A Paleocene occurrence of cornelian cherries Cornus subg. Cornus in the land-mammal site of Berru (Paris Basin, France)

Data from four DNA regions (rbcL, matK, 26S rDNA, and ITS) as well as extant and fossil morphology were used to reconstruct the phylogeny and biogeographic history of an intercontinentally disjunct plant group, the cornelian cherries of Cornus (dogwoods). The study tests previous hypotheses on the relative roles of two Tertiary land bridges, the North Atlantic land bridge (NALB) and the Bering land bridge (BLB), in plant migration across continents. Three approaches, the Bayesian, nonparametric rate smoothing (NPRS), and penalized likelihood (PL) methods, were employed to estimate the times of geographic isolations of species. Dispersal and vicariance analysis (DIVA) was performed to infer the sequence and directionality of biogeographic pathways. Results of phylogenetic analyses suggest that among the six living species, C. sessilis from western North America represents the oldest lineage, followed by C. volkensii from Africa. The four Eurasian species form a clade consisting of two sister pairs, C. mas– C. officinalis and C. chinensis–C. eydeana. Results of DIVA and data from fossils and molecular dating indicate that the cornelian cherry subgroup arose in Europe as early as the Paleocene. Fossils confirm that the group was present in North America by the late Paleocene, consistent with the DIVA predictions that, by the end of the Eocene, it had diversified into several species and expanded its distribution to North America via the NALB and to Africa via the last direct connection between Eurasia and Africa prior to the Miocene, or via long-distance dispersal. The cornelian cherries in eastern Asia appear to be derived from two independent dispersal events from Europe. These events are inferred to have occurred during the Oligocene and Miocene. This study supports the hypothesis that the NALB served as an important land bridge connecting the North American and European floras, as well as connecting American and African floras via Europe during the early Tertiary.

Data from four DNA regions (rbcL, matK, 26S rDNA, and ITS) as well as extant and fossil morphology were used to reconstruct the phylogeny and biogeographic history of an intercontinentally disjunct plant group, the cornelian cherries of Cornus (dogwoods). The study tests previous hypotheses on the relative roles of two Tertiary land bridges, the North Atlantic land bridge (NALB) and the Bering land bridge (BLB), in plant migration across continents. Three approaches, the Bayesian, nonparametric rate smoothing (NPRS), and penalized likelihood (PL) methods, were employed to estimate the times of geographic isolations of species. Dispersal and vicariance analysis (DIVA) was performed to infer the sequence and directionality of biogeographic pathways. Results of phylogenetic analyses suggest that among the six living species, C. sessilis from western North America represents the oldest lineage, followed by C. volkensii from Africa. The four Eurasian species form a clade consisting of two sister pairs, C. mas-C. officinalis and C. chinensis-C. eydeana. Results of DIVA and data from fossils and molecular dating indicate that the cornelian cherry subgroup arose in Europe as early as the Paleocene. Fossils confirm that the group was present in North America by the late Paleocene, consistent with the DIVA predictions that, by the end of the Eocene, it had diversified into several species and expanded its distribution to North America via the NALB and to Africa via the last direct connection between Eurasia and Africa prior to the Miocene, or via long-distance dispersal. The cornelian cherries in eastern Asia appear to be derived from two independent dispersal events from Europe. These events are inferred to have occurred during the Oligocene and Miocene. This study supports the hypothesis that the NALB served as an important land bridge connecting the North American and European floras, as well as connecting American and African floras via Europe during the early Tertiary.

AimEast Asia exhibits complex geomorphological and climatic characteristics. The aim of this study was to test whether the so‐called three‐step landforms of China, together with the East China Sea (ECS), have acted to shape specific phylogeographical patterns and affected the biogeographical history of the species belonging to the East Asian Flora.LocationChina and Japan.TaxonKerria japonica (L.) DC.MethodsThree chloroplast DNA regions and 15 nuclear microsatellite (nSSR) loci were sequenced and genotyped in 576/450 individuals of K. japonica. Phylogeographical analyses were performed to assess the genetic structure, historical gene flow and demographical history of these individuals, and climatic factors were examined to determine their effects on phylogeographical breaks. Furthermore, time‐calibrated phylogenetic trees and ancestral range reconstruction were used to infer the biogeographical history of K. japonica. Potential habitats at present and during the last glacial maximum (LGM) were identified using ecological niche modelling.ResultsDistinct phylogeographical breaks were found across the ECS and along the boundary of the three‐step landforms of China. Low historical gene flow and significant climatic differences were detected in each pair of adjacent regions. The results of molecular dating and ancestral range reconstruction indicated that K. japonica originated in North America during the mid‐Miocene (14.76 Ma), and intra‐specific diversification began in the late Miocene (7.78 Ma). Compared to the relatively stable distribution range of Chinese populations, Japanese populations experienced range expansion after the LGM in response to Quaternary climate change.Main conclusionsKerria japonica has a complex biogeographical history, with a mid‐Miocene origin in North America and subsequent migration into East Asia via the Bering land bridge. The onset of intra‐specific diversification was probably associated with Asian monsoon intensifications, while exposure to the ECS floor facilitated the formation of the Japanese lineage in the late Miocene. The spatiotemporal population differentiation on the Chinese mainland demonstrates the significant role of biogeographical divides delineated by the three‐step landforms of China and provides clues to understand the floristic regionalization and evolutionary history of plant diversity in East Asia, especially with respect to the Hengduan Mountains, Central China and East China.

In this paper, part of the amphisbaenian fossil record from the european Eocene is revised. There is no evidence for the existence of amphisbaenian lizards in Europe or on other continents during the Late Cretaceous. Crown amphisbaenians were present in Europe in the early Paleocene and throughout the Paleogene, with the notable exception of the middle Eocene. In particular, they were not found at Messel. European fossil taxa previously assigned to the amphisbaenians are briefly reviewed, and a description of some representative specimens from the Eocene fossil record is presented: dentary and vertebrae from Mutigny (early Eocene, France) are referred to the North American genus Anniealexandria; fossils from the late Eocene of the Phosphorites du Quercy (France) are attributed to Blanidae, and they are the earliest secure occurrence of Blanidae in the fossil record; and dentaries and maxillae from Grisolles (middle-late Eocene, Paris Basin, France) are referred to a new species, Louisamphisbaena ferox. Global distribution of fossil amphisbaenians in the Eocene reveals at least one episode of dispersal between North America and Europe during the early Eocene. Finally, some explanations are suggested for the absence of crown amphisbaenians at Messel and in the European middle Eocene.

Fossil fruits confirm that cornelian cherries (Cornus, subgenus Cornus) were established in the Northern Hemisphere in the Early Tertiary. We describe the oldest known member of the subgenus, Cornus piggae sp. n., on the basis of well‐preserved silicified endocarps from the late Paleocene of North Dakota. The endocarps are ellipsoidal, thin walled, and two to three locular, and they lack an axial longitudinal bundle. The septa and external walls of the fruit stone are riddled with cavities, a feature diagnostic of extant subgenus Cornus. For comparison, we sectioned fruits of each of the extant species and reexamined fossil fruits from the Early Eocene London Clay of southern England. These London Clay fossils differ from C. piggae by much thicker external walls (Cornus ettingshausenii [Gardner] Eyde) and higher locule number (up to 6 in Cornus multilocularis [Gardner] Eyde). Comparison with fruits of extant cornelian cherries indicates that the morphological range among the modern species is narrower than that seen in the Paleogene.

Aim The tribe Rhodniini is one of six comprising the subfamily Triatominae (Heteroptera: Reduviidae), notorious as blood‐sucking household pests and vectors ofTrypanosoma cruzithroughout Latin America. The human and economic cost of this disease in the American tropics is considerable, and these bugs are unquestionably of great importance to man. Studies of the evolution, phylogeny, biogeography, ecology, physiology and behaviour of the Rhodniini are needed to help improve existing Chagas’ disease control programmes. The objective of the study reported here was to propose biogeographical hypotheses to explain the modern geographical distribution of the species of Rhodniini.Location Neotropical region.Methods We employed mitochondrial rDNA sequences (16S) currently available in GenBank to align sequences of Rhodniini species using ClustalX. The analyses included 16S sequences from predatory reduviid subfamilies (Stenopodainae, Ectrichodiinae, Harpactorinae, Reduviinae and Salyavatinae) present in GenBank as an outgroup. Cladistic analysis used the program PAUP to derive trees based on maximum parsimony (MP) and maximum likelihood (ML). Known distribution data for Rhodniini species were obtained from reviews and plotted on maps of South and Central America using the program iMap. An area cladogram was derived from the cladistic result to show the historical connections among the studied taxa and the endemic areas. The program TreeMap (Jungle Edition) was used to deduce taxon–area associations where the optimal solutions to explain the biogeographical hypothesis of the Rhodniini in the Neotropics were those with lowest total cost.Results Parsimony and maximum‐likelihood analysis of 16S rDNA sequences included 14 species of Rhodniini, as well as five species of predatory Reduviidae representing five of the predatory subfamilies. Tanglegrams were used to show the relationship between the Neotropical areas of endemism and Rhodniini species. When TreeMap with codivergence (vicariance) events were weighted as 0 and duplication (sympatry), lineage losses (extinction) and host switching (dispersal) were all weighted as 1, 20 scenarios were found to explain the biogeographical history of Rhodniini in the Neotropical region. Twelve of the optimal solutions with the lowest total cost were used to explain the biogeography of the Rhodniini in the Neotropics. These optimal reconstructions require six vicariance events, 20 duplications (sympatry), at least three dispersals, and at least one extinction event.Main conclusions The Rhodniini have a complex biogeographical history that has involved vicariance, duplications (sympatry), dispersal and extinction events. The main geological events affecting the origin and diversification of the Rhodniini in the Neotropics were (1) uplift of the Central Andes in the Miocene or later, (2) break‐up of the Andes into three separate cordilleras (Eastern, Central and Western) in the Plio‐Pleistocene, (3) formation of a land corridor connecting South and North America in the Pliocene, and (4) uplift of the Serra do Mar and Serra da Mantiqueira mountain systems between the Oligocene and Pleistocene. The relationships and biogeographical history of the species of Rhodniini in the Neotropical region probably arose from the areas of endemism shown in our work.

We studied the biogeographical history of Dracula, an almost exclusive Andean genus of orchids. We built a phylogeny using the plastidial markers matK and ycf1 and nuclear ITS and used a combined approach of divergence time estimation and ancestral areas reconstruction. Thus, we aimed to clarify where and when the genus appeared and diversified, as well as how it colonized the Eastern and western Andean cordillera and expanded into Central and North America. Dracula originated in the Andes during the late Miocene, but its diversification was during the Pliocene and Pleistocene. The biogeographical history of the genus is marked by several independent events of peripheral isolation and dispersals. At least eight independent dispersal events occurred from the west to the east of the Andes, and none in the opposite direction. Colonization of Central and North America occurred at least three times independently. We conclude that based on our results Dracula has a recent and complex biogeographical history, where it could cross the Andes only in the west-to-east direction. Further investigation with expanded taxon sampling will be valuable to demonstrate whether this is a natural trend rather than an artefact of the available data.

Blood parasites and acute osteomyelitis in a non-avian dinosaur (Sauropoda, Titanosauria) from the Upper Cretaceous Adamantina Formation, Bauru Basin, Southeast Brazil

Despite their ecological importance, Darwin wasps (Ichneumonidae) are among the most poorly studied groups of organisms. It is therefore not surprising that their fossil record is even more poorly understood than their extant diversity. The early Eocene seems rather fossil-poor regarding Ichneumonidae in amber and only one species,Palaeometopius eocenicusMenier et al., 2004, was described so far from Oise Amber from the Paris basin. Here, two new ichneumonid genera and species,Madma oisellagen. et. sp. nov.andPappous trichomatiusgen. et. sp. nov.are described and the placement ofPalaeometopius eocenicusis revised. The three fossils are well-preserved and might represent stem taxa of Tryphoninae and Phygadeuontinae. They are a highly important addition to the early Palaeogene fossil record of Ichneumonidae that otherwise mainly consists of compression fossils, which yield far less detail of the specimens’ morphology than amber pieces. Among the more than 1,000 Oise amber pieces examined, only three Ichneumonidae specimens have been found, versus about 60 Braconidae, a ratio very different from other amber deposits. Identification of additional ichneumonid specimens from this period (lowermost Eocene) is of particular importance for a better understanding of the subfamily and species compositions of this family after the K-Pg mass extinction.

Ischyromyids are a group of large rodents with the earliest fossil record known from the late Paleocene (Clarkforkian) of North America; they are considered the earliest fossil representatives of Rodentia of modern aspect. Ischyromyids dominated early Paleogene small-mammal assemblages of North America and in the latest Paleocene migrated to western Europe and to Asia; in the latter they survived only to the beginning of the late Eocene, but were never abundant. Here we describe for the first time the calcanei of ischyromyids from the early middle Eocene of the Erlian Basin in Nei Mongol, northern China. These calcanei document the existence of three species. The morphology of the studied tarsal bones overall suggests ambulatory locomotion for these animals (‘slow cursors’), similar to that of the coypu and porcupines, but one form shows more marked cursorial capabilities. These differences show that Chinese ischyromyids, although rare, had attained greater taxonomic diversity by the middle Eocene in Nei Mongol than estimated from dental remains. We also address the question of the morphological and ecological divergence of these ischyromyids in relation to their North American counterparts, as well as the issue of a direct dispersal route from North America to Asia in the early Eocene.

The available fossil record of mammalian evolution across the Cretaceous-Tertiary (K-T) boundary is highly biased biogeographically by the results of detailed sampling of Late Cretaceous and Paleocene local faunas in what is now the Western Interior of the North American continent. In this area, which was then a coastal lowland, the mass extinction marking the K-T boundary resulted in extinction of many mammalian lineages. Analysis of the phylogenetic relationships of the mammals comprising North American early Paleocene faunas demonstrates that recovery of taxonomic diversity after the K-T boundary was the product of two processes: 1) evolutionary radiation of some locally surviving stocks and 2) immigration of mammals from other, as yet unsampled areas. Limited evidence suggests that dispersal of the groups that dominate these earliest Paleocene faunas had begun in the latest Cretaceous. Some mammalian local faunas of Late Cretaceous or early Paleocene age are known from other continents, but none of these provide as complete a fossil record of mammalian evolution during this interval. In spite of these limitations, analysis of the available, global fossil record reveals significant biogeographic provinciality of mammalian faunas and some similarities in their patterns of extinction and recovery of taxonomic diversity during the transition from the Cretaceous into the Tertiary.

«Вестник Санкт-Петербургского университета. Науки о Земле» — научно-теоретический рецензируемый журнал, обобщающий результаты исследований в области геологии, гидрогеологии и геохимии, петрологии и экологии, ландшафтного планирования и геоморфологии, экономической и социальной географии.

Squamata (lizards, snakes, and amphisbaenians) is a Triassic lineage with an extensive and complex biogeographic history, yet no large-scale study has reconstructed the ancestral range of early squamate lineages. The fossil record indicates a broadly Pangaean distribution by the end- Cretaceous, though many lineages (e.g., Paramacellodidae, Mosasauria, Polyglyphanodontia) subsequently went extinct. Thus, the origin and occupancy of extant radiations is unclear and may have been localized within Pangaea to specific plates, with potential regionalization to distinct Laurasian and Gondwanan landmasses during the Mesozoic in some groups. We used recent tectonic models to code extant and fossil squamate distributions occurring on nine discrete plates for 9,755 species, with Jurassic and Cretaceous fossil constraints from three extinct lineages. We modeled ancestral ranges for crown Squamata from an extant-only molecular phylogeny using a suite of biogeographic models accommodating different evolutionary processes and fossil-based node constraints from known Jurassic and Cretaceous localities. We hypothesized that the best-fit models would not support a full Pangaean distribution (i.e., including all areas) for the origin of crown Squamata, but would instead show regionalization to specific areas within the fragmenting supercontinent, likely in the Northern Hemisphere where most early squamate fossils have been found. Incorporating fossil data reconstructs a localized origin within Pangaea, with early regionalization of extant lineages to Eurasia and Laurasia, while Gondwanan regionalization did not occur until the middle Cretaceous for Alethinophidia, Scolecophidia, and some crown Gekkotan lineages. While the Mesozoic history of extant squamate biogeography can be summarized as a Eurasian origin with dispersal out of Laurasia into Gondwana, their Cenozoic history is complex with multiple events (including secondary and tertiary recolonizations) in several directions. As noted by previous authors, squamates have likely utilized over-land range expansion, land-bridge colonization, and trans-oceanic dispersal. Tropical Gondwana and Eurasia hold more ancient lineages than the Holarctic (Rhineuridae being a major exception), and some asymmetries in colonization (e.g., to North America from Eurasia during the Cenozoic through Beringia) deserve additional study. Future studies that incorporate fossil branches, rather than as node constraints, into the reconstruction can be used to explore this history further.

First fossil record of Canarium (Burseraceae) from the middle Miocene of Fujian, southeastern China and its paleoecological implications

At the crossroads of two biodiversity hotspots; the biogeographic patterns of Shimba Hills, Kenya Beryl A. Bwong The Shimba Hills of Kenya (SHK) is geographically located at the cross roads of two major biodiversity hotspots; the Coastal Forests of Eastern Africa (CFEA) and the Eastern Afromontane Biodiversity Region, specifically the neighbouring Eastern Arc Mountains (EAM). Results from old and recent collections of its flora and fauna indicate that Shimba Hills harbour species associated with EAM and CFEA as well as taxa that have affinity with West African Guineo-Congolian forest. However, the link between SHK and these biodiversity hotspots has never been tested appropriately using phylogenetic approaches. Using 16S mtDNA, demographic analysis and species distribution modelling, I sought to understand the phylogeographic affiliation of Shimba Hills with the neighbouring CFEA and EAM using its amphibian assemblage. Three main questions were explored, namely: a) Which are the closest relatives of SHK amphibian populations? b) Do amphibian species currently occurring in SHK have similar phylogeographic patterns to each other? c) Which historical processes, if any, account for the observed patterns of genetic diversity? I found that SHK and indeed the entire study area have a complex biogeographic history and no single pattern can explain the current amphibian assemblage in the area. Shimba Hills are more closely affiliated to the CFEA than to the EAM. Two previously undocumented putative phylogeographic breaks are recovered from the study area; one from the Kenya north coast and another in the Tanga region in Tanzania. Historical habitat stability and connectivity appear to play a significant role in species diversification in the area. Additionally, I also report on some fundamental findings on Shimba Hills amphibians during this study; Using a combination of molecular, morphological, spatial and bioacoustics methods the taxonomic status of the only endemic amphibian from Shimba Hills, Hyperolius rubrovermiculatus, is confirmed and description of a new species from the north eastern Tanzania is proposed. Secondly the taxonomic status of a Callulina rediscovered in Shimba Hills after 50 years is confirmed and I also propose the description of three new species of Callulina from the neighbouring Eastern Arc Mountains in Tanzania. Finally, I took the opportunity to compile the first ever annotated checklist of amphibians of Shimba Hills National Reserve where a new country record for the Ribbon Caecilian (Scolecomorphus vittatus) and other interesting discoveries are discussed. The reserve plus the entire SHK area contains the highest number of amphibian diversity for any known locality in Kenya. Therefore its continued conservation will ensure about 30% of Kenya’s amphibian species are preserved. Key words: Coastal forests, Eastern Arc Mountains, Phylogeography, species distribution modelling, checklist, Amphibians.