Phylogenetic relationships of the Cretaceous frog Beelzebufo from Madagascar and the placement of fossil constraints based on temporal and phylogenetic evidence

The placement of fossil calibrations is ideally based on the phylogenetic analysis of extinct taxa. Another source of information is the temporal variance for a given clade implied by a particular constraint when combined with other, well-supported calibrations. For example, the frog Beelzebufo ampinga from the Cretaceous of Madagascar has been hypothesized to be a crown-group member of the New World subfamily Ceratophryinae, which would support a Late Cretaceous connection with South America. However, phylogenetic analyses and molecular divergence time estimates based on other fossils do not support this placement. We derive a metric, Δt, to quantify temporal divergence among chronograms and find that errors resulting from mis-specified calibrations are localized when additional nodes throughout the tree are properly calibrated. The use of temporal information from molecular data can further assist in testing phylogenetic hypotheses regarding the placement of extinct taxa.     

Molecular phylogeny and historical biogeography of the large carpenter bees, genus Xylocopa (Hymenoptera: Apidae)

The biogeographical history of major groups of bees with worldwide distributions have often been explained through hypotheses based on Gondwanan vicariance or long distance dispersal events, but until recently these hypotheses have been very difficult, if not impossible, to distinguish. New fossil data, comprehensive information on Mesozoic and Cenozoic coastline positions and the availability of phylogenetically informative DNA markers now makes it feasible to test these hypotheses for some groups of bees. This paper presents historical biogeographical analyses of the genus Xylocopa Latreille, based on phylogenetic analyses of species belonging to 22 subgenera using molecular data from two nuclear genes, elongation factor‐1α (EF‐1α) and phosphoenolpyruvate carboxykinase (PEPCK), combined with previously published morphological and mitochondrial data sets. Phylogenetic analyses based on parsimony and likelihood approaches resulted in several groups of subgenera supported by high bootstrap values (>85%): an American group with the Oriental/Palaearctic subgenera Nyctomelitta and Proxylocopa as sister taxa; a geographically diverse group (Xylocopa s.l); and a group consisting of African and Oriental subgenera. The relationships among these three clades and the subgenus Perixylocopa remained unresolved. The Oriental subgenus Biluna was found to be the sister group of all other carpenter bee subgenera included in this study. Using a relaxed molecular clock calibrated using fossil carpenter bees, we show that the major splits in the carpenter bee phylogeny occurred well after the final breakup of Gondwanaland (the separation of South America and Africa, 100 Mya), but before important Miocene fusion events. Ancestral area analysis showed that the genus Xylocopa most likely had an Oriental‐Palaearctic origin and that the present world distribution of Xylocopa subgenera resulted mainly from independent dispersal events. The influence of Pleistocene glaciations on carpenter bee distributions is also discussed. © 2002 The Linnean Society of London, Biological Journal of the Linnean Society, 2002, 77 , 249–266.     

雀形目高级阶元分类与起源研究概况

对雀肜目鸟类高级阶元的分类和系统发育的研究进行了简要概述.经典分类与应用分子生物学方法建立的分类系统在高级阶元(总科)有较大差异,但科级的分类基本一致.在雀形目鸟类起源研究方面,古生物学研究结果认为其起源于劳亚古陆;而分子生物学的证据则认为其起源于冈瓦纳古陆.由于化石的证据与"分子钟"的推测年代相差较大,因此对雀形目鸟类的起源还存在争议,但是目前的研究更倾向于"冈瓦纳起源"假说.     

Première indication de la présence de phorusracidés,famille d'oiseaux géants d'amérique du sud,dans le tertiaire Européen: Ameghinornis nov. gen. (Aves,ralliformes) des phosphorites du quercy,France

Some bird remains, from the «Phosphorites du Quercy deposits are closely related to the corresponding bones of Phorusrhacidae, an extinct family of birds which underwent an extensive diversification in South America from Oligocene to Pleistocene times. It included many giant flightless species. The form of the Quercy is a rather primitive one, of medium size and of probably somewhat reduced flying ability.The simultaneous occurrence of Phorusrhacidae inFrance and South America is of great biogeographical significance. The Phorusrhacidae seem most probably to be the descendants of a rather primitive group of Ralliformes, already diversified in Gondwanaland prior to its separation into different continental masses.     

海南岛东方早二叠世双壳类动物群及其古生物地理学研究──兼评南龙杂砾岩的冰川成因说

在海南岛东方县江边地区下二叠统南龙组中发现双壳类９属１０种，其中２新种。除新种外，这些双壳类常见于华南和日本的茅口期晚期地层，其它动、植物化石的研究也得出了相同结论，本区无疑是华夏生物区系的组成部分。海南岛的琼中地体不大可能在石炭一二叠纪仍位于冈瓦纳大陆北缘或其附近，南龙杂砾岩应属裂谷成因，与冰川无关。     

Sclerostylus n. gen. from Panama and Other Neotropical Species of LeptonIchoidea (Dorylaimida)

Leptonchoid species found in soil samples taken in lowland and mid-elevation seasonal forests at four locations in Panama were as follows: Sclerostylus karri n. gen., n. sp., Basirotyleptus saccatus n. sp., B. nemoralis, B. acus, B. penetrans, Doryllium neotropicum n. sp., D. minor, Tyleptus gymnochilus, Gerthus jamesi, Dorylaimoides micoletzkyi, and Tylencholaimellus macrophallus. The discoveries corroborate our earlier suggestion of a Gondwanian origin for Tyleptus and Basirotyleptus and provide data for additional biogeographical study.     

Australasian bryogeography: fact, fallacy and fantasy

It is claimed that possible mechanisms leading to the present patterns of distribution of Australasian bryophytes cannot be rigorously deduced from the patterns themselves, and that the distribution data are all imperfect and rapidly changing. Possible causes of the major disjunctions are discussed. There are serious deficiencies in discussions of endemism.