and vegetation in the surrounding areas were changed. The increased precipitation caused an elevation of water levels in the study area; hence, the precursor peats of the seam X-1 were accumulated under wet forest mire conditions. This increase also explains the existence of ostracod and mollusk fauna related to river and spring support underlying sequences of the seam X-1. With the ceasing of accumulation of peat of the seam X-1, the climate became drier, and very shallow water conditions have been common. The development of spring support and relatively high precipitation in a short period of time allowed for final peat accumulation (seam X-0) during the early Pleistocene. Nevertheless, this period was followed by the development of relatively colder conditions in the study area, and cold small water conditions were developed during the end of the early Pleistocene. Furthermore, microthermic vegetation was common in the vicinity of the palaeomires during the early Pleistocene. Overall, the peat accumulation and water level of lakes in the study area seem to be controlled by climatic oscillations and uplift of margins of the Lake Beyşehir Basin during the Pliocene to early Pleistocene.

Morphological and Molecular Characterization of the Invasive Pestiferous Land Snail Macrochlamys indica Godwin-Austen, 1883 (Gastropoda: Ariophantidae) from Saudi Arabia

Many terrestrial gastropod species have been dispersed as a result of anthropogenic activities and have adapted to new habitats where they are considered as alien or invasive species. Several synanthropic gastropods are invasive in urban and agricultural environments worldwide. In Saudi Arabia, increased human activities have accelerated the introduction of terrestrial gastropod species, increasing the need to study its gastropod fauna. Our preliminary survey disclosed the presence of ariophantid snails in a number of agricultural nurseries. Based on morphological features of shell, body, and reproductive system, we report the first record of Macrochlamys indica from Saudi Arabia. The phylogenetic analysis obtained from DNA sequences of the mitochondrial COI and 16S regions confirmed the identity of M. indica. One third of the investigated nurseries were infested with this snail, however, we did not find any specimens of M. indica in natural habitats or open agricultural fields. The snail-infested nurseries were distributed all over Saudi Arabia. The occurrence of one haplotype of partial mitochondrial COI sequence from these nurseries suggests that the introduction of M. indica is likely very recent. Based on the obtained results, it is recommended that control measurements must be implemented in order to eradicate or at least restrict the dissemination of M. indica from nurseries to natural habitats or agricultural fields.

Surface crawling and pedal surface collecting in aquatic gastropods: A case of scientific amnesia

Aquatic gastropods, both freshwater and marine, often crawl along the water surface with the sole of the foot facing upward. Differential regulation of the activity of cilia on the sole turns the gliding mechanism into pedal surface collecting, by which food particles floating on the water are collected on the sole. Over the last 300 years, surface crawling and pedal surface collecting have been studied in numerous species, but the accumulated knowledge has fallen victim to scientific amnesia. Today, pedal surface collecting usually is considered a unique behaviour that evolved in the family Ampullariidae (Caenogastropoda), which includes the genus Pomacea with some of the globally worst invasive pests. Consequently it may appear feasible to tackle invasive Pomacea species specifically by delivering molluscicides via the water surface. Based on a review of our forgotten literature, I here argue that such an approach would have potentially devastating, unintended effects on native gastropod faunas.

Middle Ordovician shallow-water gastropods from southern Xizang (Tibet), China

Many new specimens (36 in total) of gastropods were collected from the Ordovician Alai Formation of the Chiatsun Group at Jiacun village, Nyalam County, southern Xizang (Tibet). These gastropods comprise five species assigned to two genera, including Maclurites parviumbilicatus Yu, M. cf. nyalamensis Yu, M. cf. xizangensis Yu, M. cf. subconicus Yu, and “Hormotoma” ordosensis Yu, forming a Maclurites-“Hormotoma” association. All the species are described in detail herein, and some of which are redefined. This fauna is of middle to late Darriwilian age, and palaeoecologically characterised by species of shallow-water within the photic zone. A comparison of the Maclurites community with the contemporary gastropod fauna from the Zhuozishan Formation exposed along the west margin of the North China Block shows a close palaeogeographical affinity. The occurrences of Ordovician gastropods from China are analyzed biogeographically and the results reveal that the peri-Gondwana gastropod faunal turnover event was initiated during the Middle to Late Ordovician transition. The coincident faunal turnover and the lithofacies changes in the Himalaya and western margin of North China suggest that tectonic activities and relative sea-level changes may account for the biogeographical affinities of some specific fossil groups in peri-Gondwanan regions.

Gastropod Assemblages Associated with Habitat Heterogeneity and Hydrological Shifts in Two Shallow Waterbodies

We aimed to determine the effects of water level and habitat heterogeneity on gastropod fauna in the littoral zone, and the differentiation of functional feeding guilds (FFG) of gastropods. Two periods were analyzed: 2012 (low water level, LWL) and 2013 (high water level, HWL) in the littoral zone of two shallow waterbodies (Sutla backwater, NW Croatia). Waterbody S1, covered with Ceratophyllum demersum, was sampled in the macrophyte stands, and the littoral benthal area, while waterbody S2, without macrophytes, was sampled only in the littoral benthal area. It was observed discovered that among the macrophyte stands in S1, gastropods were significantly more abundant during LWL. The same trend was observed in the littoral benthal area of S2. In contrast, gastropod abundance was higher in the littoral benthal area of S1 during HWL. Comparing gastropods in the two waterbodies, the abundance in S1 was ten times higher than in S2. The most abundant species was Gyraulus parvus, which accounted for 51–92% of the gastropods observed among the macrophytes of S1 and 86% in the adjacent benthic zone. Among the FFG groups, grazers (particularly those feeding on gymnamoebae and rotifers) had the largest proportion, followed by shredders feeding on small pieces of macrophytes. In our research, we indicate the important role of microhabitat diversity and submerged macrophytes as a rich food source for gastropods and safe shelter from predators.

INaturalist as a tool in the study of tropical molluscs.

Although terrestrial gastropods are remarkably diverse, our knowledge of them is still lacking, especially for species from the Global South. As such, new tools to help researchers collect data on these organisms are very welcome. With this in mind, we investigated Brazilian observations on iNaturalist to assess the feasibility of the data available on the platform as a basis for studies on the tropical terrestrial gastropod fauna. The observations on iNaturalist were filtered by country, Brazil, and higher taxa, namely Eupulmonata, Cyclophoroidea and Helicinoidea, yielding a sample of 4,983 observations. These observations were then reviewed in search of records of rare or little-known species, species found outside their previously known range, and interesting ecological interactions. Exotic species made up 35% to 39% of the sampled iNaturalist records. The most commonly observed species were Lissachatina fulica (Bowdich, 1822), Bradybaena similaris (Férussac, 1822), Drymaeus papyraceus (Mawe, 1823), Drymaeus interpunctus (E. von Martens, 1887), Limacus flavus (Linnaeus, 1758), Meghimatium pictum (Stoliczka, 1873), Cornu aspersum (O. F. Müller, 1774), Vaginulus taunaisii (Férussac, 1821), Ovachlamys fulgens (Gude, 1900), and Bulimulus tenuissimus (Férussac, 1832). In total, 166 observations were deemed of interest to our purposes (e.g., rare species, range extensions, ecological interactions), totalling 46 identified species and 16 observations identified at genus level. Among the selected observations, we found pictures of live specimens of species that were previously known only from their shells, such as Megalobulimus pergranulatus (Pilsbry, 1901), bringing to light their appearances in life. Two potentially new species belonging to the genera Plekocheilus Guilding, 1827 and Megalobulimus K. Miller, 1878 were revealed. Additionally, we found records of living individuals of two species that were previously presumed to be possibly extinct, Leiostracus carnavalescus Simone & Salvador, 2016, and Gonyostomus egregius (Pfeiffer, 1845). We take the opportunity to discuss individual records of interest, evaluate the quality of the data and possible improvements, as well the potential and implications of the use of the iNaturalist platform for research in Brazil and other tropical countries. While iNaturalist has its limitations, it holds great potential to help document biodiversity in the tropics.

Middle Ordovician (Whiterockian) gastropods from central Sonora, Mexico: affinities with Laurentia and the Precordillera

AbstractThe Lower–Middle Ordovician (Ibexian, Whiterockian) sedimentary rocks exposed at Rancho Las Norias includes the informally named Las Norias formation, which consists of an intercalation of carbonate and clastic sediments with abundant marine fauna. These deposits occur as the most austral sedimentary rocks of Ordovician age for Laurentia, providing a critical link to understand the distribution of Ordovician marine faunas of North America. An investigation of the gastropod fauna from the upper portion of the Las Norias formation, Sonora, Mexico, is undertaken for the first time. The gastropod assemblage includes Maclurites acuminatus, ?Monitorella sp., Lecanospira sp., Malayaspira aff. M. rugosa, Lophospira perangulata, and Hormotoma? sp. This assemblage indicates a paleogeographic relationship with Laurentia, including the USA (Nevada), Canada (British Columbia, Newfoundland), Greenland, and the Argentine Precordillera.

A low-diversity Peruvispira-dominated gastropod assemblage from the Permian Ratburi Group of Central Thailand

Permian gastropods from Thailand have been extensively studied over the last few years. The earliest known fossil collection was recovered in 1967 but has never been figured or described. Here, we document this historically important gastropod assemblage excavated from the upper-Lower to Middle Permian Ratburi Group of Khao Mang Lat in the Ban Kao District of Kanchanaburi Province, Central Thailand. The material comprises approximately 200 specimens, almost all of which represent a new species, Peruvispira kanchanaburiensis sp. nov. (Goniasmatidae), together with a single individual of Orthonychia sp. (Orthonychiidae = Platyceratidae). This exceptionally low-diversity community is unusual in comparison to Permian gastropod faunas reported from elsewhere, and could reflect either a low temperature palaeoenvironmental setting or priority effects resulting from early establishment of planktotrophic larvae within the local habitat. Baran Karapunar [karapunar@snsb.de ], SNSB-Bayerische Staatssammlung für Paläontologie und Geologie, Richard-Wagner-Str. 10, 80333 München, Germany, and Department of Earth and Environmental Sciences, Paleontology & Geobiology, Ludwig-Maximilians-Universität München, Richard-Wagner-Str. 10, 80333 München, Germany; Alexander Nützel [nuetzel@snsb.de ], SNSB-Bayerische Staatssammlung für Paläontologie und Geologie, Richard-Wagner-Str. 10, 80333 München, Germany, and Department of Earth and Environmental Sciences, Paleontology & Geobiology, Ludwig-Maximilians-Universität München, Richard-Wagner-Str. 10, 80333 München, Germany, and GeoBio-Center, Ludwig-Maximilians-Universität München, Richard-Wagner-Str. 10, 80333 München, Germany; Chatchalerm Ketwetsuriya [ketwetsuriya.c@gmail.com ], Department of Earth Sciences, Faculty of Science, Kasetsart University, 10900 Bangkok, Thailand.

Onset of Late Cretaceous diversification in Europe\u2019s freshwater gastropod fauna links to global climatic and biotic events

The Mesozoic rise of the European freshwater gastropod fauna is still poorly understood. Compared to the well documented Cenozoic history, little is known about the patterns and processes underlying the early diversification preceding their extinction crisis at the K–Pg boundary. We assess what is probably a first pulse of diversification of the Cenozoic-type fauna in the Late Cretaceous along with the potential abiotic and biotic controls for shifts in species diversification. We find strong support that the increase in the speciation rate in the Santonian (~ 85 Myr ago) is linked to a global sea level rise, which caused extensive flooding of continental areas and the formation of vast brackish-water ecosystems. The following decline of the speciation rate coincides with a rise in diversity and reflects increasing interspecific competition. The peak in the speciation rate postdates the Cenomanian–Turonian Thermal Maximum, which probably limited the potential for diversification among freshwater gastropods due to ecological constraints. The peak coincides moreover with the end phase of the Cretaceous Terrestrial Revolution, which sparked the radiation of angiosperms. The expansion and diversification of flowering plants, being an important food source for freshwater gastropods today, could have formed a necessary basis for gastropod diversification.

Mid- and long-term responses of land snail communities to the intensification of mountain hay meadows management

BackgroundSpecies-rich semi-natural grasslands are impacted by the severe land-use changes that are affecting mountain regions, compromising their high biodiversity value. In particular, sprinkler irrigation and increased fertilisation stimulate vegetation growth, modifying and homogenising habitat conditions for ground-dwelling invertebrates. Among them, land snails have been largely understudied despite their commonness and vulnerability to small-scale habitat alteration. This study investigated the mid- and long-term responses of land snail communities to management intensification of montane and subalpine hay meadows. Mid-term effects were studied using a randomised block design experiment, mimicking an intensification gradient with different levels of irrigation and fertilisation applied during 5 years. Long-term effects were examined relying on an observational approach that consisted in comparing snail communities in meadows managed intensively for > 20 years with those from the 5-year experimental module.ResultsWe show that management intensification initially boosts snail densities, but erodes species richness by − 35% in intensively-managed meadows in the long term. Contrary to our expectations, drought-tolerant (xerophilous) snails benefitted from grassland intensification, whereas mesophilous species accounted for most species losses due to intensification in the long run, indicating that the latter may be especially sensitive to the hostile microclimate conditions abruptly prevailing in a meadow after mowing. Soil pH was also a principal determinant of land snail occurrence, with almost no specimen recorded in acidic meadows (pH < 5.5), while plant diversity favoured overall snail abundance.ConclusionsDespite the fact that xerophilous snails appear tolerant to management intensification, we found that several drought-sensitive species are lost in the long term. We conclude that the preservation of species-rich land snail communities in mountain hay meadows requires the conservation and restoration of low-input grasslands on basic soils for preventing further species losses of gastropod fauna.

Small Size Gastropod Fauna from the Matli Geothermal Spring, Bhagirathi Valley, Garhwal Himalaya, Uttarakhand: Ecological Implications

Abstract The occurrence of freshwater molluscs in the geothermal springs is reported by numerous workers in different parts of the world. However, reports of such occurrences in the Indian subcontinent are either scanty or are not available in the published literature. In this study, a swarm of small size gastropod community have been encountered in the vicinity of Matli geothermal spring, which is located on the right bank of the downstream Bhagirathi river in the Garhwal Himalaya in Uttarakhand, India. Gastropod samples were collected from 3 locations near the spring and water samples were collected from the spring and the river. The samples were identified as belonging to the species Lymnaea acuminata Lamarck, 1822 according to their form and habitat. The abundance, size and thickness of the snails were higher near the spring than near the Bhagirathi river. The δ18Oshell and δ13Cshell values of all the bulk samples range from – 8.2 to – 7.8‰ (VPDB) and from – 9.5‰ (VPDB) to – 6.5‰ (VPDB), respectively. Since the temperature of the geothermal spring remains constant irrespective of seasons, no significant intra-shell variation in δ18O is observed, while intra–shell δ13C values show shell shell significant variation reflecting season change. Lymnaea accuminata is originally a freshwater gastropod which is found all along the Ganga-Brahmaputra watersheds. This species prefers a habitat near the geothermal spring owing to the abundance of nutrients in spring water and other physiological factors.

Synopsis of the terrestrial and freshwater gastropod fauna of southern Bahia, Brazil

The terrestrial and freshwater malacofauna of southern Bahia is little known, especially in comparison to the well-studied eastern portion of the state covered by remnants of Atlantic Forest. We present here a synopsis of all gastropod species known from the central southern region of Bahia state, known as ‘Centro-Sul Baiano’, focusing on four municipalities: Condeúba, Cordeiros, Mortugaba, and Piripá. The list herein contains data from the literature, historical material deposited in museum collections, and two recent expeditions undertaken in the region. The survey resulted in 21 species of gastropods, with nearly 700 voucher specimens (mostly freshwater) deposited in the collection of the Museu de Zoologia da Universidade de São Paulo (São Paulo, Brazil). Circa 30% of the species are non-indigenous; previously, the only known exotic in the region was Melanoides tuberculata (Müller, 1774). The family Achatinidae was the most diverse group in number of native species, while the typically diverse superfamily Orthalicoidea was represented by only two species.

The Neglected Angio-Neurotrophic Parasite Gurltia paralysans (Nematoda: Angiostrongylidae): Northernmost South American Distribution, Current Knowledge, and Future Perspectives.

Gurltia paralysans is a rare metastrongyloid nematode in South America that has begun to gain relevance in feline internal medicine as a differential diagnosis of progressive degenerative myelopathy disorders. The parasite life cycle has not been fully elucidated but probably involves invertebrate gastropod fauna as obligate intermediate hosts; thus, G. paralysans remaining an extremely neglected parasitosis. Feline gurltiosis intra vitam diagnosis is highly challenging due to lack of evidence in the excretion of G. paralysans eggs and larvae, neither in feces nor in other body secretions because environmental stages and the transmission route of the parasite remain unknown. Unfortunately, no experimental trials for the treatment of feline gurltiosis have been conducted to date. However, there are some reports of the successfully antiparasitic drugs used with different effectiveness and clinical improvement results in diagnosed cats. Further studies are needed to evaluate the parasite occurrence among domestic cats and the neotropical wild felid species distributed within Colombia in addition to the gastropod fauna that may harbor the developing larvae (L1–L3) stages of this underestimated parasite.

Habitat of the giant pterosaur Quetzalcoatlus Lawson 1975 (Pterodactyloidea: Azhdarchoidea): a paleoenvironmental reconstruction of the Javelina Formation (Upper Cretaceous) Big Bend National Park, Texas

ABSTRACT The Maastrichtian Javelina Formation of southwestern Texas comprises a thick sequence of stream channel and floodplain deposits accumulated in a broad southeast-trending valley, several hundred kilometers inland from the Late Cretaceous shoreline. Three pterosaur species are found here. Remains of Quetzalcoatlus lawsoni, sp. nov., are concentrated in deposits of shallow alkaline lakes that developed in abandoned reaches of stream channels. Areas surrounding the lakes were vegetated with fan palms, and the higher floodplain supported a subtropical forest dominated by the dicot tree Javelinoxylon and araucariacean conifers. The shallow lakes were inhabited by a diverse invertebrate fauna of arthropods, gastropods, and bivalves, a likely food source for the slender-beaked Quetzalcoatlus lawsoni, sp. nov., which may have had a lifestyle similar to modern large gregarious wading birds. In contrast, remains of the giant Q. northropi are rare and found instead only in stream channel facies. It may have had a more solitary lifestyle and preferred riparian habitats. The warm, dry, subtropical but nonseasonal conditions of the region may represent a preferred climatic regime for azhdarchid pterosaurs generally.