Boucardicus is a Madagascan endemic genus of the family Hainesiidae (subfamily Boucardicinae). The over 200 known species are variable in terms of shell shape, but their common trait is the presence of pre-constriction ribs, under which microtunnels run. Here we report three Boucardicus species without microtunnels, and as a consequence, transfer them to the genus Acroptychia as follows: Acroptychia boulangeri (Fischer-Piette, C.P. Blanc, F. Blanc & Salvat, 1993), Acroptychia (?) culminans (Fischer-Piette, C. P. Blanc, F. Blanc & F. Salvat, 1993) and Acroptychia (?) optio (Fischer-Piette, C. P. Blanc, F. Blanc & F. Salvat, 1993). The variability of the genus Acroptychia is briefly discussed.

The operculated land snail family Pupinidae from mainland Southeast Asia has been systematically revised based on shell morphology. Despite previous morphological studies, the evolutionary relationships within this family remained unclear. This study represents the first comprehensive molecular phylogeny of this snail group, utilising two mitochondrial (COI and 16S rRNA) and two nuclear (5.8S rRNA + ITS2 and 28S rRNA) genetic markers. Additionally, we conducted phylogenetic analyses of Pupina species from 1106 loci generated through double-digest restriction site-associated DNA sequencing (ddRADseq). It turned out that Southeast Asian Pollicaria emerged as a sister clade to Central American Aperostoma of the Megalomastomatidae, leading to the resurrection of the Pollicariidae. Among the remaining pupinid genera, Tortulosa was nested within the Coptocheilus clade, while Pupina and Pupinella were not monophyletic. The previously recognised Pupina arula species group was found to be monophyletic and was reclassified into Tylotoechus (formerly a Pupina subgenus), based on distinctive conchological characters such as an extending parietal tooth from a parietal callus and a wide, outward-curving posterior canal. However, some Pupina and Tylotoechus species were not retrieved as monophyletic, suggesting the presence of multiple ‘cryptic species’. Divergence time estimation indicated that the Pupinidae split could date back to the Late Triassic to Early Cretaceous, with the first diversification of pupinid genera occurring during the Middle Jurassic and Early Cretaceous. This successful reconstruction of a robust phylogeny using ddRADseq loci demonstrates the significant potential of RADseq techniques in elucidating the evolutionary relationships of deeply divergent taxa. Further studies incorporating the type species Tylotoechus destructus and Pupina keraudrenii are necessary to justify the usage of these genera.

Dentisphaera Páll-Gergely & Jochum, 2017 is a troglobitic land snails genus known to harbour only one species found in a single cave in North Vietnam. Based on recently collected specimens from China, three species, Dentisphaera lagredeae Chen, Grego & Páll-Gergely, sp. nov., Dentisphaera shzha Chen, Grego & Páll-Gergely, sp. nov. and Dentisphaera zhoui Chen, Lin & Páll-Gergely, sp. nov. are introduced as new to science. The distribution range of Dentisphaera is extended based on the collecting records of these new species.

Hypselostomatidae is a large family of terrestrial pulmonate molluscs currently represented by 284 extant species, most confined to Southeast Asia. The current system of grouping species into genera is based on the morphology of the apertural barriers and the level of last whorl detachment. However, these characters overlap, challenging generic definitions. In this paper, these characters are evaluated and a novel classification proposed for hypselostomatid species belonging to the genera Anauchen (17 species), Bensonella (36 species), Boysidia (7 species, in part) and Hypselostoma (85 species). We assigned all species belonging to the genera Bensonella and Hypselostoma into two and four species groups respectively, which are characterised by combinations of morphological traits. Altogether 46 new species are described, seven species in Anauchen: A. crassus Gojšina, Hunyadi & Páll-Gergely, sp. nov., A. evanidus Gojšina & Páll-Gergely, sp. nov., A. grandiportus Gojšina, Grego & Páll-Gergely, sp. nov., A. obesus Gojšina, Hunyadi & Páll-Gergely, sp. nov., A. picasso Gojšina & Páll-Gergely, sp. nov., A. turritus Gojšina, Hunyadi & Páll-Gergely, sp. nov., A. jokaii Gojšina & Páll-Gergely, sp. nov.; 19 species in Bensonella: B. alycaeus Gojšina & Páll-Gergely, sp. nov., B. cardiostoma Gojšina, Vermeulen & Páll-Gergely, sp. nov., B. cristatissima Gojšina, Hunyadi & Páll-Gergely, sp. nov., B. dha Gojšina, Hunyadi & Páll-Gergely, sp. nov., B. dracula Gojšina, Hunyadi & Páll-Gergely, sp. nov., B. exploda Gojšina, Hunyadi & Páll-Gergely, sp. nov., B. fracta Gojšina, Hunyadi & Páll-Gergely, sp. nov., B. microdentata Gojšina & Páll-Gergely, sp. nov., B. mitochondria Gojšina, Vermeulen & Páll-Gergely, sp. nov., B. mirabilis Gojšina, Hunyadi & Páll-Gergely, sp. nov., B. montawa Gojšina, Hunyadi & Páll-Gergely, sp. nov., B. multidentata Gojšina, A. Reischütz & Páll-Gergely, sp. nov., B. nitens Gojšina & Páll-Gergely, sp. nov., B. obex Gojšina, Hunyadi & Páll-Gergely, sp. nov., B. perfecta Gojšina & Páll-Gergely, sp. nov., B. sericata Gojšina & Páll-Gergely, sp. nov., B. serrata Gojšina, Hunyadi & Páll-Gergely, sp. nov., B. spelaea Gojšina, Grego & Páll-Gergely, sp. nov., B. spinosa Gojšina, Hunyadi & Páll-Gergely, sp. nov.; 20 species in Hypselostoma: H. aquila Gojšina, Hunyadi & Páll-Gergely, sp. nov., H. bubalus Gojšina, Hunyadi & Páll-Gergely, sp. nov., H. circumcarinatum Gojšina, Auffenberg & Páll-Gergely, sp. nov., H. coriaceum Gojšina & Páll-Gergely, sp. nov., H. aenigma Gojšina, Grego & Páll-Gergely, sp. nov., H. fortunatum Gojšina, Hunyadi & Páll-Gergely, sp. nov., H. fungus Gojšina, Hunyadi & Páll-Gergely, sp. nov., H. geckophilum Gojšina, Hunyadi & Páll-Gergely, sp. nov., H. iunior Gojšina & Páll-Gergely, sp. nov., H. ophis Gojšina, Hunyadi & Páll-Gergely, sp. nov., H. platybasis Gojšina, Hunyadi & Páll-Gergely, sp. nov., H. populare Gojšina, Hunyadi & Páll-Gergely, sp. nov., H. sculpturatum Gojšina, Hunyadi & Páll-Gergely, sp. nov., H. similare Gojšina, Hunyadi & Páll-Gergely, sp. nov., H. sorormajor Gojšina, Hunyadi & Páll-Gergely, sp. nov., H. sororminor Gojšina, Hunyadi & Páll-Gergely, sp. nov., H. torta Gojšina, Auffenberg & Páll-Gergely, sp. nov., H. vesovici Gojšina & Páll-Gergely, sp. nov., H. vicinum Gojšina, Auffenberg & Páll-Gergely, sp. nov., H. vujici Gojšina & Páll-Gergely, sp. nov. One replacement name is proposed: H. tertiusfrater Gojšina & Páll-Gergely, nom. nov. pro Boysidia salpinx F. G. Thompson & Dance, 1983, non Hypselostoma salpinx (van Benthem Jutting, 1961) (originally described as Gyliotrachela). Gyliotrachela and Antroapiculus are both treated as junior synonyms of Hypselostoma. An additional 28 species and subspecies are reassigned to the synonymies of other taxa.

The Cyclophoroidea are a group of land snails possessing an operculum that seals the aperture when the snail withdraws its body into the shell. Several groups have developed snorkel-like tubes, which are open at their outer ends, for gas exchange when the operculum closes the aperture. The tube of the cyclophorid subfamily Alycaeinae is, however, closed at its outer end. Recent investigations revealed that the tube of Alycaeinae, which starts to develop in subadults, is connected to several long microtunnels that run perpendicular to the tube and open near the umbilicus. We examined snails similar to Alycaeinae and discovered three types of gas-exchange systems that differ from the system in Alycaeinae. In Laotia, the microtunnels run to separate chambers, whereas in Platyrhaphe the microtunnels run to an internal tube. In both genera, the breathing device is already present in juveniles. Lastly, in Boucardicus there is no tube, but the microtunnels reach the common opening individually. Our molecular phylogeny, based on sequence data from the 28S, H3 and COI genes indicates that the microtunnel systems of these four groups have evolved independently. Based on these findings, three new subfamilies are proposed: Boucardicinae Páll-Gergely subfam. nov. (Hainesiidae), Laotiinae Páll-Gergely subfam. nov. (Diplommatinidae), and Platyrhaphidinae Páll-Gergely subfam. nov. (Cyclophoridae).

Expertise in biodiversity research (taxonomy, faunistics, conservation with taxonomic background) appears to decline worldwide. While the “taxonomic impediment” is discussed extensively in the literature, much fewer papers focus on the identification crisis, i.e., the decreasing number of experts who can identify species, and the decline of species-based biodiversity research. As a test case to explore the gravity of the identification crisis, we chose Hungary, a Central European country with a strong history of comprehensive taxonomic expertise and research output. We set out to answer two main questions. (1) What proportion of the Hungarian fauna could currently be identified by Hungarian experts, and what factors determine which groups are covered; and (2) what are the trends of biodiversity research in Hungary, and what are the underlying reasons for these trends? We show that Hungary lacks active biodiversity experts for almost half of the nearly 36,000 animal species recorded in the country, and more than a quarter of the fauna have only one or two active experts available. We also show that faunistic research experienced a golden era between ca. 1990 and 2010. Since then, however, there has been a strong decline, with the number of active experts and published papers decreased to a level like that of the 1970s. Multiple factors are identified causing this trend, such as increased pressure to publish in high impact journals and increasing administrative duties of professional scientists. The next generation of biodiversity experts needs to be fluent in modern techniques and publication strategies but also maintain robust morphology-based knowledge to be equipped for identification tasks of difficult taxa. Despite being disadvantaged by exclusive application of citation-based evaluation, we do need more positions and focused grants for biodiversity researchers to maintain the country’s knowledge base and to avoid being increasingly dependent on—equally declining—foreign expertise.

To date, the genus Diaphera Albers, 1850 was represented by a single species (D. prima Panha, 2010) in Thailand, and another (D. saurini Benthem Jutting, 1962) was known from Cambodia. Here we report D. prima for the first time from Cambodia, and describe two new species (D. pongrati, new species, D. parini, new species) from Eastern Thailand. Both new species live sympatrically with D. prima, which is reported here from Chachoengsao, Chon Buri, Rayong, and Sa Kaeo Provinces.

Landouria canalifera Páll-Gergely, Tumpeesuwan & Tumpeesuwan sp. nov. is described from Koh Samui, southern Thailand. It is characterized by a deep groove inside the umbilicus on the last ca. 1.5 whorls, corresponding with a columellar fold in the aperture. Also, there is a basal apertural tooth, corresponding with a shallow groove on the basal side of the shell just behind the peristome. These two barriers form a shallow canal in the aperture. Although the reproductive anatomy of this new species is not known, it probably belongs to the genus Landouria, which is widespread in Thailand and in the neighboring countries.