Borealodon osedax, a new stem mysticete (Mammalia, Cetacea) from the Oligocene of Washington State and its implications for fossil whale-fall communities
Contributors: Shipps, B. K., Peredo, Carlos Mauricio, Pyenson, Nicholas D.
... Baleen whales (mysticetes) lack teeth as adults and instead filter feed using keratinous baleen plates. They do not echolocate with ultrasonic frequencies like toothed whales but are instead known for infrasonic acoustics. Both baleen and infrasonic hearing are separately considered key innovations linked to their gigantism, evolutionary success and ecological diversity. The earliest mysticetes had teeth, and the phylogenetic position of many so-called toothed mysticetes remains debated, including those belonging to the nominal taxonomic groups Llanocetidae, Mammalodontidae and Aetiocetidae. Here, we report a new stem mysticete, Borealodon osedax gen. et sp. nov., from the Oligocene of Washington State, USA. Borealodon preserves multi-cusped teeth with apical wear; microCT scans of the inner ear indicate that the minimum frequency hearing limit of Borealodon was similar to mammalodontids. Borealodon is not recovered within a monophyletic Mammalodontidae nor a monophyletic Aetiocetidae; instead, it represents an unnamed lineage of stem Mysticeti, adding to the diversity of stem mysticetes, especially across the Rupelian-Chattian boundary. Furthermore, the presence of a putative chemosynthetic bivalve along with Osedax, a bone-boring annelid, found in association with the type specimen of Borealodon, offer more insights into the evolution of deep-sea whale-fall communities.
Quantifying Leaf Phenology of Individual Trees and Species in a Tropical Forest Using Unmanned Aerial Vehicle (UAV) Images
Contributors: Park, John Y., Muller-Landau, Helene, Lichstein, Jeremy W., Rifai, Sami W., Dandois, Jonathan P., Bohlman, Stephanie A.
... Tropical forests exhibit complex but poorly understood patterns of leaf phenology. Understanding species- and individual-level phenological patterns in tropical forests requires datasets covering large numbers of trees, which can be provided by Unmanned Aerial Vehicles (UAVs). In this paper, we test a workflow combining high-resolution RGB images (7 cm/pixel) acquired from UAVs with a machine learning algorithm to monitor tree and species leaf phenology in a tropical forest in Panama. We acquired images for 34 flight dates over a 12-month period. Crown boundaries were digitized in images and linked with forest inventory data to identify species. We evaluated predictions of leaf cover from different models that included up to 14 image features extracted for each crown on each date. The models were trained and tested with visual estimates of leaf cover from 2422 images from 85 crowns belonging to eight species spanning a range of phenological patterns. The best-performing model included both standard color metrics, as well as texture metrics that quantify within-crown variation, with r2 of 0.84 and mean absolute error (MAE) of 7.8% in 10-fold cross-validation. In contrast, the model based only on the widely-used Green Chromatic Coordinate (GCC) index performed relatively poorly (r2 = 0.52, MAE = 13.6%). These results highlight the utility of texture features for image analysis of tropical forest canopies, where illumination changes may diminish the utility of color indices, such as GCC. The algorithm successfully predicted both individual-tree and species patterns, with mean r2 of 0.82 and 0.89 and mean MAE of 8.1% and 6.0% for individual- and species-level analyses, respectively. Our study is the first to develop and test methods for landscape-scale UAV monitoring of individual trees and species in diverse tropical forests. Our analyses revealed undescribed patterns of high intraspecific variation and complex leaf cover changes for some species.
Contributors: Bullard, Kristen A., Cox, Stephen, Ferry, Barbara, Lasker, Polly, Zwicker, Sue, Bullard, Kristen, Cox, Stephen, Ferry, Barbara, Lasker, Polly, Zwicker, Sue
Bryophyte stable isotope composition, diversity and biomass define tropical montane cloud forest extent
Contributors: Horwath, Aline B., Royles, Jessica, Tito, Richard, Gudiño, José A., Salazar Allen, Noris, Farfan-Rios, William, Rapp, Joshua M., Silman, Miles R., Malhi, Yadvinder, Swamy, Varun
... Liverworts and mosses are a major component of the epiphyte flora of tropical montane forest ecosystems. Canopy access was used to analyse the distribution and vertical stratification of bryophyte epiphytes within tree crowns at nine forest sites across a 3400 m elevational gradient in Peru, from the Amazonian basin to the high Andes. The stable isotope compositions of bryophyte organic material (13C/12C and 18O/16O) are associated with surface water diffusive limitations and, along with C/N content, provide a generic index for the extent of cloud immersion. From lowland to cloud forest Î´13C increased from -33â ° to -27â °, while Î´18O increased from 16.3â ° to 18.0â °. Epiphytic bryophyte and associated canopy soil biomass in the cloud immersion zone was estimated at up to 45 t dry mass ha-1, and overall water holding capacity was equivalent to a 20 mm precipitation event. The study emphasizes the importance of diverse bryophyte communities in sequestering carbon in threatened habitats, with stable isotope analysis allowing future elevational shifts in the cloud base associated with changes in climate to be tracked.
Contributors: Kimball, Rebecca T., Oliveros, Carl H., Wang, Ning, White, Noor D., Barker, F. Keith, Field, Daniel J., Ksepka, Daniel T., Chesser, R. Terry, Moyle, Robert G., Braun, Michael J.
... It has long been appreciated that analyses of genomic data (e.g., whole genome sequencing or sequence capture) have the potential to reveal the tree of life, but it remains challenging to move from sequence data to a clear understanding of evolutionary history, in part due to the computational challenges of phylogenetic estimation using genome-scale data. Supertree methods solve that challenge because they facilitate a divide-and-conquer approach for large-scale phylogeny inference by integrating smaller subtrees in a computationally efficient manner. Here, we combined information from sequence capture and whole-genome phylogenies using supertree methods. However, the available phylogenomic trees had limited overlap so we used taxon-rich (but not phylogenomic) megaphylogenies to weave them together. This allowed us to construct a phylogenomic supertree, with support values, that included 707 bird species (~7% of avian species diversity). We estimated branch lengths using mitochondrial sequence data and we used these branch lengths to estimate divergence times. Our time-calibrated supertree supports radiation of all three major avian clades (Palaeognathae, Galloanseres, and Neoaves) near the Cretaceous-Paleogene (K-Pg) boundary. The approach we used will permit the continued addition of taxa to this supertree as new phylogenomic data are published, and it could be applied to other taxa as well.
Contributors: Obiang, Nestor Laurier Engone, Kenfack, David, Picard, Nicolas, Lutz, James A., Bissiengou, Pulchérie, Memiaghe, Hervé R., Alonso, Alfonso
A key to the North American genera of Stipeae (Poaceae, Pooideae) with descriptions and taxonomic names for species of Eriocoma, Neotrinia, Oloptum, and five new genera: Barkworthia, ×Eriosella, Pseudoeriocoma, Ptilagrostiella, and Thorneochloa
Contributors: Peterson, Paul M., Romaschenko, Konstantin, Soreng, Robert J., Valdés Reyna, Jesus
... Based on earlier molecular DNA studies we recognize 14 native Stipeae genera and one intergeneric hybrid in North America. We provide descriptions, new combinations, and 10 illustrations for species of Barkworthia gen. nov. , Eriocoma , Neotrinia , Oloptum , Pseudoeriocoma gen. nov. , Ptilagrostiella gen. nov. , Thorneochloa gen. nov. , and × Eriosella nothogen. nov. The following 40 new combinations are made: Barkworthiastillmanii , Eriocomaalta , E.arida , E.arnowiae , E.bloomeri , E.bracteata , E.contracta , E.coronata , E.curvifolia , E.hendersonii , E.latiglumis , E.lemmonii , E.lemmoniissp.pubescens, E.lettermanii , E.lobata , E.nelsonii , E.nelsoniissp.dorei, E.nevadensis , E.occidentalis , E.occidentalisssp.californica, E.occidentalisssp.pubescens, E.parishii , E.parishiissp.depaupertata, E.perplexa , E.pinetorum , E.richardsonii , E.robusta , E.scribneri , E.swallenii , E.thurberiana , E.wallowaensis , × Eriosellacaduca , Pseudoeriocomaacuta , P.constricta , P.editorum , P.eminens , P.hirticulmis , P.multinodis , Ptilagrostiellakingii , and Thorneochloadiegoensis . A key to the native and introduced genera of North American Stipeae, and an overview of the tribe in North America and worldwide are given. Lectotypes are designated for Eriocomacuspidata Nutt., Fendleriarhynchelytroides Steud., Stipabloomeri Bol., Stipacoronata Thurb., Stipamembranacea Pursh, Stipamormonum Mez, Stiparichardsonii Link, and Stipawilliamsii Scribn. Achnatherum s.s. and Piptatherum s.s. are now restricted to Eurasia and the Mediterranean/Asia, respectively.
Contributors: Detto, Matteo, Visser, Marco D., Wright, S. Joseph, Pacala, Stephen W.
... Data on paired seed traps from Barro Colorado Island in Panama. 200 paired traps were installed 2 m distance in March 2011 and censused weekly through February 2013 along the trails of the 50ha plot. Each trap consisted of a square ½ m2, open-topped, 1-mm mesh bag supported 0.8 to 1 m above the ground by a polyvinyl chloride frame. Fruits and seeds were identified to species, counted and further categorized as immature, mature (endosperm filled), or damaged by animals. PART definitions: 0 reproductive buds, 1 mature fruit, 2 seeds, 3 capsules, 4 fragments, 5 immature fruit, 6 flowers (female or perfect), 7 fruit with insect emergence holes / insect damaged, 8 aborted fruit, 9 male flowers, 10 fruit eaten by animal (bird, monkey, squirrel o others), 11 category for leaves, 12 "unknown", 13 leaf pedicel, 14 fragment og branch, less than 2 cm in diameter, 15 fine litter, 16 flower pedicel, 17 fruit pedicel, 18 monkey feces.
Contributors: Kitchell, Kenneth, Jr., Dundee, Harold A.