scholarly journals Craniodental morphology and phylogeny of marsupials

2021 ◽  
Author(s):  
Robin M. D. Beck ◽  
Robert Voss ◽  
Sharon Jansa

The current literature on marsupial phylogenetics includes numerous studies based on analyses of morphological data with relatively limited sampling of Recent and fossil taxa, and many studies based on analyses of molecular data that include a dense sampling of Recent taxa, but relatively few that combine both data types. Another dichotomy in the marsupial phylogenetic literature is between studies that focus on New World taxa, others that focus on Sahulian taxa. To date, there has been no attempt to assess the phylogenetic relationships of the global marsupial fauna, based on combined analyses of morphology and molecular sequences, for a dense sampling of Recent and fossil taxa. For this report, we compiled morphological and molecular data from an unprecedented number of Recent and fossil marsupials. Our morphological data consist of 180 craniodental characters that we scored for 97 species representing every currently recognized Recent genus, 42 additional ingroup (crown-clade marsupial) taxa represented by well-preserved fossils, and 5 outgroups (non-marsupial metatherians). Our molecular data comprise 24.5 kb of DNA sequences from whole-mitochondrial genomes and six nuclear loci (APOB, BRCA1, GHR, RAG1, RBP3 and VWF) for 97 marsupial terminals (the same Recent taxa scored for craniodental morphology) and several placental and monotreme outgroups. The results of separate and combined analyses of these data using a wide range of phylogenetic methods support many currently accepted hypotheses of ingroup (marsupial) relationships, but they also underscore the difficulty of placing fossils with key missing data (e.g., †Evolestes), and the unique difficulty of placing others that exhibit mosaics of plesiomorphic and autapomorphic traits (e.g., †Yalkaparidon). Unique contributions of our study are (1) critical discussions and illustrations of marsupial craniodental morphology, including descriptions and illustrations of some features never previously coded for phylogenetic analysis; (2) critical assessments of relative support for many suprageneric clades; (3) estimates of divergence times derived from tip-and-node dating based on uniquely taxon-dense analyses; and (4) a revised, higher-order classification of marsupials accompanied by lists of supporting craniodental synapomorphies. Far from the last word on these topics, this report lays the foundation for future research that may be enabled by the discovery of new fossil taxa, better-preserved material of previously described taxa, novel morphological characters, and improved methods of phylogenetic analysis.

2019 ◽  
Author(s):  
Cara Van Der Wal ◽  
Shane T. Ahyong ◽  
Simon Y. W. Ho ◽  
Luana S. F. Lins ◽  
Nathan Lo

The mantis shrimp superfamily Squilloidea, with over 185 described species, is the largest superfamily in the crustacean order Stomatopoda. To date, phylogenetic relationships within this superfamily have been comprehensively analysed using morphological data, with six major generic groupings being recovered. Here, we infer the phylogeny of Squilloidea using a combined dataset comprising 75 somatic morphological characters and four molecular markers. Nodal support is low when the morphological and molecular datasets are analysed separately but improves substantially when combined in a total-evidence phylogenetic analysis. We obtain a well resolved and strongly supported phylogeny that is largely congruent with previous estimates except that the Anchisquilloides-group, rather than the Meiosquilla-group, is the earliest-branching lineage in Squilloidea. The splits among the Anchisquilloides- and Meiosquilla-groups are followed by those of the Clorida-, Harpiosquilla-, Squilla- and Oratosquilla-groups. Most of the generic groups are recovered as monophyletic, with the exception of the Squilla- and Oratosquilla-groups. However, many genera within the Oratosquilla-group are not recovered as monophyletic. Further exploration with more extensive molecular sampling will be needed to resolve relationships within the Oratosquilla-group and to investigate the adaptive radiation of squilloids. Overall, our results demonstrate the merit of combining morphological and molecular datasets for resolving phylogenetic relationships.


Phytotaxa ◽  
2014 ◽  
Vol 186 (4) ◽  
pp. 188 ◽  
Author(s):  
Ying-Ying Zhou ◽  
HONG-WEI ZHANG ◽  
JIANG-QIN HU ◽  
Xiao-Feng Jin

Sinalliaria is described here as a new genus of the family Brassicaceae from eastern China, based on the morphological characters and molecular sequences. Sinalliaria differs from the related genus Orychophragmus in having basal leaves petiolate, simple or rarely with 1‒3 lateral lobes (not pinnatisect); cauline leaves petiolate, cordate at base (not sessile, auriculate or amplexicaul at base); petals obovate to narrowly obovate, claw inconspicuous (not broadly obovate, with a claw as along as sepal); siliques truncate (not long-beaked) at apex. The microscopic characters of seed testa also show significant differences between Sinalliaria and Orychophragmus. Phylogenetic evidence from DNA sequences of nuclear ribosomal ITS and plastid region trnL-trnF indicates that Sinalliaria is a distinct group related to Orychophragmus and Raphanus, but these three genera do not form a clade. The new genus Sinalliaria is endemic to eastern China and has only one species and one variety. The new combinations, S. limprichtiana (Pax) X. F. Jin, Y. Y. Zhou & H. W. Zhang and S. limprichtiana var. grandifolia (Z. X. An) X. F. Jin, Y. Y. Zhou & H. W. Zhang are proposed here.


Zootaxa ◽  
2004 ◽  
Vol 680 (1) ◽  
pp. 1 ◽  
Author(s):  
ARNE NYGREN

Autolytinae is revised based on available types, and newly collected specimens. Out of 170 nominal species, 18 are considered as incertae sedis, 43 are regarded as junior synonyms, and 25 are referred to as nomina dubia. The relationships of Autolytinae is assessed from 51 morphological characters and 211 states for 76 ingroup-taxa, and 460 molecular characters from mitochondrial 16S rDNA and nuclear 18S rDNA for 31 ingroup-taxa; outgroups include 12 non-autolytine syllid polychaetes. Two analyses are provided, one including morphological data only, and one with combined morphological and molecular data sets. The resulting strict consensus tree from the combined data is chosen for a reclassification. Three main clades are identified: Procerini trib. n., Autolytini Grube, 1850, and Epigamia gen. n. Proceraea Ehlers, 1864 and Myrianida Milne Edwards, 1845 are referred to as nomen protectum, while Scolopendra Slabber, 1781, Podonereis Blainville, 1818, Amytis Savigny, 1822, Polynice Savigny, 1822, and Nereisyllis Blainville, 1828 are considered


2015 ◽  
Vol 46 (3) ◽  
pp. 269-290 ◽  
Author(s):  
Ian J. Kitching ◽  
C. Lorna Culverwell ◽  
Ralph E. Harbach

Lutzia Theobald was reduced to a subgenus of Culex in 1932 and was treated as such until it was restored to its original generic status in 2003, based mainly on modifications of the larvae for predation. Previous phylogenetic studies based on morphological and molecular data have provided conflicting support for the generic status of Lutzia: analyses of morphological data support the generic status whereas analyses based on DNA sequences do not. Our previous phylogenetic analyses of Culicini (based on 169 morphological characters and 86 species representing the four genera and 26 subgenera of Culicini, most informal group taxa of subgenus Culex and five outgroup species from other tribes) seemed to indicate a conflict between adult and larval morphological data. Hence, we conducted a series of comparative and data exclusion analyses to determine whether the alternative positions of Lutzia are due to conflicting signal or to a lack of strong signal. We found that separate and combined analyses of adult and larval data support different patterns of relationships between Lutzia and other Culicini. However, the majority of conflicting clades are poorly supported and once these are removed from consideration, most of the topological disparity disappears, along with much of the resolution, suggesting that morphology alone does not have sufficiently strong signal to resolve the position of Lutzia. We critically examine the results of other phylogenetic studies of culicinine relationships and conclude that no morphological or molecular data set analysed in any study conducted to date has adequate signal to place Lutzia unequivocally with regard to other taxa in Culicini. Phylogenetic relationships observed thus far suggest that Lutzia is placed within Culex but further data and extended taxon sampling are required to confirm its position relative to Culex.


2011 ◽  
Vol 279 (1731) ◽  
pp. 1093-1099 ◽  
Author(s):  
Maria Heikkilä ◽  
Lauri Kaila ◽  
Marko Mutanen ◽  
Carlos Peña ◽  
Niklas Wahlberg

Although the taxonomy of the ca 18 000 species of butterflies and skippers is well known, the family-level relationships are still debated. Here, we present, to our knowledge, the most comprehensive phylogenetic analysis of the superfamilies Papilionoidea, Hesperioidea and Hedyloidea to date based on morphological and molecular data. We reconstructed their phylogenetic relationships using parsimony and Bayesian approaches. We estimated times and rates of diversification along lineages in order to reconstruct their evolutionary history. Our results suggest that the butterflies, as traditionally understood, are paraphyletic, with Papilionidae being the sister-group to Hesperioidea, Hedyloidea and all other butterflies. Hence, the families in the current three superfamilies should be placed in a single superfamily Papilionoidea. In addition, we find that Hedylidae is sister to Hesperiidae, and this novel relationship is supported by two morphological characters. The families diverged in the Early Cretaceous but diversified after the Cretaceous–Palaeogene event. The diversification of butterflies is characterized by a slow speciation rate in the lineage leading to Baronia brevicornis , a period of stasis by the skippers after divergence and a burst of diversification in the lineages leading to Nymphalidae, Riodinidae and Lycaenidae.


Zootaxa ◽  
2007 ◽  
Vol 1517 (1) ◽  
pp. 53-62 ◽  
Author(s):  
FRANK GLAW ◽  
ZOLTÁN T. NAGY ◽  
MIGUEL VENCES

Based on a specimen found at Montagne d'Ambre in northern Madagascar morphologically agreeing with Compsophis albiventris Mocquard, 1894, we report on the rediscovery of this enigmatic snake genus and species and its molecular phylogenetic relationships. Compsophis albiventris, considered to be the only representative of its genus and unreported since its original description, bears strong morphological similarities to species of Geodipsas Boulenger, 1896. A molecular phylogeny based on DNA sequences of three mitochondrial and nuclear genes (complete cytochrome b, fragments of 16S rRNA and c-mos) in Compsophis albiventris and three Geodipsas species corroborated close relationships between C. albiventris and Geodipsas boulengeri, and showed that the genera Compsophis and Geodipsas together form a monophyletic unit. Despite the general similarities, morphological data and chromatic features support the existence of two species groups, corresponding to Compsophis and Geodipsas. We consequently consider Geodipsas as a subgenus of Compsophis and transfer all species currently in Geodipsas into the genus Compsophis.


Phytotaxa ◽  
2016 ◽  
Vol 280 (1) ◽  
pp. 1 ◽  
Author(s):  
ALFREDO VIZZINI ◽  
MIRCA ZOTTI ◽  
MIDO TRAVERSO ◽  
ENRICO ERCOLE ◽  
PIERRE-ARTHUR MOREAU ◽  
...  

Several collections of Amanita species from section Vaginatae have been reported to be strictly associated with Helianthemum plants growing in grasslands, a still largely under-explored ectomycorrhizal habitat. The main aim of this study was to investigate the taxonomic status and phylogenetic position of strictly Helianthemum-associated Amanita sect. Vaginatae taxa, informally named Amanita “helianthemicola”. Collections from Italy, England and France were included in this study. The morphologically closely related species complex A. lividopallescens was also examined. Analyses were carried out based on both morphological and molecular data (phylogenetic analysis of the nrITS sequences). All investigated Amanita collections, which are strictly associated with Helianthemum nummularium, turned out to be conspecific with A. simulans. Amanita simulans was recently described from Sardinia (Italy) from Populus nigra habitats based on morphological characters only. As the holotype of A. simulans was lost, a neotype is designated here based on a voucher from the original collecting area. Amanita simulans is re-described, and an extensive discussion on the morphological variability, host species range, distribution and related taxa is provided. Amanita lividopallescens was confirmed as a good species, and re-delimited based on our phylogenetic analysis; moreover, it was epitypified with a recent and well-documented collection from Corse (France). Amanita stenospora is a synonym of A. lividopallescens, being a colour form of the latter without taxonomic value.


2021 ◽  
Author(s):  
E. J. Thompson ◽  
Melodina Fabillo

The taxonomy of Neurachninane has been unstable, with its member genera consisting of Ancistrachne, Calyptochloa, Cleistochloa, Dimorphochloa, Neurachne, Paraneurachne and Thyridolepis, changing since its original circumscription that comprised only the latter three genera. Recent studies on the phylogeny of Neurachninae have focused primarily on molecular data. We analysed the phylogeny of Neurachninae on the basis of molecular data from seven molecular loci (plastid markers: matK, ndhF, rbcL, rpl16, rpoC2 and trnLF, and ribosomal internal transcribed spacer, ITS) and morphological data from 104 morphological characters, including new taxonomically informative micromorphology of upper paleas. We devised an impact assessment scoring (IAS) protocol to aid selection of a tree for inferring the phylogeny of Neurachninae. Combining morphological and molecular data resulted in a well resolved phylogeny with the highest IAS value. Our findings support reinstatement of subtribe Neurachninae in its original sense, Neurachne muelleri and Dimorphochloa rigida. We show that Ancistrachne, Cleistochloa and Dimorphochloa are not monophyletic and Ancistrachne maidenii, Calyptochloa, Cleistochloa and Dimorphochloa form a new group, the cleistogamy group, united by having unique morphology associated with reproductive dimorphism.


Phytotaxa ◽  
2021 ◽  
Vol 478 (2) ◽  
pp. 179-200
Author(s):  
SHABIR A. RATHER ◽  
WANG SHU ◽  
MAYANK DHAR DWIVEDI ◽  
CHANG ZHAOYANG

In this study, we explored the evolutionary history and taxonomic treatment of the Caragana opulens complex taking information from morphological and molecular data. The complex consists of three species, C. opulens, C. licentiana and C. kansuensis. Moreover, the morphological characters currently used to differentiate the species present in the complex have been found insignificant and inconsistent and do not help diagnose the species. For the present study, we investigated its range and sampled 139 accessions from the different populations of the genus Caragana and 17 accessions of the complex. DNA sequence data from one nrDNA ITS and one cpDNA trnH-psbA loci were sequenced and analyzed using Maximum Likelihood and Bayesian methods. The resulting phylogenies were congruent in topologies. Based on morphological and molecular data, it is concluded that all three species of the complex are one of the same with significant morphological variations. Hence C. opulens is accepted as the correct name along with C. licentiana and C. kansuensis as synonyms.


Phytotaxa ◽  
2018 ◽  
Vol 356 (3) ◽  
pp. 181
Author(s):  
FABIO RENATO BORGES ◽  
ORLANDO NECCHI JR

The genus Nitella is the most species-rich within the Charales. Brazilian studies on the genus are relatively scarce and consist of floristic surveys, lacking modern and more precise information. This investigation applied scanning electron microscopy to analyze the oospore wall and molecular data associated with traditional morphological characters to analyze forty-two populations of Nitella from the midwest and southeast regions of Brazil. Forty-two new sequences of rbcL, twelve of ITS1 and twenty-three of ITS2 were generated for the five species recognized in this study: Nitella acuminata A. Braun ex Wallman, Nitella axillaris A. Braun, Nitella elegans B. P. Pal, Nitella flagellifera J. Groves & G. O. Allen and Nitella microcarpa A. Braun.. Phylogenetic analyses of sequences of these three markers were congruent in that they grouped our species with others from different countries to form five clades. Our results on ultrastrucure of the oospore wall were consistent with previous studies for the same species from other regions of the world. The data reinforced the conclusion that the use of ornamentation of oospore wall may be extremely useful for the construction of a natural system for Characeae at section level. Molecular evidence, reinforced by morphological data, for the Brazilian material analyzed suggests that Nitella subglomerata A. Braun and Nitella gollmeriana A. Braun could be synonymys of Nitella acuminata; and Nitella axilliformis K. Imahori appears to be the same as Nitella axillaris. However, no formal proposition was made considering that type specimens were not analyzed and these observations were based on a relatively small number of samples strictly from Brazil. We showed that even among geographically distant populations, such as from other continents, of some Nitella species, the degree of identity among DNA sequences was high.


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