The role of progenesis in the diversification of the interstitial annelid lineage Psammodrilidae

2018 ◽  
Vol 32 (4) ◽  
pp. 774 ◽  
Author(s):  
Katrine Worsaae ◽  
Gonzalo Giribet ◽  
Alejandro Martínez

Psammodrilidae constitutes a family of understudied, nearly completely ciliated, small-sized annelids, whose systematic position in Annelida remains unsettled and whose internal phylogeny is here investigated for the first time. Psammodrilids possess hooked chaetae typical of macroscopic tube-dwelling semi-sessile annelids, such as Arenicolidae. Yet, several minute members resemble, with their conspicuous gliding by ciliary motion and vagile lifestyle, interstitial fauna, adapted to move between sand grains. Moreover, psammodrilids exhibit a range of unique features, for example, bendable aciculae, a collar region with polygonal unciliated cells, and a muscular pumping pharynx. We here present a combined phylogeny of Psammodrilidae including molecular and morphological data of all eight described species (two described herein as Psammodrilus didomenicoi, sp. nov. and P. norenburgi, sp. nov.) as well as four undescribed species. Ancestral character state reconstruction suggests the ancestor of Psammodrilidae was a semi-sessile larger form. Miniaturisation seems to have occurred multiple times independently within Psammodrilidae, possibly through progenesis, yielding small species with resemblance to a juvenile stage of the larger species. We find several new cryptic species and generally reveal an unexpected diversity and distribution of this small family. This success may be favoured by their adaptive morphology, here indicated to be genetically susceptible to progenesis.

IMA Fungus ◽  
2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Claudio G. Ametrano ◽  
Felix Grewe ◽  
Pedro W. Crous ◽  
Stephen B. Goodwin ◽  
Chen Liang ◽  
...  

Abstract Dothideomycetes is the most diverse fungal class in Ascomycota and includes species with a wide range of lifestyles. Previous multilocus studies have investigated the taxonomic and evolutionary relationships of these taxa but often failed to resolve early diverging nodes and frequently generated inconsistent placements of some clades. Here, we use a phylogenomic approach to resolve relationships in Dothideomycetes, focusing on two genera of melanized, extremotolerant rock-inhabiting fungi, Lichenothelia and Saxomyces, that have been suggested to be early diverging lineages. We assembled phylogenomic datasets from newly sequenced (4) and previously available genomes (238) of 242 taxa. We explored the influence of tree inference methods, supermatrix vs. coalescent-based species tree, and the impact of varying amounts of genomic data. Overall, our phylogenetic reconstructions provide consistent and well-supported topologies for Dothideomycetes, recovering Lichenothelia and Saxomyces among the earliest diverging lineages in the class. In addition, many of the major lineages within Dothideomycetes are recovered as monophyletic, and the phylogenomic approach implemented strongly supports their relationships. Ancestral character state reconstruction suggest that the rock-inhabiting lifestyle is ancestral within the class.


Author(s):  
Agustín J Elias-Costa ◽  
Julián Faivovich

Abstract Cascades and fast-flowing streams impose severe restrictions on acoustic communication, with loud broadband background noise hampering signal detection and recognition. In this context, diverse behavioural features, such as ultrasound production and visual displays, have arisen in the evolutionary history of torrent-dwelling amphibians. The importance of the vocal sac in multimodal communication is being increasingly recognized, and recently a new vocal sac visual display has been discovered: unilateral inflation of paired vocal sacs. In the diurnal stream-breeding Hylodidae from the Atlantic forest, where it was first described, this behaviour is likely to be enabled by a unique anatomical configuration of the vocal sacs. To assess whether other taxa share this exceptional structure, we surveyed torrent-dwelling species with paired vocal sacs across the anuran tree of life and examined the vocal sac anatomy of exemplar species across 18 families. We found striking anatomical convergence among hylodids and species of the distantly related basal ranid genera Staurois, Huia, Meristogenys and Amolops. Ancestral character state reconstruction identified three new synapomorphies for Ranidae. Furthermore, we surveyed the vocal sac configuration of other anuran species that perform visual displays and report observations on what appears to be unilateral inflation of paired vocal sacs, in Staurois guttatus – an extremely rare behaviour in anurans.


2021 ◽  
Author(s):  
Damián Villaseñor-Amador ◽  
José Alberto Cruz ◽  
Nut Xanat Suárez

Representative locomotion types in lizards include terrestrial, arboreal, grass swimmer, sand swimmer and bipedal. Few studies explain the locomotion habit of extinct lizards, and even less asses those of bipedal ones. Here, we use quantitative methods to infer the type of locomotion of two Albian Mexican lizards (Lower Cretaceous) and three Cretaceous lizards from Brazil, North America and Spain, assessing the similarities of the hindlimb-forelimb length ratio amongst extinct and extant species. Additionally, an ancestral character state reconstruction analysis was performed, to evaluate the evolution of lizard locomotion habits. The species Huehuecuetzpalli mixtecus was bipedal while Tijubina pontei was facultative bipedal, Hoyalacerta sanzi, Tepexisaurus tepexii and Polyglyphanodon sternbergi cannot be differentiated amongst terrestrial or arboreal with the approach used in this work. The ancestral character state reconstruction analysis showed a terrestrial ancestral locomotion type, with a basal character state of hindlimbs longer than forelimbs. Equal length between hind and forelimbs appear to be a derivate state that evolved multiple times in lizard evolutionary history.


2015 ◽  
Vol 1721 ◽  
Author(s):  
A. B. Brune ◽  
W.T. Petuskey

ABSTRACTMechanical properties and new morphological data on synthetic sodium hydrogen urate monohydrate are reported and interpreted. Crystals formed in supersaturated aqueous solutions were identified by powder x-ray diffraction. Intact grains and separate needles were examined by several microscopy techniques, some reported here for the first time. The dominant morphology was spherulite-type, comprising tapered, branched blades (needles) radiating out of a common core. The pointed blade tips were truncated by (011) planes, corresponding to hydrogen-bonded planes. Branching was at about a 5° angle or its multiples, suggesting it accommodated by dislocation arrays at the low angle boundaries, as is often seen in twinning. Vicker’s micro-hardness, extrapolated to zero porosity, was 0.90 GPa, which is greater than the hardness measured by nano-indentation. Present results are anticipated to be useful in interpreting the mechanical characteristics of the material crystallized in vivo and its action concerning gout, and affording inferences on the role of the milieu on morphologies, fragmentation, and hardness.


Insects ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 166
Author(s):  
Rafał Gosik ◽  
Miłosz A. Mazur ◽  
Natalia Sawka-Gądek

In this paper, the mature larva and pupa of Bagous claudicans are described and illustrated for the first time. Measurements of younger larval instars are also given. The biology of the species is discussed in association with larval morphology and feeding habits. Overall larval and pupal morphological characters of the genus Bagous are presented. Confirmation of the larva identification as Bagous claudicans species was conducted by cytochrome oxidase I (COI) sequencing. DNA barcoding was useful for specimen identification of larval stages. The systematic position of the species within the Bagous collignensis-group, based on morphological and molecular results, is also discussed.


Nematology ◽  
2018 ◽  
Vol 20 (8) ◽  
pp. 769-779
Author(s):  
Zdeněk Mráček ◽  
Jiří Nermuť ◽  
Vladimír Půža

Summary The mucron in male steinernematid nematodes may be missing or present either in the first or second generation, or missing in both generations, with variable shape. However, for many species, the information on mucron morphology is incomplete and its taxonomic significance and distribution remain unclear. The present study assessed mucron morphology in males of 26 species using LM and SEM microscopy. For other species we summarised the published data. Furthermore, ancestral character state reconstruction analysis was performed to assess the distribution of mucron morphology within steinernematid phylogeny. In most species, papilla/spine-like or filamentous mucrons occur at least in the second generation. The species gathered in single phylogenetic groups have a similar mucron morphology. Generally, species with a prominent filamentous mucron belong to the ‘kraussei/feltiae’ and ‘carpocapsae’ groups, whereas mostly non-mucronated species occur in ‘glaseri’ and ‘riobrave’ groups. For future descriptions a precise mucron characterisation in both generations of the male is recommended.


Botany ◽  
2013 ◽  
Vol 91 (9) ◽  
pp. 573-591 ◽  
Author(s):  
Virginia Ramírez-Cruz ◽  
Gastón Guzmán ◽  
Alma Rosa Villalobos-Arámbula ◽  
Aarón Rodríguez ◽  
P. Brandon Matheny ◽  
...  

The genus Psilocybe contains iconic species of fungi renowned for their hallucinogenic properties. Recently, Psilocybe also included non-hallucinogenic species that have since been shifted to the genus Deconica. Here, we reconstruct a multigene phylogeny for Psilocybe, Deconica, and other exemplars of the families Hymenogastraceae and Strophariaceae sensu stricto (s. str.), using three nuclear markers (nLSU-rRNA, 5.8S rRNA, and rpb1). Our results confirm the monophyly of Deconica within Strophariaceae s. str., as well as numerous robust infrageneric relationships. Psilocybe is also recovered as a monophyletic group in the Hymenogastraceae, in which two principal lineages are recognized, including several nested subgroups. Most sections of Psilocybe following classifications based on morphological features are not supported in these analyses. Ancestral character state reconstruction analyses suggest that basidiospore shape in frontal view and spore wall thickness, commonly used to characterize sections in Deconica and Psilocybe, are homoplastic. Chrysocystidia, sterile cells located in the hymenium, evolved on at least two occasions in the Strophariaceae s. str., including in a novel lineage of Deconica.


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