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Haplocheirus sollers.
No full text44 pages : illustrations (1 color), map ; 26 cm.The basalmost alvarezsauroid Haplocheirus sollers is known from a single specimen collected in Upper Jurassic (Oxfordian) beds of the Shishugou Formation in northwestern China. Haplocheirus provides important data about the plesiomorphic morphology of the theropod group Alvarezsauroidea, whose derived members possess numerous skeletal autapomorphies. We present here a detailed description of the cranial anatomy of Haplocheirus. These data are important for understanding cranial evolution in Alvarezsauroidea because other basal members of the clade lack cranial material entirely and because derived parvicursorine alvarezsauroids have cranial features shared exclusively with members of Avialae that have been interpreted as synapomorphies in some analyses. We discuss the implications of this anatomy for cranial evolution within Alvarezsauroidea and at the base of Maniraptora
New genus of the Zyngoonops group.
Get PDF20 pages : illustrations (some color) ; 26 cm. Part of the oonopid PBI project. (Acknowledgments)A new genus, Hexapopha, is described for a group of species from Costa Rica that resemble those of Coxapopha Platnick in having an elevated carapace and heavily sclerotized, highly modified male endites but differ in retaining six eyes, lacking leg spines, and having no female genitalic scape. Xestaspis reimoseri Fage is transferred to Hexapopha as the type species, its female is described for the first time, and three new species (H. hone, H. jimenez, and H. osa) are described. Dysderina caeca Birabén, from Argentina, is transferred to Coxapopha
Cretaceous robber flies.
Get PDF19 pages : illustrations (some color) ; 26 cm.Cretaceous fossils of Asilidae are reviewed, and two new taxa from Burmese and Raritan (New Jersey) ambers are described. The first robber fly from Burmese amber, [dagger]Burmapogon bruckschi, new genus and species, is described based on specimens of both sexes. A scientific name is provided for the previously described but unnamed fossil assassin fly from Raritan amber, [dagger]Cretagaster raritanensis, new genus and species, preserved as a fragmentary specimen. The amber fossils are placed phylogenetically within Asilidae. Specifically, [dagger]Burmapogon is postulated to be a representative of the clade comprised of (Brachyrhopalinae + Stichopogoninae), while [dagger]Cretagaster is a member of the Leptogastrinae and postulated to be an extinct sister group to (Acronychini + Leptogastrini)
Morphological and molecular evolution of sea anemones as revealed by an emerging model organism, Aiptasia (Cnidaria, Actiniaria, Aiptasiidae)
No full textix, 201 pages : illustrations (chiefly color)Sea anemones (Cnidaria: Actiniaria) of the family Aiptasiidae Carlgren, 1924 are conspicuous members of shallow-water environments and several species within the family are widely used as model systems for studies of cnidarian-dinoflagellate symbiosis and coral bleaching. Although previously published phylogenetic studies of sea anemones recovered the family Aiptasiidae as monophyletic, they only included partial sampling of its diversity. This study explores the diversity within this group of organisms in an integrative way, from the family to population levels. In this study, I explored the morphological and molecular diversity of the group using newly collected material covering the distribution of most of the described genera and species. The family Aiptasiidae was found to be a monophyletic lineage. Similarly, most of the genera within the family represent monophyletic lineages, with the exception of the genus Aiptasia, now divided into Aiptasia and Exaiptasia. Bellactis Dube, 1983 and Ragactis Andres, 1883 are now genera included within Aiptasiidae, in agreement with previous morphological studies and the morphological homogeneity observed here by the members of this family. In addition, I discovered new diagnostic morphological characters supporting the relationships among the major clades within the family. The molecular phylogenetic results provided evidence to diagnose two species within Exaiptasia: E. pallida -- a single widespread species -- and a new cryptic species, E. brasilensis sp. nov. -- restricted geographically to the southwestern Caribbean Sea and the southwestern Atlantic Ocean. Finally, although the algal diversity within the group showed no evidence of coevolution at the family level, an interesting pattern of adaptation and cladogenesis of the endosymbiotic algae (Symbiodinium spp.) was found within host species.Richard Gilder Graduate School at the American Museum of Natural History
Paleobiology, paleoecology, and morphology of vertebrates : new approaches to old questions.
No full textxii, 179 leaves : ill. (chiefly col.) ; 28 cm. "September 26, 2012."Physical, chemical, and osteo-histological signatures in fossils can be extremely
informative about organismal life history and ecological characteristics, yet these
signatures have not yet been exploited to their fullest potential. Tools such as
microscopy and mass spectrometry have the potential to address issues and questions in
vertebrate paleontology that have, until now, remained elusive. First, this dissertation
begins with traditional methods of anatomy and systematics with the addition of
improved sampling and visualization of a historic specimen, Macrerpeton huxleyi. The
edopoid temnospondyl Macrerpeton huxleyi is redescribed on the basis of new peels of
the holotype. Phylogenetic analysis recovers Macrerpeton as the sister taxon of
Cochleosaurus within the edopoid clade Macrerpetidae (formerly Cochleosauridae).
Histological signatures in fossil bone can be used to reconstruct information about
extinct organisms, such as genome size. Nonetheless, intra-skeletal osteocyte lacunae size
variation, which could cause error in genome size estimation, has remained unexplored.
While there is variance in the sizes of these bone structures over the skeleton of modern
tetrapods, this variation is not necessarily causing any issues with genome size estimate;
instead, the actual methods of estimation create a wide range of potential values that
these methods are not able to answer certain genetic questions at a fine scale.Examining the carbon and oxygen isotopes in tooth enamel represents a quantitative method for discerning the paleoenvironments and paleoecology of fossil fauna. The Chinchilla Local Fauna from southeastern Queensland is a diverse assemblage of terrestrial Pliocene vertebrates from the Chinchilla Sand Formation. Isotopic analysis results from Chinchilla show that there were distinct dietary niches within the large marsupial vertebrate community. This study suggests that southeastern Queensland hosted a mosaic of tropical forests, wetlands and grasslands during the Pliocene. A review of the uses of biogenic materials in eggshells for stable isotope analysis is also provided. Stable isotope analysis is also used to determine paleoenvironments and paleoecology of dinosaurs during the Late Cretaceous in Mongolia. This study, which is the first to utilize stable isotope geochemistry on Mesozoic fossil tooth enamel from central Asia, documents that the environment was arid, but more importantly that dinosaur remains, such as eggshells, can be used for this type of study. These objectives are united by a need to use quantitative measurements to more accurately reconstruct vertebrate traits throughout earth history.Richard Gilder Graduate School at the American Museum of Natural History
Arabian allodapine bees.
Get PDF15 pages : color illustrations, map ; 26 cm.An interesting new species of allodapine bee (Xylocopinae: Allodapini: Allodapina) is described and figured from males and females captured in the Sarawat Mountains near al-Baha, representing the first records of the tribe for Saudi Arabia. Braunsapis alqarnii Engel and Michener, new species, is similar to the small species of the genus known from Africa and Madagascar but is distinguished on the basis of several features, most notably the male hind legs and terminalia. Notes are provided on the known allodapine fauna of the Arabian Peninsula, with a key to the species
Haetosmia vechti.
No full text20 pages : illustrations (some color) ; 26 cm.Herein we describe the nests (including structure, closure, orientation, and depth of cells) of the bee Haetosmia vechti Peters found nesting in Rehovot, Israel. The nesting biology of H. vechti mirrors the ancestral nesting biology within the Osmia group of the Osmiini. Nests in sandy soil consist of an excavated burrow, ending below in a small cluster of vertical cells. The cells possess firm walls of masticated leaf pulp of Centaurea procurrens Spreng. and Heliotropium suaveolens M. Bieb., and are covered with pebbles and sand grains. The last larval instar and pupa of Haetosmia vechti are described, as is its cocoon. The immature stages exhibit the basic features of megachilid bees, but tend to have a thinner body vestiture compared to other studied taxa. In addition, we report new information on and review published accounts concerning the pollen collecting behavior of the genus Haetosmia Popov, which contains three species. Pollen taken from scopal hairs of 68 females collected at 17 sites in Turkestan, Morocco, Israel, and the United Arab Emirates was identified as originating solely from Heliotropium L. (Boraginaceae), which strongly suggests that all three Haetosmia species are narrowly oligolectic on this plant genus. In females of all three species, the second segment of the labial palpus is densely covered with rather long, apically curved and capitate bristles, an adaptation to collect Heliotropium pollen from anthers that are hidden inside the narrow corolla tube. Similar pollen-harvesting bristles specifically adapted to exploit flowers of Heliotropium seem to have evolved independently a number of times on different continents, in bees of four families