Two hominin incisor teeth from the middle Pleistocene site of Boxgrove, Sussex, England

In 1995-1996 two isolated hominin lower incisors were found at the middle Pleistocene site of Boxgrove in England, with Lower Palaeolithic archaeology. Boxgrove 2 is a permanent lower right central incisor and Boxgrove 3 a permanent lower left lateral incisor. They were found separately, but close to one another and appear to belong to the same individual. The Boxgrove 1 tibia discovered in 1993 came from a different stratigraphic context and is thus believed to represent a different individual. This paper describes the morphology of the incisors, which is similar to other middle Pleistocene hominin specimens and, as with the tibia, suggests that they could be assigned to Homo heidelbergensis (recognising that the taxonomic status of this species is still a matter of debate). The incisors show substantial attrition associated with secondary dentine deposition in the pulp chamber and clearly represent an adult. They also show extensive patterns of non-masticatory scratches on the labial surfaces of both crown and root, including some marks which may have been made postmortem. The roots were exposed in life on their labial sides by a large dehiscence, extending almost to the root apex. This is demonstrated by deposits of calculus, polishing, and scratching on the exposed surfaces. The dehiscence may have been caused by repeated trauma to the gingivae or remodelling of the tooth-supporting tissues in response to large forces applied to the front of the dentition.     

Long-term climate record inferred from early-middle Pleistocene amphibian and squamate reptile assemblages at the Gran Dolina Cave, Atapuerca, Spain

The Gran Dolina cave site is famous for having delivered some of the oldest hominin remains of Western Europe (Homo antecessor, ca. 960 ka). Moreover, the evidence of lithic industries throughout the long vertical section suggests occupation on the part of hominins from the latest early Pleistocene (levels TD3/4, TD5, and TD6) to the late middle Pleistocene (level TD10). The Gran Dolina Sondeo Sur (TDS) has furnished a great number of small-vertebrate remains; among them some 40,000 bones are attributed to amphibians and squamates. Although they do not differ specifically from the extant herpetofauna of the Iberian Peninsula, the overlap of their current distribution areas (= mutual climatic range method) in Spain can provide mean annual temperatures (MAT), the mean temperatures of the coldest (MTC) and warmest (MTW) months, and mean annual precipitation (MAP) estimations for each sub-level, and their change can be studied throughout the sequence. Results from the squamate and amphibian study indicate that during hominin occupation the MAT (10-13 °C) was always slightly warmer than at present in the vicinity of the Gran Dolina Cave, and the MAP (800-1000 mm) was greater than today in the Burgos area. Climatic differences between “glacial” and “interglacial” phases are poorly marked. Summer temperatures (MTW) show stronger oscillations than winter temperatures (MTC), but seasonality remains almost unchanged throughout the sequence. These results are compared with those for large mammals, small mammals, and pollen analysis, giving a scenario for the palaeoclimatic conditions that occurred during the early to middle Pleistocene in Atapuerca, and hence a scenario for the hominins that once lived in the Sierra de Atapuerca.     

Key Largo Limestone revisited: Pleistocene shelf-edge facies,Florida Keys,USA

Summary New dates and analysis of 12 deep and 57 shallow cores allow a more detailed interpretation of the Pleistocene shelf edge of the Florida Platform as found in various facies of the Key Largo Limestone beneath the Florida Keys. In this study a three-phase evolution of the Quaternary units (Q1–Q5) of the Key Largo is presented with new subdivision of the Q5. (1) In the first phase, the Q1 and Q2 (perhaps deposited during oxygen-isotope stage 11) deep-water quartz-rich environment evolved into a shallow carbonate phase, (2) Subsequently, a Q3 (presumably corresponding to oxygen-isotope stage 9) flourishing reef and productive high-platform sediment phase developed. (3) Finally, a Q4 and Q5 (corresponding to oxygen-isotope stages 7 and 5) stabilization phase occurred with reefs and leeward productive lagoons, followed by lower sea levels presenting a sequence of younger (isotope substages 5c, 5a) shelf-margin wedges, sediment veneers and outlier reefs. The Key largo Limestone provides an accessible model of a carbonate shelf edge with fluctuating water depth, bordering a deep seaward basin for a period of at least 300 ka. During this time, at least four onlaps/offlaps, often separated by periods of karst development with associated diagenetic alterations, took place. The story presented by this limestone not only allows a better understanding of the history of south Florida but also aids in the interpretation of similar persistent shelf-edge sites bordering deep basins in other areas.     

Palaeoclimatic conditions in the upper Pleistocene and Holocene Bhimtal-Naukuchiatal lake basin in south-central Kumaun, North India

A 52 m thick upper Pleistocene and Holocene terrestrial succession in the Bhimtal-Naukuchiatal basin, south-central Kumaun Himalaya, India was studied using chronological, palaeontological, palynological and δ¹³C measurements. The section recorded evidence for climatic changes. At least two phases of arid climate and one phase of humid climate were recognised. Preliminary palaeomagnetic studies revealed a reversal of polarity, presumably correlatable with the Mono Lake excursion. Prior to this, no reversal event in the upper Pleistocene-Holocene terrestrial sediments of Indian subcontinent is known. A fossiliferous horizon, discovered in the lower part of the section, consisted of Sorex and Mus. This is the only report of a Late Pleistocene micromammalian assemblage in the Kumaun Himalaya.     

安徽早三叠世巢湖动物群的研究进展:生物面貌、地层分布和古生态学意义*

巢湖动物群主要分布在安徽巢湖及邻近地区下三叠统奥伦尼克阶南陵湖组中上段地层中,以保存大量完整且精美的巢湖龙化石为特点,伴生有鳍龙类、鱼龙形类、鱼类及多门类的海生无脊椎动物。巢湖动物群的研究始于20世纪70年代,近年来基于巢湖动物群中大量新材料的系统研究为二叠纪–三叠纪大灭绝发生之后三叠纪海洋生态系统的快速复苏过程提供了新的依据。本文梳理了巢湖动物群的地质背景、研究简史、生物组合特征、地层分布与时代特征、稳定同位素地球化学等方面取得的进展,并就其群落生态组成进行初步探讨。这项工作对建设巢湖动物群相关国家地质公园、开展科普教育工作、旅游开发等有着积极的意义。     

The insular herpetofauna of Mexico: Composition,conservation, and biogeographic patterns

We compile a Mexican insular herpetofaunal checklist to estimate endemism, conservation status, island threats, net taxonomic turnover among six biogeographic provinces belonging to the Nearctic and Neotropical regions, and the relationships between island area and mainland distance versus species richness. We compile a checklist of insular herpetofaunal through performing a literature and collection review. We define the conservation status according to conservation Mexican law, the Red List of International Union for Conservation of Nature, and Environmental Vulnerability Scores. We determine threat percentages on islands according to the 11 major classes of threats to biodiversity. We estimate the net taxonomic turnover with beta diversity analysis between the Nearctic and Neotropical provinces. The Mexican insular herpetofauna is composed of 18 amphibian species, 204 species with 101 subspecies of reptiles, and 263 taxa in total. Endemism levels are 11.76% in amphibians, 53.57% in reptiles, and 27.91% being insular endemic taxa. Two conservation status systems classify the species at high extinction risk, while the remaining system suggests less concern. However, all systems indicate species lacking assessment. Human activities and exotic alien species are present on 60% of 131 islands. The taxonomic turnover value is high (0.89), with a clear herpetofaunal differentiation between the two biogeographic regions. The species–area and species–mainland distance relationships are positive. Insular herpetofauna faces a high percentage of threats, with the Neotropical provinces more heavily impacted. It is urgent to explore the remaining islands (3,079 islands) and better incorporate insular populations and species in ecological, evolutionary, and systematic studies. In the face of the biodiversity crisis, islands will play a leading role as a model to apply restoration and conservation strategies.     

Multicopper oxidases: modular structure,sequence space,and evolutionary relationships

Multicopper oxidases (MCOs) use copper ions as cofactors to oxidize a variety of substrates while reducing oxygen to water. MCOs have been identified in various taxa, with notable occurrences in fungi. The role of these fungal MCOs in lignin degradation sparked an interest due to their potential for application in biofuel production and various other industries. MCOs consist of different protein domains, which led to their classification into two-, three-, and six-domain MCOs. The previously established Laccase and Multicopper Oxidase Engineering Database ( https://lcced.biocatnet.de ) was updated and now includes 51 058 sequences and 229 structures of MCOs. Sequences and structures of all MCOs were systematically compared. All MCOs consist of cupredoxin-like domains. Two-domain MCOs are formed by the N- and C-terminal domain (domain N and C), while three-domain MCOs have an additional domain (M) in between, homologous to domain C. The six-domain MCOs consist of alternating domains N and C, each three times. Two standard numbering schemes were developed for the copper-binding domains N and C, which facilitated the identification of conserved positions and a comparison to previously reported results from mutagenesis studies. Two sequence motifs for the copper binding sites were identified per domain. Their modularity, depending on the placement of the T1-copper binding site, was demonstrated. Protein sequence networks showed relationships between two- and three-domain MCOs, allowing for family-specific annotation and inference of evolutionary relationships.     

The Chacoan peccary,Catagonus wagneri (Mammalia,Tayassuidae), in the late Pleistocene (northern Uruguay,South America): paleoecological and paleobiogeographic considerations

Catagonus wagneri has the most restricted geographical distribution among extant Tayassuidae and inhabited semi-arid thorny forests of dry Chaco in Paraguay, Bolivia and Argentina. Until now, C. wagneri has only been recorded in archaeological, pre-Hispanic deposits from the Santiago del Estero Province, Argentina. A new partially complete skull from the Sopas Formation (Late Pleistocene; Uruguay) is identified as C. wagneri. This is the only fossil record of the species which extends its biochron until the late Pleistocene, and the first one substantially far from its current range; the first fossil record of the species in Uruguay; the most complete fossil material of the species; and it provides relevant ecological and climatic information. According to the ecological and climatic available information of C. wagneri, the presence of this mammal in the late Pleistocene of northern Uruguay indicates a warm climate and arid to semi-arid environments. Even though not associated with the fossil remains of C. wagneri, some mammals included in the sedimentary levels of the Sopas Formation also suggest arid to semi-arid environments. Climatic changes, in particular in the late Pleistocene and Holocene, could be invoked to explain modifications of its geographic range.http://zoobank.org/ECF04BCF-8246-4F11-AAB8-5FAA9F437BDA     

Human RhoGAP domain-containing proteins: structure,function and evolutionary relationships

Proteins containing a RhoGAP (Rho GTPase activating protein) domain usually function to catalyze the hydrolysis of GTP that is bound to Rho, Rac and/or Cdc42, inactivating these regulators of the actin cytoskeleton. Using database searches, at least 53 distinct RhoGAP domain-containing proteins are likely to be encoded in human DNA. Phylogenetic analysis of only the RhoGAP domains divides these proteins into distinct families that appear to be functionally related. We also review the current understanding of the structure and likely functions of these human proteins. The presence of RhoGAP domains in a number of different human proteins suggests that cytoskeletal changes, regulated by Rho GTPase, may be integrated with many different signaling pathways.     

A comparative study of stereolithographically modelled skulls of Petralona and Broken Hill: implications for future studies of middle Pleistocene hominid evolution

Computer generated three-dimensional stereolithographic models of middle Pleistocene skulls from Petralona and Broken Hill are described and compared. The anterior cranial fossae of these models are also compared with that of another middle Pleistocene skull, Arago 21. Stereolithographic modelling reproduces not only the outer surfaces of skulls, but also features within the substance of the bones, and details of the internal braincase. The skulls of Petralona and, to a somewhat lesser degree, Broken Hill are extremely pneumatized. Previously undescribed features associated with pneumatization are detailed, along with their possible functional significance, polarity, and potential for understanding hominid cranial variation. Petralona and Broken Hill also exhibit a dramatic suite of cerebral features that is probably related to extensive pneumatization of the skull, namely frontal lobes that are tilted and located behind rather than over the orbits, laterally flared temporal lobes, marked occipital projection, and basal location of the cerebellum. Comparison of the anterior cranial fossae of Petralona, Broken Hill, and Arago 21 suggests that external resemblance of skulls may not always correlate with endocranial similarity. We believe that stereolithographic reconstructions have the potential for helping to resolve difficult questions about the origins of Neanderthal and anatomically modern people.     

Parachoerus carlesi (Mammalia,Tayassuidae) in the Late Pleistocene (northern Argentina,South America): paleoecological and palaeobiogeographic considerations

Abstract

The Tayassuidae is one of the first families of North American immigrant mammals that arrived into South America during the ‘Great American Biotic Interchange’. They have been found associated with Late Cenozoic deposits mainly in Argentina and Brazil, but also in Uruguay, Bolivia, Colombia, Peru and Venezuela. Theirs records within Argentina come from the Pampean Region, Mesopotamia and north-central region. Here, we report the first record of P. carlesi with precise stratigraphic (26.630 ± 370 14C years BP, Late Pleistocene) data in Argentina, precisely from the Chacoan region. This specimen represents the most complete fossil material of this extinct species, increasing its morphological and morphometrical knowledge, and it provides relevant ecological and climatic information. From a palaeoenvironmental point of view, the fauna registered in this paleontological site, includes taxa mainly adapted to open or semi-open and arid or semi-arid environments. The bearing sediments and the peculiarities of the faunal assemblages, as well as the chronological data, allow confirming that arid and semiarid conditions, with scarce or absent vegetation cover were developed in this area of Argentina during the last part of MIS 3 and beginning of MIS 2. These environmental conditions favored the settlement of megamammals adapted to open environments.     

Mummified fossil of Keteleeria from the Late Pleistocene of Maoming Basin,South China,and its phytogeographical and paleoecological implications

Keteleeria is a small genus of Pinaceae now mainly restricted to eastern Asia. Although this genus has been documented with a wide distribution in the geologic record of Europe, North America, and Asia, its history in low‐latitude areas (including South China) has remained obscure. In this paper, a fossil wood of Keteleeria sp. is described from the Late Pleistocene (29–27 ka BP) of the Maoming Basin, South China. This wood is the most ancient megafossil evidence of Keteleeria within the modern distribution area of this genus. The fossil records of Keteleeria suggests that this thermophyllous genus migrated into South China by the Middle Pleistocene escaping from glacial cooling and became widespread over this region in the Late Pleistocene beginning from the interglacial stage preceding the Last Glacial Maximum. The analysis of growth rings in the fossil wood and its comparison with those of modern Keteleeria davidiana (Bertrand) Beissner indicates that in the Late Pleistocene of Maoming Basin (29–27 ka BP) there was a humid climate with less pronounced seasonality of precipitation than that seen in the subtropical monsoonal climate of modern northeastern Vietnam. Apparently, the Maoming Basin was influenced by interglacial regime with summer–monsoon circulation. The previously proposed method to distinguish between evergreen and deciduous conifers based on growth ring anatomy, is not reliable because of the wide variance and ambiguity in its results.     

Aflatoxigenicity in Aspergillus: molecular genetics, phylogenetic relationships and evolutionary implications

Aflatoxins (AFs) are toxic and carcinogenic secondary metabolites produced by isolates of Aspergillus section Flavi as well as a number of Aspergillus isolates that are classified outside of section Flavi. Characterization of the AF and sterigmatocystin (ST) gene clusters and analysis of factors governing regulation of their biosynthesis has resulted in these two mycotoxins being the most extensively studied of fungal secondary metabolites. This wealth of information has allowed the determination of the molecular basis for non-production of AF in natural isolates of A. flavus and domesticated strains of A. oryzae. This review provides an overview of the molecular analysis of the AF and ST gene clusters as well as new information on an AF gene cluster identified in the non-section Flavi isolate, Aspergillus ochraceoroseus. Additionally, molecular phylogenetic analysis using AF biosynthetic gene sequences as well as ribosomal DNA internal transcribed spacer (ITS) sequences between various section Flavi and non-section Flavi species has enabled determination of the probable evolutionary history of the AF and ST gene clusters. A model for the evolution of the AF and ST gene clusters as well as possible biological roles for AF are discussed.     

Bats, flowers and fruit: evolutionary relationships in the Old World

Old World phytophagous bats (Megachiroptera: Pteropodidae) number 173 species of which 79% are Asian and 21% African. Bats arose, presumably monophyletically, in the early Tertiary, the Megachiroptera soon diverging from the Microchiroptera. By the Cretaceous-Tertiary boundary the major groups of modern angiosperms were present, some of these probably being pollinated nocturnally by large insects and non-flying mammals and others with seeds dispersed by terrestrial vertebrates. Early bats were perhaps initially attracted to such flowers and fruit by the insects found around them, later finding the plants themselves nutritious. Megabats today feed upon floral resources, fruit and leaves from a total of at least 188 plant genera in 64 families. They may effect both pollination and seed-dispersal, and both bat-flower and bat-fruit syndromes are commonly recognized. Individual species are generally catholic in their feeding, favoured food varying with locality and season. Depending upon roosting habits and season, megabats may travel considerable distances each night to feed and may undertake seasonal migrations. Their feeding in orchards may sometimes require their control, but the future of certain species is more seriously threatened by slaughter for food and particularly by habitat destruction.     

Type II restriction endonucleases: structural, functional and evolutionary relationships.

Type II restriction endonucleases are a paradigm for site-specific cleavage of DNA. Recent structural analyses, in particular in the presence of various divalent metals, have shed new insight into the mechanisms of catalysis. In addition, during this past year the crystal structure determinations of MutH, lambda-exonuclease and FokI have revealed that these proteins are also members of the same family.     

Roadless areas and biodiversity: a case study in Alabama,USA

Roadless areas are important for biodiversity maintenance and nature conservation but remain politically controversial due to conflicting interests of conservation and development. In this study, we applied a recently developed index of roadless volume (RV) across 67 counties of Alabama, USA as a case study to examine the relationships between roadless areas and local species richness. Our results indicated that with the increase of RV across counties, both the number of total fish and exotic fish species increased, but the relationship was not significant for endemic fish species. The number of both herpetofaunal and plant species also increased with the increasing RV. For all included species, there was a significant positive correlation between species richness and RV values. The number of endangered species decreased with the increase of RV per-capita. Wildfire occurrences increased with the increase of RV. Preserving roadless areas is an important component of biodiversity conservation.