Publications (29)50.19 Total impact
-
Article: Molecular phylogeny of African hinged and helmeted terrapins (Testudines: Pelomedusidae: Pelusios and Pelomedusa)
[show abstract] [hide abstract]
ABSTRACT: 2010). Molecular phylogeny of African hinged and helmeted terrapins (Testudines: Pelomedusidae: Pelusios and Pelomedusa). — Zoologica Scripta, 00, 000–000. With 18 currently recognised species, Pelusios is one of the most speciose chelonian genera worldwide, even though the taxonomy of some species is contentious. Recent investigations suggested that the closely related, but morphologically distinct genus Pelomedusa is para-phyletic with respect to Pelusios, and that Pelomedusa consists of nine deeply divergent lin-eages. Using three mitochondrial and three nuclear DNA fragments (2054 bp mtDNA, 2025 bp nDNA), we examined for the first time the phylogeny of Pelusios by molecular means. Our analyses included all Pelusios species, except the probably extinct P. seychellensis, as well as the nine Pelomedusa lineages. The results showed that Pelusios and Pelomedusa are reciprocally monophyletic. Limited sampling of Pelusios species and homoplasy introduced by remote outgroups most likely explain the paraphyly of Pelomedusa in previous studies. The distinctiveness of most Pelusios species was confirmed, but none of the currently recognised species groups within Pelusios was monophyletic. In Pelusios rhodesianus and P. sinuatus distinct genetic lineages were discovered, suggestive of cryptic taxa. In contrast, the recognition of the weakly differentiated P. castaneus and P. chapini as full species is doubtful, as is the validity of the Malagasy and Seychellois subspecies of P. castanoides. GenBank sequences of P. williamsi were nested within P. castaneus, but the morphological distinctiveness of the two species makes it likely that the GenBank sequences (derived from a turtle from the pet trade) are misidentified. Divergence among the distinct genetic lin-eages of Pelomedusa equals or exceeds the differences among Pelusios species, supporting the view that Pelomedusa is a species complex.; -
Article: One Extinct Turtle Species Less: Pelusios seychellensis Is Not Extinct, It Never Existed.
[show abstract] [hide abstract]
ABSTRACT: Pelusios seychellensis is thought to be a freshwater turtle species endemic to the island of Mahé, Seychelles. There are only three museum specimens from the late 19(th) century known. The species has been never found again, despite intensive searches on Mahé. Therefore, P. seychellensis has been declared as "Extinct" by the IUCN and is the sole putatively extinct freshwater turtle species. Using DNA sequences of three mitochondrial genes of the historical type specimen and phylogenetic analyses including all other species of the genus, we provide evidence that the description of P. seychellensis was erroneously based on a widely distributed West African species, P. castaneus. Consequently, we synonymize the two species and delete P. seychellensis from the list of extinct chelonian species and from the faunal list of the Seychelles.PLoS ONE 01/2013; 8(4):e57116. · 4.09 Impact Factor -
Article: Basic morphological data of native Czech Emys orbicularis revealed by subfossil finds
[show abstract] [hide abstract]
ABSTRACT: Holocene Czech Emys orbicularis are rare in museum collections because the species disappeared from this region centuries ago. Fifteen reconstructed shells of subfossil Czech specimens of E. orbicularis (ranging in age from 3800–3500 BC to 1300 AD) from archaeological sites were used to assess basic morphological data. Our results provide evidence that the extinct Czech turtles fall into the size range of extant Central European E. orbicularis populations from the Hungarian Lowland. Maximum male and female straight-line carapacial lengths of the Czech specimens reached at least 160 and 175 mm, respectively.Biologia 04/2012; 64(4):795-797. · 0.56 Impact Factor -
Article: Red- and yellow-footed tortoises, Chelonoidis carbonaria and C. denticulata (Reptilia: Testudines: Testudinidae), in South American savannahs and forests: do their phylogeographies reflect distinct habitats?
[show abstract] [hide abstract]
ABSTRACT: Using sequence data of the mitochondrial cytochrome b gene, we investigated phylogeographic differentiation of the Amazonian tortoise species Chelonoidis carbonaria and C. denticulata. While C. carbonaria is generally restricted to savannah habitats and adjacent forests, C. denticulata is associated with wet tropical and subtropical forests. Our study suggests a correlation between distinct habitat preferences and phylogeography of the two species. In Maximum Parsimony, Maximum Likelihood and Bayesian analyses, haplotypes of C. carbonaria cluster in several distinct clades reflecting the species’ patchy distribution in savannah habitats. By contrast, haplotypes of C. denticulata are only weakly differentiated; a finding also confirmed by parsimony network analysis. This suggests that the contiguous Amazonian rainforest allows gene flow between populations of the forest-dwelling C. denticulata throughout the range, but significantly impedes gene flow in C. carbonaria. The phylogeographic structure and extant distribution pattern of C. carbonaria is supportive of former Amazonian rainforest fragmentation, enabling the dispersal of savannah species. Based on fossil calibration, we dated divergence times for the C. carbonaria clades using a relaxed molecular clock, resulting in average estimates ranging from 4.0–2.2mya. This implies that the onset of rainforest fragmentation could predate the Pleistocene considerably. Furthermore, our findings call for further research on geographic and taxonomic variation in C. carbonaria and for a reassessment of the conservation status of the distinct genetic units. KeywordsPhylogeography-Cytochrome b gene-Testudinidae-Rainforest-Forest refugia hypothesisOrganisms Diversity & Evolution 04/2012; 10(2):161-172. · 1.65 Impact Factor -
Article: Extremely low genetic diversity and weak population differentiation in the endangered Colombian river turtle Podocnemis lewyana (Testudines: Podocnemididae)
[show abstract] [hide abstract]
ABSTRACT: Podocnemis lewyana is an endangered endemic river turtle of Colombia. Using ten unlinked polymorphic microsatellite loci and a 691-bp-long DNA fragment corresponding to the more variable portion of the mitochondrial control region, we investigated genetic diversity and population structure throughout its range. Both neutral markers showed extremely low diversity and weak population differentiation. Our data indicate that the genetic history of P. lewyana has been impacted by multiple bottlenecks and population expansion since the Pleistocene. The observed differentiation pattern is most likely the result of historically low genetic variation resulting from restricted geographic range and aggravated by recent anthropogenically induced bottlenecks. Based on slight differences in allele frequencies among populations, we suggest that three regions should be treated as demographically independent Management Units in order to preserve maximal genetic diversity: (1) the Upper Magdalena River Basin, (2) the Lower Magdalena+Lower Cauca+San Jorge River Basins, and (3) the Sinú River Basin. Among the Management Units, only low to moderate levels of gene flow were detected; these are largely unidirectional from Management Units 1 and 3 into Management Unit 2. Podocnemis lewyana es una tortuga endémica y amenazada de Colombia. Usando diez loci polimórficos de microsatélites y un fragmento de 691 pares de bases correspondiente a la porción más variable de la región control mitocondrial, investigamos la diversidad genética y estructura poblacional a través de su rango de distribución. Ambos marcadores neutrales revelaron una diversidad extremadamente baja y débil diferenciación poblacional. Nuestros datos indican que la historia genética de P. lewyana ha sido impactada por múltiples cuellos de botella y expansión poblacional desde el Pleistoceno. El patrón de diferenciación observado es más probable el resultado de la variación genética historica baja derivada del rango de distribución restringido, agravada por cuellos de botella recientes resultado de intervención antrópica. Basados en diferencias tenues de frecuencias alélicas entre poblaciones, sugerimos que tres regiones deben ser tratadas como Unidades de Manejo (UM) demográficamente independientes con el fin de preservar al máximo la diversidad genética. (1) Cuenca del alto río Magdalena, (2) Cuencas del bajo río Magdalena+Bajo río Cauca+río San Jorge, y (3) Cuenca del río Sinú. Entre las UM se detectaron niveles bajos a moderados de flujo genético que es principalmente unidireccional de las UM 1 y 3 a la UM 2. KeywordsConservation–Genetic diversity–Microsatellites–mtDNA–Population structure Palabras clavesConservación–Diversidad genética–Microsatélites–mtDNA–Estructura poblacionalConservation Genetics 04/2012; 13(1):65-77. · 1.61 Impact Factor -
Dataset: Weak genetic divergence between the two South American toad-headed turtles Mesoclemmys dahli and M. zuliae (Testudines: Pleurodira: Chelidae)
[show abstract] [hide abstract]
ABSTRACT: Mesoclemmys dahli and M. zuliae are two endangered, little-known toad-headed turtles with small distribution ranges in Colombia and Venezuela, respectively. Using the mitochondrial cytochrome b gene as a marker, we investigate their phylogeographic differentiation. Furthermore, based on 2341 bp of mtDNA and 2109 bp of nDNA of M. dahli, M. zuliae and allied chelid turtles, we infer their divergence time using a fossil-calibrated relaxed molecular clock approach. Mesoclemmys dahli and M. zuliae are closely related species, with an estimated mean divergence time of 10.6 million years. This estimate correlates with the uplift of the Serranía de Perijá, an Andean mountain chain separating their distribution ranges, suggesting that this event could have caused the evolution of the two species. Haplotype and nucleotide diversities of M. dahli are markedly higher than in Podocnemis lewyana, another endemic turtle species of Colombia. This pronounced dissimilarity may reflect differences in the phylogeographies and demographic histories of the two species, but also different habitat preferences. -
Dataset: Phylogenetic position of Pelusios williamsi and a critique of current GenBank procedures (Reptilia: Testudines: Pelomedusidae)
[show abstract] [hide abstract]
ABSTRACT: We re-examine the phylogenetic position of Pelusios williamsi by merging new sequences with an earlier published data set of all Pelusios species, except the possibly extinct P. seychellensis, and the nine previously identified lineages of the closely allied genus Pelomedusa (2054 bp mtDNA, 2025 bp nDNA). Furthermore, we include new sequences of Pelusios broadleyi, P. castanoides, P. gabonensis and P. marani. Individual and combined analyses of the mitochondrial and nuclear data sets indicate that P. williamsi is sister to P. castanoides, as predicted by morphology. This provides evidence for the misidentification of GenBank sequences allegedly representing P. williamsi. Such mislabelled GenBank sequences contribute to continued confusion, because only the original submitter can revise their identification; an impractical procedure impeding the rectification of obvious mistakes. We recommend implementing another option for revising taxonomic identifications, paralleling the century-old best practice of natural history museums for new determinations of specimens. Within P. broadleyi, P. gabonensis and P. marani, there is only shallow genetic divergence, while some phylogeographic structuring is present in the wide-ranging species P. castaneus and P. castanoides. African hinged terrapins (genus Pelusios) are with 17-18 currently recognized species one of the most speciose genera of turtles and tortoises (Ernst, Altenburg and Barbour, 2000; Fritz and Havaš, 2007; Rhodin et al., 2010; Fritz et al., 2011). However, in a recent molecular study us-ing mitochondrial and nuclear DNA sequences of all Pelusios species except the possibly ex-tinct P. seychellensis, we have identified many taxonomic issues. Among others, GenBank se-quences of P. williamsi were phylogenetically embedded within sequences of P. castaneus (Fritz et al., 2011). According to its morphol-ogy, P. williamsi should be closely allied to P. castanoides and not to P. castaneus (Bour, 1986). In contrast to all other studied species, P. williamsi was only represented by GenBank sequences in our previous study. Therefore, we -
Article: Molecular phylogeny of Central and South American slider turtles: implications for biogeography and systematics (Testudines: Emydidae: Trachemys)
[show abstract] [hide abstract]
ABSTRACT: 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.ResumenAnalizamos la filogenia, sistemática y biogeografía de las tortugas Icoteas (Trachemys spp.) usando información de secuencias de cuatro genes mitocondriales (3242 bp) y cinco loci nucleares (3396 bp) de la mayoría de taxa Suramericanos y de la parte sur de Centroamérica, especies representantes de la parte norte de Centroamérica, Antillas y Norteamérica (16 especies y subespecies) y especies Norteamericanas relacionadas (géneros Chrysemys, Deirochelys, Graptemys, Malaclemys, Pseudemys). Mediante la aplicación de máxima verosimilitud, reloj molecular relajado y análisis de rango ancestral, presentamos evidencia de dos colonizaciones sucesivas de las Icoteas a Suramérica. Además, demostramos que la delineación actual de especies de Centro y Suramérica no es correcta. Nuestros datos sugieren que Trachemys grayi es una especie politípica distintiva y agrupa, aparte de la subespecie nominotípica, T. g. emolli and T. g. panamensis. Trachemys ornata también es politípica con las subespecies T. o. ornata, T. o. callirostris, T. o. cataspila, T. o. chichiriviche y T. o. venusta. Adicionalmente, T. adiutrix debe ser considerada como subespecie de T. dorbigni. Se infirió que todas las especies estudiadas de Trachemys se originaron en el Mioceno tardío a Plioceno temprano. El ancestro de las dos subespecies de T. dorbigni colonizo Suramérica más probablemente antes del establecimiento de la conexión terrestre entre Centro y Suramérica, mientras las dos subespecies Suramericanas de T. ornata representan un evento de migración independiente mas reciente desde Centroamérica.Journal of Zoological Systematics and Evolutionary Research 12/2011; 50(2):125 - 136. · 1.95 Impact Factor -
Article: Identity of Pelodiscus sinensis revealed by DNA sequences of an approximately 180‐year‐old type specimen and a taxonomic reappraisal of Pelodiscus species (Testudines: Trionychidae)
[show abstract] [hide abstract]
ABSTRACT: Recent studies identified several distinct genetic lineages within the softshell turtle genus Pelodiscus that could represent valid species. Traditionally, Pelodiscus was regarded to comprise only a single species (P. sinensis). These softshell turtles are economically the most important chelonians of the world, with hundreds of millions of specimens traded as food every year. Moreover, Pelodiscus is used as a model organism for embryological and physiological studies, making correct species identification of paramount interest for disciplines beyond taxonomy. However, the understanding of the diversity of Pelodiscus was seriously hampered by the unclear taxonomic allocation of the oldest available species name, Trionyx (Aspidonectes) sinensisWiegmann, 1834. To clarify its identity, we reconstructed two mitochondrial DNA fragments of 1013 bp (cytb) and 468 bp (ND4) length of one of the two surviving syntypes and designate this specimen as lectotype (ZMB 38, Museum für Naturkunde Berlin). The sequences obtained from the lectotype represent a previously unknown lineage. Using the phylogenetic placement of all lineages and uncorrected p distances of the mitochondrial cytb gene as a yardstick, we suggest that the observed sequence variation is consistent with the existence of at least four distinct species within Pelodiscus. The name P. sinensis should be restricted to turtles harbouring the mitochondrial lineages B, C, D and the lineage of the lectotype. More divergent lineages are to be identified with P. axenaria, P. maackii and P. parviformis, which are recognized as valid species.ZusammenfassungVor kurzem wurden in der Weichschildkröten-Gattung Pelodiscus mehrere verschiedene genetische Linien identifiziert, die unterschiedlichen Arten entsprechen könnten. Traditionell wurde die Gattung Pelodiscus mit der einzigen Art P. sinensis als monotypisch betrachtet. Pelodiscus sind als Nahrungsmittel weltweit die ökonomisch wichtigsten Schildkröten, mit einem jährlichen Handelsvolumen von mehreren hundert Millionen Exemplaren. Außerdem wird Pelodiscus als Modellorganismus für embryologische und physiologische Studien genutzt, so dass eine korrekte Artidentifikation auch jenseits der Taxonomie von großer Bedeutung ist. Das Verständnis der Diversität von Pelodiscus wurde bislang jedoch massiv durch die unklare taxonomische Identität des ältesten verfügbaren Namens, Trionyx (Aspidonectes) sinensisWiegmann, 1834, behindert. Um dies zu klären, rekonstruierten wir aus einem der beiden heute noch vorhandenen Syntypen zwei mitochondriale DNS-Fragmente mit einer Länge von 1013 bp (cytb) bzw. 468 bp (ND4) und bestimmen dieses Exemplar als Lectotypus (ZMB 38, Museum für Naturkunde Berlin). Die Lectotypus-Sequenzen gehören zu einer bislang unbekannten genetischen Linie. Die Phylogenie und unkorrigierte p-Distanzen des cytb-Gens aller Linien lassen darauf schließen, dass die Gattung Pelodiscus mindestens vier verschiedene Spezies enthält. Der Name P. sinensis sollte nur auf Schildkröten angewendet werden, die die mitochondriale Linie des Lectotypus oder die bereits früher identifizierten Linien B, C oder D aufweisen. Weitere, stärker divergente Linien lassen sich P. axenaria, P. maackii und P. parviformis zuordnen, die als valide Spezies anerkannt werden.Journal of Zoological Systematics and Evolutionary Research 10/2011; 49(4):335 - 339. · 1.95 Impact Factor -
Article: Molecular phylogeny of African hinged and helmeted terrapins (Testudines: Pelomedusidae: Pelusios and Pelomedusa)
[show abstract] [hide abstract]
ABSTRACT: Fritz, U., Branch, W. R., Hofmeyr, M. D., Maran, J., Prokop, H., Schleicher, A., Široký, P., Stuckas, H., Vargas-Ramírez, M., Vences, M. & Hundsdörfer, A. K. (2010). Molecular phylogeny of African hinged and helmeted terrapins (Testudines: Pelomedusidae: Pelusios and Pelomedusa). —Zoologica Scripta, 40, 115–125.With 18 currently recognised species, Pelusios is one of the most speciose chelonian genera worldwide, even though the taxonomy of some species is contentious. Recent investigations suggested that the closely related, but morphologically distinct genus Pelomedusa is paraphyletic with respect to Pelusios, and that Pelomedusa consists of nine deeply divergent lineages. Using three mitochondrial and three nuclear DNA fragments (2054 bp mtDNA, 2025 bp nDNA), we examined for the first time the phylogeny of Pelusios by molecular means. Our analyses included all Pelusios species, except the probably extinct P. seychellensis, as well as the nine Pelomedusa lineages. The results showed that Pelusios and Pelomedusa are reciprocally monophyletic. Limited sampling of Pelusios species and homoplasy introduced by remote outgroups most likely explain the paraphyly of Pelomedusa in previous studies. The distinctiveness of most Pelusios species was confirmed, but none of the currently recognised species groups within Pelusios was monophyletic. In Pelusios rhodesianus and P. sinuatus distinct genetic lineages were discovered, suggestive of cryptic taxa. In contrast, the recognition of the weakly differentiated P. castaneus and P. chapini as full species is doubtful, as is the validity of the Malagasy and Seychellois subspecies of P. castanoides. GenBank sequences of P. williamsi were nested within P. castaneus, but the morphological distinctiveness of the two species makes it likely that the GenBank sequences (derived from a turtle from the pet trade) are misidentified. Divergence among the distinct genetic lineages of Pelomedusa equals or exceeds the differences among Pelusios species, supporting the view that Pelomedusa is a species complex.Zoologica Scripta 02/2011; 40(2):115 - 125. · 2.91 Impact Factor -
Article: Gene flow across secondary contact zones of the Emys orbicularis complex in the Western Mediterranean and evidence for extinction and re‐introduction of pond turtles on Corsica and Sardinia (Testudines: Emydidae)
[show abstract] [hide abstract]
ABSTRACT: European pond turtles represent a phylogeographically deeply structured complex of distinct taxa. Here, we use mitochondrial DNA sequences (cytochrome b gene) and eight polymorphic microsatellite loci to investigate genetic differentiation and gene flow of Sicilian, Corsican and Sardinian pond turtles and of subspecies involved in two secondary contact zones in the Pyrenean region and Southern Italy. Mitochondrial and microsatellite differentiation is largely concordant in populations from the core regions of the distribution ranges of the studied taxa. Both marker systems provide no evidence for gene flow between Sicilian pond turtles (Emys trinacris) and Southern Italian subspecies of E. orbicularis. By contrast, in the contact zones limited gene flow occurs between distinct subspecies of E. orbicularis. Although the Southern Italian contact zone is significantly older than the Pyrenean contact zone of Holocene age, patterns of asymmetric introgression are similar. Introgressive hybridization leads to the exchange of mitochondria, but microsatellite data indicate only a few individuals with mixed ancestry. This suggests that incipient isolating mechanisms maintain largely discrete nuclear genomic gene pools. Furthermore, this implies that Southern Italy acted as a hotspot rather than as a melting pot of genetic diversity during the last glacial. Pond turtles from Corsica and Sardinia are not differentiated from continental populations of the subspecies E. o. galloitalica, neither in the mitochondrial nor in the quickly evolving microsatellite markers. As the fossil record argues for a continuous presence of pond turtles on both islands since the Middle Pleistocene, this suggests that the native island populations became extinct and the extant turtles were later introduced by prehistoric settlers. The lack of genetic differentiation of pond turtles from Corsica and Sardinia supports the view that the subspecies described from these islands are not valid.ZusammenfassungEuropische Sumpfschildkröten stellen einen phylogeographisch stark strukturierten Komplex distinkter Taxa dar. In der vorliegenden Arbeit verwenden wir mitochondriale DNA-Sequenzen (Cytochrom b-Gen) und acht polymorphe Mikrosatelliten-Loci um die genetische Differenzierung und möglichen Genfluss bei sizilianischen, korsischen und sardischen Sumpfschildkröten sowie bei Unterarten zu untersuchen, die in zwei sekundren Kontaktzonen in der Pyrenen-Region und in Süditalien aufeinandertreffen. Bei Populationen aus dem Kernareal der untersuchten Taxa zeigen beide Markersysteme weitgehend übereinstimmende Differenzierungsmuster. Es gibt keine Hinweise auf Genfluss zwischen sizilianischen Sumpfschildkröten (Emys trinacris) und den in Süditalien verbreiteten Unterarten von E. orbicularis. In den Kontaktzonen kommt es dagegen zu einem beschrnkten Genfluss zwischen verschiedenen Unterarten von E. orbicularis. Obwohl die süditalienische Kontaktzone deutlich lter als diejenige in den Pyrenen ist, sind in beiden hnliche asymmetrische Introgressionsmuster zu verzeichnen, die weitgehend auf die mitochondriale Ebene beschrnkt sind. Die Mikrosatelliten-Daten deuten dagegen nur auf wenige Schildkröten mit gemischter Abstammung hin. Dies lsst vermuten, dass in der Entfaltung begriffene Isolationsmechanismen helfen, weitgehend voneinander getrennte kerngenomische Genpools aufrechtzuerhalten. Dies deutet ferner darauf hin, dass Süditalien im letzten Glazial ein Mannigfaltigkeitszentrum genetischer Diversitt war und dass es dort keinesfalls zu einer kompletten genetischen Durchmischung der Refugialpopulationen kam. Korsische und sardische Sumpfschildkröten sind von kontinentaleuropischen Populationen der Unterart E. o. galloitalica weder mitochondrial noch bei den schnell evolvierenden Mikrosatelliten-Markern differenziert. Da es auf beiden Inseln seit dem Mittelpleistozn Fossilnachweise gibt, spricht dies dafür, dass die ursprünglichen Inselpopulationen ausstarben und die heutigen Sumpfschildkröten spter durch prhistorische Siedler eingeführt wurden. Die fehlende genetische Differenzierung der Sumpfschildkröten von Korsika und Sardinien spricht außerdem gegen die Validitt der von dort beschriebenen Unterarten.Journal of Zoological Systematics and Evolutionary Research 01/2011; 49(1):44 - 57. · 1.95 Impact Factor -
Article: Is the horned pitviper Ceratrimeresurus shenlii Liang and Liu, 2003 from China a valid Protobothrops?
[show abstract] [hide abstract]
ABSTRACT: Previous records of horned pitvipers from Vietnam and China are reviewed and the phylogenetic placement of four snakes from two sites in Tianjingshan Forest, China (Ruyan County, Guangdong Province; 24°43′N, 113°03′E, 563 m a.s.l.; 24°43′N, 113°02′E, 585 m a.s.l.) is examined. Using mitochondrial DNA sequence data (12S, 16S, ND4, cyt b; 2306 bp) and Bayesian and Maximum Likelihood analyses, the Tianjingshan pitvipers are revealed as sister to Protobothrops cornutus with a differentiation resembling those of P. flavoviridis and P. tokarensis. This indicates a close relationship with P. cornutus and suggests that Ceratrimeresurus shenlii Liang and Liu, 2003, previously considered a junior synonym of P. cornutus (Smith, 1930), could be a valid subspecies of P. cornutus or a recently split distinct species. However, further studies and samples from intermediate localities are needed to decide whether the observed differentiation reflects a pattern of isolation-by-distance or a phylogeographic, and thus perhaps taxonomically relevant, break.Amphibia-Reptilia 12/2010; 32(1):132-135. · 1.06 Impact Factor -
Article: Deep genealogical lineages in the widely distributed African helmeted terrapin: evidence from mitochondrial and nuclear DNA (Testudines: Pelomedusidae: Pelomedusa subrufa).
[show abstract] [hide abstract]
ABSTRACT: We investigated the phylogeographic differentiation of the widely distributed African helmeted terrapin Pelomedusa subrufa based on 1503 base pairs of mitochondrial DNA (partial cyt b and ND4 genes with adjacent tRNAs) and 1937 bp of nuclear DNA (partial Rag1, Rag2, R35 genes). Congruent among different analyses, nine strongly divergent mitochondrial clades were found, representing three major geographical groupings: (1) A northern group which includes clades I from Cameroon, II from Ghana and Ivory Coast, III from Benin, Burkina Faso and Niger, IV from the Central African Republic, and V from Kenya, (2) a northeastern group consisting of clades VI from Somalia, and VII from Saudi Arabia and Yemen, and (3) a southern group comprising clade VIII from Botswana, the Democratic Republic of Congo, Madagascar and Malawi, and clade IX from South Africa. Malagasy and continental African populations were not clearly differentiated, indicating very recent arrival or introduction of Pelomedusa in Madagascar. The southern group was in some phylogenetic analyses sister to Pelusios, rendering Pelomedusa paraphyletic with respect to that genus. However, using partitioned Bayesian analyses and sequence data of the three nuclear genes, Pelomedusa was monophyletic, suggesting that its mitochondrial paraphyly is due to either ancient introgressive hybridization or phylogenetic noise. Otherwise, nuclear sequence data recovered a lower level of divergence, but corroborated the general differentiation pattern of Pelomedusa as revealed by mtDNA. This, and the depth of the divergences between clades, indicates ancient differentiation. The divergences observed fall within, and in part exceed considerably, the differentiation typically occurring among chelonian species. To test whether Pelomedusa is best considered a single species composed of deep genealogical lineages, or a complex of up to nine distinct species, we suggest a future taxonomic revision that should (1) extend the geographical sampling of molecular data, specifically focusing on contact zones and the possible sympatric occurrence of lineages without admixture, and (2) evaluate the morphology of the various genealogical lineages using the type specimens or topotypical material of the numerous junior synonyms of P. subrufa.Molecular Phylogenetics and Evolution 03/2010; 56(1):428-40. · 3.61 Impact Factor -
Article: Unexpected early extinction of the European pond turtle (Emys orbicularis) in Sweden and climatic impact on its Holocene range.
[show abstract] [hide abstract]
ABSTRACT: Using ancient DNA sequences of subfossil European pond turtles (Emys orbicularis) from Britain, Central and North Europe and accelerator mass spectrometry radiocarbon dating for turtle remains from most Swedish sites, we provide evidence for a Holocene range expansion of the pond turtle from the southeastern Balkans into Britain, Central Europe and Scandinavia, according to the 'grasshopper pattern' of Hewitt. Northeastern Europe and adjacent Asia were colonized from another refuge located further east. With increasing annual mean temperatures, pond turtles reached southern Sweden approximately 9800 years ago. Until approximately 5500 years ago, rising temperatures facilitated a further range expansion up to Ostergötland, Sweden (approximately 58 degrees 30'N). However, around 5500 years ago pond turtle records suddenly terminate in Sweden, some 1500 years before the Holocene thermal maximum ended in Scandinavia and distinctly earlier than previously thought. This extinction coincides with a temporary cooling oscillation during the Holocene thermal maximum and is likely related to lower summer temperatures deteriorating reproductive success. Although climatic conditions improved later again, recolonization of Sweden from southern source populations was prevented by the Holocene submergence of the previous land connection via the Danish Straits that occurred approximately 8500 years ago.Molecular Ecology 03/2009; 18(6):1252-62. · 5.52 Impact Factor -
Article: Phylogeography of the endangered black-breasted leaf turtle (Geoemyda spengleri) and conservation implications for other chelonians
[show abstract] [hide abstract]
ABSTRACT: Known-locality samples of Geoemyda spengleri from three Chinese provinces (Guangdong, Guangxi, Hainan) and northern Vietnam provide clear evidence for phylogeographic structure in a southern Chinese chelonian species. Within southern China two clades of mitochondrial haplotypes from east and west of the Xi Jiang together form the sister group to haplotypes from northern Vietnam. Turtles from Hainan Island harbour haplotypes of the same clade as turtles from Guangxi, 400 km distant. These findings suggest that phylogeographic differentiation may have once existed in other co-distributed, highly endangered chelonian species. The possibility of phylogeographic structure should be considered in any in-situ and ex-situ conservation program for Chinese chelonians.Amphibia-Reptilia 01/2009; 30:57-62. · 1.06 Impact Factor -
Article: Historical DNA from museum type specimens clarifies diversity of Asian leaf turtles (Cyclemys)
[show abstract] [hide abstract]
ABSTRACT: Species boundaries in Asian leaf turtles of the genus Cyclemys are difficult to define on the basis of morphology, primarily because many populations exhibit considerable ontogenetic variation in shell and head coloration. Two recent molecular phylogenetic hypotheses of Cyclemys species relationships, based largely on market and pet-trade samples of uncertain provenance, were highly incongruent. We used historical DNA methods to sequence fragments of the mitochondrial cytochrome b gene from eight type specimens of Cyclemys (including one collected by Alfred Russel Wallace), and phylogenetically placed these type sequences into the context of published cytochrome b variation. Our phylogenetic hypothesis supports the recognition of four named species (Cyclemys atripons, Cyclemys dentata, Cyclemys oldhamii, and C. pulchristriata), as well as a fifth species of unknown geographical provenance obtained from the Hong Kong pet trade. The type sequences show that previous molecular phylogenetic studies were hampered by misidentifications, supporting the notion that Cyclemys of unknown provenance are not reliably identified to species solely on the basis of morphology. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 94, 131–141.Biological Journal of the Linnean Society 04/2008; 94(1):131 - 141. · 2.19 Impact Factor -
Article: Further specimens and phylogenetic position of the recently described leaf turtle species Cyclemys gemeli (Testudines: Geoemydidae)
[show abstract] [hide abstract]
ABSTRACT: We describe external morphology and habitat of ten specimens of Cyclemys gemeli, a recently discovered leaf turtle species from north-eastern India, previously known only from its incomplete holotype and photos of a live female. Further, we assess the phylogenetic position of C. gemeli using sequence data of the mitochondrial cytochrome b gene as well as of three nuclear DNA fragments (C-mos, Rag2 genes, intron 1 of R35 gene) and confirm its genetic distinctiveness. Mitochondrial data strongly suggest a sister group relationship of C. gemeli and C. fusca, another species occurring in Myanmar. According to our new records, the Naga Hills and the Arakan Mts could constitute the geographical divide between C. gemeli and C. fusca. Morphologically, C. gemeli resembles other dark-bellied Cyclemys species and determination by external morphology alone is quite difficult.01/2008; -
Article: Naming one of the world's rarest chelonians, the southern Batagur
[show abstract] [hide abstract]
ABSTRACT: Using mtDNA sequences of historical museum specimens, including the herein designated lectotype of Tetraonyx affinis Cantor 1847 and topotypic specimens of Trionyx (Tetraonyx) cuvieri Gray 1831 and Tetronyx longicollis Lesson 1834, we demonstrate that the name Batagur affinis (Cantor 1847) has to be used for a recently identified critically endangered terrapin species from Southeast Asia. Further, we provide evidence that Batagur baska (Gray 1830) historically was dis-tributed from north-easternmost India and Bangladesh to at least the Ayeyarwady and Bago estuaries in Myanmar while B. affinis occurs in the southern Malay Peninsula and Sumatra. The taxonomic allocation of the extant and extirpated Batagur populations in the northern Malay Peninsula, Cambodia and southern Vietnam remains unclear. A museum specimen from the mid-19 th century suggests that B. baska once also occurred in the Indus Delta of southern Pakistan.01/2008; -
Dataset: Molecular phylogeny and divergence times of ancient South American and Malagasy river turtles (Testudines: Pleurodira: Podocnemididae)
[show abstract] [hide abstract]
ABSTRACT: The eight extant podocnemidid species are the last survivors of a speciose ancient group of turtles known to have existed since the Cretaceous. One species, representing the monotypic genus Erymnochelys, occurs on Madagascar; the remaining seven species are confined to South America (Peltocephalus: one species; Podocnemis: six species). Phylogenetic relationships of all extant species were reconstructed from six mitochondrial (3385 bp) and six nuclear DNA fragments (4115 bp) in separate and combined analyses (Bayesian inference, Maximum Likelihood, Maximum Parsimony). In a total evidence approach for all concatenated genes, all methods yielded the same well-supported phylogenetic hypothesis for the three basal lineages. The Malagasy genus Erymnochelys is sister to the South American Podocnemis, and Peltocephalus constitutes the sister taxon to Erymnochelys+Podocnemis. Within Podocnemis, P. unifilis+(P. erythrocephala+P. lewyana) constitute a well-supported crown clade; P. sextuberculata, P. vogli, and P. expansa were revealed as successive sister taxa. According to Bayesian relaxed molecular clock calcu-lations calibrated with fossil evidence, Peltocephalus originated during a period of the Late Cretaceous ($86 mya), when a contiguous Gondwana landmass exclusive of Africa is likely to have still existed. The Late Cretaceous split between Erymnochelys and Podocnemis ($78 mya) coincides with the supposed submergence of the land bridge between Madagascar and Antarctica+South America, suggesting that the origin of those genera is linked to this vicariant event. The extant Podocnemis species evolved from the Late Eocene ($37 mya) to the Middle Miocene ($15 mya), during a phase characterized by dramatic global cooling, aridification, and massive Andean uplift. -
Article: Is Testudo werneri a distinct species?
[show abstract] [hide abstract]
ABSTRACT: Sequence variation of a 1066 bp long mtDNA fragment (cytochrome b gene, adjacent part of tRNA-Thr gene) of four known-locality samples of Testudo kleinmanni (Tripolitania, Libya) and of four samples of T. werneri (Negev, Israel) is compared with additional five sequences of pet trade tortoises allegedly representing T. kleinmanni. Four haplotypes, differing in one to four mutation steps occur. The most common haplotype was shared by all known-locality samples of T. kleinmanni and three T. werneri. Sequence variation within each nominal species and in the pooled sample of T. kleinmanni, T. werneri and pet trade tortoises is the lowest known for any Testudo species. We conclude there is no support for the validity of T. werneri Perälä, 2001.Biologia 03/2007; 62(2):228-231. · 0.56 Impact Factor
Top co-authors
Top Journals
Institutions
-
2005–2012
-
State Museum of Natural History Stuttgart
Stuttgart, Baden-Wuerttemberg, Germany -
DOE Joint Genome Institute
Walnut Creek, CA, USA
-
-
2009
-
Museum für Naturkunde
Berlin, Land Berlin, Germany
-
-
2008
-
Naturhistorisches Museum Wien
Vienna, Vienna, Austria
-
