Market2025 in paleomalacology
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2025 in paleomalacology

Several new taxa of fossil molluscs were described during the year 2025, which also saw other significant discoveries and events related to molluscan paleontology.

Ammonites
Ammonite research • * A study on factors influencing the spatial distribution of ammonites in the aftermath of the Permian–Triassic extinction event is published by Guenser et al. (2025). • Đaković, Mrdak & Gawlick (2025) describe three assemblages of Anisian ammonoids from the Komarani and Bulog formations (Montenegro), including fossils of Ptychites rugifer, Megaphyllites obolus, Parakellnerites rothpletzi, Apleuroceras decrescens, Proteusites labiatus, Tropigastrites lahontanus, Proarcestes pannonicus, Proarcestes subtridentinus and Aristoptychites sp. extending known geographical ranges of these taxa. • Guo et al. (2025) study the evolution of complexity of ammonoid sututres, providing evidence of morphological similarity of sutures lasting longer in earlier-occurring ammonite groups than in later-occurring ones. • Description and study on the biostratigraphy of the ammonite assemblage from the Jurassic strata from Sierra de Reyes (Mendoza Province, Argentina) is published by Riccardi, Gulisano & Gutierrez-Pleimling (2025). • A study on the biostratigraphy of the ammonite faunas from the Aalenian Achdorf Formation (Germany) is published by Dietze et al. (2025). • A study on the composition of the Middle Jurassic ammonite fauna from the Shal Formation (Iran) is published by Majidifard & Wilmsen (2025). • A study on the morphology and growth of Rehmannia richei is published by Douas Bengoudira et al. (2025). • An ammonite specimen belonging to the genus Rehmannia, preserving paired Praetriaptychus aptychi within its body chamber and likely close to their original position, is described from the Jurassic (probably Callovian) strata from Quintanas de Hormiguera (Palencia, Spain) by Martínez, Ureta & García-Frank (2025). • Jantschke et al. (2025) report the discovery of a diverse ammonite assemblage from the Oxfordian strata of the Sengenthal Formation (Germany). • Evidence of preservation of ovaries with egg remains is reported in a specimen of Neochetoceras cf. praecursor from the Kimmeridgian strata in the Solnhofen region (Germany) by Klug et al. (2025). • Taxonomic revision of the collection of Kimmeridgian ammonites from four sections in the Kachchh Basin (India) is published by Pandey et al. (2025). • Schweigert, Scherzinger & Schlampp (2025) revise the type species of the genus Progeronia, "Perisphinctes" progeron, and consider it to be a nomen dubium. • Vašíček & Skupien (2025) revise the composition of the haploceratid assemblage from the Jurassic–Cretaceous transition from the Štramberk Limestone (Czech Republic). • Cadena, Bustos & Lehmann (2025) describe bochianitid fossils from the Valanginian and Hauterivian strata of the Rosablanca Formation (Colombia), extending known range of Bochianites neocomiensis and Janenschites oosteri to the northern part of South America. • Conti et al. (2025) report a mass occurrence of ammonites from a leptoceratoidid-dominated assemblage from the Barremian Maiolica Formation (Italy), including both heteromorphic and normal coiled specimens whose coexistence might have been enabled by water column stratification. • Fosso Menkem et al. (2025) describe fossil material of Albian ammonites from the Kribi-Campo sub-Basin (Cameroon), assign the fossil-bearing deposits to the Mundeck Formation, and interpret the studied fossils as evidence of a full connection between the North and South Atlantic during the lower Albian. • Wani (2025) studies morphology and ontogeny of Pachydesmoceras denisonianum on the basis of data from a conch from the Cretaceous Karai Formation (India), interpreted as indicating that constrictions and septal spacings are not always directly linked in the studied ammonite. • Xing et al. (2025) describe a new invertebrate assemblage from the Cretaceous amber from Myanmar, preserving ammonites alongside terrestrial arthropods. • The first North American record of Masiaposites is reported from the Turonian strata of the Mancos Shale (New Mexico, United States) by Lucas et al. (2025). • Shigeta, Jenks & Eichhorn (2025) study the shell development of Neogastroplites muelleri throughout its ontogeny, and link the intraspecific variation of shells of members of this species to large differences in the morphology of the initial chambers, influencing later shell growth. • Tanabe & Misaki (2025) describe two new lower jaws of pachydiscids from the Coniacian to Santonian strata of the Yezo Group (Japan), and study the morphological characteristics of the jaw apparatuses of pachydiscids significant for taxonomy and ecological reconstructions. • A study on the ontogenetic shell development of Yabeiceras orientale, Y. cf. manasoaense, Forresteria yezoensis and F. muramotoi is published by Inose & Watanabe (2025). • A study on shell breakages in specimens of Hoploscaphites nicolletii from the Upper Cretaceous Fox Hills Formation (South Dakota, United States), interpreted as evidence of lethal attacks by durophagous predators, is published by Tajika et al. (2025). • Description of fossil material of Placenticeras costatum and P. meeki from the Maastrichtian strata from the Raton Basin (New Mexico, United States), representing the youngest confirmed records of members of the genus Placenticeras worldwide, is published by Sealey & Lucas (2025). • Tajika et al. (2025) study the variation in the whorl expansion rate within multiple Late Cretaceous ammonite species, and find no evidence of a strong correlation between the studied variation and species duration or geographic distribution. • Peterman et al. (2025) study the hydromechanical properties of ornamentation of ammonite shells, and find that ornamentation patterns with intermediate coarseness, reducing rocking behavior without significant reduction of swimming efficiency, became more abundant during the Mesozoic, likely as a result of hydromechanical selective pressures. • Machalski et al. (2025) describe new ammonite specimens from the Rødvig Formation (Denmark) representing the genera Hoploscaphites, Baculites and Fresvillia, and interpret the majority of the studied specimens as survivors of the Cretaceous–Paleogene extinction event. ==Other cephalopods==
Other cephalopods
Other cephalopod research • A study on the body size evolution of cephalopods with orthoconic conchs, nautilids, ammonoids and neocoleoids is published by Klug et al. (2025). • Song et al. (2025) identify a new cephalopod assemblage from the Ordovician (Katian) Koumenzi Formation (Qinghai, China). • Pohle et al. (2025) present a new model for the formation of cameral deposits within shells of orthoceratoids on the basis of the study of specimens of Trematoceras elegans from the San Cassiano Formation (Italy). • Korn (2025) revises the classification of Carboniferous and Permian members of Nautilida, and names new families Dasbergoceratidae, Epistroboceratidae, Stenopoceratidae, Foordiceratidae, Metacoceratidae and Planetoceratidae. • Redescription of Phacoceras oxystomum is published by Korn (2025). • A large nautilid specimen belonging to the genus Cenoceras, preserved with damage interpreted as most likely to be a bite mark produced by a pliosaurid, is described from the Bathonian strata in Poland by Jain et al. (2025). • Efremenko & Dzyuba (2025) study the composition of Early Cretaceous belemnite assemblages from the Anabar area in eastern Siberia (Russia), reporting evidence of changes of composition of the studied communities resulting from changes in the depth of their basin and migrations of belemnites of European origins. • Evidence of differences in preservation of soft tissues of specimens of Dorateuthis syriaca from different Cretaceous Lagerstätten from Lebanon is presented by Rowe et al. (2025). ==Bivalves==
Bivalves
Bivalve research • Gavirneni, Ivany & Reddin (2025) calculate resting metabolic rates for fossil bivalves, and find bivalves with higher mass-specific metabolic rates to be overall more vulnerable to extinction throughout the evolutionary history of the group. • Revision of Ordovician bivalves from the Montagne Noire (France) is published by Polechová (2025). • Shi et al. (2025) report the first discovery of silicified bivalve fossils from the Permian (Kungurian−Roadian) strata of the Wandrawandian Siltstone (Australia), and reconstruct the taphonomic history of these fossils. • Yang et al. (2025) report the first discovery of alatoconchid fossil material from the middle Permian strata of the Maokou Formation (Hubei, China). • Zhao et al. (2025) study the chronological framework of accumulation of alatoconchid fossils from the Permian Maokou Formation (China), and constrain the extinction of alatoconchids to approximately 262.8 million years ago. • Miao et al. (2025) study the fossil record of Triassic marine bivalves, and report evidence of recovery of taxonomic richness after the Permian–Triassic extinction event during the Early Triassic, and of recovery of ecological diversity in the Middle Triassic. • A study on Early Triassic bivalve communities from the Liuzhi and Bozhou sections in Guizhou (China), providing evidence of increase of species diversity in associations dominated by members of the genus Claraia, but also evidence of broad ecological uniformity in the aftermath of the Permian–Triassic extinction event, is published by Yang et al. (2025). • Hautmann (2025) interprets Triassic bivalve Pseudocorbula as a basal member of the superfamily Arcticoidea within the group Venerida, and names a new subfamily Pseudocorbulinae within the family Isocyprinidae. • Evidence from the study of unionoid bivalve specimens from the Triassic of Poland and from the Cretaceous of Brazil and the United Kingdom, indicative of evolution of advanced anatomical traits of gills after the Triassic, is presented by Skawina & Ghilardi (2025). • Evidence indicating that pattern of changes of diversity of pectinoid bivalves from the Caucasus throughout the Jurassic period differed from the global pattern is presented by Ruban (2025). • Isaji (2025) redescribes "Unio" ogamigoensis and "Archaeounio" kagaensis, transfers the former species to the genus Margaritifera and the latter one to the genus Nakamuranaia, and determines the habitat preferences of the two species, interpreting M. ogamigoensis as living in rapidly flowing streams and N. kagaensis as living in shallow lakes on floodplains. • Neubauer et al. (2025) identify the pectinid genus Velata Quenstedt (1857) as validly named and a senior synonym of Eopecten, and identify the type species of the genus Velata, "Spondylus" tuberculosus Goldfuss (1835), as a junior synonym of Velata abjecta (Phillips, 1829). • A study on the shell microstructure, ecology and biostratigraphic utility of Liostrea birmanica, based on fossil from the Middle Jurassic Daoban Formation (China), is published by Li et al. (2025). • Simões et al. (2025) describe a new mollusc-dominated assemblage from the uppermost Romualdo Formation (Brazil), including freshwater bivalves previously known only from the underlying Crato Formation. • Silva et al. (2025) describe new fossil material of bivalves from Lower Cretaceous deposits in northeastern Brazil, expanding known range of the genera Araripenaia, Cratonaia and Monginellopsis beyond the Crato and Romualdo formations. • Skelton & Gili (2025) interpret the fossil evidence as indicating that congregations of rudist bivalves had more in common in oyster reefs or colonizations of carbonate banks by members of the genus Pinna than with tropical coral reefs. • Rineau et al. (2025) report the first discovery of fossils of members of the rudist genus Sellaea from the Albian strata of the Basque-Cantabrian Basin (Spain). • Mougola et al. (2025) report on the composition of the bivalve assemblage from the Upper Cretaceous (ConiacianSantonian) strata from Cap Estérias, including first records of three bivalve genera and twelve species from the Gabon Coastal Basin described to date. • Evidence of changes of composition of Late Cretaceous bivalve communities from the Ariyalur Sub-basin (India), interpreted as likely related to changing substrate conditions, is presented by Mukhopadhyay et al. (2025). • Lucas et al. (2025) report evidence of preservation of shell color patterns in two specimens of Cataceramus glendivensis from the Maastrichtian Pierre Shale (New Mexico, United States). • Evidence from the study of the fossil record of marine bivalves, indicating that the Cretaceous–Paleogene extinction event resulted in disruption of biodiversity of marine bivalves but did not fully determine their present-day diversity, is presented by Edie, Collins & Jablonski (2025). • Villegas-Martín et al. (2025) identify a fossil wood specimens from the La Meseta Formation (Antarctica), preserved with a boring interpreted as likely produced by a large-bodied member of the genus Kuphus, and representing possible evidence of wood colonization by large-bodied shipworms in the Antarctic Peninsula during the Eocene. • Bojarski, Cierocka & Szwedo (2025) report the discovery of more than 90 inclusions of piddocks in the Miocene Mexican amber, representing various developmental stages and at least five distinct morphotypes. • Slattery et al. (2025) study the impact of different climate regimes on the evolution of members of the genus Nucula from the Late Cretaceous to the Quaternary, and find evidence that morphological change of the studied bivalves coincided with more stable climate conditions. ==Gastropods==
Gastropods
Gastropod research • A study on the evolution of the columellar folds in gastropods, based on data from extant and fossil taxa, is published by Vermeij (2025). • A study on the Ordovician gastropod assemblage from the Mójcza Limestone Formation (Poland), differing in composition from assemblages from Gondwana and from the Perunica and Avalonia microcontinents and possibly resulting from local speciation, is published by Dzik (2025). • A study on the diversity of Permian and Triassic gastropods is published by Dominici (2025), who interprets increase of diversity of carnivorous gastropods during the Middle-Late Triassic transition as related to evolution of reef ecosystems at the same time. • Evidence from the study of fossil shells of Cathaica orithyia from the Chinese Loess Plateau, indicative of a link between shell morphology and changes in climatic and environmental conditions linked to changes of Asian summer monsoons over the past 470,000 years, is presented by Shen et al. (2025). • A study on ecological niche preferences of turritelline gastropods during the Cretaceous-Paleogene transition, providing evidence of niche stability of turritellines living before and after the Cretaceous–Paleogene extinction event, is published by Goodman et al. (2025). • Bakayeva et al. (2025) revise the colombellinid genus Zittelia, and recognize 9 valid species from southern and central Europe. • Evidence from the study of extant and fossil members of the family Littorinidae, indicating that differences in shell shape are correlated with genetic distances in extant members of the group and may aid recognition of fossil taxa, is presented by Shin & Allmon (2025). • Evidence from the study of polymeric membranes in shells of Ecphora gardnerae from the Miocene strata of the St. Marys Formation (Maryland, United States), indicative of peptide and chitin preservation in the studied specimens, is presented by Cleland et al. (2025). • Fossil material of extant African taxa Acteon senegalensis and Acteon maltzani is described from the Pleistocene strata from the Taranto area by La Perna, De Santis & Caldara (2025), providing evidence of presence of both species in southern Italy during the Last Interglacial. ==Other molluscs==
Other molluscs
Other molluscan research • Redescription of the rostroconch species Hoarepora parrishi, based on data from new fossil material from the Moscovian Korobcheevo Formation (Ryazan Oblast, Russia) and Gzhelian Amerevo Formation (Moscow Oblast, Russia) that extends known geographical range of the species, is published by Mazaev (2025). ==General research==
General research
• New fossil material of molluscs, facilitating comparisons with faunas from other paleocontinents, is described from the Cambrian Stage 4 strata in North Greenland by Oh, Peel & Park (2025). • Polechová, Ebbestad & Kröger (2025) revise the diversity of Ordovician (Floian) molluscs from the Cabrières Biota (Landeyran Formation; France). • Evidence from the study of the fossil record of marine bivalves and gastropods from the Permian-Triassic transition, interpreted as indicating that taxonomic homogenization of the studied molluscs in marine communities after the Permian–Triassic extinction event was related to environmental changes that resulted in expansion of the preferred habitat of the survivors of extinction, is presented by Al Aswad et al. (2025). • Evidence from the study of the fossil record of Early Jurassic gastropods and bivalves from the epicontinental seas of the north-western Tethys Ocean, indicative of a relationship between the thermal suitability of the studied animals and changes of their occupancy in response to climate changes during the Pliensbachian and Toarcian, is presented by Reddin et al. (2025). • Description of the assemblage of ammonites and inoceramid bivalves from the Albian strata from the Mangyshlak Anticlinorium (Kazakhstan) is published by Kennedy & Walaszczyk (2025). • Aiba & Mochizuki (2025) describe new fossil material of ammonites and inoceramid bivalves from the Taneichi Formation (Japan), and interpret the composition of the studied assemblage as indicating that the middle Member of the Taneichi Formation was deposited during the Santonian–early Campanian. • Fergusen, Reed & García-Bellido (2025) determine lost pigmentation patterns in molluscan specimens from the Miocene Cadell Formation (Australia), interpret the pigmentation patterns of Lophiotoma murrayana as supporting its reassignment from the genus Lucerapex to Lophiotoma, and interpret the pigmentation of Maoricolpus murrayanus as similar to the pigmentation of extant Maoricolpus roseus, strengthening the arguments that the two species are synonymous. • Kiel et al. (2025) study the composition of the gastropod and scaphopod assemblage from the Pliocene Kairuku Limestone (Papua New Guinea). • Hsu, Osipova & Lin (2025) study the composition of the Pleistocene (Calabrian) assemblage of freshwater gastropods and bivalves from the Tananwan Formation (Taiwan), including shells of juvenile specimens of Sinotaia quadrata found within shells of female specimen, representing the second known finding of child-carrying viviparids in the fossil record. • A study on the composition of the Late Pleistocene predominantly aquatic molluscan assemblage from the Glendale Fossil Site (Nevada, United States) is published by Mead et al. (2025). • Ponder et al. (2025) review the fossil record of non-marine aquatic molluscs from Australia and New Zealand. == References ==
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