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Paleogene biological inclusions in amber.
Full text link37 pages : illustrations (some color), color maps ; 26 cm.The Chickaloon Formation in south-central Alaska contains rich coal deposits dated very close to the Paleocene-Eocene boundary, immediately beneath which occur dispersed nodules of amber along with abundant remains of Metasequoia, dicots, and monocots. The nodules are small (less than 10 mm in length), nearly 10,000 of which were screened, yielding several inclusions of fungi and plant fragments, but mostly terrestrial arthropods: 29 specimens in 10 orders and 13 families. The fungi include resinicolous hyphae and a dark, multiseptate hyphomycete. Plants include wood/bark fragments and fibers, and the microphylls of a bryophyte (probably a moss, Musci). Among the arthropods are arachnids: mites (Acari: Oribatida), Pseudoscorpionida, and the bodies and a silken cocoon of spiders (Araneae). Insecta include Blattodea, Thysanoptera, Hemiptera (Heteroptera and Aphidoidea), Coleoptera (Dermestidae: Megatominae), Trichoptera, Diptera (Chironomidae: Tanypodinae), and Hymenoptera (Formicidae: Formicinae). Nymphal aphids predominate (65% of the arthropod individuals), which were probably feeding on the source tree, likely Metasequoia. There is a bias in preservation toward small arthropods (mean body length 0.75 mm) that are surface-dwelling (nonwinged) stages and taxa. Chickaloon amber contains the most northerly fossil records of pseudoscorpions, thrips, Dermestidae, and Cenozoic ants and mites, so the deposit is contributing unique data on high-latitude paleodiversity of the Paleogene hothouse earth
Euglossine bee egg eclosion and larval development.
No full text15 pages : illustrations ; 26 cm.This study explores egg eclosion and larval biology of orchid bees (Apidae: Euglossini) in light of existing knowledge from studies dealing with a group of tribes within the Apidae referred to as corbiculate bees. It reports that Eulaema (Apeulaema) polychroma (Mocsáry) has five larval instars, and its first instar exists only briefly in that with the help of a band of spicules along both of its sides its exoskeleton is shed with the remnants of the chorion. Mature larvae of euglossines exhibit two anatomical features that are not characteristic of other corbiculates, namely the elongate, tapering area of the prothorax immediately behind the head and the small size of the cranium. These features are suggested to be accommodations allowing the development of the extremely long labiomaxillary region of the pupa, which in turn accounts for the lengthy mouthparts of the adult. Descriptions of the egg and mature larva of Euglossa (Euglossa) hemichlora Cockerell are appended as well as referenced in the text
Environment & land use in the Black Rock Desert.
Full text link216 pages : illustrations (some color), color maps ; 26 cm.This volume presents the results of data recovery excavations directed at prehistoric archaeological deposits located near Sulphur Springs, along the southeastern margin of the Black Rock Desert, in Humboldt and Pershing counties, Nevada. Although 20 sites with prehistoric assemblages were identified during this project, intact spatio-temporal components were found at only seven of these sites, of which just five were the focus of intensive data recovery excavations: 26HU1830, 26HU1876, 26HU2871, 26HU3118, and 26HU5621. A total of 372 m³ of excavation by hand was directed at dateable components within these five sites. The results of this effort yielded a substantial artifact assemblage, including a variety of flaked and ground stone tools, shell and bone beads, as well as large quantities of faunal bone and debitage. Also documented were an assortment of features, including a number of small processing facilities and the remnants of several house floors. Key to this investigation was the isolation of a series of discrete temporal components. Eleven such components were identified representing six temporal intervals: Early Archaic (5700-3800 cal b.p.), Middle Archaic (ca. 3000 cal B.P.), mixed Middle/Late Archaic (3800-600 cal B.P.), Late Archaic A (1340-1165 cal B.P.), Late Archaic B (985-855 cal B.P.), as well as Late Archaic (1300-600 cal B.P.) deposits that could not be further separated into smaller units of time. It is particularly noteworthy that many of these components have very narrow time frames, in many cases smaller than the traditional Great Basin periods. The profile of projectwide time-sensitive projectile points and radiocarbon dates, coupled with a robust artifact and feature assemblage dated to narrow time frames, allows for an assessment of changes in habitation and land-use pattern with an unusual level of resolution. Prior to about 4500 years ago, occupations appear to have been sporadic, with people making brief visits to the area during periods of increased effective moisture and spring discharge associated with the Early Holocene, and largely avoiding it for more promising areas during times of drought during the Middle Holocene. Archaeological visibility increases significantly after 4500 cal B.P., including periods when substantial houses were constructed, and people supplemented the local resource base with foods and materials obtained from distant locations possessing richer concentrations of large game and obsidian toolstone. These more intensive habitations were not constant, however, and were abandoned during a major Late Holocene drought cycle that occurred between 2800 and 1500 cal B.P. Robust habitation returns during the initial Late Archaic period but is bimodal with a sudden break at about 1000 B.P., a spike at roughly 985 to 855 cal B.P., followed by another break. The settlement profile may have been in response to the drought-wet-drought cycle of the Medieval Climatic Anomaly. Along with the role of environmental change in trans-Holocene settlement structure, the large feature and artifact assemblages provide commentary on a variety of other research themes, including the rise of Middle Archaic residential stability and logistical hunting; Middle versus Late Archaic domestic/habitation patterns; local cryptocrystalline silicate (CCS) toolstone production and obsidian conveyance patterns; subsistence-settlement variation within the Late Archaic Period; and an assessment of the missing Terminal Prehistoric record within the project area and surrounding region
New Enteromius from the Republic of Congo.
No full text16 pages : illustrations (chiefly color), color map ; 26 cm.A new species of smiliogastrin cyprinid is described from the Louesse, Lekoumou (upper Niari basin), and Djoulou (upper Ogowe basin) rivers in the Republic of Congo, west-central Africa. The new species is readily distinguished from congeners by the presence of a flexible, weakly ossified and smooth bordered last unbranched dorsal-fin ray, well-developed barbels, and a straight and complete lateral line in combination with a characteristic pigmentation patterning consisting of a distinctive, rounded black spot at the base of and extending over the first rays of the anal fin and a prominent, darkly pigmented blotch over the base of the anterior dorsal-fin rays. A combination of morphological features and pigmentation patterning that appears to be unique among Enteromius. The new species is widespread throughout the Louesse-Djoulou region, and the fact that such a seemingly common species has gone undetected until now serves to underscore how poorly known this region of the Republic of Congo remains
Sesamoid elements in bats.
Full text link38 pages : illustrations (chiefly color) ; 26 cm.Sesamoids are skeletal elements found within a tendon or ligament as it passes around a joint or bony prominence. Here we review the distribution of sesamoids in bats, the only mammals capable of powered flight. Our survey included bat species representing most extant families as well as two key Eocene fossil bats in which sesamoids are exquisitely preserved, Onychonycteris finneyi and Icaronycteris index. We identified 46 separate sesamoid elements (or sets of elements) from dissections of selected bat taxa, with no more than 23 of these present in any given species. Among the sesamoids identified in our survey, 12 have not previously been described in bats. We also identified seven sesamoids previously described in the literature that are not present in our sample of species. No sesamoids were found to be exclusive to the fossil taxa in our study; all the sesamoids observed in Onychonycteris and Icaronycteris have apparent homologs among extant species. We mapped the presence/absence of the 46 sesamoids onto a bat phylogeny. Based on these optimizations, we discuss homology issues and evolutionary history of some of the most taxonomically widespread sesamoids. Functional inferences regarding some sesamoids can be made based on what is known about bat musculoskeletal morphology, although further biomechanical studies are required to test the hypotheses proposed here. Sesamoids will continue to be a source of interesting insights about the evolution of bats and their unique locomotor abilities
Plant bugs associated with callitroid conifers.
Full text link226 pages : illustrations (some color), maps ; 26 cm.Orthotyline plant bugs inhabiting the southern conifer genus Callitris in Australia are investigated and classified systemically for the first time, with the description of 5 new genera and 32 new species from Australia. The five new callitroid-inhabiting Orthotylini genera proposed are Avititerra, Blattakeraia, Callitricola, Erysivena, and Ngullamiris. The 32 new species accommodated by these genera are: Avititerra lepidothrix, A. xerophila, Blattakeraia actinostrobi, B. hochuli, Callitricola ballina, C. boorabbin, C. cordylina, C. finke, C. finlayae, C. gammonensis, C. graciliphila, C. parawirra, C. pullabooka, C. silveirae, C. tatarnici, C. wiradjuri, C. wollemi, Erysivena apta, E. bundjalung, E. drepanomorpha, E. emeraldensis, E. endlicheriphila, E. kalbarri, E. majori, E. mareeba, E. molloy, E. notodytika, E. paluma, E. schuhi, E. schwartzi, E. sydneyensis, and Ngullamiris whadjuk. A key to the newly described Australian taxa, habitus photographs of all species, illustrations of male and female genitalia, and scanning electron micrographs of representative species are given. A phylogenetic analysis of these callitroid-inhabiting Orthotylini was undertaken, incorporating described Orthotylus Fieber species extralimital to Australia and other recently described Australian Orthotylini. Callitris host plants are mapped to the implied-weights phylogenetic analysis, and their associations are discussed. Associations between related species of Orthotylini and related species of Callitris were detected, as were three independent colonisations by a paraphyletic assemblage of callitroid-inhabiting Orthotylini. Generic concepts within Orthotylini are discussed, with reference to Orthotylus species extralimital to Australia and includes a comparison of key character systems. It is demonstrated that the endosomal spicule characters are primary determinants of generic limits in the Orthotylini, which are supported by other characters of the male and female genitalia and external characters
South American leaf-cutter bees (genus Megachile) of the subgenera Rhyssomegachile and Zonomegachile, with two new subgenera (Hymenoptera, Megachilidae). (Bulletin of the American Museum of Natural History, no. 425)
Full text link73 pages : color illustrations, color maps ; 26 cm.Leaf-cutter bees (genus Megachile Latreille) are among the most common and diverse group of bees. However, the identity and taxonomic placement of many species are problematic and species identification is often difficult. Some species are known only from a single specimen or from one of the sexes, and identification keys are not available for many groups. We address these taxonomic issues for the subgenera Rhyssomegachile Mitchell and Zonomegachile Mitchell, two poorly known South American lineages of leaf-cutter bees. We provide comparative diagnoses, redescriptions, illustrated identification keys, new geographical records, and designate needed neotypes for Megachile cara Mitchell, M. gigas Schrottky, M. guayaqui Schrottky, M. reliqua Mitchell, M. sanctipauli Schrottky, M. stabilis Mitchell, and M. turbulenta Mitchell. We resurrect M. tricosa Cockerell from synonymy with M. urbana Smith and synonymize M. turbulenta under M. tricosa. We recognize four species in Rhyssomegachile and eight species in Zonomegachile. In the latter subgenus, we revalidate M. reliqua from synonymy with M. moderata and propose the following four new species: Megachile kalina, new species, from French Guiana; M. durantae, new species, from Rondônia, Brazil; M. paisa, new species, from Antioquia, Colombia; and M. uncinata, new species, from Catamarca, Argentina. We confirm sex associations in Zonomegachile and describe its nest for the first time. Megachile tricosa, M. ardua Mitchell, and M. tacanensis Moure, currently assigned to Rhyssomegachile, exhibit morphological features that do not fit any of the known subgenera. Thus, we use a cladistic analysis to explore their phylogenetic relationships and establish two new subgenera for these species: Aporiochile Gonzalez and Engel, new subgenus, for M. tricosa and Chalepochile Gonzalez and Engel, new subgenus, for the remaining two species. We provide an updated key to the subgenera of Megachile s.l. of the Western Hemisphere
Supplemental Material for 'A second specimen of Citipati osmolskae associated with a nest of eggs from Ukhaa Tolgod, Omnogov Aimag, Mongolia. (American Museum novitates, no. 3899)'
No full textSupplemental Material for 'A second specimen of Citipati osmolskae associated with a nest of eggs from Ukhaa Tolgod, Omnogov Aimag, Mongolia. (American Museum novitates, no. 3899)
Hebius paraphyly.
No full text7 pages : 1 illustration ; 26 cm.We investigate the phylogenetic relationships of two poorly known Natricinae, Parahelicops and Pararhabdophis, for which we obtained nucleotide sequence data from one mitochondrial gene (cytochrome b) and three nuclear genes (CMOS, NT3, and RAG1). Maximum parsimony, maximum likelihood, and combined and partitioned Bayesian analyses suggest that both Parahelicops and Pararhabdophis are embedded within the genus Hebius. To align classification with phylogeny, we synonymize Parahelicops and Pararhabdophis with Hebius
Deepstaria enigmatica.
Full text link14 pages : color illustrations ; 26 cm.Deepstaria enigmatica (Semaeostomeae: Ulmaridae) is one of the largest and most mysterious invertebrate predators of the deep sea. Humans have encountered this jellyfish on only a few occasions and many questions related to its biology, distribution, diet, environmental tolerances, and behavior remain unanswered. In the 45 years since its formal description, there have been few recorded observations of D. enigmatica, due to the challenging nature of encountering these delicate soft-bodied organisms. Members of Deepstaria, which comprises two described species, D. enigmatica and D. reticulum, reside in the meso-bathypelagic region of the world's oceans, at depths ranging from ~600 to 1750 m. Here we report observations of a large D. enigmatica (68.3 cm length x 55.7 cm diameter) using a custom color high-definition low-light imaging system mounted on a scientific remotely operated vehicle (ROV). Observations were made of a specimen capturing or "bagging" prey, and we report on the kinetics of the closing motion of its membranelike umbrella. In the same area, we also noted a Deepstaria "jelly-fall" carcass with a high density of crustaceans feeding on its tissue and surrounding the carcass. These observations provide direct evidence of singular Deepstaria carcasses acting as jelly falls, which only recently have been reported to be a significant food source in the deep sea