Divergent Specialization of Simple Venom Gene Profiles among Rear-Fanged Snake Genera (Helicops and Leptodeira, Dipsadinae, Colubridae).

Many venomous animals express toxins that show extraordinary levels of variation both within and among species. In snakes, most studies of venom variation focus on front-fanged species in the families Viperidae and Elapidae, even though rear-fanged snakes in other families vary along the same ecological axes important to venom evolution. Here we characterized venom gland transcriptomes from 19 snakes across two dipsadine rear-fanged genera (Leptodeira and Helicops, Colubridae) and two front-fanged genera (Bothrops, Viperidae; Micrurus, Elapidae). We compared patterns of composition, variation, and diversity in venom transcripts within and among all four genera. Venom gland transcriptomes of rear-fanged Helicops and Leptodeira and front-fanged Micrurus are each dominated by expression of single toxin families (C-type lectins, snake venom metalloproteinase, and phospholipase A2, respectively), unlike highly diverse front-fanged Bothrops venoms. In addition, expression patterns of congeners are much more similar to each other than they are to species from other genera. These results illustrate the repeatability of simple venom profiles in rear-fanged snakes and the potential for relatively constrained venom composition within genera.

Reticulate evolution in Conidae: Evidence of nuclear and mitochondrial introgression.

Conidae is a hyperdiverse family of marine snails that has many hallmarks of adaptive radiation. Hybridization and introgression may contribute to such instances of rapid diversification by generating novel gene combinations that facilitate exploitation of distinct niches. Here we evaluated whether or not these mechanisms may have contributed to the evolutionary history of a subgenus of Conidae (Virroconus). Several observations hint at evidence of past introgression for members of this group, including incongruence between phylogenetic relationships inferred from mitochondrial gene sequences and morphology and widespread sympatry of many Virroconus species in the Indo-West Pacific. We generated and analyzed transcriptome data of Virroconus species to (i) infer a robust nuclear phylogeny, (ii) assess mitochondrial and nuclear gene tree discordance, and (iii) formally test for introgression of nuclear loci. We identified introgression of mitochondrial genomes and nuclear gene regions between ancestors of one pair of Virroconus species, and mitochondrial introgression between another pair. We also found evidence of adaptive introgression of conotoxin venom loci between a third pair of species. Together, our results demonstrate that hybridization and introgression impacted the evolutionary history of Virroconus and hence may have contributed to the adaptive radiation of Conidae.

Patterns of variation of mutation rates of mitochondrial and nuclear genes of gastropods.

BACKGROUND: Although mitochondrial DNA (mtDNA) of many animals tends to mutate at higher rates than nuclear DNA (nuDNA), a recent survey of mutation rates of various animal groups found that the gastropod family Bradybaenidae (suborder Helicina) shows a nearly 40-fold difference in mutation rates of mtDNA ([Formula: see text]m) and nuDNA ([Formula: see text]n), while other gastropod taxa exhibit only two to five-fold differences. To determine if Bradybaenidae represents an outlier within Gastropoda, I compared estimated values of [Formula: see text]m/[Formula: see text]n of additional gastropod groups. In particular, I reconstructed mtDNA and nuDNA gene trees of 121 datasets that include members of various clades contained within the gastropod subclasses Caenogastropoda, Heterobranchia, Patellogastropoda, and Vetigastropoda and then used total branch length estimates of these gene trees to infer [Formula: see text]m/[Formula: see text]n. RESULTS: Estimated values of [Formula: see text]m/[Formula: see text]n range from 1.4 to 91.9. Datasets that exhibit relatively large values of [Formula: see text]m/[Formula: see text]n (i.e., > 20), however, show relatively lower estimates of [Formula: see text]n (and not elevated [Formula: see text]m) in comparison to groups with lower values. These datasets also tend to contain sequences of recently diverged species. In addition, datasets with low levels of phylogenetic breadth (i.e., contain members of single genera or families) exhibit higher values of [Formula: see text]m/[Formula: see text]n than those with high levels (i.e., those that contain representatives of single superfamilies or higher taxonomic ranks). CONCLUSIONS: Gastropods exhibit considerable variation in estimates of [Formula: see text]m/[Formula: see text]n. Large values of [Formula: see text]m/[Formula: see text]n that have been calculated for Bradybaenidae and other gastropod taxa may be overestimated due to possible sampling artifacts or processes that depress estimates of total molecular divergence of nuDNA in groups that recently diversified.

A multi-taxonomic framework for assessing relative petrochemical vulnerability of marine biodiversity in the Gulf of Mexico.

A fundamental understanding of the impact of petrochemicals and other stressors on marine biodiversity is critical for effective management, restoration, recovery, and mitigation initiatives. As species-specific information on levels of petrochemical exposure and toxicological response are lacking for the majority of marine species, a trait-based assessment to rank species vulnerabilities to petrochemical activities in the Gulf of Mexico can provide a more comprehensive and effective means to prioritize species, habitats, and ecosystems for improved management, restoration and recovery. To initiate and standardize this process, we developed a trait-based framework, applicable to a wide range of vertebrate and invertebrate species, that can be used to rank relative population vulnerabilities of species to petrochemical activities in the Gulf of Mexico. Through expert consultation, 18 traits related to likelihood of exposure, individual sensitivity, and population resilience were identified and defined. The resulting multi-taxonomic petrochemical vulnerability framework can be adapted and applied to a wide variety of species groups and geographic regions. Additional recommendations and guidance on the application of the framework to rank species vulnerabilities under specific petrochemical exposure scenarios, management needs or data limitations are also discussed.

Effects of Predator-Prey Interactions on Predator Traits: Differentiation of Diets and Venoms of a Marine Snail.

Species interactions are fundamental ecological forces that can have significant impacts on the evolutionary trajectories of species. Nonetheless, the contribution of predator-prey interactions to genetic and phenotypic divergence remains largely unknown. Predatory marine snails of the family Conidae exhibit specializations for different prey items and intraspecific variation in prey utilization patterns at geographic scales. Because cone snails utilize venom to capture prey and venom peptides are direct gene products, it is feasible to examine the evolution of genes associated with changes in resource utilization. Here, we compared feeding ecologies and venom duct transcriptomes of individuals from three populations of Conus miliaris, a species that exhibits geographic variation in prey utilization and dietary breadth, in order to determine the extent to which dietary differences are correlated with differences in venom composition, and if expanded niche breadth is associated with increased variation in venom composition. While populations showed little to no overlap in resource utilization, taxonomic richness of prey was greatest at Easter Island. Changes in dietary breadth were associated with differences in expression patterns and increased genetic differentiation of toxin-related genes. The Easter Island population also exhibited greater diversity of toxin-related transcripts, but did not show increased variance in expression of these transcripts. These results imply that differences in dietary breadth contribute more to the structural and regulatory differentiation of venoms than differences in diet.

Molecular and morphometric data suggest the presence of a neglected species in the marine gastropod family Conidae.

Knowledge concerning the taxonomic diversity of marine organisms is crucial for understanding processes associated with species diversification in geographic areas that are devoid of obvious barriers to dispersal. The marine gastropod family Conidae contains many species complexes due to lack of clear morphological distinctiveness and existence of morphological intergradations among described species. Conus flavidus Lamarck, 1810 and Conus frigidus Reeve, 1848 are currently recognized as distinct taxa, but are often difficult to distinguish by morphological characters and include several synonyms, including Conus peasei Brazier, 1877. C. peasei was originally described by Pease in 1861 (as Conus neglectus) based on slight morphological differences of a population of C. flavidus from Hawaii that distinguished it from C. flavidus from elsewhere. To evaluate the systematics of this group and specifically test the hypothesis of synonymy of C. peasei with C. flavidus, we examined molecular and morphometric data from specimens of C. flavidus, C. frigidus and C. peasei (i.e., C. flavidus from Hawaii). Multiple clades that contain individuals from particular geographic regions are apparent in gene trees constructed from sequences of a mitochondrial gene region. In particular, sequences of C. peasei cluster together separately from sequences of C. flavidus and C. frigidus. Although individuals of C. peasei, C. flavidus and C. frigidus each contain a unique set of alleles for a nuclear locus, a conotoxin gene, alleles of C. peasei are more similar to those of C. flavidus. In addition, sequences of a region of a second nuclear gene are identical among C. peasei and C. flavidus though they are distinct from sequences of C. frigidus. Morphometric data revealed that shells of C. peasei are distinct in some aspects, but are more similar to those of C. flavidus than to those of C. frigidus. Taken together, these results suggest that C. peasei represents a distinct species. Moreover, based on the contradictory relationships inferred from the mitochondrial and nuclear sequences (as well as morphometric data), C. peasei may have originated through past hybridization among the ancestral lineages that gave rise to C. flavidus and C. frigidus.

Age-related association of venom gene expression and diet of predatory gastropods.

BACKGROUND: Venomous organisms serve as wonderful systems to study the evolution and expression of genes that are directly associated with prey capture. To evaluate the relationship between venom gene expression and prey utilization, we examined these features among individuals of different ages of the venomous, worm-eating marine snail Conus ebraeus. We determined expression levels of six genes that encode venom components, used a DNA-based approach to evaluate the identity of prey items, and compared patterns of venom gene expression and dietary specialization. RESULTS: C. ebraeus exhibits two major shifts in diet with age-an initial transition from a relatively broad dietary breadth to a narrower one and then a return to a broader diet. Venom gene expression patterns also change with growth. All six venom genes are up-regulated in small individuals, down-regulated in medium-sized individuals, and then either up-regulated or continued to be down-regulated in members of the largest size class. Venom gene expression is not significantly different among individuals consuming different types of prey, but instead is coupled and slightly delayed with shifts in prey diversity. CONCLUSION: These results imply that changes in gene expression contribute to intraspecific variation of venom composition and that gene expression patterns respond to changes in the diversity of food resources during different growth stages.

Effects of geographical heterogeneity in species interactions on the evolution of venom genes.

Geographical heterogeneity in the composition of biotic interactions can create a mosaic of selection regimes that may drive the differentiation of phenotypes that operate at the interface of these interactions. Nonetheless, little is known about effects of these geographical mosaics on the evolution of genes encoding traits associated with species interactions. Predatory marine snails of the family Conidae use venom, a cocktail of conotoxins, to capture prey. We characterized patterns of geographical variation at five conotoxin genes of a vermivorous species, Conus ebraeus, at Hawaii, Guam and American Samoa, and evaluated how these patterns of variation are associated with geographical heterogeneity in prey utilization. All populations show distinct patterns of prey utilization. Three 'highly polymorphic' conotoxin genes showed significant geographical differences in allelic frequency, and appear to be affected by different modes of selection among populations. Two genes exhibited low levels of diversity and a general lack of differentiation among populations. Levels of diversity of 'highly polymorphic' genes exhibit a positive relationship with dietary breadth. The different patterns of evolution exhibited by conotoxin genes suggest that these genes play different roles in prey capture, and that some genes are more greatly affected by differences in predator-prey interactions than others. Moreover, differences in dietary breadth appear to have a greater influence on the differentiation of venoms than differences in the species of prey.

Genomic resources notes accepted 1 August 2014-30 September 2014.

This article documents the public availability of (i) transcriptome sequence data, assembly and annotation, and single nucleotide polymorphisms (SNPs) for the cone snail Conus miliaris; (ii) a set of SNP markers for two biotypes from the Culex pipiens mosquito complex; (iii) transcriptome sequence data, assembly and annotation for the mountain fly Drosophila nigrosparsa; (iv) transcriptome sequence data, assembly and annotation and SNPs for the Neotropical toads Rhinella marina and R. schneideri; and (v) partial genomic sequence assembly and annotation for 35 spiny lizard species (Genus Sceloporus).

Application of community phylogenetic approaches to understand gene expression: differential exploration of venom gene space in predatory marine gastropods.

BACKGROUND: Predatory marine gastropods of the genus Conus exhibit substantial variation in venom composition both within and among species. Apart from mechanisms associated with extensive turnover of gene families and rapid evolution of genes that encode venom components ('conotoxins'), the evolution of distinct conotoxin expression patterns is an additional source of variation that may drive interspecific differences in the utilization of species' 'venom gene space'. To determine the evolution of expression patterns of venom genes of Conus species, we evaluated the expression of A-superfamily conotoxin genes of a set of closely related Conus species by comparing recovered transcripts of A-superfamily genes that were previously identified from the genomes of these species. We modified community phylogenetics approaches to incorporate phylogenetic history and disparity of genes and their expression profiles to determine patterns of venom gene space utilization. RESULTS: Less than half of the A-superfamily gene repertoire of these species is expressed, and only a few orthologous genes are coexpressed among species. Species exhibit substantially distinct expression strategies, with some expressing sets of closely related loci ('under-dispersed' expression of available genes) while others express sets of more disparate genes ('over-dispersed' expression). In addition, expressed genes show higher dN/dS values than either unexpressed or ancestral genes; this implies that expression exposes genes to selection and facilitates rapid evolution of these genes. Few recent lineage-specific gene duplicates are expressed simultaneously, suggesting that expression divergence among redundant gene copies may be established shortly after gene duplication. CONCLUSIONS: Our study demonstrates that venom gene space is explored differentially by Conus species, a process that effectively permits the independent and rapid evolution of venoms in these species.

Extensive and continuous duplication facilitates rapid evolution and diversification of gene families.

The origin of novel gene functions through gene duplication, mutation, and natural selection represents one of the mechanisms by which organisms diversify and one of the possible paths leading to adaptation. Nonetheless, the extent, role, and consequences of duplications in the origins of ecological adaptations, especially in the context of species interactions, remain unclear. To explore the evolution of a gene family that is likely linked to species associations, we investigated the evolutionary history of the A-superfamily of conotoxin genes of predatory marine cone snails (Conus species). Members of this gene family are expressed in the venoms of Conus species and are presumably involved in predator-prey associations because of their utility in prey capture. We recovered sequences of this gene family from genomic DNA of four closely related species of Conus and reconstructed the evolutionary history of these genes. Our study is the first to directly recover conotoxin genes from Conus genomes to investigate the evolution of conotoxin gene families. Our results revealed a phenomenon of rapid and continuous gene turnover that is coupled with heightened rates of evolution. This continuous duplication pattern has not been observed previously, and the rate of gene turnover is at least two times higher than estimates from other multigene families. Conotoxin genes are among the most rapidly evolving protein-coding genes in metazoans, a phenomenon that may be facilitated by extensive gene duplications and have driven changes in conotoxin functions through neofunctionalization. Together these mechanisms led to dramatically divergent arrangements of A-superfamily conotoxin genes among closely related species of Conus. Our findings suggest that extensive and continuous gene duplication facilitates rapid evolution and drastic divergence in venom compositions among species, processes that may be associated with evolutionary responses to predator-prey interactions.

Cryptic species differentiated in Conus ebraeus, a widespread tropical marine gastropod.

Anomalous mitochondrial and nuclear gene sequences in individuals of the widely distributed tropical marine gastropod Conus ebraeus that were not distinguishable by shell shape and color pattern characters suggested the presence of a second, cryptic species. We tested this hypothesis by genetic, morphological, and ecological comparisons of additional individuals from the site in Okinawa where the two forms co-occurred. Radular tooth size and shape, prey type in nature, and microhabitats utilized differed markedly between the two forms. Adults with typical C. ebraeus DNA and radular teeth preyed primarily on errant polychaetes (Eunicidae); those with anomalous DNA and teeth ate mainly sedentary capitellids. Juveniles (shell length <13 mm) had more similar teeth and ate primarily syllids. Radular teeth of the anomalous form agreed with those of Conus judaeus, distinguished from C. ebraeus by Rudolph Bergh in 1895 solely on tooth characters of one specimen from the Philippines. Samples from other widely scattered Pacific localities revealed only typical C. ebraeus gene sequences. Both forms occurred in Seychelles (western Indian Ocean), where their radular teeth and diets were consistent with the data from Okinawa, but DNA of available material was degraded. Although C. judaeus was long dismissed as an aberrant specimen and junior synonym of C. ebraeus, our results support its validity as a distinct species. These results highlight the importance of molecular and radular tooth characters relative to those of the shell. Moreover, cryptic species could well be important components of species richness in Conus specifically and marine molluscan biodiversity more generally.

Geographic variation in venom allelic composition and diets of the widespread predatory marine gastropod Conus ebraeus.

BACKGROUND: Members of the predatory gastropod genus Conus use a venom comprised of a cocktail of peptide neurotoxins, termed conotoxins or conopeptides, to paralyze prey and conotoxin gene family members diversify via strong positive selection. Because Conus venoms are used primarily to subdue prey, the evolution of venoms is likely affected by predator-prey interactions. METHODOLOGY/PRINCIPAL FINDINGS: To identify the selective forces that drive the differentiation of venoms within species of Conus, we examined the distribution of alleles of a polymorphic O-superfamily conotoxin locus of Conus ebraeus at Okinawa, Guam and Hawaii. Previous analyses of mitochondrial cytochrome oxidase I gene sequences suggest that populations of C. ebraeus, a worm-eating Conus, are not structured genetically in the western and central Pacific. Nonetheless, because the sample size from Guam was relatively low, we obtained additional data from this location and reexamined patterns of genetic variation at the mitochondrial gene at Okinawa, Guam and Hawaii. We also utilized a DNA-based approach to identify prey items of individuals of C. ebraeus from Guam and compared this information to published data on diets at Okinawa and Hawaii. Our results show that conotoxin allelic frequencies differ significantly among all three locations, with strongest differentiation at Hawaii. We also confirm previous inferences that C. ebraeus exhibits no genetic differentiation between Okinawa, Guam and Hawaii at the mitochondrial locus. Finally, DNA-based analyses show that eunicid polychaetes comprise the majority of the prey items of C. ebraeus at Guam; while this results compares well with observed diet of this species at Okinawa, C. ebraeus preys predominantly on nereid polychaetes at Hawaii. CONCLUSIONS/SIGNIFICANCE: These results imply that strong selection pressures affect conotoxin allelic frequencies. Based on the dietary information, the selection may derive from geographic variation in dietary specialization and local coevolutionary arms races between Conus and their prey.

Ecological release and venom evolution of a predatory marine snail at Easter Island.

BACKGROUND: Ecological release is coupled with adaptive radiation and ecological diversification yet little is known about the molecular basis of phenotypic changes associated with this phenomenon. The venomous, predatory marine gastropod Conus miliaris has undergone ecological release and exhibits increased dietary breadth at Easter Island. METHODOLOGY/PRINCIPAL FINDINGS: We examined the extent of genetic differentiation of two genes expressed in the venom of C. miliaris among samples from Easter Island, American Samoa and Guam. The population from Easter Island exhibits unique frequencies of alleles that encode distinct peptides at both loci. Levels of divergence at these loci exceed observed levels of divergence observed at a mitochondrial gene region at Easter Island. CONCLUSIONS/SIGNIFICANCE: Patterns of genetic variation at two genes expressed in the venom of this C. miliaris suggest that selection has operated at these genes and contributed to the divergence of venom composition at Easter Island. These results show that ecological release is associated with strong selection pressures that promote the evolution of new phenotypes.

Hidden diversity in a hyperdiverse gastropod genus: discovery of previously unidentified members of a Conus species complex.

Molecular sequence data are a powerful tool for delimiting species, particularly in cases where morphological differences are obscure. Distinguishing species in the Conus sponsalis complex of tropical marine gastropods has long been difficult, because descriptions and identification has relied exclusively on shell characters, primarily color patterns, and these often appear to intergrade among putative species. Here we use molecular sequence data from two mitochondrial gene regions (16S rRNA and cytochrome oxidase subunit I) and one nuclear locus (a four-loop conotoxin gene) to characterize the genetic discontinuity of the nominal species of this group currently accepted as valid: the Indo-West Pacific C. sponsalis, C. nanus, C. ceylanensis, C. musicus and C. parvatus, and the eastern Pacific C. nux. In these analyses C. nanus and C. sponsalis resolve quite well and appear to represent distinct evolutionary units that are mostly congruent with morphology-based distinctions. We also identified several cryptic entities whose genetic uniqueness suggests species-level distinctions. Two of these fit the original description of C. sponsalis; three forms appear to represent C. nanus but differ in adult shell size or possess a unique shell color pattern.

Differentiation of venoms of predatory marine gastropods: divergence of orthologous toxin genes of closely related Conus species with different dietary specializations.

Venoms of Conus are remarkably diverse among species and the genes that encode conotoxins show high rates of evolution. Yet no prior studies have specifically explored how conotoxin gene evolution contributes to the differentiation of venoms of closely related Conus species. Previous investigations of four-loop conotoxin expression patterns of six closely related Conus species identified 12 sets of putative orthologous loci from these species, including eight pairs of loci that are coexpressed by two of these six species, C. abbreviatus and C. miliaris. Here I analyze the molecular evolution of orthologous conotoxin loci of these species and specifically examine the divergence of the eight orthologous counterparts of C. abbreviatus and C. miliaris. Tree and maximum likelihood-based analyses of these sequences reveal that positive selection promotes the divergence of orthologous genes among species and that the evolution of orthologues of C. abbreviatus and C. miliaris is asymmetric among species. The asymmetric evolution of conotoxin loci among species may result from lineage-specific dietary shifts or interspecific differences in the impact of selection from predator-prey interactions on conotoxin loci.

Did tectonic activity stimulate oligo-miocene speciation in the Indo-West Pacific?

Analyses of molecular phylogenies of three unrelated tropical marine gastropod genera, Turbo, Echinolittorina, and Conus, reveal an increase in the rate of cladogenesis of some Indo-West Pacific (IWP) clades beginning in the Late Oligocene or Early Miocene between 23.7 and 21.0 million years ago. In all three genera, clades with an increased rate of diversification reach a maximum of diversity, in terms of species richness, in the central IWP. Congruence in both the geographical location and the narrow interval of timing suggests a common cause. The collision of the Australia and New Guinea plate with the southeast extremity of the Eurasian plate approximately 25 Mya resulted in geological changes to the central IWP, including an increase in shallow-water areas and length of coastline, and the creation of a mosaic of distinct habitats. This was followed by a period of rapid diversification of zooxanthellate corals between 20 and 25 Mya. The findings reported here provide the first molecular evidence from multiple groups that part of the present-day diversity of shallow-water gastropods in the IWP arose from a rapid pulse of speciation when new habitats became available in the Late Oligocene to Early Miocene. After the new habitats were filled, the rate of speciation likely decreased and this combined with high levels of extinction (in some groups), resulted in a slow down in the rate of diversification in the genera examined.

Hybridization in large-bodied New World primates.

Well-documented cases of natural hybridization among primates are not common. In New World primates, natural hybridization has been reported only for small-bodied species, but no genotypic data have ever been gathered that confirm these reports. Here we present genetic evidence of hybridization of two large-bodied species of neotropical primates that diverged approximately 3 MYA. We used species-diagnostic mitochondrial and microsatellite loci and the Y chromosome Sry gene to determine the hybrid status of 36 individuals collected from an area of sympatry in Tabasco, Mexico. Thirteen individuals were hybrids. We show that hybridization and subsequent backcrosses are directionally biased and that the only likely cross between parental species produces fertile hybrid females, but fails to produce viable or fertile males. This system can be used as a model to study gene interchange between primate species that have not achieved complete reproductive isolation.

Explosive radiation of Cape Verde Conus, a marine species flock.

Nearly 50 species of the marine gastropod genus Conus are restricted to the Cape Verde archipelago. This unusual concentration of endemics within a single set of oceanic islands is extremely uncharacteristic of marine taxa. Here we used phylogenetic analyses of 90 Conus species, including 30 endemics from Cape Verde, to reveal the relationships and origins of the endemic Cape Verde Conus. Results show that these species group in two distinct clades and represent a marine species flock that is restricted to a very narrowly confined geographical area. Species' originations occurred in exceptionally limited parts of the archipelago and in some cases radiations took place solely within single islands. Finally, comparison of levels of divergence between Cape Verde endemics and other Conus species suggests that the radiation of Conus in Cape Verde occurred during the last few million years.

Species-level phylogeography and evolutionary history of the hyperdiverse marine gastropod genus Conus.

Phylogenetic and paleontological analyses are combined to reveal patterns of species origination and divergence and to define the significance of potential and actual barriers to dispersal in Conus, a species-rich genus of predatory gastropods distributed throughout the world's tropical oceans. Species-level phylogenetic hypotheses are based on nucleotide sequences from the nuclear calmodulin and mitochondrial 16S rRNA genes of 138 Conus species from the Indo-Pacific, eastern Pacific, and Atlantic Ocean regions. Results indicate that extant species descend from two major lineages that diverged at least 33 mya. Their geographic distributions suggest that one clade originated in the Indo-Pacific and the other in the eastern Pacific + western Atlantic. Impediments to dispersal between the western Atlantic and Indian Oceans and the central and eastern Pacific Ocean may have promoted this early separation of Indo-Pacific and eastern Pacific + western Atlantic lineages of Conus. However, because both clades contain both Indo-Pacific and eastern Pacific + western Atlantic species, migrations must have occurred between these regions; at least four migration events took place between regions at different times. In at least three cases, incursions between regions appear to have crossed the East Pacific Barrier. The paleontological record illustrates that distinct sets of Conus species inhabited the Indo-Pacific, eastern Pacific + western Atlantic, and eastern Atlantic + former Tethys Realm in the Tertiary, as is the case today. The ranges of <1% of fossil species (N=841) spanned more than one of these regions throughout the evolutionary history of this group.