Multivariate Morphometric Analyses Research Articles

Alike but genetically divergent: The resurrection of Urotrygon asterias (Jordan & Gilbert, 1883) from its closest relatives, the Munda and the Blotched stingray.

The genus Urotrygon comprises small- to medium-sized endemic round rays on the American continent and has undergone several synonymization processes. Here, we used an integrative taxonomic approach, including meristic, morphometric, and mtDNA analyses, to resolve the particularly intricate relationship among Urotrygon munda Gill, 1863, Urotrygon chilensis (Günther, 1872), and Urotrygon asterias (Jordan & Gilbert, 1883). The latter species is currently a synonym of U. munda but is also considered the U. chilensis "northern morphotype." These taxonomic entities have historically been confounded, mainly due to their phenotypical resemblance along their geographic distribution in the eastern Pacific. We assessed 78 specimens (43 "northern" and 30 "southern morphotypes" of U. chilensis, as well as 5 U. munda) using 19 external variables for taxonomic and morphometric analysis. Distinct meristic patterns, including pectoral and pelvic ceratotrichia, vertebrae number, and thorn distribution along the dorsal midline, were observed in the series-type specimens of the three taxonomic entities. Our multivariate morphometric analyses consistently differentiated the three groups as distinct taxonomic entities, with an overall classification accuracy of 66.7%. The meristic results also provided reliable information distinguishing the three entities. Based on the nicotinamide adenine dinucleotide (NADH2) and cytochrome oxidase subunit I (COI) genes, our phylogenetic analysis were consistent with the morphometric and meristic data, supporting these three entities as distinct species having their own evolutionary lineages. Our comprehensive approach confidently demonstrated that the northern U. chilensis morphotype matched and corresponded to the description of the Starry round ray, U. asterias, confirming its taxonomic resurrection as a valid species distinct from U. chilensis and U. munda. The geographic distribution of U. asterias spans from the tropical west coast of Mexico (including the Gulf of California) to Costa Rica, revealing that microevolutionary processes have well-defined population clades within this range. Furthermore, U. chilensis is unequivocally established as the sole Urotrygon species occurring south of the Guayaquil marine ecoregion. In addition, the public COI and NADH2 sequences available for Urotrygon hosted in the ad hoc online databases were found to be misidentified, emphasizing the need for rigorous taxonomic scrutiny in this group. Finally, our research underscores the significance of an integrative approach that combines morphometric, meristic, and molecular techniques with historical data to disentangle the complexities of closely related taxa.

Carpinus austrobalcanica – A new highly polyploid species from the Balkan Peninsula closely related to European hornbeam

The Balkan Peninsula was the primary glacial refugium for many temperate tree species and contributed overproportionally to the postglacial recolonisation of central and eastern Europe. This is also the case for Carpinus betulus, the European hornbeam, whose main glacial refugium was in the Balkans. During our fieldwork in the southern Balkans, we discovered trees with a morphology similar to that of C. betulus, but differing in their rough, highly rigged bark and the shape of their fruit involucre. The aim of this study was to investigate the evolutionary origin and differentiation of these morphologically distinct populations of C. betulus from the North Pindus Mountain range in northern Greece and southern Albania using an integrative approach. Our study combined phylogenetic analyses of plastid and nuclear internal transcribed spacer sequences, amplified fragment length polymorphism fingerprinting, relative genome size estimation, and multivariate morphometric analyses. After establishing the genetic and morphological divergence of the aforementioned populations, we described them as a new species, Carpinus austrobalcanica D.Lakušić, Kuzmanović, Stevanoski, Schönsw. & Frajman, sp. nov. We provide diagnosis, description, geographical distribution, and conservation status of this enigmatic newly described tree species locally endemic to the southern Balkans.

Alpha-taxonomy underestimates the diversity in Jacquemontia (Convolvulaceae): a new hypothesis for Jacquemontia evolvuloides complex based on morphological, anatomical, and morphometric analyses

Interpreting plant morphological variability makes species delimitation a challenge. Jacquemontia evolvuloides and its relatives have been the target of different taxonomic classifications, either as multiple species and subspecies/varieties or as a single polymorphic species. Here we applied univariate and multivariate morphometric analyses, using both macro- and micromorphological characters of 22 populations comprising this species complex. Our analysis revealed six morphotypes with clear discontinuities in both macro- and micromorphological characters. One morphotype corresponds to J. evolvuloides, two correspond to previously named species, putted under a synonym, here re-established (J. agrestis and J. decumbens) and three morphotypes correspond to new species, described here. We present a complete taxonomic treatment of J. evolvuloides and related species, with descriptions, distribution maps, photographs, and illustrations, that indicate new synonyms.

A review of the glacial environment arthropod trace fossils Umfolozia and Warvichnium with the description of new ichnotaxa

AbstractTrace fossils are important records of the presence and behaviour of animals in the past, especially in deposits where few body fossils are preserved. They tend to provide the main palaeobiological record for past glacial environments, and are thus very important for understanding the ecology of these palaeoenvironments. Two ichnogenera are common in glacial sediments: Umfolozia and Warvichnium. Both Umfolozia and Warvichnium are attributed to arthropods; the former occurs across the Late Palaeozoic Ice Age (LPIA) and the latter occurs during both the LPIA and the Quaternary glacial event. Here, we review the stratigraphic record, ichnotaxonomy, palaeoecology, palaeoenvironments and possible tracemakers of these two ichnogenera. In addition to assessing morphological ichnotaxobases, we use multivariate morphometric analysis and inferential statistical tests to support our ichnotaxonomic revisions. The diagnosis of Umfolozia is revised, with the description of a new ichnospecies, Umfolozia terere, and the emendation of Umfolozia riojana (formerly Umfolozia longula). We revised Warvichnium, maintaining the original Warvichnium ulbrichi and allocating two morphologies to the ichnogenus Irichnus: Irichnus saltatorius and I. paripinnatus isp. nov. These trace fossils record several behaviours, and have implications for palaeoenvironmental interpretations and the evolution of invertebrate ecosystems. Using Umfolozia and Warvichnium as case studies, we demonstrate the application of morphometric analysis in ichnotaxonomy and highlight this as a tool that may be applied to other trace‐fossil groups.

High phenotypic plasticity at the dawn of the eosauropterygian radiation.

The initial radiation of Eosauropterygia during the Triassic biotic recovery represents a key event in the dominance of reptiles secondarily adapted to marine environments. Recent studies on Mesozoic marine reptile disparity highlighted that eosauropterygians had their greatest morphological diversity during the Middle Triassic, with the co-occurrence of Pachypleurosauroidea, Nothosauroidea and Pistosauroidea, mostly along the margins of the Tethys Ocean. However, these previous studies quantitatively analysed the disparity of Eosauropterygia as a whole without focussing on Triassic taxa, thus limiting our understanding of their diversification and morphospace occupation during the Middle Triassic. Our multivariate morphometric analyses highlight a clearly distinct colonization of the ecomorphospace by the three clades, with no evidence of whole-body convergent evolution with the exception of the peculiar pistosauroid Wangosaurus brevirostris, which appears phenotypically much more similar to nothosauroids. This global pattern is mostly driven by craniodental differences and inferred feeding specializations. We also reveal noticeable regional differences among nothosauroids and pachypleurosauroids of which the latter likely experienced a remarkable diversification in the eastern Tethys during the Pelsonian. Our results demonstrate that the high phenotypic plasticity characterizing the evolution of the pelagic plesiosaurians was already present in their Triassic ancestors, casting eosauropterygians as particularly adaptable animals.

Revision of the extinct island-shrews Nesophontes (Mammalia: Eulipotyphla: Nesophontidae) from Cuba

Nesophontes is an extinct, shrew-like mammal endemic to the Greater Antilles. Within this genus, the Cuban taxa have a challenging taxonomic history. The dichotomy in the interpretation of species limits arises from the ample size variation observed in skeletal remains. Here, I provide a detailed systematic revision of Cuban species through multivariate morphometric and qualitative analyses. These include discrete osteological characteristics of the cranium, dentary, dentition, humerus, femur, pelvis, and endocranial casts from a wide range of specimens, several maturity levels, and radiocarbon-dated paleontological contexts, all of which can help resolve current taxonomic ambiguities and elucidate the species limits of the Cuban taxa. Furthermore, stable isotopes of carbon and nitrogen were obtained to approximate aspects of diet, habitat, and resource partitioning between the Cuban Nesophontes. Collectively, these analyses support the presence of three species that are divided into two morphotypes. The larger included Nesophontes major and Nesophontes longirostris, whereas Nesophontes micrus is smallest. Morphotypes of N. major and N. micrus showed further intraspecific variation, which could be attributed to sexual dimorphism. Chronologic and geographic variations, at least during the Late Holocene, were quantitatively detected but poorly supported. The isotope signals suggest slight microhabitat segregation between N. major and N. micrus, but overall similar diets. Altogether, these new data provide insights into the morphology and natural history of these peculiar and extinct Antillean land mammals.

Integrative taxonomy supports the recognition of four taxa in the Notholaena trichomanoides complex (Pteridaceae) in Cuba

Abstract With nearly 40 species, the fern genus Notholaena has its evolutionary centre in the deserts of Mexico and the southwestern United States. Previous studies have focused on assessing the monophyly of the genus and the patterns of farina evolution, but little attention has been given to species complexes. Notholaena trichomanoides s.l. is endemic to the Greater Antilles, growing on all four islands. Although at least two varieties have been described, many authors have hesitated to recognize them and have treated this complex as only one taxon. A multivariate morphometric analysis including 80 representatives of N. trichomanoides from the Greater Antilles allowed us to recognize four morphological groups. Twenty individuals from seven populations representing all these morphological groups were sampled in Cuba. Differences among the four lineages were supported by molecular phylogenetics (including three plastid and two nuclear markers), molecular species delimitation, morphology and geological preferences. Ploidy levels inferred using spore sizes calibrated by chromosome counts revealed the existence of diploid and tetraploid lineages within the complex. Time-calibrated trees suggest that the divergence of the common ancestral populations of N. trichomanoides s.l. and those of its sister taxon N. ekmanii occurred between the Middle Miocene and the Miocene–Pliocene boundary followed by a recent diversification within the complex, ranging between the Middle Pliocene and the Middle Pleistocene.

Species boundaries within the recently diverged South American monocot‐like Eryngium (Apiaceae, Saniculoideae) based on biogeographic, climatic, morphological, and molecular data: E. cerradense, a new species from Paraguay

AbstractThe species of Eryngium with a monocot‐like habit are among the most taxonomically complex. They show low phenotypic and molecular differentiation due to their recent, rapid, and reticulate speciation during the Quaternary period. In this study, we evaluate the boundaries of the monocot‐like Eryngium regnellii and a closely related entity from the grasslands in the Cerrado of Paraguay. We integrated evidence from multiple data sources to test species delimitation: we estimated the phylogenetic position of both entities within Eryngium based on ITS nrDNA and cpDNA sequences; we carried out univariate and multivariate morphometric analyses to test statistically significant differences and to recognize morphological diagnostic characters; we also analyzed geographic distribution, habitat, and bioclimatic variables to evaluate divergence in environmental niche, and finally, we used Bayesian coalescent‐based delimitation approaches to test genetic structure. Divergence in morphology, environmental niche, and genetic structure between E. regnellii and the lineage from Paraguay support the hypothesis of evolutionary independence among these two lineages. Therefore, based on an integrative approach, we recognize and describe a new species from Paraguay: Eryngium cerradense.

Morphological and molecular analyses confirm the presence of the newly described bat species Molossus melini in the Espinal ecoregion from Argentina.

The online version contains supplementary material available at 10.1007/s13364-023-00679-1.

Problematic putative pachycephalosaurids: Synchrotron µCT imaging shines new light on the anatomy and taxonomic validity of Gravitholus albertae from the Belly River Group (Campanian) of Alberta, Canada

The taxonomic validity of the holotype and sole specimen of the pachycephalosaurid Gravitholus albertae (TMP 1972.027.0001) from the Belly River Group (Alberta, Canada), remains unresolved forty years after its first description. The diagnosis for this species is tenuous at best and extensive cranial fusion has prevented a thorough description and taxonomic referral of TMP 1972.027.0001. We used synchrotron µCT imaging to identify fused sutures and segment the individual elements that comprise TMP 1972.027.0001. This allowed for a detailed description of the specimen in a more thorough comparative framework with other known pachycephalosaurid specimens. Using new observations of contacts between cranial elements, the morphological distinction of TMP 1972.027.0001 from other Belly River Group pachycephalosaurids was tested with bivariate and multivariate morphometric analyses. TMP 1972.027.0001 is morphologically consistent as an end-stage semaphorant of Stegoceras validum. Furthermore, we find no taxonomically significant morphometric distinctions between Gravitholus albertae, Hanssuesia sternbergi, and Stegoceras validum, and propose the former two are synonymous with the later. Large Stegoceras validum frontoparietals show statistically significant dimorphism in the thickness of the frontonasal boss, which is not apparent amongst juvenile and subadult specimens. Pathologies consistent with intraspecific combat (“headbutting”) appear restricted to frontoparietal domes with proportionally taller frontonasal bosses, and suggests that the two morphs represent sexual dimorphs, rather than separate species. Foraminacephale brevis and Stegoceras validum are the only named pachycephalosaurids recognised in the Dinosaur Park Formation. The stratigraphic and temporal range of Stegoceras validum is extended into the underlying Oldman Formation. Pachycephalosaurid diversity in the Campanian is reduced as a result of these revised taxonomic hypotheses. A revised phylogenetic character matrix, recognising taxonomic synonymies and ontogenetically dependent character states results in a largely unresolved Pachycephalosauria.

Integrative Taxonomy Approach Reveals Cryptic Diversity within the Phoretic Pseudoscorpion Genus Lamprochernes (Pseudoscorpiones: Chernetidae).

Pseudoscorpions represent an ancient, but homogeneous group of arachnids. The genus Lamprochernes comprises several morphologically similar species with wide and overlapping distributions. We implemented an integrative approach combining molecular barcoding (cox1), with cytogenetic and morphological analyses in order to assess species boundaries in European Lamprochernes populations. The results suggest ancient origins of Lamprochernes species accompanied by morphological stasis within the genus. Our integrative approach delimited three nominal Lamprochernes species and one cryptic lineage Lamprochernes abditus sp. nov. Despite its Oligocene origin, L. abditus sp. nov. can be distinguished from its closest relative only by molecular and cytogenetic differences, or alternatively, by a complex multivariate morphometric analysis involving other Lamprochernes species. The population structure and common haplotype sharing across geographically distant populations in most Lamprochernes species suggest that a phoretic manner of dispersal is efficient in this group.

Morphological Continua Make Poor Species: Genus-Wide Morphometric Survey of the European Bee Orchids (Ophrys L.).

Despite (or perhaps because of) intensive multidisciplinary research, opinions on the optimal number of species recognised within the Eurasian orchid genus Ophrys range from nine to at least 400. The lower figure of nine macrospecies is based primarily on seeking small but reliable discontinuities in DNA 'barcode' regions, an approach subsequently reinforced and finessed via high-throughput sequencing studies. The upper figure of ca. 400 microspecies reflects the morphological authoritarianism of traditional taxonomy combined with belief in extreme pollinator specificity caused by reliance on pollination through pseudo-copulation, enacted by bees and wasps. Groupings of microspecies that are less inclusive than macrospecies are termed mesospecies. Herein, we present multivariate morphometric analyses based on 51 characters scored for 457 individual plants that together span the full morphological and molecular diversity within the genus Ophrys, encompassing 113 named microspecies that collectively represent all 29 mesospecies and all nine macrospecies. We critique our preferred morphometric approach of accumulating heterogeneous data and analysing them primarily using principal coordinates, noting that our conclusions would have been strengthened by even greater sampling and the inclusion of data describing pseudo-pheromone cocktails. Morphological variation within Ophrys proved to be exceptionally multidimensional, lacking strong directional trends. Multivariate clustering of plants according to prior taxonomy was typically weak, irrespective of whether it was assessed at the level of macrospecies, mesospecies or microspecies; considerable morphological overlap was evident even between subsets of the molecularly differentiable macrospecies. Characters supporting genuine taxonomic distinctions were often sufficiently subtle that they were masked by greater and more positively correlated variation that reflected strong contrasts in flower size, tepal colour or, less often, plant size. Individual macrospecies appear to represent morphological continua, within which taxonomic divisions are likely to prove arbitrary if based exclusively on morphological criteria and adequately sampled across their geographic range. It remains unclear how much of the mosaic of subtle character variation among the microspecies reflects genetic versus epigenetic or non-genetic influences and what proportion of any contrasts observed in gene frequencies can be attributed to the adaptive microevolution that is widely considered to dictate speciation in the genus. Moreover, supplementing weak morphological criteria with extrinsic criteria, typically by imposing constraints on geographic location and/or supposed pollinator preference, assumes rather than demonstrates the presence of even the weakest of species boundaries. Overall, it is clear that entities in Ophrys below the level of macrospecies have insufficiently structured variation, either phenotypic or genotypic, to be resolved into discrete, self-circumscribing ("natural") entities that can legitimately be equated with species as delimited within other less specialised plant genera. Our search for a non-arbitrary (meso)species concept competent to circumscribe an intermediate number of species has so far proven unsuccessful.

Morphometric analysis of lungfish endocasts elucidates early dipnoan palaeoneurological evolution.

The lobe-finned fish, lungfish (Dipnoi, Sarcoptergii), have persisted for ~400 million years from the Devonian Period to present day. The evolution of their dermal skull and dentition is relatively well understood, but this is not the case for the central nervous system. While the brain has poor preservation potential and is not currently known in any fossil lungfish, substantial indirect information about it and associated structures (e.g. labyrinths) can be obtained from the cranial endocast. However, before the recent development of X-ray tomography as a palaeontological tool, these endocasts could not be studied non-destructively, and few detailed studies were undertaken. Here, we describe and illustrate the endocasts of six Palaeozoic lungfish from tomographic scans. We combine these with six previously described digital lungfish endocasts (4 fossil and 2 recent taxa) into a 12-taxon dataset for multivariate morphometric analysis using 17 variables. We find that the olfactory region is more highly plastic than the hindbrain, and undergoes significant elongation in several taxa. Further, while the semicircular canals covary as an integrated module, the utriculus and sacculus vary independently of each other. Functional interpretation suggests that olfaction has remained a dominant sense throughout lungfish evolution, and changes in the labyrinth may potentially reflect a change from nektonic to near-shore environmental niches. Phylogenetic implications show that endocranial form fails to support monophyly of the 'chirodipterids'. Those with elongated crania similarly fail to form a distinct clade, suggesting these two paraphyletic groups have converged towards either head elongation or truncation driven by non-phylogenetic constraints.

Species Delimitation of the Atlantic Forest Endemic Inga subnuda (Leguminosae, Caesalpinioideae, Mimosoid Clade) Subspecies Based on Morphological, Ecological, and Palaeoecological Data

Abstract— Inga subnuda is one of 31 Inga species endemic to the Brazilian Atlantic Forest and is currently treated as having two subspecies (I. subnuda subsp. subnuda and I. subnuda subsp. luschnathiana). However, due to intermixed leaf and floral traits, these subspecies are difficult to morphologically distinguish. This study aimed to better understand the boundaries of these two subspecies and to test if these taxa should be treated at the species level. Morphological variation and bioclimatic data related to the two subspecies of the complex were assessed using multivariate morphometric analyses and ecological niche modeling. Different groups were recognized using morphological quantitative characters. The climatic space was similar but not identical, and recent climatic cycles that could have shaped the current distributions of the subspecies are discussed. The results of our integrative study suggest the subspecies are distinct species. Thus, we propose changing the status of I. subnuda subsp. luschnathiana to the rank of species. The new taxon is described and illustrated.

Morphometric analysis of the wing for aphids (Hemiptera: Aphididae) associated with potatoes

Aphids are one of the major pests which harm crops worldwide. Among them, in potatoes, they not only give damages to the plants by sucking but also mediates viruses. For controlling these aphids, it is important to identify early migrating aphids, but morphological identification of the winged aphids initially corrected in the potato field is so difficult. This study, therefore, aims to confirm the morphological classification for seven species associated with potatoes based on multivariate morphometric analyses. We used landmarks representing the major point of the fore wings of a total of 140 individuals migrating to potatoes and performed a multivariate analysis of variance (MANOVA), one-way analysis of variance (ANOVA), principal component analysis (PCA), and canonical variate analysis (CVA). As a result, it indicated that classification between genera was possible although four out of seven species are included in the same genus as the genus Aphis. In the results of discriminant function analysis, 85.7 % of the 140 individuals used in the analysis were correctly classified. It has been confirmed that the shape of the fore wing of these seven species of aphids migrating to potatoes is different. It is suggestive that those species can be identified using the forewing.

Re-establishment of Sileneneglecta Ten. (Caryophyllaceae) with taxonomic notes on some related taxa.

Sileneneglecta has been misunderstood and confused with S.nocturna, although several morphological characters (petal shape, calyx indumentum, hairiness of stamen filaments, seed size, seed-coat surface and shape) allow separation of these species. Moreover, S.mutabilis (which has been considered conspecific with S.neglecta) and S.martinolii (an alleged endemic species to south-western Sardinia) are considered here as taxonomic synonyms of S.nocturna and S.neglecta, respectively. These taxonomic conclusions are strongly supported by multivariate morphometric analyses of 21 characters.

Taxonomic assessment of Sorbus subgenus Aria in the Malé Karpaty Mountains

In this paper we present a taxonomic assessment of Sorbus subgen. Aria in the Malé Karpaty Mts (western Slovakia and north-eastern Austria). Detailed field observations, morphological comparison, herbarium revisions, multivariate morphometric analyses, flow cytometry and molecular (nuclear microsatellite markers) analyses were used to assess the taxonomic diversity within this group. Diploids, triploids and tetraploids were detected. Diploids are represented by a single taxon, S. aria, which shows considerable morphological and genetic variability. Sorbus aria ranges from rare to locally abundant throughout the area studied. Triploids are confined to the central and southern parts of the region and include several single, presumably apomictic individuals and rare apomictic lineages, which are not treated as separate species here due to the very limited number of individuals recorded. Tetraploids show similar distribution patterns to those of triploids: S. danubialis and S. collina occur in the southern part of the mountains, while S. petraea, a new species described here, inhabits the central part of the mountain range. The entire population of S. petraea includes approximately one hundred individuals. It occurs mainly in the surroundings of Vysoká Mt. by the village of Kuchyňa, where it forms several small populations and approximately 30 individuals grow on Čierna skala hill by the village of Plavecký Mikuláš. In addition to these recent occurrences, there are two herbarium specimens from the 1960s documenting the species on Vápená Mt. The low genetic and morphological variability and flow cytometric seed screening indicate an apomictic mode of reproduction in this species and justify its recognition at the species level. Sorbus collina is reported here in Slovakia for the first time. We have not confirmed the occurrence of S. austriaca, S. buekkensis, S. carpatica, S. graeca, S. pannonica, S. thaiszii and S. zolyomii in the Malé Karpaty Mts and consider the previously published records to be erroneous. Lectotypes are designated for S. thaiszii and S. zolyomii. A determination key, detailed distribution maps and photographs of representative herbarium specimens of all taxa of S. subgen. Aria occurring in the Malé Karpaty Mts are provided. A line drawing and a photograph of the newly described species are also presented.

An assessment of the taxonomic validity of three species of marsupial frogs (Anura: Hemiphractidae: Gastrotheca) from the Yungas of Bolivia based on external morphology and cranial osteology.

The genus Gastrotheca (Anura: Hemiphractidae) is a group of marsupial frogs particularly diverse in Andean regions. Several taxonomic studies of this genus have been conducted in the humid cloud forestsor Yungasof the Andean eastern slopes of central Bolivia (departments of Cochabamba and Santa Cruz). Yet, the distinction among three species that occur sympatrically in these forests, G. lauzuricae (proposed as a junior synonym of G. coeruleomaculatus in 2015), G. piperata, and G. splendens, remains unclear since the morphological characters that purportedly support their differentiation are variable and partly shared among them. We have carried out external morphological studies, including multivariate morphometric analyses, to assess how they support the taxonomic status of these three species. We also evaluated characters of the cranial osteology of a sample of six individuals using micro CT-scanning. Principal component and linear discriminant analyses resulted in a great overlap among the putative species. Cranial osteological comparisons did not reveal highly significant differences among them, but suggested that different degrees of hyperossification could be related to the developmental state of individuals. Our results indicate that most morphological and osteological reported differences between the three species likely represent intraspecific variation. Thus, we propose that the three nominal species belong to a single biological entity, for which the name Gastrotheca splendens (Schmidt, 1857) has priority. We also restrict the name Gastrotheca coeruleomaculatus (Werner, 1899) to externally similar congeneric populations from the Yungas forests of department of La Paz, but highlighting the need of a detailed evaluation of their taxonomic identity.

Biosystematics of Platanthera bifolia s.l. (Orchidaceae): inferences from analysis of Scandinavian population samples

Over the years, various authors have (sub)divided the Eurasian moth pollinated Platanthera bifolia into several taxa. Advanced studies using multivariate morphometric analysis and/or genetic fingerprinting have all included regions where the situation appears particularly complex. With the aim to resolve variation patterns in a region where the situation seems less complex, we analysed morphometric and AFLP data from 13 Scandinavian populations using a range of uni‐ and multivariate statistical methods. Variation was largely continuous, though with (individuals from) short‐spurred and long‐spurred populations, respectively, forming loose groups. Provided that successful pollinator shifts usually occur between moth species with small difference in proboscis length, this pattern is congruent with the hypothesis that spur length in P. bifolia s.l. has mainly evolved through pollinator shifts followed by selection in response to proboscis length of the prevailing local pollinator species. Acknowledging an important adaptive role of spur length, observing that spur length was among the main contributors to morphological variation, and noting this pattern to be congruent with both AFLP patterns and habitat requirements, we advocate the formal distinction between a short‐spurred and a long‐spurred taxon. Adopting the operational definitions of species, subspecies and variety provided in Flora Nordica, the two taxa should be recognized as P. bifolia var. bifolia and P. bifolia var. latissima, respectively. A key to the varieties is provided.

Species-Specific Cuticular Phenotypes in Eutardigrada: A Morphometric Approach to Analyze the Variation of Star-Shaped Pores in Minibiotus Species

The use and characterization of cuticular attributes for separation and description of species has been traditionally used in heterotardigrades; however, despite that eutardigrades show structures in the cuticle with this potential use, the intra and interspecific variation of these characters using multivariate analysis (e.g., PCA, CVA) had not been analyzed. In this present study, the shape and size of the star-shaped pores of four Minibiotus species were analyzed under univariate and multivariate morphometric analysis of six morphological characters. Our approach to evaluate the variation of pores indicate the presence of species-specific cuticular phenotypes among M. citlalium, M. constellatus, M. sidereus and M. pentannulatus. The morphological differences in these elements of sculpture allowed us to acknowledge their range of variation, as well as the identification of new potential characters o recognize these taxa, which are included in a taxonomic key to identify them together with M. eichhorni, M. pseudostellarus and M. vinciguerrae.