A new zosterophyll from the Lower Devonian of Wales

A new monotypic genus is described from impression and compression fossils preserved in the Senni Beds of the Lower Old Red Sandstone of S Wales. The new species has scattered reniform lateral sporangia suggesting zosterophyll affinity, but supporting anatomical evidence is lacking. The axes of the plant are characterized by occasional large surface protuberances, sometimes extended into lateral projections of variable length and morphology. Taphonomic factors account for some of the observed features of the fossils, and their unusual orientation in the sediment suggests that Tarella may have grown on exposed point bars.     

Extensive Miocene speciation in and out of Indochina: The biogeographic history of Typhonium sensu stricto (Araceae) and its implication for the assembly of Indochina flora

The Asian paleotropical flora is characterized by abundance of endemic species, high biodiversity, and complex geological and climatic histories. However, the main driving mechanism underlying such high tropical biodiversity remains unclear. Hence, the present study aimed to investigate the biogeographic origin of the Asian paleotropical flora by tracking the speciation and diversification history of a typical tropical perennial, Typhonium sensu stricto (s.s.) (Araceae), using a time-calibrated whole-plastome phylogeny. In particular, we tested whether the Asian paleotropic region is a macroevolutionary source or sink. We observed that Typhonium s.s. originated in Indochina during the early–middle Miocene epoch, ca. 17.24 Ma (95% highest posterior density [HPD]: 12.83 ̶ 21.99 Ma). Most of the in situ diversification within the genus Typhonium s.s. has been underway since 14.73 Ma, with an accelerated lineage diversification at ca. 15−17 Ma, which may have been triggered by the intensification of the Asian monsoon system around the middle Miocene. Furthermore, the underground tuberous stem of Typhonium s.s. might have played an essential role in the adaptation to the seasonality caused by the monsoon in Indochina. Our results also suggested that peripatric speciation may be important in the diversification of T. trilobatum and T. roxburghii. This study provides a framework for studies in biogeography and evolution of the Asian paleotropical flora.     

Deadwood-rich managed forests provide insights into the old-forest association of wood-inhabiting fungi

A major question in fungal conservation is why many species are confined to old forests, and how they could be supported by contemporary landscape matrix. Specifically, forestry that retains large biological legacies across landscape could reduce old-forest dependencies to species that require unusual substrate conditions. We sampled polypores in 112 2 ha plots (both old and harvested stands) in a semi-natural forestry context in Estonia and modelled the habitat factors of species confined to old growth. The results confirmed that old-growth assemblages emerged mostly due to diverse and abundant substrate supply (notably downed CWD). Only 10 species (five spruce-dwellers) were confined to old growth; of these, only Fomitopsis rosea and Oxyporus corticola were additionally affected by forest connectivity. The forestry system studied appeared particularly favourable for the species inhabiting deciduous wood. To better address habitat degradation in conservation, expert lists of ‘old-forest (indicator) fungi’ should be replaced with evidence-based focal taxa.     

Browridge development in cercopithecidae: A test of two models

Theoretical discussions of primate browridge formation have resulted in several interpretations of its form and function. Lateral radiographs of adult Old World monkeys, representing most cercopithecine and colobine genera, were examined to address whether both biomechanical and spatial factors influence the development of a supraorbital torus. A linear measurement of browridge size was compared with a series of measures related to each model. Partial correlations were used to ascertain the relative independence of biomechanical (model I or II) and spatial effects upon torus formation. Allometric (size-related) shape changes were evaluated with log-linear bivariate regression analysis; subfamily differences in scaling patterns, with an analysis of covariance. When spatial and biomechanical (I or II) factors were both significantly related to brow size, additive and interactive multiple regression models were used to further assess the manner by which each set mutually affects variation in browridge dimensions. Correlation analyses were repeated with size-corrected antilogged residuals to eliminate a potentially spurious effect of skull size. Old World monkeys provide support of the spatial model. Also of interest is that skull size emerges as a primary influence on torus formation. Several alternative explanations are also put forward to account for browridge development in each subfamily.     

Sheep red blood cell receptor and the epitope detected by Leu-5 monoclonal antibody in primates

The expression of the epitope detected by the monoclonal antibody Leu-5 and the rosette formation with sheep red blood cells was examined for the mononuclear cells of 25 primate species including human subject. The plot of rosette-forming cells against Leu-5-positive cells enabled us to classify these species into three large groups: hominoids--Old World monkeys (Leu-5-positive cells greater than or equal to rosette-forming cells), New World monkeys (Leu-5-positive cells less than rosette-forming cells), and prosimians (Leu-5-positive cells less than 5%, some of them with both Leu-5-positive cells and rosette-forming cells less than 5%).