Historical DNA solves century-old mystery on sessility in freshwater gastropods.

Extinction rates are increasing unabatedly but resources available for conservation action are limited. Therefore, some conservationists are pushing for ecology- and evolution-based conservation choices, prioritizing taxa with phylogenetic and trait-based originality. Extinction of original taxa may result in a disproportionate loss of evolutionary innovations and potentially prevent transformative changes in living systems. Here, we generated historical DNA data from an almost 120-year-old syntype of the enigmatic sessile snail Helicostoa sinensis from the Three Gorges region of the Yangtze River (PR China), using a next-generation sequencing protocol developed for ancient DNA. In a broader phylogenetic context, we assessed the phylogenetic and trait-based originality of this enigmatic taxon to solve the century-old puzzle of sessility in freshwater gastropods. Our multi-locus data confirm the phylogenetic and trait-based originality of H. sinensis. It is an ultra-rare, subfamily-level taxon (Helicostoinae stat. nov.) within the family Bithyniidae, which exhibits the evolutionary innovation of sessility. While we conservatively classify H. sinensis as "Critically Endangered", there is mounting evidence of the biological annihilation of this endemic species. Although rapidly rising extinction rates in invertebrates are increasingly recognized, the potential loss of originality in these "little things that run the world" has received little attention. We therefore call for comprehensive surveys of originality in invertebrates, particularly from extreme environments such as rapids of large rivers, as a basis for urgently needed ecology- and evolution-based conservation decisions.

Becoming a limpet: An 'intermittent limpetization' process driven by host features in the kleptoparasitic gastropod family Capulidae.

A coiled shell is the most evident feature of the typical Bauplan of a gastropod mollusc. However, at least 54 families independently evolved an apparently simplified shell morphology: the limpet. Species with this largely uncoiled, depressed shell morphology occur in almost every aquatic habitat and are associated to a number of different lifestyles and diets. The marine gastropod family Capulidae includes 18 recognised genera, the large majority of which are coiled, but with a number of limpet-like species. Capulid shell plasticity is also associated to a broad range of feeding ecologies, from obligate suspension feeders to kleptoparasites. To investigate the evolution of the limpet-like shell in the family Capulidae we performed an ancestral state reconstruction analysis on a time-calibrated phylogenetic tree (COI, 16S, and ITS2) including 16 species representing a good deal of its morphological diversity. Our results identified at least three capulid lineages that independently evolved limpet-like shells, suggesting that a recurrent limpetization process characterizes this family. One of the limpet-like genera was undescribed and was here named Cryocapulus n. gen. We suggest that capulids evolved from a coiled suspension feeder lineage and that the shift to kleptoparasitism, which occurred in the family ancestor, may have represented a strategy to save energy through the exploitation of the water current produced by the host. Probably the major drivers of shell evolution in capulids are related to their ecology, most of them being kleptoparasites, include the shape and the kind of host substrate, and lead to the repeated acquisition of a limpet-like shape.

Frogs and tuns and tritons - A molecular phylogeny and revised family classification of the predatory gastropod superfamily Tonnoidea (Caenogastropoda).

The Tonnoidea is a moderately diverse group of large, predatory gastropods with ∼360 valid species. Known for their ability to secrete sulfuric acid, they use it to prey on a diversity of invertebrates, primarily echinoderms. Tonnoideans currently are classified in seven accepted families: the comparatively well known, shallow water Bursidae, Cassidae, Personidae, Ranellidae, and Tonnidae, and the lesser-known, deep water Laubierinidae and Pisanianuridae. We assembled a mitochondrial and nuclear gene (COI, 16S, 12S, 28S) dataset for ∼80 species and 38 genera currently recognized as valid. Bayesian analysis of the concatenated dataset recovered a monophyletic Tonnoidea, with Ficus as its sister group. Unexpectedly, Thalassocyon, currently classified in the Ficidae, was nested within the ingroup as the sister group to Distorsionella. Among currently recognized families, Tonnidae, Cassidae, Bursidae and Personidae were supported as monophyletic but the Ranellidae and Ranellinae were not, with Cymatiinae, Ranella and Charonia supported as three unrelated clades. The Laubierinidae and Pisanianuridae together form a monophyletic group. Although not all currently accepted genera have been included in the analysis, the new phylogeny is sufficiently robust and stable to the inclusion/exclusion of nonconserved regions to establish a revised family-level classification with nine families: Bursidae, Cassidae, Charoniidae, Cymatiidae, Laubierinidae, Personidae, Ranellidae, Thalassocyonidae and Tonnidae. The results reveal that many genera as presently circumscribed are para- or polyphyletic and, in some cases support the rescue of several genus-group names from synonymy (Austrosassia, Austrotriton, Laminilabrum, Lampadopsis, Personella, Proxicharonia, Tritonoranella) or conversely, support their synonymization (Biplex with Gyrineum). Several species complexes are also revealed that merit further investigation (e.g., Personidae: Distorsio decipiens, D. reticularis; Bursidae: Bursa tuberosissima; Cassidae: Echinophoria wyvillei, Galeodea bituminata, and Semicassis bisulcata). Consequently, despite their teleplanic larvae, the apparently circumglobal distribution of some tonnoidean species is the result of excessive synonymy. The superfamily is estimated to have diverged during the early Jurassic (∼186 Ma), with most families originating during a narrow ∼20 My window in Albian-Aptian times as part of the Mesozoic Marine Revolution.

Putting keyhole limpets on the map: phylogeny and biogeography of the globally distributed marine family Fissurellidae (Vetigastropoda, Mollusca).

Fissurellidae are marine gastropods with a worldwide distribution and a rich fossil record. We integrate molecular, geographical and fossil data to reconstruct the fissurellid phylogeny, estimate divergence times and investigate historical routes of oceanic dispersal. With five molecular markers for 143 terminals representing 27 genera, we resolve deep nodes and find that many genera (e.g., Emarginula, Diodora, Fissurella) are not monophyletic and need systematic revision. Several genera classified as Emarginulinae are recovered in Zeidorinae. Future work should prioritize emarginuline genera to improve understanding of ancestral traits and the early evolution of fissurellids. Tree calibration with the fossilized birth-death model indicates that crown fissurellids originated around 175 Ma, and generally resulted in younger ages for the earliest nodes than the node dating approach. Model-based biogeographic reconstruction, supported by fossils, infers an Indo-West Pacific origin, with a westward colonization of new oceans via the Tethys Seaway upon the breakup of Pangea. Western Atlantic clades then served as source for dispersal towards other parts of the globe. As the sister group to all other fissurellids, Rimula is ranked in its own subfamily, Rimulinae stat. nov. New synonyms: Hemitominae syn. nov. of Zeidorinae stat. nov.; Cranopsissyn. nov. of Puncturella; Variegemarginulasyn. nov. of Montfortula.

Mass extinction in poorly known taxa.

Since the 1980s, many have suggested we are in the midst of a massive extinction crisis, yet only 799 (0.04%) of the 1.9 million known recent species are recorded as extinct, questioning the reality of the crisis. This low figure is due to the fact that the status of very few invertebrates, which represent the bulk of biodiversity, have been evaluated. Here we show, based on extrapolation from a random sample of land snail species via two independent approaches, that we may already have lost 7% (130,000 extinctions) of the species on Earth. However, this loss is masked by the emphasis on terrestrial vertebrates, the target of most conservation actions. Projections of species extinction rates are controversial because invertebrates are essentially excluded from these scenarios. Invertebrates can and must be assessed if we are to obtain a more realistic picture of the sixth extinction crisis.

The phylogeny and systematics of the Nassariidae revisited (Gastropoda, Buccinoidea).

Nassariidae are a group of scavenging, predominantly marine, snails that are diversified on soft bottoms as well as on rocky shores, and are the subject of numerous research papers in ecology, ecotoxicology or paleontology. A weak and/or apparently continuous variation in shell characters has resulted in an intimidating taxonomy, with complex synonymy lists. Over 1320 extant nominal species have been described, of which 442 are currently regarded as valid. Above species level, the state of the art is equally hazy, with four subfamilies and twelve genera currently accepted, and many other names in the graveyard of synonymy. A molecular analysis based on three mitochondrial (COI, 16S, 12S) and two nuclear (28S, H3) markers was conducted. Our dataset includes 218 putative nassariid species, comprising 9 of the 12 valid genera, and 25 nominal genera represented by their type species. The monophyly of the Nassariidae as classically construed is not confirmed. Species of Antillophos, Engoniophos, Phos, Nassaria, Tomlinia and Anentome (formerly considered Buccinidae) are included inside the Nassariidae clade. Within the Nassariinae, the tree unexpectedly demonstrates that species from the Atlantic and the Indo-Pacific form different clades which represent several independent diversification events. Through an integrative approach, the reconstruction of ancestral states was addressed for eight characters supposedly informative for taxonomy. Using numerous fossil calibration points, Nassariidae appear to have originated 120 MYA ago in Atlantic temperate waters during the Lower Cretaceous. Our results have a profound impact on nassariid taxonomy, especially with regard to the validity of subfamily- and genus-level names.

A multilocus molecular phylogeny of Fasciolariidae (Neogastropoda: Buccinoidea).

The neogastropod family Fasciolariidae Gray, 1853 - tulips, horse-conchs, spindles, etc., comprises important representatives of tropical and subtropical molluscan assemblages, with over 500 species in the subfamilies Fasciolariinae Gray, 1853, Fusininae Wrigley, 1927 and Peristerniinae Tryon, 1880. Fasciolariids have had a rather complicated taxonomical history, with several genus names for a long time used as waste baskets to group many unrelated species; based on shell characters, recent taxonomic revisions have, however, began to set some order in its taxonomy. The present work is the first molecular approach to the phylogeny of Fasciolariidae based on a multigene dataset, which provides support for fasciolariids, an old group with a fossil record dating back to the Cretaceous. Molecular markers used were the mitochondrial genes 16S rRNA and cytochrome c oxidase subunit I, and the nuclear genes 18S rRNA, 28S rRNA and histone H3, sequenced for up to 116 ingroup taxa and 17 outgroups. Phylogenetic analyses revealed monophyly of Dolicholatirus Bellardi, 1884 and Teralatirus Coomans, 1965, however it was not possible to discern if the group is the sister clade to the remaining fasciolariids; the latter, on the other hand, proved monophyletic and contained highly supported groups. A first split grouped fusinines and Pseudolatirus Bellardi, 1884; a second split grouped the peristerniine genera Peristernia Mörch, 1852 and Fusolatirus Kuroda and Habe, 1971, while the last group comprised fasciolariines and the remaining peristerniines. None of these clades correspond to the present-day accepted circumscription of the three recognized subfamilies.

A new phylogeny of the Cephalaspidea (Gastropoda: Heterobranchia) based on expanded taxon sampling and gene markers.

The Cephalaspidea is a diverse marine clade of euthyneuran gastropods with many groups still known largely from shells or scant anatomical data. The definition of the group and the relationships between members has been hampered by the difficulty of establishing sound synapomorphies, but the advent of molecular phylogenetics is helping to change significantly this situation. Yet, because of limited taxon sampling and few genetic markers employed in previous studies, many questions about the sister relationships and monophyletic status of several families remained open. In this study 109 species of Cephalaspidea were included covering 100% of traditional family-level diversity (12 families) and 50% of all genera (33 genera). Bayesian and maximum likelihood phylogenetics analyses based on two mitochondrial (COI, 16S rRNA) and two nuclear gene markers (28S rRNA and Histone-3) were used to infer the relationships of Cephalaspidea. The monophyly of the Cephalaspidea was confirmed. The families Cylichnidae, Diaphanidae, Haminoeidae, Philinidae, and Retusidae were found non-monophyletic. This result suggests that the family level taxonomy of the Cephalaspidea warrants a profound revision and several new family and genus names are required to reflect the new phylogenetic hypothesis presented here. We propose a new classification of the Cephalaspidea including five new families (Alacuppidae, Colinatydidae, Colpodaspididae, Mnestiidae, Philinorbidae) and one new genus (Alacuppa). Two family names (Acteocinidae, Laonidae) and two genera (Laona, Philinorbis) are reinstated as valid. An additional lineage with family rank (Philinidae "Clade 4") was unravelled, but no genus and species names are available to reflect the phylogeny and formal description will take place elsewhere.

Extinction in a hyperdiverse endemic Hawaiian land snail family and implications for the underestimation of invertebrate extinction.

The International Union for Conservation of Nature (IUCN) Red List includes 832 species listed as extinct since 1600, a minuscule fraction of total biodiversity. This extinction rate is of the same order of magnitude as the background rate and has been used to downplay the biodiversity crisis. Invertebrates comprise 99% of biodiversity, yet the status of a negligible number has been assessed. We assessed extinction in the Hawaiian land snail family Amastridae (325 species, IUCN lists 33 as extinct). We did not use the stringent IUCN criteria, by which most invertebrates would be considered data deficient, but a more realistic approach comparing historical collections with modern surveys and expert knowledge. Of the 325 Amastridae species, 43 were originally described as fossil or subfossil and were assumed to be extinct. Of the remaining 282, we evaluated 88 as extinct and 15 as extant and determined that 179 species had insufficient evidence of extinction (though most are probably extinct). Results of statistical assessment of extinction probabilities were consistent with our expert evaluations of levels of extinction. Modeling various extinction scenarios yielded extinction rates of 0.4-14.0% of the amastrid fauna per decade. The true rate of amastrid extinction has not been constant; generally, it has increased over time. We estimated a realistic average extinction rate as approximately 5%/decade since the first half of the nineteenth century. In general, oceanic island biotas are especially susceptible to extinction and global rate generalizations do not reflect this. Our approach could be used for other invertebrates, especially those with restricted ranges (e.g., islands), and such an approach may be the only way to evaluate invertebrates rapidly enough to keep up with ongoing extinction.

When everything converges: integrative taxonomy with shell, DNA and venomic data reveals Conus conco, a new species of cone snails (Gastropoda: Conoidea).

Cone snails have long been studied both by taxonomists for the diversity of their shells and by biochemists for the potential therapeutic applications of their toxins. Phylogenetic approaches have revealed that different lineages of Conus evolved divergent venoms, a property that is exploited to enhance the discovery of new conotoxins, but is rarely used in taxonomy. Specimens belonging to the Indo-West Pacific Conus lividus species complex were analyzed using phenetic and phylogenetic methods based on shell morphology, COI and 28S rRNA gene sequences and venom mRNA expression and protein composition. All methods converged to reveal a new species, C. conco n. sp. (described in Supplementary data), restricted to the Marquesas Islands, where it diverged recently (∼3mya) from C. lividus. The geographical distribution of C. conco and C. lividus and their phylogenetic relationships suggest that the two species diverged in allopatry. Furthermore, the diversity of the transcript sequences and toxin molecular masses suggest that C. conco evolved unique toxins, presumably in response to new selective pressure, such as the availability of new preys and ecological niches. Furthermore, this new species evolved new transcripts giving rise to original toxin structures, probably each carrying specific biological activity.

Lost and found: the Eocene family Pyramimitridae (Neogastropoda) discovered in the recent fauna of the Indo-Pacific.

Most neogastropod families have a continuous record from the Cretaceous or Paleogene to the Recent. However, the fossil record also contains a number of obscure nominal families with unusual shell characters that are not adequately placed in the current classification. Some of these are traditionally regarded as valid, and some have been "lost" in synonymy. One such "lost" family is the Pyramimitridae, established by Cossmann in 1901 for the Eocene genus Pyramimitra, and currently included in the synonymy of Buccinidae. Examination of several species of inconspicuous, small turriform gastropods has revealed a radula type so far unknown in Neogastropoda, and their shell characters identify them as members of the "extinct" family Pyramimitridae. Neither the radular morphology nor the anatomy reveal the relationships of this enigmatic, "living fossil" family. Molecular data (12S, 16S, 28S, COI) confirm the recognition of Pyramimitridae as a distinct family, but no sister group was identified in the analysis. The family Pyramimitridae Cossmann, 1901, is thus restored as a valid family of Neogastropoda that includes the genera Pyramimitra Conrad, 1865, Endiatoma Cossmann, 1896, Vaughanites Woodring, 1928, Hortia Lozouet, 1999, and Teremitra new genus. Pyramimitrids occur in the Recent fauna at bathyal depths of the Indo-Pacific from Taiwan to Madagascar and New Zealand, with three genera and nine species (all but one new).

Re-evaluating the case for poecilogony in the gastropod Planaxis sulcatus (Cerithioidea, Planaxidae).

BACKGROUND: Planaxis sulcatus has been touted as a textbook example of poecilogony, with members of this wide-ranging Indo-Pacific marine gastropod said to produce free-swimming veligers as well as brooded juveniles. A recent paper by Wiggering et al. (BMC Evol Biol 20:76, 2020) assessed a mitochondrial gene phylogeny based on partial COI and 16S rRNA sequences for 31 individuals supplemented by observations from the brood pouch of 64 mostly unsequenced individuals. ABGD and bGYMC supported three reciprocally monophyletic clades, with two distributed in the Indo-Pacific, and one restricted to the northern Indian Ocean and Red Sea. Given an apparent lack of correlation between clade membership and morphological differentiation or mode of development, the reported 3.08% maximum K2P model-corrected genetic divergence in COI among all specimens was concluded to represent population structuring. Hence, the hypothesis that phylogenetic structure is evidence of cryptic species was rejected and P. sulcatus was concluded to represent a case of geographic poecilogony. RESULTS: Our goal was to reassess the case for poecilogony in Planaxis sulcatus with a larger molecular dataset and expanded geographic coverage. We sequenced an additional 55 individuals and included published and unpublished sequence data from other sources, including from Wiggering et al. Our dataset comprised 108 individuals (88 COI, 81 16S rRNA) and included nine countries unrepresented in the previous study. The expanded molecular dataset yielded a maximum K2P model-corrected genetic divergence among all sequenced specimens of 12.09%. The value of 3.08% erroneously reported by Wiggering et al. is the prior maximal distance value that yields a single-species partition in ABGD, and not the maximum K2P intraspecific divergence that can be calculated for the dataset. The bGMYC analysis recognized between two and six subdivisions, while the best-scoring ASAP partitions recognized two, four, or five subdivisions, not all of which were robustly supported in Bayesian and maximum likelihood phylogenetic analyses of the concatenated and single gene datasets. These hypotheses yielded maximum intra-clade genetic distances in COI of 2.56-6.19%, which are more consistent with hypothesized species-level thresholds for marine caenogastropods. CONCLUSIONS: Based on our analyses of a more comprehensive dataset, we conclude that the evidence marshalled by Wiggering et al. in support of Planaxis sulcatus comprising a single widespread, highly variable species with geographic poecilogony is unconvincing and requires further investigation in an integrative taxonomic framework.

The Sixth Mass Extinction: fact, fiction or speculation?

There have been five Mass Extinction events in the history of Earth's biodiversity, all caused by dramatic but natural phenomena. It has been claimed that the Sixth Mass Extinction may be underway, this time caused entirely by humans. Although considerable evidence indicates that there is a biodiversity crisis of increasing extinctions and plummeting abundances, some do not accept that this amounts to a Sixth Mass Extinction. Often, they use the IUCN Red List to support their stance, arguing that the rate of species loss does not differ from the background rate. However, the Red List is heavily biased: almost all birds and mammals but only a minute fraction of invertebrates have been evaluated against conservation criteria. Incorporating estimates of the true number of invertebrate extinctions leads to the conclusion that the rate vastly exceeds the background rate and that we may indeed be witnessing the start of the Sixth Mass Extinction. As an example, we focus on molluscs, the second largest phylum in numbers of known species, and, extrapolating boldly, estimate that, since around AD 1500, possibly as many as 7.5-13% (150,000-260,000) of all ~2 million known species have already gone extinct, orders of magnitude greater than the 882 (0.04%) on the Red List. We review differences in extinction rates according to realms: marine species face significant threats but, although previous mass extinctions were largely defined by marine invertebrates, there is no evidence that the marine biota has reached the same crisis as the non-marine biota. Island species have suffered far greater rates than continental ones. Plants face similar conservation biases as do invertebrates, although there are hints they may have suffered lower extinction rates. There are also those who do not deny an extinction crisis but accept it as a new trajectory of evolution, because humans are part of the natural world; some even embrace it, with a desire to manipulate it for human benefit. We take issue with these stances. Humans are the only species able to manipulate the Earth on a grand scale, and they have allowed the current crisis to happen. Despite multiple conservation initiatives at various levels, most are not species oriented (certain charismatic vertebrates excepted) and specific actions to protect every living species individually are simply unfeasible because of the tyranny of numbers. As systematic biologists, we encourage the nurturing of the innate human appreciation of biodiversity, but we reaffirm the message that the biodiversity that makes our world so fascinating, beautiful and functional is vanishing unnoticed at an unprecedented rate. In the face of a mounting crisis, scientists must adopt the practices of preventive archaeology, and collect and document as many species as possible before they disappear. All this depends on reviving the venerable study of natural history and taxonomy. Denying the crisis, simply accepting it and doing nothing, or even embracing it for the ostensible benefit of humanity, are not appropriate options and pave the way for the Earth to continue on its sad trajectory towards a Sixth Mass Extinction.

Adapting mark-recapture methods to estimating accepted species-level diversity: a case study with terrestrial Gastropoda.

We introduce a new method of estimating accepted species diversity by adapting mark-recapture methods to comparisons of taxonomic databases. A taxonomic database should become more complete over time, so the error bar on an estimate of its completeness and the known diversity of the taxon it treats will decrease. Independent databases can be correlated, so we use the time course of estimates comparing them to understand the effect of correlation. If a later estimate is significantly larger than an earlier one, the databases are positively correlated, if it is significantly smaller, they are negatively correlated, and if the estimate remains roughly constant, then the correlations have averaged out. We tested this method by estimating how complete MolluscaBase is for accepted names of terrestrial gastropods. Using random samples of names from an independent database, we determined whether each name led to a name accepted in MolluscaBase. A sample tested in August 2020 found that 16.7% of tested names were missing; one in July 2021 found 5.3% missing. MolluscaBase grew by almost 3,000 accepted species during this period, reaching 27,050 species. The estimates ranged from 28,409 ± 365 in 2021 to 29,063 ± 771 in 2020. All estimates had overlapping 95% confidence intervals, indicating that correlations between the databases did not cause significant problems. Uncertainty beyond sampling error added 475 ± 430 species, so our estimate for accepted terrestrial gastropods species at the end of 2021 is 28,895 ± 630 species. This estimate is more than 4,000 species higher than previous ones. The estimate does not account for ongoing flux of species into and out of synonymy, new discoveries, or changing taxonomic methods and concepts. The species naming curve for terrestrial gastropods is still far from reaching an asymptote, and combined with the additional uncertainties, this means that predicting how many more species might ultimately be recognized is presently not feasible. Our methods can be applied to estimate the total number of names of Recent mollusks (as opposed to names currently accepted), the known diversity of fossil mollusks, and known diversity in other phyla.

Molecular phylogeny of the nutmeg shells (Neogastropoda, Cancellariidae).

Cancellariidae, or nutmeg shells, is a family of marine gastropods that feed on the body fluids and the egg cases of marine animals. The 300 or so living species are distributed worldwide, mostly on soft bottoms, from intertidal to depths of about 1000 m. Although they are a key group for the understanding of neogastropod evolution, they are still poorly known in terms of anatomy, ecology and systematics. This paper reports the first mitochondrial multi-gene phylogenetic hypothesis for the group. Data were collected for 50 morphospecies, representative of 22 genera belonging to the three currently recognized subfamilies. Sequences from three genes (12S, 16S and COI) were analyzed with Maximum Likelihood analysis and Bayesian Inference, both as single gene datasets and in two partitioned concatenated alignment. Largely consistent topologies were obtained and discussed with respect to the traditional subfamilial arrangements. The obtained phylogenetic trees were also used to produce Robinson-Foulds supertrees. Our results confirmed the monophyly of the subfamily Plesiotritoninae, while Admetinae and Cancellariinae, as currently conceived, were retrieved as polyphyletic. Based on our findings we propose changes to the systematic arrangement of these subfamilies. At a lower taxonomic rank, our results highlighted the rampant homoplasy of many characters traditionally used to segregate genera, and thus the need of a critical re-evaluation of the contents of many genera (e.g. Nipponaphera, Merica, Sydaphera, Bivetia), the monophyly of which was not recovered.

Evolution of the Toxoglossa venom apparatus as inferred by molecular phylogeny of the Terebridae.

Toxoglossate marine gastropods, traditionally assigned to the families Conidae, Terebridae, and Turridae, are one of the most populous animal groups that use venom to capture their prey. These marine animals are generally characterized by a venom apparatus that consists of a muscular venom bulb and a tubular venom gland. The toxoglossan radula, often compared with a hypodermic needle for its use as a conduit to inject toxins into prey, is considered a major anatomical breakthrough that assisted in the successful initial radiation of these animals in the Cretaceous and early Tertiary. The pharmacological success of toxins from cone snails has made this group a star among biochemists and neuroscientists, but very little is known about toxins from the other Toxoglossa, and the phylogeny of these families is largely in doubt. Here we report the first molecular phylogeny for the Terebridae and use the results to infer the evolution of the venom apparatus for this group. Our findings indicate that most of the genera of terebrids are polyphyletic, and one species ("Terebra" (s.l.) jungi) is the sister group to all other terebrids. Molecular analyses combined with mapping of venom apparatus morphology indicate that the Terebridae have lost the venom apparatus at least twice during their evolution. Species in the genera Terebra and Hastula have the typical venom apparatus found in most toxoglossate gastropods, but all other terebrid species do not. For venomous organisms, the dual analysis of molecular phylogeny and toxin function is an instructive combination for unraveling the larger questions of phylogeny and speciation. The results presented here suggest a paradigm shift in the current understanding of terebrid evolution, while presenting a road map for discovering novel terebrid toxins, a largely unexplored resource for biomedical research and potential therapeutic drug development.

Hidden in plain sight: two co-occurring cryptic species of Supplanaxis in the Caribbean (Cerithioidea, Planaxidae).

The cerithioid Supplanaxis nucleus (Bruguière, 1789) is widespread in the Caribbean, where it lives in often dense aggregates on hard surfaces in the middle-high intertidal. Molecular evidence shows that it comprises two species that are in fact morphologically diagnosable. We fix the nomenclature of Supplanaxis nucleus by designating a sequenced neotype from Bruguière's historical locality of Barbados, and identify the second, cryptic species as S. nancyae (Petuch, 2013). The two live syntopically across the Caribbean and form a closely related species group with the Panamic S. planicostatus (G.B. Sowerby I, 1825). Planaxis nucleola Mörch, 1876, described from St Croix, in the Virgin Islands, never again recorded in the literature but listed as a synonym of S. nucleus in taxonomic authority lists, is recognized as a valid species of Hinea Gray, 1847. Proplanaxis Thiele, 1929 and Supplanaxis Thiele, 1929, are synonyms and the latter is given precedence over the former.

The current status of Pogonodon Cope, 1880 (Carnivora: Nimravidae) and a substitution name for its junior homonym Pogonodon Bouchet, 1997 (Caenogastropoda: Triphoridae).

This nomenclatural note addresses the problem regarding the taxonomic status of the extinct large nimravid Pogonodon Cope, 1880 (Chordata. Mammalia, Nimravidae), from the Oligocene of North America and its junior homonym, the recent triphorid marine snail Pogonodon Bouchet, 1997 (Mollusca, ) from the Mediterranean. Here we propose Ionthoglossa nov. gen. as a substitute name for the latter and provide a brief history of the two taxa from the literature available.

Not knowing, not recording, not listing: numerous unnoticed mollusk extinctions.

Mollusks are the group most affected by extinction according to the 2007 International Union for Conservation of Nature (IUCN) Red List, despite the group having not been evaluated since 2000 and the quality of information for invertebrates being far lower than for vertebrates. Altogether 302 species and 11 subspecies are listed as extinct on the IUCN Red List. We reevaluated mollusk species listed as extinct through bibliographic research and consultation with experts. We found that the number of known mollusk extinctions is almost double that of the IUCN Red List. Marine habitats seem to have experienced few extinctions, which suggests that marine species may be less extinction prone than terrestrial and freshwater species. Some geographic and ecologic biases appeared. For instance, the majority of extinctions in freshwater occurred in the United States. More than 70% of known mollusk extinctions took place on oceanic islands, and a one-third of these extinctions may have been caused precipitously by introduction of the predatory snail Euglandina rosea. We suggest that assessment of the conservation status of invertebrate species is neglected in the IUCN Red List and not managed in the same way as for vertebrate species.

Morphological proxies for taxonomic decision in turrids (mollusca, neogastropoda): a test of the value of shell and radula characters using molecular data.

The state of the art of turrid (=Turridae s. l.) systematics is that shells - when they include the protoconch - are reliable species-level identifiers, but inadequate proxies for allocation to genera or subfamilies. Generally, the radula is used for allocation to a (sub)family, but the hypothesis that the radula is a more adequate proxy than the shell for relationships has not yet been tested by molecular data. Species of Xenuroturris may have drastically different radulae, with either "semi-enrolled" or "duplex" marginal teeth, although their shells are very similar or even almost indistinguishable. Molecular data confirm that specimens with different types of radulae constitute different species, but two species of a pair with respectively semi-enrolled and duplex teeth end up being not closely related. However, it is still unresolved whether species with semi-enrolled (= Iotyrris ) and duplex teeth (= Xenuroturris ) form two supported monophyletic clades. Iotyrris devoizei n.sp. and I. musivum n.sp. are described from Vanuatu, where they occur sympatrically with I. cingulifera and Xenuroturris legitima .