6932 research outputs found
Sort by
Evidence for guild structure in hyperdiverse mammalian communities.
No full text43 pages : 1 map ; 26 cm.The ecological mechanisms that sustain high species richness in Neotropical bat communities have attracted research attention for several decades. Although many ecologists have studied the feeding behavior and diets of Neotropical bats on the assumption that food is a limiting resource, other resource axes that might be important for species coexistence are often ignored. Diurnal refugia, in particular, are a crucial resource for bats, many of which exhibit conspicuous morphological or behavioral adaptations to the roost environment. Here we report and analyze information about roost occupancy based on >500 field observations of Amazonian bats. Statistical analyses of these data suggest the existence of distinct groups of species roosting (1) in foliage, (2) exposed on the trunks of standing trees, (3) in cavities in standing trees, (4) in or under fallen trees, (5) beneath undercut earth banks, and (6) in arboreal insect nests; additionally, we recognize other groups that roost (7) in animal burrows, and (8) in rocks or caves. Roosting-guild membership is hypothesized to have a filtering effect on Amazonian bat community composition because some types of roosts are absent or uncommon in certain habitats. Among other applications of our results, cross-classifying bat species by trophic and roosting guilds suggests that the often-reported deficit of gleaning animalivores in secondary vegetation by comparison with primary forest might reflect habitat differences in roost availability rather than food resources. In general, ecological and evolutionary studies of Neotropical bats would be enhanced by considering both trophic- and roosting-guild membership in future analyses, but additional fieldwork will be required to determine the roosting behavior of many data-deficient species
Male reproductive system of goblin spiders.
No full textSupplemental Material for 'Evolutionary morphology of the primary male reproductive system and spermatozoa of goblin spiders (Oonopidae; Araneae). (Bulletin of the American Museum of Natural History, no. 396)' - http://hdl.handle.net/2246/661
New records of Pteropus from Indonesia.
No full text23 pages : color illustrations, map ; 26 cm.Bat species in the genus Pteropus (flying foxes) occur throughout most of Southeast Asia, but little is known about their distribution and patterns of local diversity across much of Indonesia. To help address this problem, a field survey of Pteropus species in Central and West Seram, Maluku Province, Indonesia, was conducted in 2012 and 2013. This study resulted in new records of rare Moluccan bats, including new locality records for four near-endemic species: P. chrysoproctus, P. melanopogon, P. ocularis, and P. temminckii. Together with data from additional specimens, these records provide new information about morphological variation in Moluccan Pteropus. High local diversity of large-bodied bats with restricted geographic ranges raises interesting questions about evolution in Pteropus and about ecological niche partitioning in Paleotropical pteropodid communities. More monitoring efforts in Maluku are needed, as the roosts located during the 2012-2013 survey are some of the only known sites where these species may be found, and none of these sites are located in protected areas. Without updated natural history data and taxonomic revision, proper management decisions cannot be made for any of these threatened species despite mounting anthropogenic pressure on their populations
Ants (Hymenoptera, Formicidae) through space, time, and sociality : a history from amber.
No full textviii, 236 pages : illustrations (chiefly color)With over 13,000 ecologically diverse species exhibiting worldwide ubiquity in vegetated terrestrial ecosystems, ants are one of nature's greatest success stories. Colonies range from a few dozen tiny workers housed inside of an acorn to millions of nomadic army ants known to consume even vertebrates. The ant fossil record is very rich, comprising thousands of amber and impression specimens spanning a hundred million years, the vast majority of which is Cenozoic. Until very recently, early ant history has been obfuscated by a lack of well-preserved fossils from the Cretaceous. Here, utilizing CT-scanning methodology and traditional methods, diverse species of ~99 million-year-old Cretaceous ants are described from Burmese amber, which together comprise over one-third of all known Cretaceous ants. Among them are trap-jaw predators with scythelike mandibles not known in any living or extinct ants, as well as enigmatic feeders with hair-coated mouthparts, and several species with morphology analogous to that found in modern ants while retaining plesiomorphic features. These and other unusual Cretaceous taxa are contextualized for the first time, with results that challenge traditional viewpoints regarding the diversity, phylogenetic placement, and sociality of the earliest ants known. In the age of molecular phylogenetics the role of fossils can be unclear. Most frequently, fossils are included in analyses solely as calibration points for divergence date estimates, a practice that relies on assumed taxonomy and excludes biogeographic information. To explore alternative roles for fossils in molecular-based biogeographic, phylogenetic, and temporal reconstruction, combined analysis methodology is explored -- first, with respect to a small genus, and then finally applied to a large sampling of all ant subfamilies. The genus Leptomyrmex is endemic to eastern Australia, New Caledonia and New Guinea. Over 25 years ago, a putative fossil Leptomyrmex was described from Dominican amber dated to the Miocene. In the absence of compelling evidence other than taxonomic discussions in literature, researchers have typically excluded the Dominican fossil from phylogenetic and biogeographic reconstruction. To test the placement of the fossil, published molecular sequences for modern Leptomyrmex and related groups were merged with a novel morphological matrix. Through combined analysis the fossil was recovered among modern Australasian Leptomyrmex, indicating that the current distribution is a reflection of a great contraction and more complex biogeographic history. This same methodology is applied to a much larger dataset including members of all modern ant subfamilies in a preliminary total-evidence analysis of ants.Richard Gilder Graduate School at the American Museum of Natural History
Phylogenetics of Teleogramma, a riverine clade of African cichlid fishes, with a description of the deepwater molluskivore--Teleogramma obamaorum--from the lower reaches of the middle Congo River. (American Museum novitates, no. 3831)
No full text18 pages : illustrations (some color) ; 26 cm.The lower Congo River and nearby habitats harbor numerous endemic lineages of cichlid fishes, including some with highly specialized morphologies. Based on morphological and molecular data, we herein describe a new species of Teleogramma, a member of the chromidotilapiine clade found on rocky outcrops in the lower reaches of the middle Congo River. The new species, T. obamaorum, is distinguished from congeners by numerous morphological and ecological attributes, including the lack of dorsoventral head and body depression, absence of sexual dichromatism, and features of laterosensory anatomy, pharyngeal and gut morphology, and dietary preference. Phylogenetic analyses of two nuclear and two mitochondrial loci using Bayesian and maximum-likelihood inference lend strong support for the taxonomic validity of T. obamaorum and provide preliminary estimates of species relationships within the genus. The discovery of a new, ecomorphologically distinctive cichlid species in the Congo River suggests that additional research focus on riverine clades has the potential to greatly contribute to our understanding of evolutionary dynamics in this hyperdiverse group of teleost fishes
The mitochondrial genome of Allonautilus (Mollusca, Cephalopoda) : base composition, noncoding-region variation, and phylogenetic divergence. (American Museum novitates, no. 3834)
No full text13 pages : illustrations (chiefly color) ; 26 cm.We used next-generation methods to sequence the mitochondrial genome of Allonautilus scrobiculatus from two large, overlapping amplicons generated by PCR. The genome was circular, 16,132 base pairs in length, and possessed the same sequence and orientation of genes as the previously sequenced mitogenome of Nautilus macromphalus. These two mitogenomes were approximately 8% divergent overall, but differentiation varied greatly among genes: some tRNA sequences were identical between the two taxa, whereas ATP8 differed by over 15%. The largest of the noncoding regions of the genome included a 62 base pair repeat that was essentially identical between the two genera; however, this repeat was present as six copies in N. macromphalus, but varied between four and five among individuals of Allonautilus. A 146 base pair deletion (in Allonautilus compared to Nautilus) included one copy of the repeat plus an adjacent 84 bp; because of this indel, the "CA" microsatellite in N. macromphalus was missing from Allonautilus. Base composition varied along the Allonautilus sequence, and was correlated with the strand on which genes coded. Base composition also varied within the largest noncoding region. A phylogeny of 24 extant cephalopods indicates that there is less molecular divergence between Allonautilus and Nautilus than there is among congeneric species of Octopus and Sepia
Supplemental Material for 'The herpetological collection of Maximilian, Prince of Wied (1782-1867), with special reference to Brazilian materials. (Bulletin of the American Museum of Natural History, no. 395)'
No full textSupplemental Material for 'The herpetological collection of Maximilian, Prince of Wied (1782-1867), with special reference to Brazilian materials. (Bulletin of the American Museum of Natural History, no. 395)' - http://hdl.handle.net/2246/659
Osteological contributions to the natural history of the chimpanzees (Troglodytes) & orangs (Pithecus). No. V, Comparison of the lower jaw & vertebrate column of the Troglodytes Gorilla, Troglodytes niger, Pithecus Satyrus, and different varieties of the human race
No full text33 leaves ; 38 cm.Holograph ms. The article was subsequently published in: Transactions of the Zoological Society of London, v. 4, pt. 4 (p. 89-115). The part was published some time between 1855 and 1862, the latter being the publication date printed on the vol. t.p. (the individual parts are undated). The article is numbered VIII in that vol. The statement below its caption title ("Read September 9, 1851") should have read "Read September 9, 1852.
Konetontli.
No full text78 pages : illustrations (some color), maps ; 26 cm.The Mexican vaejovid scorpion genus Konentontli González-Santillán and Prendini, 2013, was created to accommodate five species united, among other characters, by a subaculear tubercle on the telson. Species of Konetontli are among the smallest vaejovid scorpions. Their very small size, cryptic coloration, and apparently seasonal surface activity may explain their rarity in collections and it is likely that more undescribed species await discovery. In the present contribution, we describe four new species (Konetontli ignes, sp. nov.; Konetontli ilitchi, sp. nov.; Konetontli juxtlahuaca, sp. nov.; Konetontli migrus, sp. nov.) and revalidate Konetontli zihuatanejensis (Baldazo-Monsivaiz, 2003), comb. nov., previously synonymized with Konetontli acapulco (Armas and Martín-Frías, 2001), raising to 10 the number of species in the genus; redescribe previously described species, including the first description of the female of Konetontli nayarit (Armas and Martín-Frías, 2001); and present new records, comprehensive distribution maps, and a key to the identification of the species
Azendohsaurus madagaskarensis.
No full text126 pages : illustrations, map ; 26 cm.During the Triassic, archosauromorphs became one of the first groups of diapsid reptiles to diversify in terms of body size and morphological disparity in both terrestrial and marine ecosystems across Pangaea. This seemingly rapid divergence, and the numerous unique body plans stemming from it, concomitantly has confounded reconstructions of archosauromorph relationships. Teasing apart homology from homoplasy of anatomical characters in this broad suite of body types remains an enormous challenge with the current sample of taxa. Here, we present the postcranial anatomy of Azendohsaurus madagaskarensis, an early archosauromorph from ?Middle to Upper Triassic strata of Madagascar. Azendohsaurus madagaskarensis is known from nearly the entire skeleton in an ontogenetically variable sample. The holotype locality consists of a monotypic bone bed; preservation ranges from complete but disarticulated bones to articulated sections of the skeleton. Azendohsaurus madagaskarensis embodies an aberrant constellation of archosauromorph features, including an elongated neck, a short, stocky tail, robust limbs, and unexpectedly short digits terminating in large recurved unguals on the manus and pes. Together with the cranium, the postcrania reveal A. madagaskarensis to be another representative of a growing coterie of highly apomorphic and bizarre Triassic archosauromorphs. At the same time, recovery and description of the full anatomy of A. madagaskarensis helps to identify a monophyletic grouping of specialized taxa that includes the North American Late Triassic-aged archosauromorphs Trilophosaurus, Spinosuchus, and Teraterpeton, Indian Pamelaria, and Moroccan Azendohsaurus laaroussii. Moreover, information derived from the skeleton of A. madagaskarensis solidifies the systematic position of these taxa among other archosauromorphs. Using the most comprehensively sampled phylogenetic analysis of early archosauromorphs, we found the clade encompassing the aforementioned taxa as the nearest outgroup of Prolacerta broomi + Archosauriformes. The newly recognized clade containing Azendohsaurus, Trilophosaurus, Spinosuchus, Pamelaria, and Teraterpeton demonstrates high morphological disparity even within a closely related group of archosauromorphs, underscores the polyphyly of protorosaurs (5 prolacertiforms), and suggests that most major divergences within this group occurred in the Triassic. Furthermore, our results indicate that craniodental character states ascribed to a herbivorous diet were much more pervasive across Triassic Archosauromorpha than previously conjectured