Exquisitely preserved fossil snakes of messel: Insight into the evolution, biogeography, habitat preferences and sensory ecology of early boas

Our knowledge of early evolution of snakes is improving, but all that we can infer about the evolution of modern clades of snakes such as boas (Booidea) is still based on isolated bones. Here, we resolve the phylogenetic relationships of Eoconstrictor fischeri comb. nov. and other booids from the early-middle Eocene of Messel (Germany), the best-known fossil snake assemblage yet discovered. Our combined analyses demonstrate an affinity of Eoconstrictor with Neotropical boas, thus entailing a South America-to-Europe dispersal event. Other booid species from Messel are related to different New World clades, reinforcing the cosmopolitan nature of the Messel booid fauna. Our analyses indicate that Eoconstrictor was a terrestrial, medium- to large-bodied snake that bore labial pit organs in the upper jaw, the earliest evidence that the visual system in snakes incorporated the infrared spectrum. Evaluation of the known palaeobiology of Eoconstrictor provides no evidence that pit organs played a role in the predator–prey relations of this stem boid. At the same time, the morphological diversity of Messel booids reflects the occupation of several terrestrial macrohabitats, and even in the earliest booid community the relation between pit organs and body size is similar to that seen in booids todayFil: Scanferla, Carlos Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; Argentina. Senckenberg Research Institute; AlemaniaFil: Smith, Krister T.. Senckenberg Research Institute; Alemania. Goethe Universitat Frankfurt; Alemani

Los microvertebrados del Plio-Pleistoceno y su contexto paleoambiental, Celendín, Cajamarca

El estudio reporta las nuevas colectas de microinvertebrados, taxanómicamente estudiados de las cavidades cársticas de Santa Rosa de Celendín, pudiéndose definir sus paleoambientes. El área de estudio es el caserío de Santa Rosa de Celendín, a 2625 m.s.n.m. en el Valle altoandino de la Cordillera Occidental Andina del Norte del Perú. En la localidad se tienen numerosos hallazgos de roedores fósiles. Se indica que los estudios sedimentológicos, palinológicos, petrográficos y estratigráficos de la cueva muestra que la cavidad pertenece a un sistema cárstico, típico de la región, socavada en calizas de la Formación Celendín, durante el Coniaciano al Santoniano inferior. Los vertebrados fueron hallados junto con fósiles de plantas por determinar. Al interior de las cavidades cársticas se observan facies de arena, limo y lodo con abundantes clastos aislados y algunos imbricados al noroeste. En estos sedimentos se conservan los microinvertebrados fósiles. En estas facies no se observa estratificación. Esos mismos cultivos se expanden hasta las zonas de cultivos, fuera de los límites cársticos. Se detalla la fauna de mamíferos y reptiles fósiles del Pleistoceno superior de Celendín, mencionándose un mínimo de cinco especies de roedores, representados por húmeros y mandíbulas con dientes. Se anotan también reptiles fósiles representados por tres mandíbulas y cuatro vértebras. Esta asociación sugiere el intérvalo Plioceno a Pleistoceno. Los fósiles se hallan muy fragmentados, desmembrados por la sedimentación, más los fragmentos se hallan sin desgaste. Las cuevas se caracterizan por tres capas (externa a internamente): 1) Rocas que forman las cavidades cársticas (calizas packstone); 2) Productos de la descomposición por humedad, sedimentos amarillentos sin fósiles, conteniendo fragmentos de estalactitas; y 3) Sedimentos pardos que contienen los fluidos que llevan o cubren a los microinvertebrados y fragmentos de vegetales fósiles. Las características en la sedimentación sugieren flujos de agua y abundante humedad. Se concluye que los sedimentos cársticos del Plioceno y Pleistoceno de Santa Rosa de Celendín, constituyen un relleno que conserva una compleja fauna de vertebrados fósiles. Anteriormente se han reportado en el Perú registros de micromamíferos del Paleogéno en la Amazonía peruana (Campbell, 2000), aunque sin registros de micromamíferos asociados a reptiles fósiles de esa edad ni del Plioceno ni Pleistoceno. Se recomiendan estudios detallados. El trabajo forma parte del Proyecto GR11: Paleontologia Cuaternaria del Noroeste del Perú, de INGEMMET

A Genomewide Screen for Suppressors of Alu-Mediated Rearrangements Reveals a Role for PIF1

Alu-mediated rearrangement of tumor suppressor genes occurs frequently during carcinogenesis. In breast cancer, this mechanism contributes to loss of the wild-type BRCA1 allele in inherited disease and to loss of heterozygosity in sporadic cancer. To identify genes required for suppression of Alu-mediated recombination we performed a genomewide screen of a collection of 4672 yeast gene deletion mutants using a direct repeat recombination assay. The primary screen and subsequent analysis identified 12 candidate genes including TSA, ELG1, and RRM3, which are known to play a significant role in maintaining genomic stability. Genetic analysis of the corresponding human homologs was performed in sporadic breast tumors and in inherited BRCA1-associated carcinomas. Sequencing of these genes in high risk breast cancer families revealed a potential role for the helicase PIF1 in cancer predisposition. PIF1 variant L319P was identified in three breast cancer families; importantly, this variant, which is predicted to be functionally damaging, was not identified in a large series of controls nor has it been reported in either dbSNP or the 1000 Genomes Project. In Schizosaccharomyces pombe, Pfh1 is required to maintain both mitochondrial and nuclear genomic integrity. Functional studies in yeast of human PIF1 L319P revealed that this variant cannot complement the essential functions of Pfh1 in either the nucleus or mitochondria. Our results provide a global view of nonessential genes involved in suppressing Alu-mediated recombination and implicate variation in PIF1 in breast cancer predisposition

Best practices for justifying fossil calibrations.

Our ability to correlate biological evolution with climate change, geological evolution, and other historical patterns is essential to understanding the processes that shape biodiversity. Combining data from the fossil record with molecular phylogenetics represents an exciting synthetic approach to this challenge. The first molecular divergence dating analysis (Zuckerkandl and Pauling 1962) was based on a measure of the amino acid differences in the hemoglobin molecule, with replacement rates established (calibrated) using paleontological age estimates from textbooks (e.g., Dodson 1960). Since that time, the amount of molecular sequence data has increased dramatically, affording ever-greater opportunities to apply molecular divergence approaches to fundamental problems in evolutionary biology

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

Relatório de estágio em farmácia comunitária

Relatório de estágio realizado no âmbito do Mestrado Integrado em Ciências Farmacêuticas, apresentado à Faculdade de Farmácia da Universidade de Coimbr

Taxonomic revision of the snakes of the genera Palaeopython and Paleryx (Serpentes, Constrictores) from the Paleogene of Europe

Large constrictor snakes, referred to the genera Palaeopython and Paleryx, are an ecologically prominent part of the fauna of Europe during the Paleogene. Most species were named over a century ago and their taxonomy is largely based on isolated vertebrae. Furthermore, the majority of named taxa originate from imprecisely known localities within the Phosphorites du Quercy, in southern France, and thus their exact age is not known. We critically review and re-diagnose these genera based on personal examination of all existing type material, an array of new specimens, and a detailed literature review. We consider Palaeopython and Paleryx to be valid and propose vertebral characters to distinguish them. We recognize three valid species of Palaeopython, i.e. Palaeopythoncadurcensis (type species) from the Phosphorites du Quercy, Palaeopythonceciliensis from Geiseltal, and Palaeopythonhelveticus from Dielsdorf (Switzerland), and one valid species of Paleryx, i.e. Paleryxrhombifer (type species) from Hordle Cliff (England). Four other species, which were previously treated as members of Palaeopython and Paleryx, i.e. “Palaeopython” filholii and “Palaeopython” neglectus from the Phosphorites du Quercy, “Palaeopython” fischeri from Messel, and “Paleryx” spinifer from Geiseltal, are also considered as valid but pertain to other genera. Among these four taxa, “Palaeopython” fischeri has been recently assigned to its own genus, Eoconstrictor. A new genus, Phosphoroboa gen. nov. is established to accommodate “Palaeopython” filholii. We designate a lectotype for Palaeopythoncadurcensis and establish that the paralectotype maxilla and dentary are reasonably referred to this species. New material attributed to Palaeopythoncadurcensis is described from the old collections of the Phosphorites du Quercy. Paleryxcayluxi, another species established from the old collections of the Phosphorites du Quercy, is synonymized here with Palaeopythoncadurcensis. We further clarify important errors in the original description and figures of Paleryxcayluxi, identify the exact specimens that comprise the type series, and designate a lectotype. Much new material is described for Palaeopythonceciliensis from its type area in Geiseltal and intracolumnar variation is considered. We describe additional vertebral and cranial material of Paleryxrhombifer from its type area in Hordle Cliff. Based on this cranial material, we suggest non-booid affinities for Paleryxrhombifer. We designate a lectotype for Paleryxdepressus and agree with its previous suggested synonymy with Paleryxrhombifer. We re-describe the lectotype and paralectotypes of “Palaeopython” neglectus and refer and describe new material of this species from the Phosphorites du Quercy, paying special attention to intracolumnar variation; we also defer a decision on its generic relations until more abundant and complete material can be studied. We describe new vertebral material of the booid Eoconstrictor cf. fischeri from Geiseltal; similar material was previously known only from Messel and Dielsdorf. We determine that Eoconstrictorfischeri contains two distinct and unrelated species and describe intracolumnar variation in the nominotype. We clarify certain issues regarding the type series of Paleryxspinifer, designate a lectotype, and report previously unrecognized cranial material associated with the latter specimen; we transfer this species to Eoconstrictor based on cranial features and recombine it as Eoconstrictorspinifer comb. nov. We finally describe much new vertebral and cranial material of Phosphoroboafilholii comb. nov. from the Phosphorites du Quercy (both from the old collections but also from the late Eocene localities of Escamps A and C), paying special attention to intracolumnar variation. Based on this cranial material from Escamps, we identify Phosphoroboa gen. nov. as a booid. An analytical approach is undertaken in many isolated remains in order to quantify vertebral structures and assess intracolumnar variation, as well as associating isolated cranial elements to vertebral-based taxa. 3D models of the type material of the Geiseltal and Messel taxa are presented. The importance of vertebrae in the taxonomy of fossil Constrictores is addressed, although it is acknowledged that it is cranial material that can afford the most reliable phylogenetic conclusions. The diversity, distribution, biogeographic origins, and final demise and extinction of large Constrictores in the Paleogene of Europe are discussed

Revision of the cranial anatomy and phylogenetic relationships of the Eocene minute boas Messelophis variatus and Messelophis ermannorum (Serpentes, Booidea)

We provide a detailed anatomical description of the skull of the fossil minute boas Messelophis variatus Baszio, 2004 and Messelophis ermannorum Schaal & Baszio, 2004 from the Middle Eocene Messel Formation (Germany), as well as a cladistic analysis to infer their phylogenetic relationships. Reanalysis of new and known specimens of both species demonstrates previously unrecognized anatomical characters in the skull of these fossil snakes. Both morphological and combined (morphology plus DNA) analyses place both species of Messelophis within a clade composed of boine, ungaliophiine, and erycine taxa. Cranial features that support this systematic arrangement include a well-developed medial foot process of the prefrontal, an expanded lateral flange of the prefrontal, and a well-developed surangular crest of the compound bone, among others. As a result of the incompleteness of some crucial cranial regions, such as the basicranium, their exact relationships within this clade are currently unresolved. Messelophis species display several contrasting traits that greatly exceed the morphological disparity found among extant genera of snakes. This cranial and postcranial anatomical variation between M.variatus and M.ermannorum demonstrates that this last species should be allocated to a new genus. Rieppelophisgen.nov. is therefore erected for the species Rieppelophis ermannorumcomb.nov.Fil: Scanferla, Carlos Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Smith, Krister T.. Senckenberg Research Institute; AlemaniaFil: Schaal, Stephan F.K. Senckenberg Research Institute; Alemani