Morphological Convergence Research Articles

Replicated radiations in the South American marsh pitcher plants (Heliamphora) lead to convergent carnivorous trap morphologies.

The evolution of carnivorous pitcher traps across multiple angiosperm lineages represents a classic example of morphological convergence. Nevertheless, no comparative study to-date has examined pitcher evolution from a quantitative morphometric perspective. In the present study, we used comparative morphometric approaches to quantify the shape space occupied by Heliamphora pitchers and to trace evolutionary trajectories through this space to examine patterns of divergence and convergence within the genus. We also investigated pitcher development, and, how the packing of pitchers is affected by crowding, a common condition in their natural environments. Our results showed that Heliamphora pitchers have diverged along three main axes in morphospace: (1) pitcher curvature; (2) nectar spoon elaboration; and (3) pitcher stoutness. Both curvature and stoutness are correlated with pitcher size, suggesting structural constraints in pitcher morphological evolution. Among the four traits (curvature, spoon elaboration, stoutness, and size), all but curvature lacked phylogenetic signal and showed marked convergence across the phylogeny. We also observed tighter packing of pitchers in crowded conditions, and this effect was most pronounced in curved, slender pitchers. Overall, our study demonstrates that diversification and convergent evolution of carnivory-related traits extends to finer evolutionary timescales, reinforcing the notion that ecological specialization may not necessarily be an evolutionary dead end.

Intersectional polyphyly of the puzzling Scapania obcordata (Marchantiidae) suggests convergent evolution: resurrection and European occurrence of S. jensenii

We present an example of morphological convergence among two species of Scapania that were considered to be conspecific. We resurrect S. jensenii from synonymy with the morphologically and molecularly variable S. obcordata because our molecular data show that they are distantly related. Chloroplast trnL-trnF and nuclear ITS sequences resolved S. obcordata in sect. Curtae and S. jensenii in sect. Apiculatae sister to S. obscura and we detected morphological differences in secondary pigmentation and leaf anatomy. The similarity comprises the absence of a pronounced keel in vegetative leaves and a weakly defined stem cortex. These features are virtually unknown in other species of Scapania and probably result from convergence in adaptation to the same environmental conditions, as both taxa inhabit alluvial plains characterised by regular disturbance by flooding and covering with sand and silt. While S. obcordata is widespread in the northern Holarctic and known from the Antarctic, S. jensenii is known from a few localities in Greenland, mainland Norway, the Chukchi Peninsula and the Swiss Alps. Its rarity, the absence of female plants, and the lack of genetic variability suggest that S. jensenii underwent a bottleneck event.

Premature convergence in morphology and control co-evolution: a study

This article addresses the co-evolution of morphology and control in evolutionary robotics, focusing on the challenge of premature convergence and limited morphological diversity. We conduct a comparative analysis of state-of-the-art algorithms, focusing on QD (Quality-Diversity) algorithms, based on a well-defined methodology for benchmarking evolutionary algorithms. We introduce carefully chosen indicators to evaluate their performance in three core aspects: task performance, phenotype diversity, and genotype diversity. Our findings highlight MNSLC (Multi-BC NSLC), with the introduction of aligned novelty to NSLC (Novelty Search with Local Competition), as the most effective algorithm for diversity preservation (genotype and phenotype diversity), while maintaining a competitive level of exploitability (task performance). MAP-Elites, although exhibiting a well-balanced trade-off between exploitation and exploration, fall short in protecting morphological diversity. NSLC, while showing similar performance to MNSLC in terms of exploration, is the least performant in terms of exploitation, contrasting with QN (Fitness-Novelty MOEA), which exhibits much superior exploitation, but inferior exploration, highlighting the effects of local competition in skewing the balance toward exploration. Our study provides valuable insights into the advantages, disadvantages, and trade-offs of different algorithms in co-evolving morphology and control.

Nepenthes limiana (Nepenthaceae), a new pitcher plant from the northern Titiwangsa Range of Peninsular Malaysia

Nepenthes limiana, a pitcher plant from the northern Titiwangsa Range of Peninsular Malaysia, is described as new. It is the northernmost known species of the recently defined N. macfarlanei group, whose members are characterised by the presence of conspicuous hairs on the lower surface of the lid. It differs from other members of this group in exhibiting adaptations to seasonal drought in the form of thickened roots and narrow laminae that are reminiscent of those produced by the pyrophytic Nepenthes of Indochina and northernmost Malaysia. Coupled with the presence of decurrent leaf bases, which are not present in any other N. macfarlanei group species but which are present in the pyrophytic Nepenthes, these characters could indicate either morphological convergence or an as yet uncharacterised relationship between N. limiana and the Nepenthes species of Indochina.

Phylogeny and infrageneric classification of Clerodendrum (Lamiaceae)

Abstract The infrageneric classification of the genus Clerodendrum (Lamiaceae) has been highly problematic due to different concepts and subdivisions being applied to the treatment of Asian, Australian, and African species. Earlier molecular phylogenetic studies based on Sanger sequencing and limited sampling have indicated that previous morphology-based infrageneric classifications are not congruent with the phylogeny due to morphological convergence in many lineages. Advances in high-throughput DNA sequencing provide more information allowing more robust phylogenetic reconstruction at larger scale. We present the first comprehensive phylogenetic study of Clerodendrum that includes representatives of all previously recognized infrageneric taxa and using targeted sequencing data obtained from the Angiosperms353 enrichment to resolve the phylogenetic relationships. In agreement with previous phylogenetic work, our phylogeny shows that Asian and Australian species form a sister clade to an African Clade. Clerodendrum is monophyletic with the exclusion of some tropical coastal species, including some Australian species, which fall within a clade containing Volkameria and New World genera. We recognize two subgenera: subgen. Clerodendrum for Asian and Australian species and the new subgen. Afroclerodendrum for African and Malagasy species. Our findings support an infrageneric classification of Clerodendrum with a total of 13 sections based on molecular phylogenetic evidence and morphology that clearly accommodate the Asian, remaining Australian, and African species. Of these, we propose three new sections: sect. Albiflora, sect. Fortunata and sect. Megaflora for clades presenting unique morphological characters. The sectional classification and taxonomic consequences are discussed.

Can flowers help to disentangle the Vriesea oligantha complex (Bromeliaceae: Tillandsioideae)? Taxonomic implications and contributions to the floral anatomy and biology of Stigmatodon

Abstract The Vriesea oligantha complex comprises Vriesea lancifolia, Vriesea oligantha, and Vriesea pseudoligantha, which were recently transferred to Stigmatodon. Such species exhibit strong morphological convergence to live in rocky fields, which makes difficult their identification in the wild or in herbarium specimens. In a previous work, leaf characters helped in the species delimitation and evidenced a new taxon. Considering that morphology, anatomy, and aspects of floral biology can contribute to better define species limits and to indicate potential pollinators, individuals from nine populations of V. oligantha complex were comparatively studied. The typical V. oligantha is mainly distinguished by tubular flowers, with simple petal appendages and diurnal anthesis. The remaining individuals studied from different populations exhibit campanulate corollas, with denticulate petal appendages and nocturnal anthesis, not allowing for the separation of V. lancifolia, V. pseudoligantha, and a fourth taxon. Floral anatomy is less variable than the external morphology, with little contribution to the species delimitation; however, it is helpful in the circumscription of Stigmatodon. The infralocular septal nectaries and the floral features provide evidence that the main pollinators of campanulate and tubular flowers are bats and hummingbirds, respectively. Specific pollinator guilds in combination with fragmented populations may explain the limited gene flow amongst populations.

First filter feeding in the Early Triassic: cranial morphological convergence between Hupehsuchus and baleen whales

Modern baleen whales are unique as large-sized filter feeders, but their roles were replicated much earlier by diverse marine reptiles of the Mesozoic. Here, we investigate convergence in skull morphology between modern baleen whales and one of the earliest marine reptiles, the basal ichthyosauromorph Hupehsuchus nanchangensis, from the Early Triassic, a time of rapid recovery of life following profound mass extinction. Two new specimens reveal the skull morphology especially in dorsal view. The snout of Hupehsuchus is highly convergent with modern baleen whales, as shown in a morphometric analysis including 130 modern aquatic amniotes. Convergences in the snout include the unfused upper jaw, specialized intermediate space in the divided premaxilla and grooves around the labial margin. Hupehsuchus had enlarged its buccal cavity to enable efficient filter feeding and probably used soft tissues like baleen to expel the water from the oral cavity. Coordinated with the rigid trunk and pachyostotic ribs suggests low speeds of aquatic locomotion, Hupehsuchus probably employed continuous ram filter feeding as in extant bowhead and right whales. The Early Triassic palaeoenvironment of a restrictive lagoon with low productivity drove Hupehsuchus to feed on zooplankton, which facilitated ecosystem recovery in the Nanzhang-Yuan’an Fauna at the beginning of the Mesozoic.

Are the recently described fossil Mole Crickets of Myanmar amber real gryllotalpids? (Orthoptera: Gryllotalpidae & Gryllidae).

We report five new Myanmar amber specimens attributable to "Mole Cricket" †Pherodactylus rectanguli n. comb., hitherto regarded as a Mole Cricket (Orthoptera: Grylloptalpidae). The new material includes two adult males, two adult females, and one nymph. The specimens are redescribed, and additional new characters are provided for their delimitation and corresponding species identification. We carry out a comparison between these new specimens with other taxa of mole crickets from Myanmar amber and extant true crickets. The result indicates that some species merely represent different nymphal development stages or adults of †Pherodactylus rectanguli n. comb., however, they were misidentified as different species. We also treated genera †Tresdigitus n. syn. and †Chunxiania n. syn. as synonyms of genus †Pherodactylus Poinar, Su & Brown, 2020, and treat †Tresdigitus gracilis Jiang, Xu, Jarzembowski & Xiao, 2022 n. syn. and †Chunxiania fania n. syn. as synonyms of †Pherodactylus rectanguli n. comb. †Burmagryllotalpa longa is valid, because its shape of the pronotum curved without lateral carinae. The morphological convergences and specializations of subterranean dwelling species are discussed. The robust fore tibia and long apical spurs of †P. micromorphus, †P. rectanguli n. comb. and †B. longa are insufficient evidence for an assignment to the family Gryllotalpidae. Instead, we suggest place them into the subfamily Gryllinae (Gryllidae), tribe Sclerogryllini, and group them into their own subtribe Pherodactylina n. subtr.. A key to the identification of recent and fossil Sclerogryllini is also provided. Their taxonomy and morphology are discussed.

Substrate- and life habit-induced morphological convergence and divergence in Recent marine bivalve communities

Abstract The morphological disparity of the marine benthos, through the Phanerozoic, is shaped by multiple abiotic and biotic factors, among which substrate and ecology are key contributors. However, the relationship among substrate, ecology, and morphology is not straightforward—a substrate can be occupied by phylogenetically unrelated families with different life habits, influencing morphological convergence. In contrast, related taxa may differ in substrate and life habits, indicating morphological divergence. Here we evaluate the effect of substrate and ecology on the community-level morphological disparity of 398 Recent marine bivalve species from coastal India, using geometric morphometrics. We further evaluate whether the observed patterns are decoupled from taxonomic identities, i.e., phylogenetic (in)dependence. We find that the Recent marine bivalve assemblages show significant morphological differences while living in different substrates or having different life habit traits. However, while sharing a specific substrate or life habit trait (tiering/motility), different families do not show shape convergence, i.e., families maintain their mean shape, except for families living in soft sediments, for which they show strong substrate-driven morphological convergence. These instances of morphological divergence and convergence suggest that the association among sediment preference, ecology, and shape can be rather complex, and can often transgress phylogenetic boundaries in bivalves.

A new species of the Miniopterus australis species complex (Chiroptera: Miniopteridae) from the Western Ghats, India.

The genus Miniopterus is highly diverse in cryptic species. Based on integrated approaches of morphometrics, echolocation call analysis, and molecular phylogenetics, we present evidence of a hitherto undescribed species, Srini's Bent-winged bat Miniopterus srinii sp. nov.. The new species, found in the Western Ghats of southern Karnataka, India, closely resembles the Small Bent-winged bat Miniopterus pusillus, found elsewhere in Karnataka, Kerala, and Tamil Nadu, India. Although it shows external similarity with Miniopterus pusillus sensu stricto from the Nicobar Islands, the new species is relatively larger and distinct in craniodental measurements and echolocation call parameters, despite slight overlaps. Importantly, Miniopterus srinii exhibits morphological convergence with Miniopterus pusillus as despite similarities in morphologies, there is a significant genetic distance of 10.84 ± 0.22%. The new cryptic species shares distribution with Miniopterus phillipsi and Miniopterus pusillus in the Western Ghats, further highlighting the need to study both the genus' cryptic diversity, and the region's conservation importance.

Phylogenomics and deep convergence in cockroach hind-wing morphology

Despite regular advances in Blattodea systematics, several relationships remain controversial or untested in formal phylogenetic reconstructions. This common situation for understudied metazoan groups limits our power to answer questions about phenotypic evolution. In this study, we infer the evolutionary history of Blattodea using newly sampled taxa that improve phylogenetic resolution while also illuminating the evolutionary history of an unusual phenotype—the apically folded hind-wing. Taxa newly sequenced include those with a hind-wing apical fold (Anaplecta pulchella, A. pygmaea, A. sp. cf. malaysensis, Diplopterina parva, Prosoplecta semperi, Anaplectoidea klossi, and Oulopteryx illuminata sp. nov. that we describe herein, including its male genitalia) and other rare taxa (Dipteretrum hamstroemi, Duchailluia togoensis, Lauraesilpha mearetoi, Buboblatta vlasaki). The phylogenetic design utilizes 41 genes over 91 species in total, analyzed in a maximum likelihood and coalescent framework. To quantify the phylogenetic uncertainty of the analysis, support for various topologies is assessed. We find unambiguous support for the surprising position of Neotropical Oulopteryx (Oulopterygidae) as sister to New Caledonian/Australian Tryonicidae. This, and other phylogenetic findings, reveal that the apically folded hind-wing may have arisen nine times in Blattodea. Further investigations are needed, notably with an increased taxonomic sampling, to demonstrate stronger support for the placement of rogue taxa (e.g., Anaplecta) and to investigate the evolutionary correlates of wing evolution.

Towards resolving the problematic status of the digenean genus Astiotrema Looss, 1900: Taxa excluded from Astiotrema (sensu stricto) with special reference to plagiorchioid genera closely related to the restricted concept of Astiotrema.

The restricted concept of Astiotrema Looss, 1900 has been revised to include only eight species and various representative synonyms. However, several remaining taxa of Astiotrema (sensu lato) still need more inspection and scrutiny to determine their correct taxonomic position. Following a comprehensive review, four new genera are erected to accommodate some taxa excluded from Astiotrema (sensu stricto), three of which are closely related to this restricted concept of Astiotrema. Plesioastiotrema n. gen. is erected to accommodate Plesioastiotrema monticellii (Stossich, 1904) n. comb. (syn. Astiotrema monticellii Stossich, 1904) as the type-species and Plesioastiotrema magniovum (Fischthal & Kuntz, 1965) n. comb. (syn. Astiotrema magniovum Fischthal & Kuntz, 1965). Homeoastiotrema n. gen. is established for its type-species, Homeoastiotrema turneri (Bray, Van Oosterhout, Blais & Cable, 2006) n. comb., to accommodate Astiotrema turneri Bray, Van Oosterhout, Blais & Cable, 2006. Ichthyastiotrema n. gen. is erected with its type-species, Ichthyastiotrema fotedari (Dhar, 1977) n. comb. (syn. Astiotrema fotedari Dhar, 1977). A distinct morphologically and taxonomically distant taxon from Astiotrema (sensu stricto) is proposed in its own genus, Alloastiotrema n. gen. with its type-species, Alloastiotrema birmanii (Khan, Gul-E-Lala, Ghazi, Khatoon, Waheed & Khan, 2021) n. comb., to accommodate Astiotrema birmanii Khan, Gul-E-Lala, Ghazi, Khatoon, Waheed & Khan, 2021 and positioned distant from Astiotrema (sensu stricto). Astiotrema erinaceum (Poirier, 1886) Stossich, 1904, Astiotrema trituri Grabda, 1959 and Astiotrema (Biguetrema) tananarivense Deblock & Capron, 1962 are adopted synonyms of Galactosomum erinaceum (Poirier, 1886) Bittner & Sprehn, 1928, Neoastiotrema trituri (Grabda, 1959) Tkach, 2008 and Laiogonimus tananarivensis (Deblock & Capron, 1962) Fischthal & Thomas, 1968, respectively. Astiotrema lazeri El-Naffar, Saoud & Hassan, 1984 and Astiotrema gangeticus Gupta & Singh, 1985 nec Harshey, 1932 are synonymized with Glossidium pedatum Looss, 1899 and Orientocreadium batrachoides Tubangui, 1931, respectively. Based on its contradiction to the diagnosis of members of the Orientocreadiidae Yamaguti, 1958, we declare Orientocreadium lucknowensis Nigam, Chandra, Johri & Saxena, 2015 as incertae sedis. Longigula Qiu, Zhang & Li, 1983 and Kalipharynx Boeger & Thatcher, 1983 are morphologically closest to Astiotrema (sensu stricto) compared to members of the Plagiorchiidae Lühe, 1901 based on both genera possessing a cirrus-pouch with a unipartite, saccular seminal vesicle. The problematic status of Pseudoparamacroderoides Gupta & Agrawal, 1968 (sensu lato), the closest related genus to Astiotrema (sensu stricto), is discussed through evaluating the differential characteristics among listed species to indicate the extent of their validity and identifying the genuine species within this genus to re-evaluate the confusing and overlapping species to help understand their relationships with closely related plagiorchioids. Accordingly, only three species are recognized within Pseudoparamacroderoides Gupta & Agrawal, 1968 (sensu stricto): Pseudoparamacroderoides dongthapensis Truong, Curran & Bullard in Truong, Curran, Dutton & Bullard, 2021; Pseudoparamacroderoides pseudobagri (Wang in Wang, Zhao, Chen & Tao, 1983) n. comb. (syns. Astiotrema pseudobagri [Wang in Wang, Zhao, Chen & Tao, 1983] Karar, Blend, Dronen & Adel, 2021; Gauhatiana pseudobagri Wang in Wang, Zhao, Chen & Tao, 1983); and Pseudoparamacroderoides seenghali Gupta & Agrawal, 1968 (Syn. Pseudoparamacroderoides vittati Kakaji, 1969 n. syn.). Pseudoparamacroderoides raychaudhurii Agarwal & Kumar, 1983 is re-evaluated as Alloglossidium raychaudhurii (Agarwal & Kumar, 1983) n. comb. Anomalomacroderoiditrema n. gen. is erected for the type-species, Anomalomacroderoiditrema keni (Agarwal & Agarwal, 1984) n. comb., to accommodate specimens of Pseudoparamacroderoides keni Agarwal & Agarwal, 1984. Although the morphological convergence of Gauhatiana Gupta, 1953 within the Plagiorchioidea Lühe, 1901 has been suggested, it is neither a plagiorchiid nor a macroderoidid and does not appear closely related to Astiotrema (sensu stricto); it evidently is a member of the Monorchiidae Odhner, 1911. Alloglyptus Byrd, 1950 is taxonomically positioned as a gorgoderoid in the Allocreadiidae Looss, 1902, neither a plagiorchioid taxon nor closely related to Astiotrema (sensu stricto). The ambiguity of the seminal receptacle in some taxa of Astiotrema is discussed.

Mitogenomic phylogeny of Muricidae (Gastropoda: Neogastropoda)

AbstractMuricidae is one of the most species‐rich and morphologically diverse families in Gastropoda, with a worldwide distribution. The classification of Muricidae has traditionally been based on shell and radular characteristics; however, the phylogenetic relationships within the family are debated due to morphological convergence and plasticity. In this study, to explore the phylogenetic relationships of Muricidae, we sequenced 11 muricid mitochondrial (mt) genomes and compared them with 13 previously reported complete muricid mt genomes. All muricid mt genomes shared the same gene arrangement and exhibited conserved genome size and nucleotide composition. Three‐nucleotide deletions in atp8 and nad4, and three‐nucleotide insertions in nad2 were detected in Rapaninae. Both maximum likelihood and Bayesian inference analyses supported the monophyly of each subfamily studied (Ocenebrinae, Muricinae, Rapaninae and Ergalataxinae). Ergalataxinae was recovered as the sister taxon of Rapaninae, refuting the traditional morphology‐based placement of Ergalataxinae within Rapaninae. In Rapaninae, Indothais was confirmed to be monophyletic and determined to be a valid genus. Similarly, Drupina was determined to be an independent genus rather than a subgenus of Drupa. Purpura was recovered as a paraphyletic group, with Purpura panama being sister to Reishia + Rapana + Indothais and clustering with Purpura bufo.

Unveiling the evolutionary relationships and the high cryptic diversity in Andean rainfrogs (Craugastoridae: Pristimantis myersi group).

Pristimantis is the most diverse genus of terrestrial frogs. Historically, it has been divided into several phenetic groups in order to facilitate species identification. However, in light of phylogenetic analysis, many of these groups have been shown to be non-monophyletic, denoting a high degree of morphological convergence and limited number of diagnostic traits. In this study, we focus on the Pristimantis myersi group, an assemblage of small rainfrogs distributed throughout the Andes of Ecuador and Colombia, whose external morphology is highly conserved, and its species diversity and evolutionary relationships largely unknown. We inferred a new phylogenetic hypothesis for the frog genus Pristimantis, including all available sequences of the mtDNA 16S rRNA, as well as new DNA sequences from 175 specimens. Our sampling included 19 of the 24 species currently recognized as part of the Pristimantis myersi group. Our new evolutionary hypothesis recovered the P. myersi group as non-monophyletic and composed of 16 species. Therefore, we exclude P. albujai, P. bicantus, P. sambalan, and P. nelsongalloi in order to preserve the monophyly of the group. We discovered at least eight candidate species, most of them hidden under the names of P. leoni, P. hectus, P. festae, P. gladiator, and P. ocreatus. Our results reveal the occurrence of a high level of cryptic diversity to the species level within the P. myersi group and highlight the need to redefine some of its species and reassess their conservation status. We suggest that the conservation status of six species within the group need to be re-evaluated because they exhibit smaller distributions than previously thought; these species are: P. festae, P. gladiator, P. hectus, P. leoni, P. ocreatus, and P. pyrrhomerus. Finally, given that the Pristimantis myersi group, as defined in this work, is monophyletic and morphologically diagnosable, and that Trachyphrynus is an available name for the clade containing P. myersi, we implement Trachyphrynus as a formal subgenus name for the Pristimantis myersi group.

The systematics and evolution of the Sri Lankan rainforest land snail Corilla: New insights from RADseq-based phylogenetics

The stylommatophoran land-snail genus Corilla is endemic to Sri Lanka and India’s Western Ghats. On the basis of habitat distribution and shell morphology, the 10 extant Sri Lankan species fall into two distinct groups, lowland and montane. Here, we use phylogenetic analyses of restriction-site-associated DNA sequencing (RADseq) data and ancestral-state reconstructions of habitat association and shell morphology to clarify the systematics and evolution of Sri Lankan Corilla. Our dataset consists of 9 species of Corilla. Phylogenetic analyses were based on 88 assemblies (9,604–4,132,850 bp) generated by the RADseq assembler ipyrad, using four parameter combinations and different levels of missing data. Trees were inferred using a maximum likelihood (ML) approach. Ancestral states were reconstructed using maximum parsimony (MP) and ML approaches, with 1 binary state character analysed for habitat association (lowland vs montane) and 6 binary state characters analysed for shell morphology (shape, colour, lip width, length of upper palatal folds, orientation of upper palatal folds and collabral sculpture). Over a wide range of missing data (40–87 % missing individuals per locus) and assembly sizes (62,279–4,132,850 bp), nearly all trees conformed to one of two topologies (A and B), most relationships were strongly supported and total branch support approached the maximal value. Apart from the position of Corilla odontophora ‘south’, topologies A and B showed similar, well-resolved relationships at and above the species level. Our study agrees with the shell-based taxonomy of C. adamsi, C. beddomeae, C. carabinata, C. colletti and C. humberti (all maximally supported as monophyletic species). It shows that C. erronea and C. fryae constitute a single relatively widespread species (for which the valid name is C. erronea) and that the names C. gudei and C. odontophora each apply to at least two distinct, yet conchologically-cryptic species. The MP and ML ancestral-state reconstructions yielded broadly similar results and provide firm evidence that diversification in Sri Lankan Corilla has involved evolutionary convergence in the shell morphology of lowland lineages, with a pale shell and wide lip having evolved on at least two separate occasions (in C. carabinata and C. colletti) from montane ancestors having a dark, narrow-lipped shell.

Total-evidence phylogeny and evolutionary morphology of New World pitvipers (Serpentes: Viperidae: Crotalinae).

Crotalines (pitvipers) in the Americas are distributed from southern Canada to southern Argentina, and are represented by 13 genera and 163 species that constitute a monophyletic group. Their phylogenetic relationships have been assessed mostly based on DNA sequences, while morphological data have scarcely been used for phylogenetic inquiry. We present a total-evidence phylogeny of New World pitvipers, the most taxon/character comprehensive phylogeny to date. Our analysis includes all genera, morphological data from external morphology, cranial osteology and hemipenial morphology, and DNA sequences from mitochondrial and nuclear genes. We performed analyses with parsimony as an optimality criterion, using different schemes for character weighting. We evaluated the contribution of the different sources of characters to the phylogeny through analyses of reduced datasets and calculation of weighted homoplasy and retention indexes. We performed a morphological character analysis to identify synapomorphies for the main clades. In terms of biogeography, our results support a single colonization event of the Americas by pitvipers, and a cladogenetic event into a Neotropical clade and a North American/Neotropical clade. The results also shed light on the previously unstable position of some taxa, although they could not sufficiently resolve the position of Bothrops lojanus, which may lead to the paraphyly of either Bothrops or Bothrocophias. The morphological character analyses demonstrated that an important phylogenetic signal is contained in characters related to head scalation, the jaws and the dorsum of the skull, and allowed us to detect morphological convergences in external morphology associated with arboreality.

An updated classification of cyanobacterial orders and families based on phylogenomic and polyphasic analysis.

Cyanobacterial taxonomy is facing a period of rapid changes thanks to the ease of 16S rRNA gene sequencing and established workflows for description of new taxa. Since the last comprehensive review of the cyanobacterial system in 2014 until 2021, at least 273 species in 140 genera were newly described. These taxa were mainly placed into previously defined orders and families although several new families were proposed. However, the classification of most taxa still relied on hierarchical relationships inherited from the classical morphological taxonomy. Similarly, the obviously polyphyletic orders such as Synechococcales and Oscillatoriales were left unchanged. In this study, the rising number of genomic sequences of cyanobacteria and well-described reference strains allowed us to reconstruct a robust phylogenomic tree for taxonomic purposes. A less robust but better sampled 16S rRNA gene phylogeny was mapped to the phylogenomic backbone. Based on both these phylogenies, a polyphasic classification throughout the whole phylum of Cyanobacteria was created, with ten new orders and fifteen new families. The proposed system of cyanobacterial orders and families relied on a phylogenomic tree but still employed phenotypic apomorphies where possible to make it useful for professionals in the field. It was, however, confirmed that morphological convergence of phylogenetically distant taxa was a frequent phenomenon in cyanobacteria. Moreover, the limited phylogenetic informativeness of the 16S rRNA gene, resulting in ambiguous phylogenies above the genus level, emphasized the integration of genomic data as a prerequisite for the conclusive taxonomic placement of a vast number of cyanobacterial genera in the future.

Taxonomic revision of the genus Spiranthes (Orchidaceae) in Taiwan

The taxonomy of Spiranthes is highly challenging due to its phenotypic plasticity, morphological convergence, and hybridization. This paper presents a re-evaluation of the genus Spiranthes (Orchidaceae) in Taiwan, with special reference to the taxonomic identity of S. suishaensis that has often been considered the earlier name of S. nivea or S. hongkongensis. Nonetheless, the floral dissection of the type specimen revealed that S. suishaensis has a well-developed rostellum that separates the stigma and pollinarium of each flower, in contrast to autogamous taxa such as S. nivea and S. hongkongensis. Given the morphological evidence and that only S. sinensis was collected in the S. suishaensis type locality, we concluded that S. suishaensis is neither an earlier name for S. nivea nor S. hongkongensis but a synonym of S. sinensis. During morphological comparisons of S. suishaensis with other taxa of S. sinensis complex, we also found that the taxon illegitimately described as “S. minutiflora” could be treated as a variant of S. nivea. Given that it is distinguishable from S. nivea var. nivea by its more densely pubescent rachis and ovaries (vs. sparsely pubescent rachis and ovaries), narrower sepals with white tinged with pink or purple at apex (vs. wider and entirely white sepals), and papillose labellum disc (vs. almost glabrous labellum disc), we described it as a new variety of S. nivea, which we propose to name S. nivea var. papillata T.C. Hsu & Suetsugu. Consequently, we concluded that three species (S. sinensis, S. hongkongensis, and S. nivea [including var. nivea and var. papillata]) and one hybrid, S. australis × S. sinensis, occur in Taiwan.

Morphological disparity and evolutionary rates of cranial and postcranial characters in sloths (Mammalia, Pilosa, Folivora)

AbstractSloth morphological evolution has been widely studied qualitatively, with comparative anatomy and morpho‐functional approaches, or through quantitative assessments of morphological variation using morphometrics. Only recently, however, have folivoran morphological disparity and evolutionary rates begun to be evaluated using discrete character data. Nonetheless, patterns of morphological evolution in separate character partitions have not been investigated, neither the relative influence of, on the one hand, phylogeny, and on the other, dietary and locomotory adaptations of sloths. Here we evaluate those patterns using a phylomorphospace approach, quantifying morphological disparity and evolutionary rates, and investigating possible drivers of morphological evolution for cranial and postcranial characters in Folivora. The evolution of the morphology in those partitions is associated with distinct patterns of disparity among clades and ecological groups, even though the two partitions do not differ substantially in overall evolutionary tempo. Historical processes shaped the morphological evolution of sloths more consistently than ecological ones, although changes in postcranial characters also seem to be associated with locomotory adaptations, in which morphological convergences were much more common. We also discuss important methodological trade‐offs in investigations of partitioned datasets mostly composed of fossil taxa.

Correlation with a limited set of behavioral niches explains the convergence of somatic morphology in mygalomorph spiders.

Understanding the drivers of morphological convergence requires investigation into its relationship with behavior and niche space, and such investigations in turn provide insights into evolutionary dynamics, functional morphology, and life history. Mygalomorph spiders (trapdoor spiders and their kin) have long been associated with high levels of morphological homoplasy, and many convergent features can be intuitively associated with different behavioral niches. Using genus-level phylogenies based on recent genomic studies and a newly assembled matrix of discrete behavioral and somatic morphological characters, we reconstruct the evolution of burrowing behavior in the Mygalomorphae, compare the influence of behavior and evolutionary history on somatic morphology, and test hypotheses of correlated evolution between specific morphological features and behavior. Our results reveal the simplicity of the mygalomorph adaptive landscape, with opportunistic, web-building taxa at one end, and burrowing/nesting taxa with structurally modified burrow entrances (e.g., a trapdoor) at the other. Shifts in behavioral niche, in both directions, are common across the evolutionary history of the Mygalomorphae, and several major clades include taxa inhabiting both behavioral extremes. Somatic morphology is heavily influenced by behavior, with taxa inhabiting the same behavioral niche often more similar morphologically than more closely related but behaviorally divergent taxa, and we were able to identify a suite of 11 somatic features that show significant correlation with particular behaviors. We discuss these findings in light of the function of particular morphological features, niche dynamics within the Mygalomorphae, and constraints on the mygalomorph adaptive landscape relative to other spiders.