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First freshwater gastropod preserved in amber suggests long-distance dispersal during the Cretaceous Period

Published online by Cambridge University Press:  29 April 2021

Tingting Yu Open the ORCID record for Tingting Yu [Opens in a new window] ,
Thomas A. Neubauer Open the ORCID record for Thomas A. Neubauer [Opens in a new window]  and
Adrienne Jochum
Tingting Yu*
Affiliation:
State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing210008, China University of Chinese Academy of Sciences, Beijing100049, China
Thomas A. Neubauer
Affiliation:
Department of Animal Ecology and Systematics, Justus Liebig University, 35392Giessen, Germany Naturalis Biodiversity Center, 2300 RA Leiden, The Netherlands
Adrienne Jochum
Affiliation:
Naturhistorisches Museum der Burgergemeinde Bern, 3005 Bern, Switzerland Senckenberg Forschungsinstitut und Naturmuseum, 60325 Frankfurt am Main, Germany
*
Author for correspondence: Tingting Yu, Email: ttyu@nigpas.ac.cn
Rights & Permissions [Opens in a new window]

Abstract

Burmese amber continues to provide unique insights into the terrestrial biota inhabiting tropical equatorial forests during mid-Cretaceous time. In contrast to the large amount and great diversity of terrestrial species retrieved so far, aquatic biota constitute rare inclusions. Here we describe the first freshwater snail ever preserved in amber. The new species Galba prima sp. nov. belongs in the family Lymnaeidae, today a diverse and near globally distributed family. Its inclusion in terrestrial amber is probably a result of the amphibious lifestyle typical of modern representatives of the genus. The finding of a freshwater snail on the Burma Terrane, back then an island situated at some 1500 km from mainland Asia, has implications for the dispersal mechanisms of Mesozoic lymnaeids. The Cenomanian species precedes the evolution of waterfowl, which are today considered a main vector for long-distance dispersal. In their absence, we discuss several hypotheses to explain the disjunct occurrence of the new species.

Keywords

Burmese amberbiogeographyairborne dispersalpalaeoecologyLymnaeidae
Type
Rapid Communication
Information
Geological Magazine , Volume 158 , Issue 7 , July 2021 , pp. 1327 - 1334
Copyright
© The Author(s), 2021. Published by Cambridge University Press

1. Introduction

Amber fossils provide a unique window into the geological past of the Earth’s biosphere. The exceptional preservation of fossils in amber frequently provides access to the finest morphological details and occasionally even the shapes of organic material such as soft bodies or feathers (e.g. Poinar & Hess, Reference Poinar and Hess1985; Henwood, Reference Henwood1992; Grimaldi et al. Reference Grimaldi, Bonwich, Delannoy and Doberstein1994; Xing et al. Reference Xing, McKellar, O’Connor, Bai, Tsend and Chiappe2019, Reference Xing, O’Connor, Niu, Cockx, Mai and McKellar2020; Wang et al. Reference Wang, Matzke-Karasz, Horne, Zhao, Cao, Zhang and Wang2020).

Burmese amber in northern Myanmar has provided among the most abundant fossils from amber deposits. Descriptions of amber inclusions dating back to the early 20th century (Cockerell, Reference Cockerell1916) indicate that the region has been mined for over 100 years. Since the turn of the century, scientists have become increasingly aware of the outstanding potential of Burmese amber to advance palaeontological research. Burmese amber has provided a rare insight into mid-Cretaceous terrestrial forest environments that were creeping, crawling and slithering with insects, arachnids, myriapods, crustaceans, nematodes, annelids, snails, amphibians and reptiles (Ross, Reference Ross2019). Particularly over the last decade, the excavation of exceptional fossils has attracted researchers worldwide and sparked a major wave of species discoveries (Ross, Reference Ross2019). Approximately 1200 species of animal and plants have been described and many more are awaiting description (Ross, Reference Ross2019; Sokol, Reference Sokol2019). In addition, a number of marine animals have been recorded trapped in the treacherous resin (Smith & Ross, Reference Smith and Ross2018; Xing et al. Reference Xing, Sames, McKellar, Xi, Bai and Wan2018 a; Yu et al. Reference Yu, Kelly, Mu, Ross, Kennedy, Broly, Xia, Zhang, Wang and Dilcher2019).

Here, we present a novel finding of two freshwater snails of the family Lymnaeidae preserved in Burmese amber. We describe a new species and discuss the implications of this record for palaeoecology and biogeography of the Lymnaeidae. We propose five hypotheses to explain the disjunct occurrence on an island in the mid-Cretaceous Tethys Sea.

2. Materials and methods

The material derives from a former amber mine near Noije Bum in Tanaing Township in northernmost Myanmar. We are aware of the toxic situation associated with the mining of Burmese amber, involving armed conflict and civilian casualties since November 2017. While we clearly condemn the actions violating international human rights and humanitarian law, we argue in line with Haug et al. (Reference Haug, Azar, Ross, Szwedo, Wang, Arillo, Baranov, Bechteler, Beutel, Blagoderov, Delclòs, Dunlop, Feldberg, Feldmann, Foth, Fraaije, Gehler, Harms, Hedenäs, Hyžný, Jagt, Jagt-Yazykova, Jarzembowski, Kerp, Khine, Kirejtshuk, Klug, Kopylov, Kotthoff, Kriwet, McKellar, Nel, Neumann, Nützel, Peñalver, Perrichot, Pint, Ragazzi, Regalado, Reich, Rikkinen, Sadowski, Schmidt, Schneider, Schram, Schweigert, Selden, Seyfullah, Solórzano-Kraemer, Stilwell, van Bakel, Vega, Wang, Xing and Haug2020) that our specimens were mined legally before November 2017 and do not qualify as “blood amber”.

Dating of zircons embedded in the volcanoclastic matrix containing the amber yielded a maximum age of c. 99 Ma (Shi et al. Reference Shi, Grimaldi, Harlow, Wang, Wang, Yang, Lei, Li and Li2012). This agrees with biostratigraphic data based on ammonites found in the amber-bearing beds and within the amber, indicating a late Albian – early Cenomanian age (Cruickshank & Ko, Reference Cruickshank and Ko2003; Yu et al. Reference Yu, Kelly, Mu, Ross, Kennedy, Broly, Xia, Zhang, Wang and Dilcher2019).

The amber pieces containing the two shells are translucent yellow. The specimens were photographed using a Zeiss AXIO Zoom V16 microscope system with the stacking function at the State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS). The final images are composites of approximately 50 individual focal planes that were combined with the software Helicon Focus 6.

Additionally, the holotype and paratype individuals were scanned with a ZEISS Xradia 520 versa 3D X-ray microscope at the micro-CT lab of NIGPAS. A charge-coupled device detector and a 0.4× objective, providing isotropic voxel sizes from 0.5 mm with the help of geometric magnification, were used to obtain high resolution. The running voltage for the X-ray source was set at 50 kV (for NIGP1) and 60 kV (for NIGP2), and a thin filter (LE2) was applied to avoid beam-hardening artefacts. A total of 2001 projections over 360° were collected and the exposure time for each projection was set at 2 s (for NIGP1) and 2.5 s (for NIGP2) to obtain a high signal-to-noise ratio. Volume data were processed with the program VGSTUDIO MAX 3.0 (Volume Graphics, Heidelberg, Germany). Images were edited and arranged using the CorelDraw Graphics Suite X8.

Shell measurements include shell height (H), greatest width of shell perpendicular to height (D), aperture height parallel to shell height (h) and aperture width perpendicular to aperture height (d). All specimens are stored at the collection of NIGPAS. The publication and the nomenclatural act contained here are registered under http://zoobank.org/urn:lsid:zoobank.org:pub:6A5BFAA2-D508-4D63-861A-6DDDB071B689.

3. Systematic palaeontology

Class GASTROPODA Cuvier, Reference Cuvier1795

Subclass HETEROBRANCHIA Burmeister, Reference Burmeister1837

Superorder HYGROPHILA Férussac, Reference Férussac1822

Superfamily LYMNAEOIDEA Rafinesque, Reference Rafinesque1815

Family LYMNAEIDAE Rafinesque, Reference Rafinesque1815

Genus Galba Schrank, Reference Schrank1803

Type species. Galba truncatula O. F. Müller, Reference Müller1774; type by subsequent designation; Recent, Europe.

Galba prima sp. nov.

(Fig. 1)

Fig. 1. Galba prima sp. nov. (a–d, g, h, j, k) holotype (NIGP173920). (e, f, i, l–n) paratype (NIGP173921); note the spire is slightly deformed. (c, d, g, j, m, n) are microtomographic reconstructions; (h) shows surface rendering with transparency. All scale bars represent 1 mm.

ZooBank LSID: urn:lsid:zoobank.org:act:095524C3-D5A1-4DC5-A26B-5142A2D39B5A

Derivation of name. The species epithet refers to it being the first freshwater gastropod species found in amber.

Holotype. NIGP173920.

Paratype. NIGP173921.

Type locality and horizon. Former amber mine near Noije Bum Village, Tanaing Township, Myitkyina District, Kachin State, northern Myanmar (26° 15ʼ N, 96° 33ʼ E); unnamed horizon, mid-Cretaceous, lower Cenomanian, c. 99 Ma.

Diagnosis. Small shell with slightly coeloconoid spire, weakly stepped whorls separated by deep suture, large and inflated body whorl, slender ovate aperture, nearly straight columella without fold, and small, circular umbilicus.

Description. Shell small, consisting of about 6–6.5 whorls. Height:width ratio is 1.66 (paratype) and 1.84 (holotype). Protoconch blunt, low domical; no surface details visible. Spire slightly coeloconoid, spire angle 60–65°. Whorls stepped, with straight-sided or weakly convex lower part and strongly convex upper part; whorls separated by deep suture; spire whorls increase gradually in height, with the last whorl being broad, slightly inflated and 71–78% of total shell height. Columella not twisted, forming almost straight pillar from apex to umbilicus. Peristome thin and sharp all around aperture; columellar lip slightly reflected towards umbilicus. Umbilicus small, circular, c. 0.25 mm in diameter. Aperture slender ovoid, adapically angulated, not expanded; height of aperture attains 57–63% of total height. Surface smooth except for faint, weakly prosocline growth lines.

Measurements. Holotype: H = 7.89 mm, D = 4.28 mm, h = 4.34 mm, d = 2.38 mm; paratype: H = 6.19 mm, D = 3.74 mm, h = 3.69 mm, d = 1.61 mm.

Remarks. Modern genus classification of extant Lymnaeidae is largely based on anatomical characteristics and molecular data (e.g. Correa et al. Reference Correa, Escobar, Durand, Renaud, David, Jarne, Pointier and Hurtrez-Boussès2010; Vinarski Reference Vinarski2013), while fossil shells can only be distinguished based on general morphology, sculpture and protoconch characteristics. We attribute the species to the genus Galba due to the small shell with stepped whorls, the inflated and expanded body whorl, the comparatively small, non-expanded aperture, the thin peristome without columellar fold (Fig. 1c, g, h) and the presence of an umbilicus (Fig. 1f).

Species of Aenigmomphiscola Kruglov & Starobogatov, Reference Kruglov and Starobogatov1981, Hinkleyia Baker, Reference Baker1928, Ladislavella Dybowski, Reference Dybowski1913, Omphiscola Rafinesque, Reference Rafinesque1819, Stagnicola Jeffreys, Reference Jeffreys1830 and Walterigalba Kruglov & Starobogatov, Reference Kruglov and Starobogatov1985 have more elongated shells, often with cyrtoconoid spires, and columella folds, while Ampullaceana Servain, Reference Servain1882, Peregriana Servain, Reference Servain1882 and Radix Montfort, Reference Montfort1810 species are typically more globular with broader apertures (Vinarski & Grebennikov, Reference Vinarski and Grebennikov2012; Vinarski et al. Reference Vinarski, Bolotov, Schniebs, Nekhaev and Hundsdoerfer2017, Reference Vinarski, Aksenova and Bolotov2020 a; Glöer, Reference Glöer2019). Even the more slender representatives of Radix, such as Radix labiata (Rossmässler, Reference Rossmässler1835), can be well distinguished from Galba prima sp. nov. by their expanded apertures. Lymnaea s.s. species are much larger and have a twisted axis (Vinarski, Reference Vinarski2015; Anistratenko et al. Reference Anistratenko, Vinarski, Anistratenko, Furyk and Degtyarenko2018; Glöer, Reference Glöer2019). Similarly, shells of Bulimnea Haldeman, Reference Haldeman1841 have a twisted columella and lack an umbilicus (Baker, Reference Baker1911). The Australian Austropeplea Cotton, Reference Cotton1942 also bears a more expanded aperture and no umbilicus (Dell, Reference Dell1956; Ponder et al. Reference Ponder, Hallan, Shea, Clark, Richards, Klunzinger and Kessner2020).

Some species of Orientogalba Kruglov & Starobogatov, Reference Kruglov and Starobogatov1985, a genus native to Asia, have a similar shell habitus with inflated body whorl and short spire, such as O. viridis (Quoy & Gaimard, 1833–Reference Quoy and Gaimard1835) and O. ollula (Gould, Reference Gould1859), but they lack the umbilicus (Vinarski et al. Reference Vinarski, Aksenova and Bolotov2020 a). Also, O. viridis has an expanded aperture (Vinarski et al. Reference Vinarski, Aksenova and Bolotov2020 a). Orientogalba lenaensis (Kruglov & Starobogatov, Reference Kruglov and Starobogatov1985), in turn, is much more slender and has a high spire (Sitnikova et al. Reference Sitnikova, Sysoev and Prozorova2014).

The fossil Mesozoic genus Proauricula Huckriede, Reference Huckriede1967, which was tentatively considered a basal basommatophoran and predecessor of modern Lymnaeidae by Bandel (Reference Bandel1991), has a more slender shell with columellar plicae and distinct spiral striation on the teleoconch (Huckriede, Reference Huckriede1967; Bandel, Reference Bandel1991; Pan & Zhu, Reference Pan and Zhu2007). In fact, the overall shape and especially the distinct columellar plicae make a relationship to Lymnaeidae very unlikely. The shape and apertural characteristics are more similar to Ellobiidae, where the genus was originally placed by Huckriede (Reference Huckriede1967) and which was also adopted by Pan & Zhu (Reference Pan and Zhu2007). Here, we accept this original classification and place Proauricula tentatively in the Ellobiidae. That family was well represented during the Mesozoic Era by several genera and species (Yen, Reference Yen1951, Reference Yen1952 a, b, Reference Yen1954; Bandel, Reference Bandel1991; Bandel & Riedel, Reference Bandel and Riedel1994; Pan & Zhu, Reference Pan and Zhu2007; Isaji, Reference Isaji2010).

Of the 13 mid-Cretaceous lymnaeids, only two species are currently classified in Galba, that is, G. yongkangensis Yü in Yü & Pan, Reference Yü and Pan1980 and G. meikiensis Yü in Yü & Pan, Reference Yü and Pan1980 from the Albian Guantou Formation in China. The former is more elongate and has a cyrtoconoid spire, while the latter can be distinguished from Galba prima sp. nov. by its higher last and penultimate whorl (Yü & Pan, Reference Yü and Pan1980). Similarly, Radix undensis Martinson, Reference Martinson1956 from Aptian–Albian strata of Siberia has a higher, globular last whorl and a very short spire. The four Cenomanian species from France, introduced in the genus “Limnaea” by Repelin (Reference Repelin1902), are more slender and have higher spires; only some specimens of L. munieri Repelin, Reference Repelin1902 have a similar morphology, but the species clearly differs from G. prima sp. nov. in having convex, non-stepped whorls. The American “Lymnaea” nitidula (Meek, Reference Meek1860), “Lymnaea” ativuncula White, Reference White1886 and “Lymnaea” tengchieni Kadolsky, Reference Kadolsky1995 (= L. cretacea Yen, Reference Yen1951, non Thomä, Reference Thomä1845) are distinctly more slender, while “Lymnaea” sagensis Yen, Reference Yen1946 has a globular shell and more reminiscent of a viviparid than a lymnaeid. An unidentified ?Austropeplea sp. from Albian–Cenomanian strata of New Zealand is only incompletely preserved, but the species appears to be broader and bears spiral microsculpture.

4. Discussion

Unsurprisingly, amber mostly preserves terrestrial biota, but a number of freshwater organisms are also known from amber deposits, including arthropods, nematodes and amoebae (Gray, Reference Gray1988; Schmidt et al. Reference Schmidt, Schönborn and Schäfer2004; Yu et al. Reference Yu, Kelly, Mu, Ross, Kennedy, Broly, Xia, Zhang, Wang and Dilcher2019). The species described herein is the first freshwater snail ever recorded in amber. This mode of preservation is likely due to the species’ lifestyle and aquatic niche: several extant members of the Lymnaeidae, including species of Galba, are amphibious (Dillon, Reference Dillon2000). For example, Galba truncatula (Müller, Reference Müller1774) is commonly found outside the water and can withstand droughts for an extensive period of time; some individuals have been found surviving for over a year in aestivation (Kendall, Reference Kendall1949). However, extensive droughts were rather unlikely in the Cenomanian tropical forests of the Burma Terrane (Poinar et al. Reference Poinar, Lambert and Wu2007; Xing et al. Reference Xing, Stanley, Bai and Blackburn2018 b; Yu et al. Reference Yu, Kelly, Mu, Ross, Kennedy, Broly, Xia, Zhang, Wang and Dilcher2019). Rather, the snail might have been captured in resin flowing down or dropping from trees close to a water body. Since extant Galba is typically found in stagnant and often temporary water bodies, such as lakes, ponds, ditches, mires and puddles (Kendall, Reference Kendall1949; Økland, Reference Økland1990), we assume a similar aquatic biome close to the place of deposition.

The present finding also has implications for the biogeography of the family Lymnaeidae. Galba prima sp. nov. is among the few fossil Lymnaeidae known from early Late Cretaceous time. The only other relatives of similar age have been reported from Cenomanian strata of France (Repelin, Reference Repelin1902) and the Albian–Cenomanian deposits of New Zealand (Beu et al. Reference Beu, Marshall and Reay2014; see also Section 3 above on Systematic Palaeontology). Slightly older records have been documented from Aptian–Albian strata of North America (White, Reference White1886; Yen, Reference Yen1946, Reference Yen1951, Reference Yen1954), Russia (Martinson, Reference Martinson1956) and China (Yü & Pan, Reference Yü and Pan1980; Pan & Zhu, Reference Pan and Zhu2007).

However, Galba prima sp. nov. is not the earliest member of the genus; alleged records of Galba date back to the Middle Jurassic Epoch of China (Pan, Reference Pan1977; Yü & Pan, Reference Yü and Pan1980). Their attribution to the genus (and in some cases even to the family Lymnaeidae) has not yet been confirmed with certainty and requires a detailed reassessment of the respective species.

The disjunct distribution of the family and particularly the isolated occurrence of Galba prima sp. nov. on the Burma Terrane are striking – how did a freshwater snail reach an island at least 1500 km from the nearest mainland (Fig. 2)? In the following, we propose five hypotheses that could explain the disjunct occurrence. Some of these hypotheses may also serve as an explanatory model for the existence of terrestrial and other freshwater biota on the Burma Terrane. All hypotheses rely on the recently published tectonic model for the Burma Terrane as an island in the Cenomanian Tethys Ocean (Westerweel et al. Reference Westerweel, Roperch, Licht, Dupont-Nivet, Win, Poblete, Ruffet, Swe, Thi and Aung2019; Fig. 2).

  1. (1) Modern Lymnaeidae, as well as many other freshwater snails, are commonly distributed via waterbirds (Green & Figuerola, Reference Green and Figuerola2005; Kappes & Haase, Reference Kappes and Haase2012; van Leeuwen & van der Velde, Reference van Leeuwen and van der Velde2012; van Leeuwen et al. Reference van Leeuwen, van der Velde, van Lith and Klaassen2012, Reference van Leeuwen, Huig, van der Velde, van Alen, Wagemaker, Sherman, Klaassen and Figuerola2013; Vinarski et al. Reference Vinarski, Bolotov, Aksenova, Babushkin, Bespalaya, Makhrov, Nekhaev and Vikhrev2020 b). Although some species may occasionally be transported by song birds (e.g. Zenzal et al. Reference Zenzal, Lain and Sellers2017), this seems to be the exception rather than the rule. Passive transport of snails via travelling and migrating birds provides a unique opportunity for long-distance dispersal across watersheds. Snails travel attached to feathers or feet and can survive ingestion and defecation. Dispersal via waterfowl has been hypothesized to explain many a disjunct fossil occurrence in Cenozoic strata (Harzhauser et al. Reference Harzhauser, Mandic, Neubauer, Georgopoulou and Hassler2016; Aksenova et al. Reference Aksenova, Bolotov, Gofarov, Kondakov, Vinarski, Bespalaya, Kolosova, Palatov, Sokolova, Spitsyn, Tomilova, Travina and Vikhrev2018; Esu & Girotti, Reference Esu and Girotti2018) and likely contributed markedly to the already large distribution of the family in Mesozoic strata. However, waterfowl (Anseriformes) did not evolve before latest Cretaceous time, and even the oldest neognathe bird is younger than the new Cenomanian Lymnaeidae (c. 85 Ma according to Claramunt & Cracraft, Reference Claramunt and Cracraft2015). Little is known about the flight capabilities of Mesozoic birds. Early Cretaceous ornithurines already possessed anatomical features similar to those of modern migratory birds, such as a keeled sternum (Falk, Reference Falk2011). Based on the appearance of the same types of bird routes across great distances, Falk (Reference Falk2011) suggested that ornithurine birds might have evolved long-distance migration in or before the Early Cretaceous Epoch, but clear evidence is lacking. Enantiornithines, a group widely represented in the global Cretaceous fossil record, have been recorded several times in Burmese amber (Xing et al. Reference Xing, McKellar, Xu, Li, Bai, Persons, Miyashita, Benton, Zhang, Wolfe, Yi, Tseng, Ran and Currie2016, Reference Xing, O’Connor, McKellar, Chiappe, Tseng, Li and Bai2017, Reference Xing, McKellar, O’Connor, Bai, Tsend and Chiappe2019, Reference Xing, O’Connor, Niu, Cockx, Mai and McKellar2020). Their plumage would likely have been suitable for transporting the tiny snail, but current knowledge indicates that this group was only capable of flap-gliding and bounding flight (e.g. Liu et al. Reference Liu, Chiappe, Serrano, Habib, Zhang and Meng2017; Serrano et al. Reference Serrano, Chiappe, Palmqvist, Figueirido, Marugán-Lobón and Sanz2018). Probably, enantiornithines were already present on the Burma Terrane before it detached from Gondwana during the Jurassic Period (Matthews et al. Reference Matthews, Maloney, Zahirovic, Williams, Seton and Müller2016).

  2. (2) An alternative winged animal group existing during the Cenomanian Age were pterosaurs (Order Pterosauria). So far, they have not been considered potential dispersal agents for invertebrates, but previous studies suggest that Cretaceous pterosaurs may have dispersed angiosperm seeds (Fleming & Lips, Reference Fleming and Lips1991). In addition to the aforementioned ornithurine birds, pterosaurs were likely capable of long-distance travels (Witton & Habib, Reference Witton and Habib2010). Some species probably fed on molluscs (Bestwick et al. Reference Bestwick, Unwin, Butler, Henderson and Purnell2018). Pterosaurs may therefore have dispersed freshwater snails via ingestion or by attachment to the feet or scales on the legs or tail, comparable to similar occurrences in modern birds. However, no pterosaur fossil has so far been retrieved from Burmese amber deposits that could potentially support this hypothesis. Other animal groups, such as amphibians or larger insects, which have occasionally been found carrying freshwater molluscs (e.g. Walther et al. Reference Walther, Benard, Boris, Enstice, Tindauer-Thompson and Wan2008; Kolenda et al. Reference Kolenda, Najbar, Kusmierek and Maltz2017), are unlikely to play a significant role in long-distance dispersal.

  3. (3) Driftwood is known to be a potential transoceanic vector for terrestrial and amphibious animals (e.g. Trewick, Reference Trewick2001; Measey et al. Reference Measey, Vences, Drewes, Chiari, Melo and Bourles2007) as well as brackish-water gastropods, such as Littorinidae (Reid, Reference Reid1986) or estuarine Neritidae (Kano et al. Reference Kano, Fukumori, Brenzinger and Warén2013). While these brackish-water snails have a marine larval phase facilitating wider dispersal, Lymnaeidae are restricted to freshwater environments. We cannot exclude that Galba prima sp. nov. boarded driftwood in a river or estuary and survived the long journey (perhaps during aestivation), but we believe it is fairly unlikely given the great distance and ecological constraints. However, driftwood (or any kind of drifting islands) may have facilitated dispersal of Cenomanian land snails (compare Dörge et al. Reference Dörge, Walther, Beinlich and Plachter1999), which may have had a higher chance of long-term survival due to their ability to close the shell with an operculum or epiphragm (Ożgo et al. Reference Ożgo, Örstan, Kirschenstein and Cameron2016).

  4. (4) Several studies have indicated the possibility of dispersal via wind, particularly strong storms. Numerous examples of “raining fishes” exist from the recent past as well as historical documents worldwide, where storms carried both marine and freshwater fishes over large distances (Rees, Reference Rees1965). A case of freshwater Anodonta, a genus of unionid bivalves, raining down over Germany after a storm was reported in the 19th century (Rees, Reference Rees1965). Ożgo et al. (Reference Ożgo, Örstan, Kirschenstein and Cameron2016) demonstrated land snail dispersal by strong storms in northern Europe. They concluded that wind currents associated with storm cells may also facilitate long-distance dispersal. A similar hypothesis was proposed by Vagvolgyi (Reference Vagvolgyi1975) explaining how land snails could colonize remote Pacific islands. The terrestrial ecosystems in the area that comprises Southeast Asia today were also likely perturbed by tropical storms as long ago as during the Cenomanian Age. Considering the overall high temperature in the Cretaceous greenhouse (Mills et al. Reference Mills, Krause, Scotese, Hill, Shields and Lenton2019), storm frequency and intensity were probably higher than today (Ghosh et al. Reference Ghosh, Prasanna, Banerjee, Williams, Gagan, Chaudhuri and Suwas2018). The prevailing wind stress reconstructed for the mid-Cretaceous period by Poulsen et al. (Reference Poulsen, Seidov, Barron and Peterson1998) points from mainland Asia towards the Tethys Ocean, matching the required dispersal direction. Since the Burma Terrane was south of the equator during the Cenomanian Age according to the latest palaeogeographic model (Westerweel et al. Reference Westerweel, Roperch, Licht, Dupont-Nivet, Win, Poblete, Ruffet, Swe, Thi and Aung2019), the only storms that could potentially transport the snails towards the Burma Terrane would have originated in the southern Woyla Arc or the southern Sundaland Block and moved westwards along the Southern Hemisphere trade winds (Fig. 2). However, no fossil record is available to support this hypothesis.

  5. (5) Finally, Lymnaeidae may have reached the Burma Terrane when it was still attached to Gondwana prior to the opening of the Neotethys Ocean during latest Jurassic time (Matthews et al. Reference Matthews, Maloney, Zahirovic, Williams, Seton and Müller2016) and they survived there until the Cenomanian Age (without fossil record). However, this still leaves open how the family got there in the Jurassic Period, when their fossil record was limited to the Northern Hemisphere. Despite the patchiness of the fossil record, especially for freshwater habitats during the Mesozoic Era, the lack of any evidence makes this, in our opinion, the least plausible hypothesis.

Fig. 2. Reconstruction of the Burma Terrane during the Cenomanian Age (95 Ma). Modified from Westerweel et al. (Reference Westerweel, Roperch, Licht, Dupont-Nivet, Win, Poblete, Ruffet, Swe, Thi and Aung2019).

Given the uncertainties involved in many of these hypotheses, we do not support a particular explanation model. However, considering the great distance and ecological constraints, we believe airborne dispersal – whether via ornithurine birds, pterosaurs or storms – is the most plausible means.

Acknowledgements

We are grateful to Gerald Mayr for discussing long-distance dispersal capabilities of Mesozoic birds and pterosaurs. David Bullis and an anonymous reviewer provided helpful comments that improved an earlier version of the paper. This research was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (TY, XDA19050101, XDB26000000), the Second Tibetan Plateau Scientific Expedition and Research (TY, 2019QZKK0706) and National Natural Science Foundation of China (TY, 41688103).

Conflict of interest

None.

Footnotes

a

These authors contributed equally to this work.

References

Aksenova, OV, Bolotov, IN, Gofarov, MYu, Kondakov, AV, Vinarski, MV, Bespalaya, YV, Kolosova, YS, Palatov, DM, Sokolova, SE, Spitsyn, VM, Tomilova, AA, Travina, OV and Vikhrev, IV (2018) Species richness, molecular taxonomy and biogeography of the Radicine Pond Snails (Gastropoda: Lymnaeidae) in the Old World. Scientific Reports 8, 11199, doi: 10.1038/s41598-018-29451-1.CrossRefGoogle ScholarPubMed
Anistratenko, VV, Vinarski, MV, Anistratenko, OYu, Furyk, YI and Degtyarenko, EV (2018) New data on pond snails (Mollusca: Gastropoda: Lymnaeidae) inhabiting the Ukrainian Transcarpathian: diversity, distribution and ecology. Ecologica Montenegrina 18, 1–14, doi: 10.37828/EM.2018.18.1.CrossRefGoogle Scholar
Baker, FC (1911) The Lymnaeidae of North and Middle America, recent and fossil. Chicago: Chicago Academy of Sciences, 539 p.Google Scholar
Baker, FC (1928) The freshwater mollusca of Wisconsin. Part I. Gastropoda. Wisconsin Geological and Natural History Survey Bulletin 70, 1–507.Google Scholar
Bandel, K (1991) Gastropods from brackish and fresh water of the Jurassic - Cretaceous transition (a systematic reevaluation). Berliner geowissenschaftliche Abhandlungen, A 134, 9–55.Google Scholar
Bandel, K and Riedel, F (1994) The late Cretaceous gastropod fauna from Ajka (Bakony Mountains, Hungary): a revision. Annalen des Naturhistorischen Museums in Wien, Serie A 96, 1–65.Google Scholar
Bestwick, J, Unwin, DM, Butler, RJ, Henderson, DM and Purnell, MA (2018) Pterosaur dietary hypotheses: a review of ideas and approaches. Biological Reviews 93, 2021–48, doi: 10.1111/brv.12431.CrossRefGoogle ScholarPubMed
Beu, AG, Marshall, BA and Reay, MB (2014) Mid-Cretaceous (Albian–Cenomanian) freshwater Mollusca from the Clarence Valley, Marlborough, New Zealand, and their biogeographical significance. Cretaceous Research 49, 134–51, doi: 10.1016/j.cretres.2014.02.011.CrossRefGoogle Scholar
Burmeister, H (1837) Handbuch der Naturgeschichte, vol. 2. Zoologie. Berlin: Enslin, xii + 369–858 pp.Google Scholar
Claramunt, S and Cracraft, J (2015) A new time tree reveals Earth history’s imprint on the evolution of modern birds. Science Advances 1, e1501005, doi: 10.1126/sciadv.1501005.CrossRefGoogle ScholarPubMed
Cockerell, TDA (1916) Insects in Burmese amber. American Journal of Science, Fourth Series 42, 135–8, doi: 10.2475/ajs.s4-42.248.135.Google Scholar
Correa, AC, Escobar, JS, Durand, P, Renaud, F, David, P, Jarne, P, Pointier, J-P and Hurtrez-Boussès, S (2010) Bridging gaps in the molecular phylogeny of the Lymnaeidae (Gastropoda: Pulmonata), vectors of Fascioliasis. BMC Evolutionary Biology 10, 381, doi: 10.1186/1471-2148-10-381.CrossRefGoogle Scholar
Cotton, BC (1942) Some Australian freshwater Gasteropoda. Transactions of the Royal Society of South Australia 66, 75–82.Google Scholar
Cruickshank, RD and Ko, K (2003) Geology of an amber locality in the Hukawng Valley, Northern Myanmar. Journal of Asian Earth Sciences 21, 441–55, doi: 10.1016/S1367-9120(02)00044-5.CrossRefGoogle Scholar
Cuvier, G (1795) Second Mémoire sur l’organisation et les rapports des animaux à sang blanc, dans lequel on traite de la structure des Mollusques et de leur division en ordre, lu à la société d’Histoire Naturelle de Paris, le 11 prairial an troisième. Magasin Encyclopédique, ou Journal des Sciences, des Lettres et des Arts 2, 433–49.Google Scholar
Dell, RK (1956) The fresh-water mollusca of New Zealand. Parts II and III. Transactions of the Royal Society of New Zealand 84, 71–90.Google Scholar
Dillon, RT (2000) The Ecology of Freshwater Molluscs. Cambridge: Cambridge University Press, 509 p.CrossRefGoogle Scholar
Dörge, N, Walther, C, Beinlich, B and Plachter, H (1999) The significance of passive transport for dispersal in terrestrial snails (Gastropoda, Pulmonata). Zeitschrift für Ökologie und Naturschutz 8, 1–10.Google Scholar
Dybowski, B (1913) Bemerkungen und Zusätze zu der Arbeit von Dr. W. Dybowski “Mollusken aus der Uferregion des Baikalsees”. Ezhegodnik Zoologicheskogo Muzeja Imperatorskoy Akademii Nauk 17, 165–218.Google Scholar
Esu, D and Girotti, O (2018) Valvata mathiasi sp. nov. (Gastropoda: Heterobranchia: Valvatidae) from the Lower Pliocene of the Val di Pesa (Tuscany, Central Italy). Archiv für Molluskenkunde 147, 49–54, doi: 10.1127/arch.moll/147/049-054.CrossRefGoogle Scholar
Falk, AR (2011) Tracking Mesozoic birds across the world. Journal of Systematic Palaeontology 9, 85–90, doi: 10.1080/14772019.2010.512616.CrossRefGoogle Scholar
Férussac, AEJPJFdd (1821–1822) Tableaux systématiques des animaux mollusques classés en familles naturelles, dans lesquels on a établi la concordance de tous les systèmes; suivis d’un prodrome général pour tous les mollusques terrestres ou fluviatiles, vivants ou fossiles. Paris, Londres: Bertrand, Sowerby, 110 p.Google Scholar
Fleming, TH and Lips, KR (1991) Angiosperm endozoochory: were pterosaurs Cretaceous seed dispersers? The American Naturalist 138, 1058–65.CrossRefGoogle Scholar
Ghosh, P, Prasanna, K, Banerjee, Y, Williams, IS, Gagan, MK, Chaudhuri, A and Suwas, S (2018) Rainfall seasonality on the Indian subcontinent during the Cretaceous greenhouse. Scientific Reports 8, 8482, doi: 10.1038/s41598-018-26272-0.CrossRefGoogle ScholarPubMed
Glöer, P (2019) The Freshwater Gastropods of the West-Palaearctis. Volume I. Fresh- and brackish waters except spring and subterranean snails. Identification key, Anatomy, Ecology, Distribution. Hetlingen: privately published by P Glöer, 399 p.Google Scholar
Gould, AA (1859) Descriptions of shells collected by the North Pacific Exploring Expedition. Proceedings of the Boston Society of Natural History 7, 40–45.CrossRefGoogle Scholar
Gray, J (1988) Evolution of the freshwater ecosystem: the fossil record. Palaeogeography, Palaeoclimatology, Palaeoecology 62, 1–214.CrossRefGoogle Scholar
Green, AJ and Figuerola, J (2005) Recent advances in the study of long-distance dispersal of aquatic invertebrates via birds. Diversity and Distributions 11, 149–56, doi: 10.1111/j.1366-9516.2005.00147.x.CrossRefGoogle Scholar
Grimaldi, D, Bonwich, E, Delannoy, M and Doberstein, S (1994) Electron microscopic studies of mummified tissues in amber fossils. American Museum Novitates 3097, 1–31.Google Scholar
Haldeman, SS (1841) A monograph of the Limniades and other freshwater univalve shells of Northern America. Limnea. Philadelphia: J. Dobson, 16 p.Google Scholar
Harzhauser, M, Mandic, O, Neubauer, TA, Georgopoulou, E and Hassler, A (2016) Disjunct distribution of the Miocene limpet-like freshwater gastropod genus Delminiella . Journal of Molluscan Studies 82, 129–36, doi: 10.1093/mollus/eyv040.Google Scholar
Haug, JT, Azar, D, Ross, A, Szwedo, J, Wang, B, Arillo, A, Baranov, V, Bechteler, J, Beutel, R, Blagoderov, V, Delclòs, X, Dunlop, J, Feldberg, K, Feldmann, R, Foth, C, Fraaije, RHB, Gehler, A, Harms, D, Hedenäs, L, Hyžný, M, Jagt, JWM, Jagt-Yazykova, EA, Jarzembowski, E, Kerp, H, Khine, PK, Kirejtshuk, AG, Klug, C, Kopylov, DS, Kotthoff, U, Kriwet, J, McKellar, RC, Nel, A, Neumann, C, Nützel, A, Peñalver, E, Perrichot, V, Pint, A, Ragazzi, E, Regalado, L, Reich, M, Rikkinen, J, Sadowski, E-M, Schmidt, AR, Schneider, H, Schram, FR, Schweigert, G, Selden, P, Seyfullah, LJ, Solórzano-Kraemer, MM, Stilwell, JD, van Bakel, BWM, Vega, FJ, Wang, Y, Xing, L and Haug, C (2020) Comment on the letter of the Society of Vertebrate Paleontology (SVP) dated April 21, 2020 regarding “Fossils from conflict zones and reproducibility of fossil-based scientific data”: Myanmar amber. Paläontologische Zeitschrift 94, 431–7, doi: 10.1007/s12542-020-00524-9.CrossRefGoogle Scholar
Henwood, A (1992) Exceptional preservation of dipteran flight muscle and the taphonomy of insects in amber. Palaios 7, 203–12, doi: 10.2307/3514931.CrossRefGoogle Scholar
Huckriede, R (1967) Molluskenfaunen mit limnischen und brackischen Elementen aus Jura, Serpulit und Wealden NW-Deutschlands und ihre paläogeographische Bedeutung. Geologisches Jahrbuch, Beiheft 67, 1–263.Google Scholar
Isaji, S (2010) Terrestrial and freshwater pulmonate gastropods from the Early Cretaceous Kuwajima Formation, Tetori Group, Japan. Paleontological Research 14, 233–43, doi: 10.2517/1342-8144-14.4.233.CrossRefGoogle Scholar
Jeffreys, JG (1830) A synopsis on the testaceous pneumonobranchous Mollusca of Great Britain. Transactions of the Linnean Society of London 16, 323–92.CrossRefGoogle Scholar
Kadolsky, D (1995) Stratigraphie und Molluskenfaunen von “Landschneckenkalk” und “Cerithienschichten” im Mainzer Becken (Oberoligozän bis Untermiozän?), 2: Revision der aquatischen Mollusken des Landschneckenkalkes. Archiv für Molluskenkunde 124, 1–55.CrossRefGoogle Scholar
Kano, Y, Fukumori, H, Brenzinger, B and Warén, A (2013) Driftwood as a vector for the oceanic dispersal of estuarine gastropods (Neritidae) and an evolutionary pathway to the sunken-wood community. Journal of Molluscan Studies 79, 378–82, doi: 10.1093/mollus/eyt032.CrossRefGoogle Scholar
Kappes, H and Haase, P (2012) Slow, but steady: dispersal of freshwater molluscs. Aquatic Sciences 74, 1–14, doi: 10.1007/s00027-011-0187-6.CrossRefGoogle Scholar
Kendall, SB (1949) Bionomics of Limnaea truncatula and the Parthenitae of Fasciola hepatica under drought conditions. Journal of Helminthology 23, 57–68, doi: 10.1017/S0022149X00032375.CrossRefGoogle Scholar
Kolenda, K, Najbar, A, Kusmierek, N and Maltz, TK (2017) A possible phoretic relationship between snails and amphibians. Folia Malacologica 25, 281–5, doi: 10.12657/folmal.025.019.CrossRefGoogle Scholar
Kruglov, ND and Starobogatov, YaI (1981) A new genus of the Lymnaeidae and taxonomy of the subgenus Omphiscola (Lymnaea) (Pulmonata, Gastropoda). Zoologicheskiy Zhurnal 60, 965–77.Google Scholar
Kruglov, ND and Starobogatov, YaI (1985) The volume of the subgenus Galba and of other similar subgenera of the genus Lymnaea (Gastropoda, Pulmonata). Zoologicheskiy Zhurnal 64, 24–35.Google Scholar
Liu, D, Chiappe, LM, Serrano, F, Habib, M, Zhang, Y and Meng, Q (2017) Flight aerodynamics in enantiornithines: information from a new Chinese Early Cretaceous bird. PLoS ONE 12, e0184637, doi: 10.1371/journal.pone.0184637.CrossRefGoogle ScholarPubMed
Martinson, GG (1956) Opredelitel’ mezozoyskikh i kaynozoyskikh presnovodnykh mollyuskov Vostochnoy Sibiri. Moskva, Leningrad: Izdatel’stvo Akademii Nauk SSSR, 92 p.Google Scholar
Matthews, KJ, Maloney, KT, Zahirovic, S, Williams, SE, Seton, M and Müller, RD (2016) Global plate boundary evolution and kinematics since the late Paleozoic. Global and Planetary Change 146, 226–50, doi: 10.1016/j.gloplacha.2016.10.002.CrossRefGoogle Scholar
Measey, GJ, Vences, M, Drewes, RC, Chiari, Y, Melo, M and Bourles, B (2007) Freshwater paths across the ocean: molecular phylogeny of the frog Ptychadena newtoni gives insights into amphibian colonization of oceanic islands. Journal of Biogeography 34, 7–20, doi: 10.1111/j.1365-2699.2006.01589.x.CrossRefGoogle Scholar
Meek, FB (1860) Descriptions of new fossil remains collected in Nebraska and Utah, by the exploring expeditions under the command of Captain J. H. Simpson, of U. S. Topographical Engineers [extracted from that officer’s forthcoming report]. Proceedings of the Academy of Natural Sciences of Philadelphia 12, 308–15.Google Scholar
Mills, BJW, Krause, AJ, Scotese, CR, Hill, DJ, Shields, GA and Lenton, TM (2019) Modelling the long-term carbon cycle, atmospheric CO2, and Earth surface temperature from late Neoproterozoic to present day. Gondwana Research 67, 172–86, doi: 10.1016/j.gr.2018.12.001.CrossRefGoogle Scholar
Montfort, PD de (1810) Conchyliologie systématique et classification méthodique de coquilles; offrant leurs figures, leur arrangement générique, leurs descriptions caractéristiques, leurs noms; ainsi que leur synonymie en plusieurs langues. Ouvrage destiné à faciliter lʼétude des coquilles, ainsi que leur disposition dans les cabinets d’histoire naturelle. Coquilles univalves, non cloisonnées. Tome second. Paris: Schoell, 676 p.Google Scholar
Müller, OF (1773–1774) Vermium terrestrium et fluviatilium historia, seu animalium Infusoriorum, Helminthicorum et Testaceorum non marinorum succincta historia. Havniae et Lipsiae: Heineck & Faber, xxxiii + 135, xxxvi + 214 pp.Google Scholar
Økland, J (1990) Lakes and Snails. Environment and Gastropoda in 1,500 Norwegian Lakes, Ponds and Rivers. Oegstgeest: Backhuys, 516 p.Google Scholar
Ożgo, M, Örstan, A, Kirschenstein, M and Cameron, R (2016) Dispersal of land snails by sea storms. Journal of Molluscan Studies 82, 341–3, doi: 10.1093/mollus/eyv060.CrossRefGoogle Scholar
Pan, H (1977) Mesozoic and Cenozoic fossil Gastropoda from Yunnan. In Mesozoic Fossils from Yunnan 2 (ed. Nanjing Institute of Geology and Palaeontology), pp. 83–152. Beijing: Science Press.Google Scholar
Pan, H and Zhu, X (2007) Early Cretaceous non-marine gastropods from the Xiazhuang Formation in North China. Cretaceous Research 27, 215–24, doi: 10.1016/j.cretres.2006.12.001.CrossRefGoogle Scholar
Poinar, G, Lambert, JB and Wu, Y (2007) Araucarian source of fossiliferous Burmese amber: spectroscopic and anatomical evidence. Journal of the Botanical Research Institute of Texas 1, 449–55.Google Scholar
Poinar, GOJr and Hess, R (1985) Preservative qualities of recent and fossil resins: electron micrograph studies on tissue preserved in Baltic amber. Journal of Baltic Studies 16, 222–30, doi: 10.1080/01629778500000141.CrossRefGoogle Scholar
Ponder, WF, Hallan, A, Shea, ME, Clark, SA, Richards, K, Klunzinger, MW and Kessner, V (2020) Australian Freshwater Molluscs. Revision 1. Available at https://keys.lucidcentral.org/keys/v3/freshwater_molluscs/ (accessed 4 December 2020).Google Scholar
Poulsen, CJ, Seidov, D, Barron, EJ and Peterson, WH (1998) The impact of paleogeographic evolution on the surface oceanic circulation and the marine environment within the mid-Cretaceous Tethys. Paleoceanography 13, 546–59.CrossRefGoogle Scholar
Quoy, JRC and Gaimard, JP (1832–1835) Voyage de découvertes de l’Astrolabe exécuté par ordre du Roi, pendant les années 1826–1829, sous le commandement de M. J. Dumont d’Urville. Zoologie. Paris: Tastu.Google Scholar
Rafinesque, CS (1815) Analyse de la nature ou tableau de l’univers et des corps organisés. Palermo: privately published by CS Rafinesque, 223 p.Google Scholar
Rafinesque, CS (1819) Prodrome de 70 nouveaux genres d’animaux découverts dans l’intérieur des Etas-Unis d’Amérique, durant l’année 1818. Journal de Physique, de Chimie et d’Histoire Naturelle 88, 417–29.Google Scholar
Rees, WJ (1965) The aerial dispersal of Mollusca. Journal of Molluscan Studies 36, 269–82, doi: 10.1093/oxfordjournals.mollus.a064955.CrossRefGoogle Scholar
Reid, DG (1986) The Littorinid Molluscs of Mangrove Forests in the Indo-Pacific Region. London: British Museum, 227 p.Google Scholar
Repelin, J (1902) Description des faunes et des gisements du Cénomanien saumâtre ou d’eau douce du Midi de la France. Annales du Musée d’histoire naturelle de Marseille. Section de Géologie 7, 1–133.Google Scholar
Ross, AJ (2019) Burmese (Myanmar) amber checklist and bibliography 2018. Palaeoentomology 2, 22–84, doi: 10.11646/palaeoentomology.2.1.5.CrossRefGoogle Scholar
Rossmässler, EA (1835–1837) Iconographie der Land- und Süsswasser-Mollusken, mit vorzüglicher Berücksichtigung der europäischen noch nicht abgebildeten Arten. 1. Band. Dresden, Leipzig: Arnold. Heft 1: 132 p. (1835); Heft 2: 26 p. (1835); Heft 3: 33 p. (1836); Heft 4: 27 p. (1836); Hefte 5–6: 70 p. (1837).Google Scholar
Schmidt, AR, Schönborn, W and Schäfer, U (2004) Diverse fossil amobae in German Mesozoic amber. Palaeontology 47, 185–97.CrossRefGoogle Scholar
Schrank, FvP (1803) Fauna Boica. Durchgedachte Geschichte der in Baiern einheimischen und zahmen Thiere. Dritten und lezten Bandes zweyte Abtheilung. Landshut: Krüll, 372 p.Google Scholar
Serrano, FJ, Chiappe, LM, Palmqvist, P, Figueirido, B, Marugán-Lobón, J and Sanz, JL (2018) Flight reconstruction of two European enantiornithines (Aves, Pygostylia) and the achievement of bounding flight in Early Cretaceous birds. Palaeontology 61, 359–68, doi: 10.1111/pala.12351.CrossRefGoogle Scholar
Servain, G (1882) Histoire Malacologique du lac Balaton en Hongrie. Paris: Paul Klincksieck, 125 p.Google Scholar
Shi, G, Grimaldi, DA, Harlow, GE, Wang, J, Wang, J, Yang, M, Lei, W, Li, Q and Li, X (2012) Age constraint on Burmese amber based on U-Pb dating of zircons. Cretaceous Research 37, 155–63, doi: 10.1016/j.cretres.2012.03.014.CrossRefGoogle Scholar
Sitnikova, TYa, Sysoev, AV and Prozorova, LA (2014) Types of freshwater gastropods described by Ya.I. Starobogatov, with additional data on the species: family Lymnaeidae. Zoologicheskie Issledovania 16, 7–37.Google Scholar
Smith, RDA and Ross, AJ (2018) Amberground pholadid bivalve borings and inclusions in Burmese amber: implications for proximity of resin-producing forests to brackish waters, and the age of the amber. Earth and Environmental Science Transactions of The Royal Society of Edinburgh 107, 239–47, doi: 10.1017/S1755691017000287.CrossRefGoogle Scholar
Sokol, J (2019) Troubled treasure. Science 364, 722–9, doi: 10.1126/science.364.6442.722.CrossRefGoogle ScholarPubMed
Thomä, C (1845) Fossile Conchylien aus den Tertiärschichten bei Hochheim und Wiesbaden gesammelt und im naturhistorischen Museum zu Wiesbaden ausgestellt. Jahrbücher des Vereins für Naturkunde in Nassau 2, 125–2.Google Scholar
Trewick, SA (2001) Molecular evidence for dispersal rather than vicariance as the origin of flightless insect species on the Chatham Islands, New Zealand. Journal of Biogeography 27, 1189–200, doi: 10.j.1365-2699.2000.00492.x.CrossRefGoogle Scholar
Vagvolgyi, J (1975) Body size, aerial dispersal, and origin of the Pacific land snail fauna. Systematic Zoology 24, 465–88, doi: 10.2307/2412906.CrossRefGoogle Scholar
van Leeuwen, CHA, Huig, N, van der Velde, G, van Alen, TA, Wagemaker, CAM, Sherman, CDH, Klaassen, M and Figuerola, J (2013) How did this snail get here? Several dispersal vectors inferred for an aquatic invasive species. Freshwater Biology 58, 88–99, doi: 10.1111/fwb.12041.CrossRefGoogle Scholar
van Leeuwen, CHA and van der Velde, G (2012) Prerequisites for flying snails: external transport potential of aquatic snails by waterbirds. Freshwater Science 31, 963–72, doi: 10.1899/12-023.1.CrossRefGoogle Scholar
van Leeuwen, CHA, van der Velde, G, van Lith, B and Klaassen, M (2012) Experimental quantification of long distance dispersal potential of aquatic snails in the gut of migratory birds. PLoS ONE 7, e32292, doi: 10.1371/journal.pone.0032292.CrossRefGoogle ScholarPubMed
Vinarski, MV (2013) One, two, or several? How many lymnaeid genera are there? Ruthenica 23, 41–58.Google Scholar
Vinarski, MV (2015) Conceptual shifts in animal systematics as reflected in the taxonomic history of a common aquatic snail species (Lymnaea stagnalis). Zoosystematics and Evolution 91, 91–103, doi: 10.3897/zse.91.4509.CrossRefGoogle Scholar
Vinarski, MV, Aksenova, OV and Bolotov, IN (2020a) Taxonomic assessment of genetically-delineated species of radicine snails (Mollusca, Gastropoda, Lymnaeidae). Zoosystematics and Evolution 96, 577–608, doi: 10.3897/zse.96.52860.CrossRefGoogle Scholar
Vinarski, MV, Bolotov, IN, Aksenova, OV, Babushkin, ES, Bespalaya, YV, Makhrov, AA, Nekhaev, IO and Vikhrev, IV (2020b) Freshwater mollusca of the Circumpolar Arctic: a review on their taxonomy, diversity and biogeography. Hydrobiologia, published online 27 April 2020, doi: 10.1007/s10750-020-04270-6.CrossRefGoogle Scholar
Vinarski, MV, Bolotov, IN, Schniebs, K, Nekhaev, IO and Hundsdoerfer, AK (2017) Endemics or strangers? The integrative re-appraisal of taxonomy and phylogeny of the Greenland Lymnaeidae (Mollusca: Gastropoda). Comptes Rendus Biologies 340, 541–57, doi: 10.1016/j.crvi.2017.09.005.CrossRefGoogle Scholar
Vinarski, MV and Grebennikov, ME (2012) A review of the species of the genus Aenigmomphiscola Kruglov et Starobogatov, 1981 (Gastropoda: Pulmonata: Lymnaeidae). Ruthenica 22, 159–70.Google Scholar
Walther, AC, Benard, MF, Boris, LP, Enstice, N, Tindauer-Thompson, A and Wan, J (2008) Attachment of the freshwater limpet Laevapex fuscus to the hemelytra of the water bug Belostoma flumineum . Journal of Freshwater Ecology 23, 337–9, doi: 10.1080/02705060.2008.9664207.CrossRefGoogle Scholar
Wang, H, Matzke-Karasz, R, Horne, DJ, Zhao, X, Cao, M, Zhang, H and Wang, B (2020) Exceptional preservation of reproductive organs and giant sperm in Cretaceous ostracods. Proceedings of the Royal Society B: Biological Sciences 287, 20201661, doi: 10.1098/rspb.2020.1661.CrossRefGoogle ScholarPubMed
Westerweel, J, Roperch, P, Licht, A, Dupont-Nivet, G, Win, Z, Poblete, F, Ruffet, G, Swe, HH, Thi, MK and Aung, DW (2019) Burma Terrane part of the Trans-Tethyan arc during collision with India according to palaeomagnetic data. Nature Geoscience 12, 863–8, doi: 10.1038/s41561-019-0443-2.CrossRefGoogle ScholarPubMed
White, CA (1886) On the fresh-water invertebrates of the North American Jurassic. United States Geological Survey Bulletin 29, 691–725.Google Scholar
Witton, MP and Habib, MB (2010) On the size and flight diversity of giant pterosaurs, the use of birds as pterosaur analogues and comments on pterosaur flightlessness. PLoS ONE 5, e13982, doi: 10.1371/journal.pone.0013982.CrossRefGoogle ScholarPubMed
Xing, L, McKellar, RC, O’Connor, JK, Bai, M, Tsend, K and Chiappe, LM (2019) A fully feathered enantiornithine foot and wing fragment preserved in mid-Cretaceous Burmese amber. Scientific Reports 9, 927, doi: 10.1038/s41598-018-37427-4.CrossRefGoogle ScholarPubMed
Xing, L, McKellar, RC, Xu, X, Li, G, Bai, M, Persons, WS IV, Miyashita, T, Benton, MJ, Zhang, J, Wolfe, AP, Yi, Q, Tseng, K, Ran, H and Currie, PJ (2016) A feathered dinosaur tail with primitive plumage trapped in mid-Cretaceous amber. Current Biology 26, P3352–60, doi: 10.1016/j.cub.2016.10.008.CrossRefGoogle ScholarPubMed
Xing, L, O’Connor, JK, McKellar, RC, Chiappe, LM, Tseng, K, Li, G and Bai, M (2017) A mid-Cretaceous enantiornithine (Aves) hatchling preserved in Burmese amber with unusual plumage. Gondwana Research 49, 264–77, doi: 10.1016/j.gr.2017.06.001.CrossRefGoogle Scholar
Xing, L, O’Connor, JK, Niu, K, Cockx, P, Mai, H and McKellar, RC (2020) A new Enantiornithine (Aves) preserved in mid-Cretaceous Burmese amber contributes to growing diversity of Cretaceous plumage patterns. Frontiers in Earth Sciences 8, 264, doi: 10.3389/feart.2020.00264.CrossRefGoogle Scholar
Xing, L, Sames, B, McKellar, RC, Xi, D, Bai, M and Wan, X (2018a) A gigantic marine ostracod (Crustacea: Myodocopa) trapped in mid-Cretaceous Burmese amber. Scientific Reports 8, 1365, doi: 10.1038/s41598-018-19877-y.CrossRefGoogle ScholarPubMed
Xing, L, Stanley, EL, Bai, M and Blackburn, DC (2018b) The earliest direct evidence of frogs in wet tropical forests from Cretaceous Burmese amber. Scientific Reports 8, 8770, doi: 10.1038/s41598-018-26848-w.CrossRefGoogle ScholarPubMed
Yen, T-C (1946) On lower Cretaceous fresh-water mollusks of Sage Creek, Wyoming. Notulae Naturae of The Academy of Natural Sciences of Philadelphia 166, 1–13.Google Scholar
Yen, T-C (1951) Fresh-water mollusks of Cretaceous age from Montana and Wyoming. Part 1: A fluviatile fauna from the Kootenai formation near Harlowton, Montana. United States Geological Survey Professional Paper 233-A, 1–9.Google Scholar
Yen, T-C (1952a) Freshwater molluscan fauna from an Upper Cretaceous porcellanite near Sage Junction, Wyoming. American Journal of Science 250, 344–59, doi: 10.2475/ajs.250.5.344.CrossRefGoogle Scholar
Yen, T-C (1952b) Molluscan fauna of the Morrison Formation. United States Geological Survey Professional Paper 233-B, 21–51.Google Scholar
Yen, T-C (1954) Nonmarine mollusks of Late Cretaceous age from Wyoming, Utah and Colorado. Part 1: A fauna from western Wyoming. United States Geological Survey Professional Paper 254-B, 45–59.Google Scholar
Yu, T, Kelly, R, Mu, L, Ross, A, Kennedy, J, Broly, P, Xia, F, Zhang, H, Wang, B and Dilcher, D (2019) An ammonite trapped in Burmese amber. Proceedings of the National Academy of Sciences of the United States of America 116, 11345–50, doi: 10.1073/pnas.1821292116.CrossRefGoogle ScholarPubMed
Yü, W and Pan, H (1980) Mesozoic non-marine gastropods from Zhejiang and South Anhui. In Divisions and Correlation of the Mesozoic Volcano-Sedimentary Rocks in Zhejiang and Anhui Provinces, China (ed. Anonymous), pp. 135–72. Nanjing: Academia Sinica, Nanjing Institute of Geology and Paleontology.Google Scholar
Zenzal, TJ, Lain, EJ and Sellers, JM (2017) An indigo bunting (Passerina cyanea) transporting snails during spring migration. The Wilson Journal of Ornithology 129, 898–902, doi: 10.1676/16-182.1.CrossRefGoogle Scholar
Figure 0

Fig. 1. Galba prima sp. nov. (a–d, g, h, j, k) holotype (NIGP173920). (e, f, i, l–n) paratype (NIGP173921); note the spire is slightly deformed. (c, d, g, j, m, n) are microtomographic reconstructions; (h) shows surface rendering with transparency. All scale bars represent 1 mm.

Figure 1

Fig. 2. Reconstruction of the Burma Terrane during the Cenomanian Age (95 Ma). Modified from Westerweel et al. (2019).