# First supralittoral gastropod (Eupulmonata: Ellobiidae) preserved in uppermost Albian-lowermost Cenomanian opaque amber of Charente-Maritime (France)

Didier Merle, Didier Néraudeau, Paul Tafforeau

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Didier Merle, Didier Néraudeau, Paul Tafforeau. First supralittoral gastropod (Eupulmonata: Ellobiidae) preserved in uppermost Albian-lowermost Cenomanian opaque amber of Charente-Maritime (France). Geological Magazine, 2025, 162, pp.e50. 10.1017/S0016756825100368. hal-05392708

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**Cite this article:** Merle D, Néraveau D, and Tafforeau P. First supralittoral gastropod (Eupulmonata: Ellobiidae) preserved in uppermost Albian-lowermost Cenomanian opaque amber of Charente-Maritime (France). *Geological Magazine* **162**(e50): 1-6. https://doi.org/10.1017/S0016756825100368

Received: 20 June 2025
Revised: 17 October 2025
Accepted: 23 October 2025

**Keywords:**
Amber; synchrotron imaging; Cretaceous;
paleoecology; Ellobiidae

**Corresponding author:** Didier Merle;
Email: didier.merle@mnhn.fr

# First supralittoral gastropod (Eupulmonata: Ellobiidae) preserved in uppermost Albian-lowermost Cenomanian opaque amber of Charente-Maritime (France)

Didier Merle¹ ID, Didier Néraveau² and Paul Tafforeau³

¹Sorbonne Université, UMR 7207 (CR2P, MNHN, CNRS), 57 rue Cuvier, Paris, France; ²Université Rennes, Géosciences Rennes, Bât.15 campus Beaulieu, Rennes, France and ³European Synchrotron Radiation Facilities (ESRF), 6, rue Jules-Horowitz, 38043, Grenoble, France

**Abstract**

Marine molluscs are exceptional in Cretaceous ambers. *Palaeoellobium decampsi* gen. nov., sp. nov. is the first gastropod ever preserved in French uppermost Albian-lowermost Cenomanian opaque amber. It belongs to the Ellobiidae that are distributed in the Cenozoic supralittoral zones in close vicinity of the mangroves. It has been discovered by non-destructive X-ray phase-contrast imaging. The forest of conifers that produced the amber embedding this gastropod did not form its habitat, and it may have been transported to the foreshore detritus. *Palaeoellobium decampsi* contributes to the understanding of the ellobiid early adaptive radiation known by few taxa, compared with the significant Cenozoic diversification.

## 1. Introduction

Finding marine or brackish organisms in fossil resin seems a priori unlikely. However, several discoveries in the last 20 years, in the mid-Cretaceous Burmese amber, have demonstrated the possibility for aquatic animals, including marine ones, to be exceptionally preserved in Cenomanian resin (Mao et al., 2018; Xing et al., 2018; Yu et al., 2019a, b; Bolotov et al., 2021). As far as microorganisms are concerned, Girard et al. (2008) have also described different microfossils included in the mid-Cretaceous Charentese amber, such as foraminifers, radiolarians, amoebae, larval spines of sea urchins, diatoms and demosponges. The gastropod discovered in Charente-Maritime is the first gastropod reported from European Cretaceous amber and is one of the exceptional marine invertebrates discovered there. Gastropods previously discovered in Cretaceous amber come mainly from Cenomanian Burmese amber and are freshwater or terrestrial species (Hirano et al., 2019; Neubauer et al., 2019a; Xing et al., 2019: Yu et al., 2019a, revised by Neubauer et al., 2019b; Yu & Neubauer, 2021; Yu et al., 2021; Balashov & Anistratenko, 2024). Yu et al. (2019a) described two new species of gastropods and identified them as marine Epitoniidae, but, on revision, Neubauer et al. (2019b) considered them terrestrial cyclophoroids. However, in association with an ammonite found in mid-Cretaceous Burmese amber, several specimens of gastropods have been attributed to the genus *Mathilda* (family Mathildae) (Yu et al., 2019b). But, it is certainly not a *Mathilda* and not even a marine gastropod. *Mathilda* would have a heterostrophic protoconch, while this one's protoconch is large, normally coiled and has few whorls - clearly a direct developer. This is a terrestrial species, probably *Pseudopomatias* or another Pupinidae (T. A. Neubauer, personal communication). Finally, the discovery of an Ellobiidae, a supralittoral gastropod, in European Cretaceous amber is an extremely rare occurrence.

## 2. Material and methods

### 2.a. Geographical and geological settings

The amber containing the gastropod described herein was collected from the quarry of Archingeay-Les Nouillers (Fig. 1), in the Charente-Maritime region (SW France) (Néraveau et al., 2002). The sandy base of the section, which yields lignitic clay with amber (Néraveau et al., 2002, fig. 2, facies A1sl), has provided fossil plants (Moreau et al., 2017) and a few pyritized brackish oysters (Videt & Platel, 2005). It was dated first as possibly uppermost Albian (100 Ma) based on palynological studies (Néraveau et al., 2002; Dejax & Masure, 2005; Peyrot et al., 2005), but more likely to be lowermost Cenomanian according to the following works (Batten et al., 2010; Peyrot et al., 2019). Since the first publication about the amber deposit, in 2002 (Néraveau et al., 2002), the Lagerstätte of Archingeay-Les Nouillers has provided hundreds of terrestrial arthropod inclusions (mainly insects, but also arachnids and myriapods) and

© The Author(s), 2025. Published by Cambridge University Press. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution and reproduction, provided the original article is properly cited.
<figure><img src="image_2.png" /><figcaption>**Figure 1.** Geographical and geological location of the amber deposit of Archingeay–Les Nouillers (white star) where *Palaeoellobium decampsi* gen. nov., sp. nov. has been discovered. Dark grey areas correspond to Cenomanian outcrops.</figcaption></figure>

abundant forest microorganisms (fungi), but only a few specimens of organisms linked to aquatic or foreshore environments (Perrichot *et al.*, 2010). Moreover, a few unpublished coastal isopods have been found, including a specimen associated with a gastropod in the same piece of amber.

## 2.b. The fossiliferous content of the amber drop including the gastropod

The piece of amber is of milky caramel colour and totally opaque (Fig. 2). Its maximum length measures 35 mm, and its diameter is ca. 23 mm. It also contains a complete specimen and an isolated leg of a Blattodea, a species of Dermaptera, a species of Opiliones, and a coastal isopod.

The fossiliferous amber sample is housed at the University of Rennes, in the collections of the Geological Institute, with the catalogue number ARC-423.

## 2.c. The imaging by microtomography

Propagation phase-contrast X-ray synchrotron microtomography (afterwards PPC-SrµCT) was used to image the specimen and its morphological features (Tafforeau *et al.*, 2006). The specimen was scanned following the protocols described in Lak *et al.* (2008) with a set energy of 30 keV (using a double Si 111 Bragg monochromator) and a 960 mm distance between the camera and the sample. Scan acquisition consisted of 1,999 images over 180 degrees, with 0.7 s of exposure time and 5.06 µ of voxel size. After the scan, the slices were reconstructed using a filtered back-projection algorithm adapted for local tomography applications (PyHST software, ESRF). The later three-dimensional processing was made using VGStudiomax 2.1 software (Volume Graphics, Heidelberg, Germany). Before scanning, the hardly fractured amber piece was set in a protective epoxy block for conservation purposes (Fig. 2).

## 3. Systematic palaeontology

Class GASTROPODA Cuvier, 1795

Subclass HETEROBRANCHIA Burmeister, 1837

Superorder EUPULMONATA Haszprunar & Huber, 1990

Order ELLOBIIDA Van Mol, 1967

Family ELLOBIIDAE L. Pfeiffer, 1854

Subfamily ELLOBIINAE L. Pfeiffer, 1854

<figure><img src="image_3.png" /><figcaption>**Figure 2.** Piece of amber (maximum length 35 mm) containing *Palaeoellobium decampsi* gen. nov., sp. nov. Before scanning in microtomography, the hardly fractured amber piece was set in a protective epoxy block for conservation purposes. Scale bar: 10 mm. Photo: P. Tafforeau, ESRF.</figcaption></figure>

Genus *Palaeoellobium* gen. nov.

LSID urn:lsid:zoobank.org:act:317DE264-5560-407C-B053-61DF1EE07E3D.

Type species. *Palaeoellobium decampsi* sp. nov.

Etymology. A combination of *palaiós* (in Greek) and *Ellobium*, type genus of the family Ellobiidae.

Diagnosis. Medium-sized, ovate shell with conical spire. Heterostrophic protoconch. Fine non-lamellar undulating ribs more prominent adapically than abapically; no spiral sculpture.
Aperture moderately wide. Columellar callus moderately delimited. Columellar fold obsolete; parietal fold prominent. Outer lip sharp without marked palatal swelling. Umbilical zone puckered.

Description. As for type species.

Stratigraphic and geographic range. Uppermost Albian to lowermost Cenomanian, Charente-Maritime, SW France.

Included species. Type species only.

*Palaeoellobium decampsi* gen. nov., sp. nov.
(Fig. 3)

LSID urn:lsid:zoobank.org:act:53B4D03D-BC81-4853-B870-13B2B718ACB6.

Derivation of name. Dedicated to Christian Décamps, the lead singer of the pop music group Ange.

Holotype. Arc-423.5 (Geological Institute of the University of Rennes, France), shell height: 10 mm, greatest width of a shell perpendicular to height: 4.9 mm (Fig. 3). The holotype corresponds to an external imprint of a shell. Within the aperture (Fig. 3d, f), some structures can be seen that could be the remains of soft anatomical parts. However, it is impossible to identify any organs.

Type locality. Archingeay-Les Nouillers area, quarry located in the village of Les Nouillers, Charente-Maritime, SW France.

Type stratum. Uppermost Albian to lowermost Cenomanian.

Shell description. Middle-sized, elongate ovate shells with conical spire; apical angle 47° (based on Fig. 3d). Heterostrophic protoconch, slightly deviated to the right in ventral view. Moderately high spire of eight weakly convex whorls. Suture narrowly incised with narrow subsutural inflexion. Last whorl convex with the convex base, representing 63% of the total height. Axial sculpture displaying approximately 15-20 ribs on the first teleoconch whorls and 25-30 ribs on the penultimate and last whorl. Fine non-lamellar undulating ribs more prominent adapically and tending to fade gradually abapically. Aperture moderately wide, posteriorly angulated, with a faintly incised basal margin and representing 53% of total height. Columellar callus moderately delimited, very weakly thickened callus rim in abapical half of aperture and poorly distinct adapically. Columellar fold obsolete. Parietal fold prominent, equally positioned centrally. Outer lip sharp without marked palatal swelling. Dense growth lines immediately behind the outer lip (Fig 2b). Umbilical zone puckered (Fig. 3f).

Discussion. The shell shape, the aperture and the heterostrophic protoconch of *Palaeoellobium decampsi* gen. nov., sp. nov. are reminiscent of members of the family Ellobiidae represented by a few Cretaceous genera. *Proauricula* (Huckriede, 1967) (type species: *Auricula jaccardi*, de Loriol & Jaccard, 1865) from the Early Cretaceous of Eurasia differs from *Palaeoellobium decampsi* gen. nov., sp. nov. by having inflated, rounded teleoconch whorls and a dense network of very low lamellar ribs that do not tend to fade gradually abapically (see Huckriede, 1967, pl. 16, figs 9-1; Pan & Zhu, 2007, fig. 4a-b). *Zaptychius* (Walcott, 1883) (type species: *Zaptychius carbonaria*, Walcott, 1883; Zaptychinae) is mainly known from the Paleozoic. However, Pan & Zhu, 2007 (p. 221, fig. 4a-b) described *Zaptychius costatus* from the Early Cretaceous of North China. This species has a sculpture of finely lamellar and flexuous axial ribs, incised spiral lines and a prominent columellar fold within the aperture. Among the rare Ellobiidae known from the European Late Cretaceous deposits, *Palaeoellobium* gen. nov. can be compared to two monotypic genera coming from the Santonian of Ajka

(Hungary): *Leopoldium* (Bandel & Riedel, 1994) (type species: *Auricula balatonica*, Tausch, 1886; Ellobiinae) and *Auriculinella* (Tausch, 1886) (type species: *Auriculinella whitei*, Tausch, 1886; Ellobiinae). *Leopoldium balatonicum* (Tausch, 1886) has a junior synonym, *Auricula hungarica* (Tausch, 1886) (see Bandel & Riedel, 1994), and is devoid of sculpture and displays a prominent columellar fold, lacking in *Palaeoellobium decampsi* gen. nov., sp. nov. (see Tausch, 1886, pl. 2, fig. 25; Bandel & Riedel, 1994, pl. 15, figs 1-2). *Auriculinella whitei* (Tausch, 1886) bears a very strong axial sculpture appearing on the early teleoconch whorls (see Bandel & Riedel, 1994, pl. 15, figs 5-7) and a prominent columellar fold (see Tausch, 1886, pl. 2, fig. 26). Among Cenozoic and present-day taxa, *Ellobium* (Röding, 1798) (type species: *Ellobium aurismidae*, Linnaeus, 1758; Ellobiinae) can display numerous very close-set and low axial ribs often crossed by spiral lines more developed adapically, whereas *Palaeoellobium decampsi* nov. gen., nov. sp., lacks spiral sculpture and has fewer but prominent ribs. *Eoellobium* (Harzhauser, Pacaud & Landau, 2023) (type species: *Auricula heberti*, Vasseur, 1881; Ellobiinae) has a strong subsutural cord lacking in *Palaeoellobium decampsi* nov. gen., nov. sp. Its rugose sculpture of close-set and numerous axial ribs crossed by weak spiral threads recalls more that of *Zaptychius* or some *Ellobium* than that of *Palaeoellobium*. In addition, *Paleoellobium* n. gen. bears sparser ribs appearing earlier during the ontogeny than in *Eoellobium*. Although their shell shape is very different, species of *Zospeum* (Bourguignat, 1856) (type species: *Z. spelaeum*, Rossmässler, 1839; Carychinae) can have a similarly puckered umbilical zone as well as the densely aligned ribbing behind the apertural lip (Jochum et al., 2024). *Myosotella* (Monterosato, 1906) (type species *Myosotella myosotis*, Draparnaud, 1801; Pythinae) is reminiscent of *Palaeoellobium* gen. nov. in its general size, teleoconch shape and sharp apertural lip with the parietal fold equally positioned centrally. However, *Myosotella* usually displays a stronger columellar fold with one or two additional parietal folds. Moreover, when *Myosotella* bears an axial sculpture, it resembles more growing striae than true ribs. They are much weaker, more numerous and more ‘close-set’ than those of *Palaeoellobium* n. gen. The protoconch of *Myosotella* is more bulbous or slightly turned more to the left (see Martins, 1996, figs 41-60), whereas it is narrower and turned right in *Palaeoellobium* n. gen. Finally, although this gastropod from the Charente-Maritime amber shares characters with other Ellobiidae, clearly demonstrating its membership to this family, its particular combination of characters associating fine non-lamellar undulating ribs tending to fade abapically, a subsutural inflexion, a lack of spiral sculpture and an umbilical zone puckered by growth lines is unique and easily justifies the creation of a new genus.

## 4. Amber source, ecology of Ellobiidae and palaeoenvironmental discussion

### 4.a. Amber source and taphonomic considerations

The botanical source of the amber from Archingeay-Les Nouillers is thought to be araucarian (*Agathoxylon*), based on the analysis of the fossil wood remains (Perrichot, 2003). However, other conifers of the fossil family Cheirolepidiaceae (*Brachyoxylon* and *Protopodocarpoxylon*) could also have contributed to the resin production (Perrichot, 2003). These different kinds of conifers constituted the coastal forest that produced the fossil resin that embedded the gastropod. The external imprint of the shell, associated with probable imprints of 'remains of soft parts together with the crack' linked to the putrefaction gases, suggests that the whole animal was trapped in the amber and not only its shell. The
<figure><img src="image_4.png" /><figcaption>**Figure 3.** *Palaeoellobium decampsi* gen. nov., sp. nov. Holotype Arc-423.5, microtomographic reconstruction. (a-b) Dorsal views, (c) profile view, (d) apertural view, (e) apical view and (f) abapical view. Abbreviations: si - subsutural inflection; il - inner lip; pf - parietal fold; cc - columellar callus; cf - columellar fold. Scale bar: 1 mm.</figcaption></figure>
small size of the shell made it easy to transport (dead or alive)
during strong winds or floods.

4.b. Ecology of present-day and fossil Ellobiidae

Ellobiidae are pulmonate gastropods typical of the upper and
supralittoral zones of the mangroves of tropical regions (Martins,
1980, 1996; Harzhauser et al., 2023). The various genera of
Ellobiinae live in somewhat different habitats. *Blauneria*
(Shuttleworth, 1854) lives buried in the black sediment and under
rocks and rotting plant material at the high-tide mark (Marcus &
Marcus, 1965; Martins, 1996). *Leucophytia* (Winckworth, 1949)
lives closer to the low-tide mark than *Blauneria* and *Ellobium*
(Martins, 1996). In the Azores, it lives under rocks buried in gravel
and sometimes in the intertidal zone (Martins, 1980). *Ellobium* is
common on the muddy surfaces of Indo-Pacific mangroves, just
below the high-tide mark, around roots and decaying wood (Berry
et al., 1967). It is also found on mangrove trunks (Piamklad et al.,
2014) or between long grass (Raven & Vermeulen, 2007). Ellison
et al. (1999) and Groh (2010) discussed *Ellobium* as a mangrove-
associated gastropod genus. They concluded that while a general
affinity to the mangrove ecosystem can be stated for the genus, an
obligate relationship with mangrove trees is not obvious for most
of the species. Harzhauser et al. (2023) also suggest that the lowest
common denominator for the Indo-West-Pacific species of
*Ellobium* in terms of habitat is an occurrence in the saltmarshes
above the high-tide line in close vicinity of the mangroves. There
are few data on the ecology of fossil Ellobiidae. However, in the
Paleogene of the Paris Basin, they are found in coastal marine
sediments from the Ypresian onwards (DM personal observa-
tions). From the European Early Cretaceous, Huckriede (1967:
204) found *Proauricula* in freshwater and brackish facies. The
palaeoenvironment of the Santonian of Aijka coal swamps is well
characterized by its gastropod fauna, indicating freshwater and
more or less brackish influence (Bandel & Riedel, 1994).

4.c. Palaeoenvironmental discussion

The coastal forest of conifers that produced the fossil resin embedding the gastropod does not correspond to the habitat of the ellobiids. Another coastal macroorganism has been found associated with the ellobiid in the same amber piece, a ligid crustacean, typical of rocky foreshore environments. Thus, the amberiferous forest was probably bordering the foreshore, and some coastal organisms got stuck in resin flow coming from the tree roots or falling from the branches. A few other terrestrial arthropods are also present in the same amber drop and highlight the trapping by the same resin flow of both coastal species from the foreshore and crawling insects from the forest margin. It can be noticed that there is no direct fossil evidence of mangrove trees with coastal angiosperms in Cretaceous times, since typical modern mangrove flora appears to have originated during Paleocene times and was pantropic in the Eocene (Plaziat et al., 2001). However, other kinds of interfaces between marine biotopes and conifer forests were probably developed on the coastline of Western Europe.

**Acknowledgements.** The authors want to thank Vincent Perrichot for the entomological information about the amber drop containing the ellobiid, Malvina Lak for her contribution to the discovery on survey and microtomographical imaging of the specimen, Carmen Soriano for her contribution to the new 3D rendering of the specimen and the European Synchrotron Radiation Facility of Grenoble for the technical support of the microtomography, Ninon

Robin (University of Rennes) for her technical help, Quentin Wackenheim (MNHN) for the information about ellobiids and Bernard Landau (Naturalis Biodiversity Center, Leiden) for English proofreading the manuscript. The authors are greatly indebted to the reviewers Thomas A. Neubauer (Bayerische Staatssammlung für Paläontologie und Geologie, München, Germany), Adrienne Jochum (Natural History Museum Bern, Switzerland) and the editor for their useful corrections and suggestions improving the original manuscript. This work was supported by the ANR Project AMBRACE (coord. D. Néraudeau).

Competing interests. None.

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