The bifacially-flaked stemmed obsidian artifacts from Easter Island -known as mata’a -vary greatly in terms of the shape and form of their stems. The stem variability appears to be largely stylistic in nature as its variation does not affect the function of the tool and thus is free to change. Since performance is not a factor in structuring variation , patterns of similarity across stylistic c...

Phylogenetic studies of asexual lineages and their sexual progenitors are useful for inferring the causes of geographical parthenogenesis and testing hypotheses regarding the evolution of sex. With five known parthenogens and well-studied ecology, Timema walking-sticks are a useful system for studying these questions. Timema are mainly endemic to California and they exhibit the common pattern o...

Numerical analyses (correspondence analysis, ascending hierarchical classification, cladistic approach) were applied to the morphological characters of the adults of the genus Phlebotomus Rondani & Berté 1840. They confirm the reliability of the classic classifications, and also redefine the taxonomic and phylogenetic position of certain taxa. Thus, Spelaeophlebotomus Theodor 1948. Idiophleboto...

Tyrannosaurid theropods were dominant terrestrial predators in Asia and western North America during the last of the Cretaceous. The known diversity of the group has dramatically increased in recent years with new finds, but overall understanding of tyrannosaurid ecology and evolution is based almost entirely on fossils from latitudes at or below southern Canada and central Asia. Remains of a n...

Turtles have been known since the Upper Triassic (210Myr old); however, fossils recording the first steps of turtle evolution are scarce and often fragmentary. As a consequence, one of the main questions is whether living turtles (Testudines) originated during the Late Triassic (210Myr old) or during the Middle to Late Jurassic (ca 160Myr old). The discovery of the new fossil turtle, Condorchel...

While key early(iest) fossils were recently discovered for several crown afrotherian mammal orders, basal afrotherians, e.g., early Cenozoic species that comprise sister taxa to Paenungulata, Afroinsectiphilia or Afrotheria, are nearly unknown, especially in Africa. Possible stem condylarth-like relatives of the Paenungulata (hyraxes, sea-cows, elephants) include only Abdounodus hamdii and Ocep...

A new species of Anthomyzidae (Diptera), viz., Mumetopia interfeles Roháček sp. nov. (both sexes), is described from Chile, based on a large series collected small grassy area (consisting non-native species, Hordeum murinum L.) among houses in the city Valparaíso. Its systematic affiliation, phylogenetic relationships, and biology are discussed. Cases mass occurrence adult Anthomyzidae, particu...

North America has a diverse cicada fauna with multiple genera from all three Cicadidae subfamilies, yet molecular phylogenetic analyses have been completed only for the well-studied periodical cicadas (Magicicada Davis). The genus Tibicen Latreille, a large group of charismatic species, is in need of such work because morphological patterns suggest multiple groups with complicated relationships...