Aristolochia quiricoana (Aristolochiaceae), a new species from southern Costa Rica

Background and Aims: Aristolochia is the largest genus in Aristolochiaceae and is widely distributed in the world. A recent synopsis of Aristolochia in Costa Rica recognized 19 species; nevertheless, recent botanical exploration in southwestern Costa Rica has revealed yet another new species of this genus. Methods: The new species resulted from fieldwork in Buenos Aires, Puntarenas Province. Specimens from several herbaria were examined, as well as the type material of the most morphologically similar species. Comments about its distribution, habitat, phenology, conservation status and morphological distinction from related species are provided.Key results: Aristolochia quiricoana, a member of Aristolochia series Thyrsicae, is described and illustrated from the southern Pacific region of Costa Rica, where it is apparently endemic. It is similar to A. ornithorhyncha, from which it is distinguished by its shorter pedicels, wider, oblong perigone limbs with a shorter appendix, and a different floral color pattern.Conclusions: The new taxon described here represents the 22nd species documented in Aristolochia series Thyrsicae, as well as the 20th species of the genus from Costa Rica.

Taxonomic status and phylogenetic position of Oxymycterus juliacae Allen 1900 (Rodentia: Cricetidae)

The phylogenetic position of the “Upper yungas inca hocicudo” Oxymycterus juliacae, one of the lesser-known species of the genus Oxymycterus, is still unresolved. Several authors considered it a subspecies or synonym of Oxymycterus inca, but more recently, it was recognized as a valid species based on morphometric analysis and morphological traits. The objectives of this study were then to substantiate the morphological distinction of O. juliacae and evaluate its phylogenetic position using cytochrome b sequences. We evaluated the morphology of O. juliacae and compared it with congeneric species. In addition, a Cytochrome b gene matrix was subjected to analyses of maximum likelihood and Bayesian inference. Our results support the morphometric and morphological distinction of O. juliacae and found that this species is more closely related to Oxymycterus willkaurco than to O. inca. Therefore, the recognition of O. juliacae as a full species is supported and a rediagnosis is provided. In addition, we found O. inca is more related to other lowland species from Argentina, Brazil, and Uruguay, than to central Andean species. More efforts are needed to secure genetic material of Oxymycterus species, mainly the Andean species, for a better understanding of their phylogenetic relationship.

Revision of Ordovician chitinozoan Lagenochitina esthonica sensu lato: morphometrics, biostratigraphy and paleobiogeography

Lagenochitina esthonica is a globally distributed chitinozoan in Early to Middle Ordovician rocks. It is regarded as an index species for the early Floian in North America and has a stratigraphically constrained range in other regions. Lagenochitina esthonica is distinguished from other chitinozoans by a distinct flexure, a nearly rounded-square chamber, and a cylindrical neck with a flaring collar. However, since the first description of the species in the 1950s, it has included two varieties: a relatively short form with a test length ~400 μm, and a slender form usually longer than 600 μm. In order to revise the taxonomy of the L. esthonica group, we carried out a statistical morphometric study of a large collection of well-preserved specimens from the Baltic region where the taxon was first established. Additionally, the stratigraphic and geographic distribution of both forms was analyzed based on available occurrence data. The results show that the short form occurs in the upper Tremadocian to lower Dapingian, whereas the slender form is mostly reported from the lower and middle Darriwilian. Both forms are identified on Baltica; the short form has also been reported from Laurentia and South China, whereas the other is known also from Avalonia and Gondwana. The morphological distinction, together with differences in stratigraphic and spatial ranges, suggest that the two forms represent separate species: the original stout L. esthonica, based on the morphology of the holotype, and the slender L. megaesthonica n. sp., described herein. The updated taxonomy enhances the stratigraphic and biogeographic usefulness of lagenochitinids globally. UUID: http://zoobank.org/ec49166e-2a8d-4941-8723-f023853c5a7e.

Thalictrum changii (Ranunculaceae), a new species from southern Xizang (Tibet), China

Thalictrum changii (Ranunculaceae), a new species from southern Xizang (Tibet), China, is illustrated and described. Morphologically, T. changii is most closely similar to T. yunnanense in habit and in having 2–3-ternate leaves, paniculate-corymbiform inflorescence, clavate filaments, sessile, fusiform achenes, and glandular-pubescent leaves, inflorescence rachis, pedicels and achenes, but differs by having subcoriaceous (vs. papery) leaflets, narrowly elliptic (vs. suborbicular), longer (ca. 5 mm vs. ca. 3.5 mm) and persistent (vs. caducous) sepals, and longer (ca. 3 mm vs. ca. 1.5 mm) carpels with longer (ca. 1.5 mm vs. ca. 0.5 mm) styles. The confusion in the geographical distribution of T. yunnanense and its closely allied species T. scabrifolium is clarified. Morphological distinction between the two varieties of T. yunnanense, namely var. yunnanense and var. austroyunnanense, is discussed. An identification key to T. changii and its closely allied taxa is also provided.

Constraints on the ecomorphological convergence of zooplanktivorous butterflyfishes

Whether distantly related organisms evolve similar strategies to meet the demands of a shared ecological niche depends on their evolutionary history and the nature of form-function relationships. In fishes, the visual identification and consumption of microscopic zooplankters, selective zooplanktivory, is a distinct type of foraging often associated with a suite of morphological specialisations. Previous work has identified inconsistencies in the trajectory and magnitude of morphological change following transitions to selective zooplanktivory, alluding to the diversity and importance of ancestral effects. Here we investigate whether transitions to selective zooplanktivory have influenced the morphological evolution of marine butterflyfishes (family Chaetodontidae), a group of small-prey specialists well known for several types of high-precision benthivory. Using Bayesian ancestral state estimation, we inferred the recent evolution of zooplanktivory among benthivorous ancestors that hunted small invertebrates and browsed by picking or scraping coral polyps. Traits related to the capture of prey appear to be functionally versatile with little morphological distinction between species with benthivorous and planktivorous foraging modes. In contrast, multiple traits related to prey detection or swimming performance are evolving toward novel, zooplanktivore-specific optima. Despite a relatively short evolutionary history, general morphological indistinctiveness, and evidence of constraint on the evolution of body size, convergent evolution has closed a near significant amount of the morphological distance between zooplanktivorous species. Overall, our findings describe the extent to which the functional demands associated with selective zooplanktivory have led to generalisable morphological features among butterflyfishes and highlight the importance of ancestral effects in shaping patterns of morphological convergence.

Thalictrum kangdingense (Ranunculaceae), a new synonym of T. megalostigma from China

Based on critical observations on herbarium specimens (including type material) and living plants in the wild from its type locality, we demonstrate that Thalictrum kangdingense, recently described from Kangding county in western Sichuan province, China, is readily distinguishable from T. xinningense by an array of morphological characters but is actually conspecific with T. megalostigma, a species with its type locality also in Kangding. We therefore reduce T. kangdingense to the synonymy of T. megalostigma herein. The morphological distinction between T. baicalense and T. megalostigma is also clarified.

CONQUILIOMETRIA DE GASTRÓPODES NERITÍDEOS DA PRAIA DE ACCRA, BARBADOS, MAR DO CARIBE

The present study aims to characterize the conquiliometry of four species of neritid gastropod molluscs (Nerita tessellata, Nerita fulgurans, Nerita versicolor and Nerita peloronta), collected at Accra Beach, Barbados Island. For the characterization of the neritid conquiliometric pattern, the external measures (total length, width and height of the shell) and the measures of length and width of the shell opening were first measured, classifying the allometry of the morphometric relationships performed. The results presented here indicate that the neritids used in this study have morphometry significantly correlated, with allometry classified as "negative". Furthermore, it indicates the height and length measurements of the opening that determine the morphological distinction between N. fulgurans and the other species of neritids used.

A new Hyphessobrycon (Characiformes: Characidae) of the Hyphessobrycon heterorhabdus species-group from the lower Amazon basin, Brazil

ABSTRACT A new species of Hyphessobrycon belonging to the Hyphessobrycon heterorhabdus species-group from the lower rio Tapajós, state of Pará, Brazil, is described. The new species is allocated into the Hyphessobrycon heterorhabdus species-group due to its color pattern, composed by an anteriorly well-defined, horizontally elongated humeral blotch that becomes diffuse and blurred posteriorly, where it overlaps with a conspicuous midlateral dark stripe that becomes blurred towards the caudal peduncle and the presence, in living specimens, of a tricolored longitudinal pattern composed by a dorsal red or reddish longitudinal stripe, a middle iridescent, golden or silvery longitudinal stripe, and a more ventrally-lying longitudinal dark pattern composed by the humeral blotch and dark midlateral stripe. It can be distinguished from all other species of the group by possessing humeral blotch with a straight or slightly rounded ventral profile, lacking a ventral expansion present in all other species of the group. The new species is also distinguished from Hyphessobrycon heterorhabdus by a 9.6% genetic distance in the cytochrome c oxidase I gene. The little morphological distinction of the new species when compared with its most similar congener, H. heterorhabdus, indicates that the new species is one of the first truly cryptic fish species described from the Amazon basin.

The Early Stage of Perception of Contemporary Art Music: A matter of time

By way of a multidisciplinary approach, this article advances the idea that our listening to certain practices of contemporary art music (electroacoustic, classical contemporary, and electronic music) relies on precise connections to the early stage of perception. These styles of music are characterised by essential sound configurations that evolve in time, thus eliciting a sensorial impact which transcends features regarding sound sources and affective responses. Listeners grasp what Scruton calls ‘pure events’ in a ‘world of sound’, being able to distinguish, separate and sort acoustic stimuli. The article establishes a key parallel among seminal works of Bregman, McAdams, Kubovy, Bayle and other authors, highlighting a fundamental agreement of perceptual studies in psychology, neurophysiology and musicology for the understanding of the early stage of sound perception. Music practices typical of this perspective develop certain sound configurations, such as figure/ground arrangements, recurrent elements and morphological distinction, that closely mirror our innate mechanisms of prediction in perception. A parallel is made between studies in the philosophy of perception and the neurophysiology which allows us to postulate the idea that these styles of music are essentially based on pure temporal proto-objects.

Clarification of morphological distinction between Artemisia sichuanensis var. sichuanensis (Asteraceae, Anthemideae) and A. sichuanensis var. tomentosa, with reduction of A. erlangshanensis to the synonymy of the latter variety

Based on observations on both herbarium specimens (including type material) and living plants in the wild, we demonstrate that Artemisia sichuanensis var. sichuanensis (Asteraceae, Anthemideae) differs from A. sichuanensis var. tomentosa only by the leaves abaxially sparsely pubescent (vs. densely gray arachnoid tomentose). In addition, A. erlangshanensis is found to be identical with A. sichuanensis var. tomentosa, and is thus synonymized herein.