A comprehensive phylogeny of extinct and extant Rhizomyinae (Rodentia): evidence for multiple intercontinental dispersals

The subfamily Rhizomyinae is known from the Late Oligocene up to the present. Today this group comprises six species, which live in southern Asia and eastern Africa. Despite the current moderate diversity of the rhizomyines, they had a greater diversification and wider distribution in the past: from Asia, their land of origin, to Africa, which they entered during the Early Miocene. So far 33 fossil species can be referred to this group. A cladistic analysis involving fossil and living species has been carried out. Prokanisamys spp. turned out to be the most basal taxa of the ingroup. This analysis calls into question the monophyly of several genera, and allows the proposal of a phylogenetic definition of the tribes Tachyoryctini and Rhizomyini. It also provides information about the origin of the African rhizomyines and allows inferring multiple dispersal phenomena from Asia to Africa in Early and Late Miocene times.     

Systematics and phylogeny of Vasseuromys (Mammalia,Rodentia, Gliridae) with a description of a new species from the late Miocene of eastern Europe

Vasseuromys is a species‐rich genus of small‐ to medium‐sized glirids spanning the latest Oligocene to late Miocene of Europe and western Asia. Despite extensive discoveries over the past 50 years, little phylogenetic work has been done on Vasseuromys. This study presents the first phylogenetic analysis of the genus that includes all the described species and a new taxon Vasseuromys tectus sp. nov. from the late Miocene of eastern Europe, providing the first insights into the evolutionary relationships within the clade. Results suggest that the genus is clearly paraphyletic. Two strongly supported genus‐level clades are recognized within ‘Vasseuromys’: a restricted Vasseuromys clade (containing the three species, V. pannonicus, V. rugosus and V. tectus) and the Glirulus clade that includes ‘Vasseuromys’ duplex. The remaining ‘Vasseuromys’ species are found to constitute a set of paraphyletic taxa, with the polyphyletic ‘Ramys’ nested within it. The genus Gliruloides is synonymized with Glirulus. Vasseuromys tectus sp. nov. is the most derived member of the genus in having a greater number of cheek teeth ridges including constantly present anterotrope, centrotrope, second prototrope on M1–2, third metatrope on M2, two to three posterotropids on p4 and strong ectolophids on lower molars. The results of the study confirm a European origin for Vasseuromys while suggesting that the late Miocene species of the genus dispersed from the east in the early Turolian.     

Molecular phylogeny of Central and South American slider turtles: implications for biogeography and systematics (Testudines: Emydidae: Trachemys)

We analyse phylogeny, systematics and biogeography of slider turtles (Trachemys spp.) using sequence data of four mitochondrial genes (3242 bp) and five nuclear loci (3396 bp) of most South American and southern Central American taxa and representatives of northern Central American, West Indian and North American slider species (16 species and subspecies) and allied North American species (genera Chrysemys, Deirochelys, Graptemys, Malaclemys, Pseudemys). By applying maximum likelihood, relaxed molecular clock and ancestral range analyses, we provide evidence for two successive colonizations of South America by slider turtles. In addition, we show that the current species delineation of Central and South American slider turtles is incorrect. Our data suggest that Trachemys grayi is a distinct polytypic species that embraces, besides the nominotypical subspecies, T. g. emolli and T. g. panamensis. Trachemys ornata is also polytypic with the subspecies T. o. ornata, T. o. callirostris, T. o. cataspila, T. o. chichiriviche and T. o. venusta. Moreover, T. adiutrix should be regarded as a subspecies of T. dorbigni. All studied Trachemys species are inferred to have originated in the Late Miocene to Early Pliocene. The ancestor of the two subspecies of T. dorbigni colonized South America most probably prior to the establishment of the land bridge connecting Central and South America, whereas the two South American subspecies of T. ornata represent a younger independent immigration wave from Central America.     

Tortoise (Reptilia,Testudinidae) radiations in Southern Africa from the Eocene to the present

Africa, inclusive of the West Indian Ocean islands, harbours 11 of the world's 16 extant testudinid genera. Fossil records indicate that testudinids originated in Asia and dispersed first to North America and Europe (Early Eocene) and later to Africa (Late Eocene). We used mitochondrial (1870 bp) and nuclear (1416 bp) DNA sequence data to assess whether molecular data support the late cladogenesis of Southern African testudinid lineages. Our results revealed strong support for the monophyly of a clade consisting of Kinixys, the two Malagasy genera and four Southern African genera (Psammobates, Stigmochelys, Homopus and Chersina). Kinixys diverged from this clade in the Late Palaeocene, suggesting that testudinids occupied Africa at an earlier date than indicated by fossil records. The Southern African tortoises consist of three, strongly supported clades: Psammobates + Stigmochelys; the five‐toed Homopus + Chersina; and the four‐toed Homopus. Due to the paraphyly of Homopus, we propose the taxonomic resurrection of Chersobius for the five‐toed Homopus species (boulengeri, signatus and solus). Cladogenesis at the genus level occurred mainly in the Eocene, with Chersina and Chersobius diverging in the Oligocene. The latter divergence coincided with species‐level radiations within Homopus (areolatus and femoralis) and Psammobates (oculifer, geometricus and tentorius). Our phylogeny could not resolve relationships within Psammobates, indicating rapid speciation between the Late Oligocene and Early Miocene. The Chersobius species were the last to diverge in the Early to Mid‐Miocene. By the Mid‐Miocene, P. tentorius started to differentiate into four lineages instead of the three recognized subspecies: P. t. tentorius, P. t. trimeni and two P. t. verroxii subclades occurring north and south of the Orange River, respectively. Terminal radiations in several taxa suggest the existence of cryptic species and a more diverse tortoise fauna than currently recognized. Factors contributing to this diversity may include the early origin of African testudinids and climatic fluctuations over a heterogeneous landscape.     

New observations on the Late Miocene–Early Pliocene Lutrinae (Mustelidae: Carnivora,Mammalia) from the Middle Awash,Afar Rift,Ethiopia

New observations on the Late Miocene and Earliest Pliocene mustelids from the Middle Awash of Ethiopia are presented. The Middle Awash study area samples the last six million years of African vertebrate evolutionary history. Its Latest Miocene (Asa Koma Member of the Adu-Asa Formation, 5.54–5.77 Ma) and Earliest Pliocene (Kuseralee and Gawto Members of the Sagantole Formation, 5.2 and 4.85 Ma, respectively) deposits sample a number of large and small carnivore taxa among which mustelids are numerically abundant. Among the known Late Miocene and Early Pliocene mustelid genera, the Middle Awash Late Miocene documents the earliest Mellivora in eastern Africa and its likely first appearance in Africa, a new species of Plesiogulo, and a species of Vishnuonyx. The latter possibly represents the last appearance of this genus in Africa. Torolutra ougandensis is known from both the Late Miocene and Early Pliocene deposits of the Middle Awash. The genus Sivaonyx is represented by at least two species: S. ekecaman and S. aff. S. soriae. Most of the lutrine genera documented in the Middle Awash Late Miocene/Early Pliocene are also documented in contemporaneous sites of eastern Africa. The new observations presented here show that mustelids were more diverse in the Middle Awash Late Miocene and Early Pliocene than previously documented.     

Multilocus phylogeny and species delimitation within the genus Glauconycteris (Chiroptera,Vespertilionidae), with the description of a new bat species from the Tshopo Province of the Democratic Republic of the Congo

The genus Glauconycteris Dobson, 1875 currently contains 12 species of butterfly bats, all endemic to sub‐Saharan Africa. Most species are rarely recorded, with half of the species known from less than six geographic localities. The taxonomic status of several species remains problematic. Here, we studied the systematics of butterfly bats using both morphological and molecular approaches. We examined 45 adult specimens for external anatomy and skull morphology, and investigated the phylogeny of Glauconycteris using DNA sequences from three mitochondrial genes and 116 individuals, which in addition to outgroup taxa, included nine of the twelve butterfly bat species currently recognized. Four additional nuclear genes were sequenced on a reduced sample of 69 individuals, covering the outgroup and Glauconycteris species. Our molecular results show that the genus Glauconycteris is monophyletic, and that it is the sister‐group of the Asian genus Hesperoptenus. Molecular dating estimates based on either Cytb or RAG2 data sets suggest that the ancestor of Glauconycteris migrated into Africa from Asia during the Tortonian age of the Late Miocene (11.6–7.2 Mya), while the basal diversification of the crown group occurred in Africa at around 6 ± 2 Mya. The species G. superba is found to be the sister‐group of G. variegata, questioning its placement in the recently described genus Niumbaha. The small species living in tropical rainforests constitute a robust clade, which contains three divergent lineages: (i) the “poensis” group, which is composed of G. poensis, G. alboguttata, G. argentata, and G. egeria; (ii) the “beatrix” group, which contains G. beatrix and G. curryae; and (iii) the “humeralis” group, which includes G. humeralis and a new species described herein. In the “poensis” group, G. egeria is found to be monophyletic in the nuclear tree, but polyphyletic in the mitochondrial tree. The reasons for this mito‐nuclear discordance are discussed.     

The first species of Sinopa (Hyaenodontida,Mammalia) from outside of North America: implications for the history of the genus in the Eocene of Asia and North America

The first Sinopa species, S. jilinia sp. nov., from outside of North America is described. It comes from the Huadian Formation, locality Gonglangtou, Jilin Province, north‐east China. The new species represents the northernmost and one of the latest and most complete Asian Prototomus‐like hyaenodontidans known. It also represents one of the youngest specimens of Sinopa, because the age of the Huadian Formation is correlated to the later Uintan and only one doubtful citation of North American Sinopa younger than the early Uintan exists. S. jilinia sp. nov. is characterized by having m3 clearly smaller than m1, very strong and extended labial molar cingulids, backward leaning protoconids in all molars and its m3 cristid obliquum joining the postvallid very labially. With S. jilina, Sinopa is the first hyaenodontidan genus known to be present on two continents during the time interval between the earliest Eocene (c. 55.0 Ma) and latest middle Eocene (40 Ma). Its occurrence in the Huadian Formation supports the idea of a faunal exchange between North America and Asia in the early middle Eocene, a hypothesis formerly based mainly on the presence of the omomyid primate Asiomomys in the Huadian Formation, on a small radiation of East Asian trogosine tillodonts and on a couple of perissodactyl genera shared between the middle Eocene of North America and the Irdinmanhan of East Asia. As with the new Sinopa species, these Asian taxa had their closest relatives in North America.     

Ancient DNA from an extinct Mediterranean micromammal—Hypnomys morpheus (Rodentia: Gliridae)—Provides insight into the biogeographic history of insular dormice

The dormice (Gliridae) are a family of rodents represented by relatively few extant species, though the family was much more species-rich during the Early Miocene. Intergeneric phylogenetic relationships among glirids in some cases remain unresolved, despite extensive molecular and morphological analyses. Uncertainty is greatest with respect to the relationships among fossil taxa and how extinct lineages are related to modern species. The fossil genus Hypnomys from the Balearic Islands (western Mediterranean Sea) includes the Late Pleistocene–Holocene species Hypnomys morpheus, which has variously been considered a close relative or subgenus of the extant Eliomys. In the present study, we sequenced ancient mitochondrial DNA from H. morpheus, which suggests a sister relationship with the extant members of Eliomys. In addition, the pairwise sequence variation between Hypnomys and Eliomys is higher than that observed between congeneric glirid species (e.g., many Graphiurus spp.), which allows us to reject the hypothesis that Hypnomys is a subgenus of Eliomys. Our molecular dating analyses suggest that Hypnomys and Eliomys diverged 13.67 million years ago (95% highest posterior density [HPD] = 7.39–20.07). The relatively early split between these genera together with the molar morphology of early representatives of Hypnomys points to a Middle-Late Miocene origin from a continental glirid with a complex molar pattern, such as Vasseuromys or a closely related genus.     

Molecular phylogenetics of mouse opossums: new findings on the phylogeny of Thylamys (Didelphimorphia,Didelphidae)

The mouse opossums of the genus Thylamys constitute a group of species mainly adapted to open xeric‐like habitats and restricted to the southern portion of South America. We used molecular data (mitochondrial and nuclear sequences) to evaluate the phylogenetic and biogeographical relationships of all currently known living species of the genus, recognizing a new taxon from the middle and high elevations of the Peruvian Andes and evaluating the phylogenetic structuring within T. pallidior and T. elegans, as well as the validity of T. sponsorius, T. cinderella and T. tatei, and the haplogroups recognized within T. pusillus. Our results confirm the monophyly of the genus and that the Caatinga and the Cerrado inhabitants Thylamys karimii and T. velutinus are the most basal species in the radiation of Thylamys. We also calibrated a molecular clock which hypothesized a time of origin of the genus of about 24 My, with most species differentiating in middle and late Miocene and Plio‐Pleistocene times of South America.     

Phylogenetic assessment and biogeographic analyses of tribe <Emphasis Type="Italic">Peracarpeae</Emphasis> (Campanulaceae)

Peracarpeae is a small tribe consisting of three genera: Homocodon, Heterocodon and Peracarpa, with a disjunct distribution between eastern Asia and western North America. Homocodon is endemic to southwestern China and was previously placed in the western North American genus Heterocodon. Our phylogenetic analysis using four plastid markers (matK, atpB, rbcL and trnL-F) suggests the polyphyly of Peracarpeae. Homocodon is sister to a clade consisting of the eastern Asian Adenophora, Hanabusaya and species of Campanula from the Mediterranean region and North America, rather than forming a clade with Heterocodon. Homocodon and its Eurasia relatives are estimated to have diverged in the early Miocene (16.84 mya, 95% HPD 13.35–21.45 mya). The eastern Asian Peracarpa constitutes a clade with the North American Heterocodon, Githopsis and three species of Campanula, supporting a disjunction between eastern Asia and North America in Campanulaceae. The Asian-North American disjunct lineages diverged in the early Miocene (16.17 mya, 95% HPD 13.12–20.9 mya). The biogeographic analyses suggest that Homocodon may be a relict of an early radiation in eastern Asia, and that Peracarpa and its closest North American relatives most likely originated from a Eurasian ancestor.     

Neogene reef coral assemblages of the Bocas del Toro region, Panama: the rise of Acropora palmata

Temporal patterns are evaluated in Neogene reef coral assemblages from the Bocas del Toro Basin of Panama in order to understand how reef ecosystems respond to long-term environmental change. Analyses are based on a total of 1,702 zooxanthellate coral specimens collected from six coral-bearing units ranging in age from the earliest Late Miocene to the Early Pleistocene: (1) Valiente Formation (12–11 Ma), (2) Fish Hole Member of the Old Bank Formation (5.8–5.6 Ma), (3) La Gruta Member of the Isla Colon Formation (2.2–1.4 Ma), (4) Ground Creek Member of the Isla Colon Formation (2.2–1.4 Ma), (5) Mimitimbi Member of the Urracá Formation (1.2–0.8 Ma), and (6) Hill Point Member of the Urracá Formation (1.2–0.8 Ma). Over 100 coral species occur in the six units, with faunal assemblages ranging from less than 10% extant taxa (Valiente Formation) to over 85% extant taxa (Ground Creek Member). The collections provide new temporal constraints on the emergence of modern Caribbean reefs, with the La Gruta Member containing the earliest occurrence of large monospecific stands of the dominant Caribbean reef coral Acropora palmata, and the Urracá Formation containing the last fossil occurrences of 15 regionally extinct taxa. Canonical correspondence analysis of 41 Late Miocene to Recent reef coral assemblages from the Caribbean region suggests changes in community structure coincident with effective oceanic closure of the Central American Seaway (~3.5 Ma). These changes, including increased Acropora dominance, may have contributed to a protracted period of elevated extinction debt prior to the major peak in regional coral extinctions (~2–1 Ma).     

Phylogeny and diversification of the cloud forest Morpho sulkowskyi group (Lepidoptera,Nymphalidae) in the evolving Andes

The monophyletic Morpho sulkowskyi butterfly group, endemic of Andean cloud forests, was studied to test the respective contributions of Mio‐Pliocene intense uplift period and Pleistocene glacial cycles on Andean biodiversity. We sampled nine taxa covering the whole geographical range of the group. Two mitochondrial and two nuclear genes were analysed using a Bayesian method. We established a dated phylogeny of the group using a relaxed clock method and a wide‐outgroup approach. To discriminate between two hypotheses, we used a biogeographical probabilistic method. Results suggest that the ancestor of the M. sulkowskyi group originated during the Middle–Late Miocene uplift of the Eastern Cordillera in northern Peru. Biogeographical inference suggests that the M. sulkowskyi and Morpho lympharis clades diverged in the northern Peruvian Andes. The subsequent divergences, from the Late Miocene to the Late Pliocene, should have resulted from a dispersal towards the Northern Andes (M. sulkowskyi clade), after the closure of the West Andean Portal separating the Central and Northern Andes, and a southwards dispersal along the Peruvian and Bolivian Eastern Cordilleras (M. lympharis clade). Only a few divergences occurred at the very end of the Pliocene or during the Pleistocene, a period when the more recent uplifts interfered with Pleistocene glacial cycles.     

Miocene pollen record of KC-1 core in the Qaidam Basin,NE Tibetan Plateau and implications for evolution of the East Asian monsoon

Thick Cenozoic deposits in the Qaidam Basin provide great potential for understanding the tectonic history, paleoclimatic changes, and evolution of the East Asian Monsoon. This study examines the pollen record from the KC-1 core for the interval covering the later Early to Late Miocene (18–5 Ma). Thermophilic taxa percentages are high between 18 and 14 Ma and decrease after this time, a pattern which fits well with the Middle Miocene Climatic Optimum (MMCO) between 18 and 14 Ma and global climatic cooling after 14 Ma. During the same period, xerophytic taxa percentages gradually increase and those of the conifers gradually decrease, suggesting an aridification process in the Qaidam region driven by the gradual strengthening of the East Asian winter monsoon (EAWM) and weakening of the East Asian summer monsoon (EASM). The global climate cooling process appears to have driven the climatic development of the Qaidam Basin region throughout the Miocene, but the uplift of the Tibetan Plateau also contributed.     

Evolutionary history of the genus Sorex (Soricidae,Eulipotyphla) as inferred from multigene data

The genus Sorex is one of the most diverse and ecologically successful lineages of the family Soricidae. We present the first multilocus nuclear phylogeny focusing on the nominal subgenus Sorex s.str., which is distributed mainly in the northern Palearctic. The nuclear tree (six exons) provides more resolution than the mitochondrial data (cytb) and supports subdivision into eight species groups within Sorex s.str., most of which correspond to those recognized from chromosome data. The European species S. alpinus is consistently placed as the basal lineage in the Palearctic clade, while the next split separates the east‐Tibetan group of striped shrews (S. aff. cylindricauda, S. bedfordiae, S. excelsus). Within the remaining species, the following well‐supported clades are identified at the supra‐group level: “araneus” species group+S. samniticus; the “caecutiens” group+the “minutus” group, the latter also including S. minutissimus, S. gracillimus and S. thibetanus. S. raddei and S. roboratus represent separate lineages with no close relatives. The fossil‐calibrated molecular clock placed the divergence between Sorex s.str. and Otisorex at the Early/Middle Miocene boundary. Basal radiation of the crown Sorex s.str. was estimated to have occurred in the middle of the Late Miocene. A more than threefold increase in the diversification rate is inferred for the Early Pliocene. Taxonomic implications including potential genus ranks for Sorex s.str. and Otisorex are discussed. S. alpinus is placed in the monotypic subgenus Homalurus. The full species status of S. buchariensis and S. thibetanus and close relationships between S. cf. cansulus and S. caecutiens are confirmed.     

Pleistocene Chinese cave hyenas and the recent Eurasian history of the spotted hyena,Crocuta crocuta

The living hyena species (spotted, brown, striped and aardwolf) are remnants of a formerly diverse group of more than 80 fossil species, which peaked in diversity in the Late Miocene (about 7–8 Ma). The fossil history indicates an African origin, and morphological and ancient DNA data have confirmed that living spotted hyenas (Crocuta crocuta) of Africa were closely related to extinct Late Pleistocene cave hyenas from Europe and Asia. The current model used to explain the origins of Eurasian cave hyena populations invokes multiple migrations out of Africa between 3.5–0.35 Ma. We used mitochondrial DNA sequences from radiocarbon‐dated Chinese Pleistocene hyena specimens to examine the origin of Asian populations, and temporally calibrate the evolutionary history of spotted hyenas. Our results support a far more recent evolutionary timescale (430–163 kya) and suggest that extinct and living spotted hyena populations originated from a widespread Eurasian population in the Late Pleistocene, which was only subsequently restricted to Africa. We developed statistical tests of the contrasting population models and their fit to the fossil record. Coalescent simulations and Bayes Factor analysis support the new radiocarbon‐calibrated timescale and Eurasian origins model. The new Eurasian biogeographic scenario proposed for the hyena emphasizes the role of the vast steppe grasslands of Eurasia in contrast to models only involving Africa. The new methodology for combining genetic and geological data to test contrasting models of population history will be useful for a wide range of taxa where ancient and historic genetic data are available.     

Impact of climate changes from Middle Miocene onwards on evolutionary diversification in Eurasia: Insights from the mesobuthid scorpions

The aridification from Middle Miocene onwards has transformed the Asian interior into an arid environment, and the Pleistocene glacial–interglacial oscillations exerted further ecological impact. Therefore, both aridification and glaciation would have considerably influenced the evolution of many mid‐latitude species in temperate Asia. Here, we tested this perspective by a phylogeographic study of the mesobuthid scorpions across temperate Asia using one mitochondrial and three nuclear genes. Concordant mitochondrial and nuclear gene trees were obtained, which are consistent with species tree inferred using a Bayesian approach. The age of the most recent common ancestor (MRCA) of all the studied scorpions was estimated to be 12.49 Ma (late Middle Miocene); Mesobuthus eupeus diverged from the clade composing Mesobuthus caucasicus and Mesobuthus martensii in early Late Miocene (10.21 Ma); M. martensii diverged from M. caucasicus at 5.53 Ma in Late Miocene. The estimated MRCA ages of M. martensii and the Chinese lineage of M. eupeus were 2.37 and 0.68 Ma, respectively. Central Asia was identified as the ancestral area for the lineage leading to M. martensii and M. caucasicus and the Chinese lineage of M. eupeus. The ancestral habitat of the genus Mesobuthus is likely to have been characterized by an arid environment; a shift towards more humid habitat occurred in the MRCA of M. martensii and a lineage of M. caucasicus, finally leading to the adaptation of M. martensii to humid environment. Our data strongly support the idea that the stepwise intensified aridifications from Mid‐Miocene onwards drove the diversification of mesobuthid scorpions, and suggest that M. martensii and M. eupeus observed today in China originated from an ancestral lineage distributed in Central Asia. Both the colonization and the ensuing evolution of these species in East Asia appear to have been further moulded by Quaternary glaciations.     

A cercopithecid primate from the late miocene of Molayan,Afghanistan, with remarks onMesopithecus

The first fossil primate discovered in Afghanistan comes from the Late Miocene of Molayan, Khurdkabul Basin. The materials consist of an almost-complete juvenile mandible and an isolated P₃. These two specimens do not significantly differ from thePikermi Mesopithecus pentelicus and are assigned to this species. The primate mandible from the Late Miocene of Maragheh, Iran, which has always been referred by all authors toM. pentelicus, differs from the Pikermi and Molayan materials. It must be assigned to another taxon, probably a new one. The geographic range ofM. pentelicus turns out to be considerably wider in view of the discovery of the species in Molayan, eastern Afghanistan.     

The origin and phylogeny of Margaritiferidae (Bivalvia,Unionoida): a synthesis of molecular and fossil data

The family Margaritiferidae is a small but widely distributed group within the Unionoida, or freshwater mussels, whose taxonomy and systematics has been the subject of numerous publications. Despite several efforts, there is no consensus on which characters reliably diagnose this family. Herein, we present the results of a phylogenetic analysis of the most comprehensive data set for Margaritiferidae in terms of taxa and phylogenetic markers assembled to date, including eleven out of the twelve margaritiferid species currently considered valid. In addition, we review the fossil record of the family and attempt to integrate fossil and DNA sequence data to provide a diagnosis of Margaritiferidae, identify its origin and biogeographic patterns, and determine the systematic relationships of its constituent species and their taxonomic affinities. We assembled a molecular data set comprised of five markers: COI, 16S, 28S, 18S and histone 3 for a total of 59 specimens representing eleven species of Margaritifera. Our results indicate that the family Margaritiferidae is a monophyletic group comprised of the single genus Margaritifera, which includes the following 12 species: M. dahurica, M. margaritifera, M. monodonta, M. middendorffi, M. laevis, M. marrianae, M. hembeli, M. falcata, M. laosensis, M. auricularia and M. marocana plus the unstudied M. homsensis. Estimates of divergence times using fossil calibrations or mean substitution rates produced dramatically different results. Divergence estimates based on the fossil calibrations were 10 times higher than those obtained applying the mean substitution rates. The current distribution of the family implies dispersal across marine or brackish waters by their host fish, leaving a fossil record on four continents that dates to the Mesozoic. Margaritiferidae appear to be derived from putative ancestor in the Silesunionidae, with a likely origin in Asia. We suggest that Margaritiferidae had spread along the Tethys margins and crossed the Atlantic already in the Late Triassic or Early Jurassic. Further dispersal events, in the Late Cretaceous or Eocene, may be linked to salinity‐depleted coastal waters or freshwater layering.