多凿齿蜥类(Squamata,Polyglyphanodontia)的分类学与系统发育学综述*

多凿齿蜥类(Squamata, Polyglyphanodontia)是晚白垩世时有鳞类中的优势类群之一, 地理分布广, 体形大小迥异, 形态多样性高。特别表现为多样且独特的牙齿形态, 如横向凿状牙齿和类似哺乳动物臼齿的多尖型牙齿。多凿齿蜥类在经历了晚白垩世的繁盛之后却在白垩纪末和恐龙、翼龙以及有鳞类中的沧龙共同灭绝。近年来多凿齿蜥类化石已报道的属种众多(共计60余种), 但因其兼具臼齿蜥类和鬣蜥类的形态特征、早期研究描述简略和图版不足, 多凿齿蜥类的成员组成、该类群在有鳞类中的系统位置以及类群内的系统关系还存在争议。本研究较全面地梳理了曾归入多凿齿蜥类的属种的分类学和该类群的系统发育学分析结果, 讨论了多凿齿蜥类的定义以及该类群内的形态多样性。     

The recognition of ancestors

The recognition of ancestors is problematic using cladistic logic alone because monophyletic groups (clades) are defined by shared derived characters (synapomorphies) which their ancestors must have lacked. Nevertheless, ancestors possess three key attributes. They belong within a larger, paraphyletic group. They will be morphologically most similar to their immediate descendants, and they evolved before any and all of their descendants. Recognition of ancestors requires both morphological and stratigraphic data and, in practice, the task is to reduce the size of the paraphyletic group within which the ancestor must lie. All ancestor‐descendant relationships are phylogenetic hypotheses. Despite the legendary incompleteness of the fossil record, testing the validity of available data is far more difficult for character analysis than for stratigraphy.     

Phylogeny and ultrastructure of Miliammina fusca: evidence for secondary loss of calcification in a Miliolid Foraminifer

The classification of the Foraminifera, a widely distributed group of largely marine protists, has traditionally been based on morphological characters. The most important of these are the composition and structure of the shell or "test." Here, we use both phylogenetic analysis of the genes for small subunit rRNA and beta-tubulin and ultrastructural analysis to document a reversion in wall type from more derived calcareous tests to an agglutinated test. These data indicate that the genus Miliammina, and possibly other members of the Rzehakinidae, should be placed in the Order Miliolida as opposed to their current assignment in Order Textulariida. We also address the effects this reversion may have had on the ability of rzehakinacids to effectively colonize marginal marine environments. Finally, the hypothesis that some multilocular agglutinated foraminiferans descended from calcareous lineages has implications for interpretation of the foraminiferal fossil record.     

Phylogeny and adaptive diversity of rodents of the family Ctenomyidae (Caviomorpha): delimiting lineages and genera in the fossil record

Differentiation of genera of the modern (Late Miocene to Recent) South American rodent family Ctenomyidae would have been linked to the acquisition of disparate adaptations to digging and life underground. In accordance with this hypothesis, the delimitation of lineages and genera in the ctenomyid fossil record is evaluated here following an adaptation-rooted criterion that involves both an assessment of the monophyly and of the adaptive profiles of recognized clades. The application of such a criterion, including morphofunctional information, delimited four cohesive lineages among crown ctenomyids (i.e. euhypsodont species of the Late Miocene to Recent): Eucelophorus (Early Pliocene–Middle Pleistocene), Xenodontomys-Actenomys (Late Miocene–Pliocene), Praectenomys (Pliocene) and Ctenomys (including Paractenomys ; Pliocene–Recent); in addition, the results supported the status of Xenodontomys as a paraphyletic ancestor of Actenomys . The cladogenesis that gave rise to the crown group would have occurred immediately after the acquisition of euhypsodonty in a Xenodontomys simpsoni -like ancestor during the Late Miocene. This putative ancestor would have had fossorial habits and moderate digging specializations, an adaptive profile maintained in Xenodontomys-Actenomys . Eucelophorus and Ctenomys would have independently evolved subterranean habits at least since the Pliocene. Although the earliest history of the only living representative, Ctenomys , is known only fragmentarily, remains from Esquina Blanca (Uquía Formation), in north-western Argentina, suggest a minimum age of around 3.5 Ma (Early–Late Pliocene) for the differentiation of the genus. This date agrees with recent molecular estimates.     

Oldest cingulate skulls provide congruence between morphological and molecular scenarios of armadillo evolution

The cingulates of the mammalian order Xenarthra present a typical case of disagreement between molecular and morphological phylogenetic studies. We report here the discovery of two new skulls from the Late Oligocene Salla Beds of Bolivia (approx. 26 Ma), which are the oldest known well-preserved cranial remains of the group. A new taxon is described: Kuntinaru boliviensis gen. et sp. nov. A phylogenetic analysis clusters K. boliviensis together with the armadillo subfamily Tolypeutinae. These skulls document an early spotty occurrence for the Tolypeutinae at 26 Ma, in agreement with the temporal predictions of previous molecular studies. The fossil record of tolypeutines is now characterized by a unique occurrence in the Late Oligocene, and a subsequent 12 Myr lack in the fossil record. It is noteworthy that the tolypeutines remain decidedly marginal in the Late Palaeogene and Early Neogene deposits, whereas other cingulate groups diversify. Also, the anatomical phylogenetic analysis herein, which includes K. boliviensis, is congruent with recent molecular phylogenetic analyses. Kuntinaru boliviensis is the oldest confident calibration point available for the whole Cingulata.     

中国绿杯菌属研究

对采自中国12个省的绿杯菌属Chlorociboria标本进行了分类研究,鉴定出3个种,分别为小孢绿杯菌C.aeruginascens、绿杯菌C.aeruginosa和波托绿杯菌C.poutoensis。其中波托绿杯菌为中国新记录种,对该种的形态学特征进行了描述和图示,并对其分类地位提供了DNA序列分析的佐证。