Allohyaena (Mammalia: Carnivora): giant hyaenid from the Late Miocene of Hungary

The topotypic material of the giant Late Miocene hyaenid Allohyaena kadici Kretzoi is described. New data on the deciduous dentition shows unambiguously that A. kadici is a hyaenid and not a percrocutid as reported by some previous authors. A. kadici is compared to the large hyaenids Adcrocuta eximia and Crocuta crocuta. These comparisons show that A. kadici has a mixture of primitive characters such as dp4 morphology, retention of m2, long and slender premolars and a large protocone on P4, and derived characters such as a preparastyle on P4, an internal root on P3 and a uniquely derived talonid structure of ml. This combination of features makes A. kadici difficult to classify, but it is considered to probably be most closely related to derived, bone-cracking hyaenids such as Pachycrocuta and Crocuta. A. kadici is rare in the fossil record, being found at only two sites. We suggest that the reason for this rarity is that it had a geographic and stratigraphic range which is poorly sampled in the Miocene fossil record of Europe.     

Global phylogeography in Sanionia uncinata (Amblystegiaceae: Bryophyta)

Global phylogeographic patterns in Sanionia uncinata are addressed based on information in internal transcribed spacer (ITS) (214 specimens) and the plastid markers trnL‐trnF (221) and rpl16 (217). ITS suggests a monophyletic Sanionia and a paraphyletic S. uncinata; this was neither supported nor rejected by plastid data. Northern or Eastern Eurasia and Alaska appear important in the early evolution of Sanionia and some populations dispersed into the Southern Hemisphere relatively early. Some haplotypes or groups of haplotypes are morphologically and ecologically distinct, biologically meaningful units that correspond with S. orthothecioides, S. symmetrica and S. georgicouncinata s.l. The latter includes two species that are indistinguishable by morphology, S. georgicouncinata s.s. (Southern Hemisphere) and S. nivalis (Northern Hemisphere). Tropical African and South American S. uncinata populations have separate origins and the Southern Hemisphere was colonized at least twice. In the northern circum‐Arctic region, the haplotype composition differs between the North Atlantic and Beringian areas. Eastern Eurasia has a higher S. uncinata haplotype diversity than other Holarctic regions, implying less devastating effects of recurrent glacial periods. For Eastern and Western Eurasia, North America and the Southern Hemisphere, most of the haplotype variation was found within the regions, but 14–18% can be referred to among region variation. Plastid haplotype diversity was lower in the Southern Hemisphere than in the Arctic to subarctic, possibly attributable to founder effects. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 168 , 19–42.     

Plio-Pleistocene Carnivora of eastern Africa: species richness and turnover patterns

This paper presents an up-to-date and detailed overview of the Plio-Pleistocene fossil record of Carnivora in eastern Africa. Major events in the carnivoran lineages present in the region are discussed and stratigraphic ranges of all species-level taxa are provided. The compiled data are used for quantitative analyses of species richness and turnover. Sampling is considered to be adequate for the interval 3.6–1.5 Mya, and poorer in the half-million-year time slices before and after this interval. Species richness peaks around 3.6–3.0 Mya and declines gradually from that time until the end of the time period analysed. Calculation of origination and extinction rates indicate that there are two peaks of origination: at 3.9–3.3 Mya (although the earlier half of this interval is biased through poor sampling) and at 2.1–1.8 Mya. The origination rate is zero in the interval 3.0–2.4 Mya. The extinction rate peaks at around 3.0 Mya after which it falls slightly, remaining nearly constant until 1.8 Mya, after which it increases considerably. The data support the hypothesis that the modern carnivoran guild of eastern Africa originated relatively recently, mostly within the last million years. There is no support in these data for a turnover pulse in Carnivora between 3 and 2 Mya.  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 144 , 121–144.     

EARLY CAMBRIAN BRACHIOPODS FROM NORTH-EAST GREENLAND

Abstract:  A diverse assemblage of late Early Cambrian brachiopods is described from the Bastion and Ella Island formations of North-East Greenland. The fauna includes nine species, representing all three extant brachiopod subphyla in addition to the stem group brachiopod Mickwitzia cf. occidens . Four linguliforms: Eoobolus priscus , Botsfordia caelata , Micromitra bella , Vandalotreta sp., three rynchonelliforms: Obolella crassa , Kutorgina reticulata , and an unidentified chileid plus a possible craniiform species occur. The fauna shows similarities to late Early Cambrian (Dyeran Stage) brachiopod faunas of eastern Canada and the United States, but also to faunas from the late Early Cambrian (Botomian–Toyonian equivalent) of Australia, Antarctica and Siberia.     

The search for reference conditions for stream vegetation in northern Europe

1. The European Water Framework Directive provides a framework for improving the ecological quality of stream ecosystems, with deviation from reference used as a measure of ecological status.
2. Here we examine the possibility of using less impacted stream sites from Latvia, Lithuania and Poland to establish a Danish reference network for macrophyte assemblages, and as a guiding image for identification of possible references sites within Denmark. Both approaches were evaluated using historical Danish records.
3. Four different macrophyte assemblages were identified for mid-sized streams in the Central and Eastern Lowland ecoregions. Macrophyte assemblages could not be delineated using physical stream site characteristics; however a gradual change in assemblage composition was attributed to differences in alkalinity and human impact.
4. Assemblages of contemporary vegetation in Denmark were quite similar to those found in Polish, Latvian and Lithuanian streams (26–35%). However, more importantly, from species-based predictions we noted higher similarity, particularly with Latvian and Lithuanian streams, before intensive land use commenced in Denmark ( c. 1900). These results show that stream sites from these three countries can be considered in a Danish reference network.
5. Two of the four macrophyte assemblages comprised species such as Fontinalis antipyretica, Myriophyllum spicatum , Nuphar lutea , Potamogeton alpinus and P. perfoliatus that have a very scattered occurrence in the contemporary vegetation in Denmark. These groups were closely associated with the predictions from historic records, thereby lending support the conjecture that these assemblages could be part of the guiding image for the identification of potential reference sites within Denmark.     

Divergent character displacement in the song of two allospecies: the Pied Flycatcher Ficedula hypoleuca, and the Collared Flycatcher Ficedula albicollis

Songs of the three flycatcher forms, Ficedula hypoleuca hypoleuca, Ficedula albicollis albicollis and Ficedula albicollis semitorquata , were distinguishable from one another using a multivariate analysis. F. albicollis semitorquata , which has an intermediate song character, is considered to be a primary allopatric form while the nominate subspecies of albicollis is assumed to be dispersed into sympatry with F. h. hypoleuca . The differences in song between the nominate albicollis and F. hypoleuca are accentuated in their zone of sympatry and are mostly due to divergence in the albicollis song. The song is primarily an epigamic vocalization in the two species and conforms to the pattern characteristic of divergent character displacement associated with reproductive behaviour. Two alarm calls are quite similar in the two species and are the main vocalizations associated with territorial combat. Their interspecific territorial behaviour has apparently not been affected in areas of sympatry.     

Rate of Change in Dormancy Level and Light Requirement in Weed Seeds During Stratification

The rate of change in dormancy level and light requirement,induced during stratification at 3.2 °C, was investigatedin seeds ofStellaria media, Cerastium fontanum, Veronica agrestisandTaraxacumofficinale.Two stratification environments, soil and wet filterpaper in petri-dishes, were used. On nine occasions during a6 week stratification period, germination was tested under threelight conditions at 3.5/18.5 °C: (1) darkness; (2) light;and (3) short-term light exposure followed by darkness. Priorto stratification, germination in all species was 89% in lightand 53% in darkness. Within 2 weeks of stratification, germinabilityinV. agrestisandS. mediaseeds decreased in all treatments. InC.fontanumandT. officinaleseeds, germinability also decreasedafter 2 weeks but only in the dark treatment, indicating inductionof a light requirement. After two more weeks of stratification,the induced dormancy inS. mediaseeds stratified in soil becameweaker and the light requirement inT. officinaleseeds was lost.Differences between the two stratification environments and/orinteractions between light conditions, stratification environmentsand time were found for all species. These results suggest that:(1) the dormancy level and the light requirement of seeds maychange dramatically over relatively short-time periods duringstratification; and (2) germinability depends on the stratificationenvironment experienced by the seeds. Predicting the dormancylevel or light requirement in a seed batch is difficult andrequires a thorough knowledge of the effect of the stratificationconditions used.Copyright 1997 Annals of Botany Company Burial; Cerastium fontanumBaumg.; chickweed; cold stratification; common mouse-ear; dandelion; dormancy; light requirement; seed; Stellaria media(L.) Vill.; speedwell; Taraxacum officinalegroup; Veronica agrestisL.; weed     

Effects of bioturbation by tube-dwelling chironomid larvae on oxygen uptake and denitrification in eutrophic lake sediments

1. Oxygen uptake and denitrification were determined in two bioturbated sediments from a eutrophic lake in southern Sweden. In laboratory mesocosms, an organic profundal sediment was incubated with Chironomus plumosus L. and a sandy littoral sediment with an organic-rich top layer was incubated with Polypedilum sp. Both species of chironomid are sediment tube-dwelling. 2. Oxygen consumption, expressed per gram of larval dry weight, was enhanced to the same extent by the larvae in both sediments. Measurements of the respiration rate of individual larvae revealed that the respiration per gram dry weight of the smaller Polypedilum sp. was more than three times higher than that of C. plumosus. 3. Denitrification was measured using the ‘nitrogen isotope pairing’ technique. In the organic sediment, denitrification of nitrate from the water phase (dw) and denitrification of nitrate from coupled nitrification (dn) were each correlated with the biomass of C. plumosus. In the sandy sediment, dw was correlated with the biomass of Polypedilum sp., while dn did not show any correlation with Polypedilum sp. 4. Oxygen uptake in the organic sediment was increased by a factor of 2.5, dw 5-fold and dn 2.5-fold at a biomass of 10 g m^–2 dry weight of C. plumosus. The same biomass of Polypedilum sp. in the sandy sediment resulted in a 2-fold stimulation of oxygen uptake and a 3-fold stimulation of dw, while dn was not affected. These differences in stimulation between oxygen uptake and denitrification by the larvae in the sediments suggest that the stimulation pattern cannot be explained by simple extension of the sediment surface. The burrows evidently reduce the distance between the nitrate source in the water column and the denitrifiers in the anoxic zones. 5. This study indicates that bioturbation by macrofauna elements can have a great impact on denitrification in lake sediments, and that different organisms can influence nitrogen turnover in specific ways.