scholarly journals Muscular characters in the phylogeny of Liolaemus (Squamata: Iguania: Liolaemidae): a reappraisal

Zootaxa ◽  
2006 ◽  
Vol 1205 (1) ◽  
pp. 55 ◽  
Author(s):  
V. ABDALA ◽  
C. ABDALA ◽  
M. J. TULLI

Liolaemus is one of the most speciosus genera of lizards, having more than 200 species. It is composed of small to moderate-sized lizards that live throughout most of austral South America. Many groups whose phylogenetic relationships have been controversial compose the genus. The proposed phylogenetic relationships of these lizards have been based on data-sets from many sources. In all of the morphological data-sets, three myologycal characters have been considered particularly important:1) insertion of the m. tibialis anticus hypertrophied in association with the presence of a sharp, bladelike process of the tibia, 2) medial head of the m. flexor tibialis internus covered by a hypertrophied m. puboisquitibialis, and 3) presence of melanic pigment within the medial portion of the epimysium of the m. pterygomandibularis. Important taxonomic and anatomical questions about these characters remain: 1) Can the size of the m. puboisquiotibilis be scored with only two character states? 2) Is there a close relationship between the hypertrophied m. flexor tibialis internus and the patch of the enlarged proximal postfemoral scales? and 3) Are these muscular characters exclusive to some of the groups of Liolaemus that have been proposed? Focusing on these questions, we have conducted a taxonomic and anatomic review of these characters in 42 species representing all of the proposed groups of Liolaemus. The analyzed samples show that variations in the considered muscular characters are much more gradual than previously stated. The only exception is the insertion of the m. tibialis anticus hypertrophied in relation to a bladelike hypertrophy of the tibia, which characterizes the montanus group of E theridge (1995). These characters seem to have the same phylogenetic information as any other morphological character. Although the coding we used is more complex, it shows more precisely the subtlety of the change in the character states.

1995 ◽  
Vol 69 (S42) ◽  
pp. 1-19 ◽  
Author(s):  
Pierre J. Lespérance ◽  
Sylvain Desbiens

The thorax of Hypodicranotus has ten segments and a spine on the eighth. The ages of Erratencrinurus s.l. spicatus and Erratencrinurus (Erratencrinurus?) vigilans in the Lake St. John district do not confirm their temporal roles leading to subgenera of Erratencrinurus, as has been recently suggested. Phylogenetic analyses of large data sets of species previously referred to Encrinuroides and Physemataspis yield a minimal length cladogram containing 18 species. Encrinuroides is restricted to four species, two of which have biogeographic affinities with Iapetus. These results lead to three clades, named the Walencrinuroides n. gen. clade, Frencrinuroides n. gen. clade, and finally the Physemataspis clade, with an enlarged concept of the genus with the erection of Physemataspis (Prophysemataspis) n. subgen. These last three clades are restricted to North America and Scotland, with alternating predominance of one region. Walencrinuroides s.l. gelaisi n. gen. n. sp. is described. New morphological data on Erratencrinurus s.l. spicatus confirm its close relationship with the clades discussed above. Data are insufficient for phylogenetic analysis of selected cheirurine species here surveyed. Eye position, glabellar segmentation, and pygidial shape differentiate the genera Ceraurus and Gabriceraurus; emended diagnoses of these genera are presented. Ceraurus globulobatus and C. matranseris are distinct, but morphologically close to one another. The status of Gabriceraurus dentatus can be stabilized on its extant types.


Zootaxa ◽  
2004 ◽  
Vol 629 (1) ◽  
pp. 1 ◽  
Author(s):  
MARIAM LEKVEISHVILI ◽  
HANS KLOMPEN

Phylogenetic relationships among the families in the infraorder Sejina and the position of Sejina relative to other infraorders of Mesostigmata are re-examined based on molecular and morphological data. Data sets included DNA sequence data for complete 18S, EF-1 , partial CO1genes, and 69 morphological characters. The two families of Heterozerconina consistently group within Sejina, and we propose to synonymize Heterozerconina with Sejina (Sejina s.l). Microgyniina is not the closest relative of Sejina. Rather, Sejina s.l. most often groups with Gamasina. Uropodellidae and Ichthyostomatogasteridae are sister groups and this lineage forms the sister group to Discozerconidae plus Heterozerconidae. Overall, we recognize 5 families within Sejina: Uropodellidae, Ichthyostomatogasteridae, Sejidae, Discozerconidae, and Heterozerconidae.


2009 ◽  
Vol 57 (1) ◽  
pp. 76 ◽  
Author(s):  
Silvana M. Sede ◽  
Daniela Tosto ◽  
Paola Talia ◽  
Melissa Luckow ◽  
Lidia Poggio ◽  
...  

The neotropical genus Camptosema in its southern distribution is represented by the following four species: Ca. paraguariense, Ca. praeandinum, Ca. rubicundum and Ca. scarlatinum. Ca. rubicundum is the only species with all the diagnostic characters of the genus, i.e. tubular calyx. The other three taxa are related morphologically and cytologically to Galactia and Collaea, two closely allied genera in the subtribe Diocleinae. Individual and combined phylogenetic analyses of morphology, ITS and trnL-F were conducted to examine the position of these species as well as to explore their relationship with Galactia and Collaea species in southern South America. In none of the analyses does Camptosema species form a monophyletic group. Instead, they are scattered in different groups. These results together with cytological, morphological and AFLP data provide good support for re-evaluating the taxonomic position of these species within Camptosema.


2019 ◽  
Vol 62 (6) ◽  
pp. 563-575 ◽  
Author(s):  
Priscila Barreto de Jesus ◽  
Fabio Nauer ◽  
Goia de Mattos Lyra ◽  
Valter Loureiro de Araújo ◽  
Igor Araújo Santos de Carvalho ◽  
...  

Abstract Hypnea is a monophyletic genus with a complex nomenclatural and taxonomic history, and is an important commercial source of carrageenan. Phylogenies of this genus have been accessed based primarily on Asian species; however, recent studies performed in South America revealed a great diversity of species, for which phylogenetic relationships need to be evaluated. Three infrageneric sections are recognized in the genus: Pulvinatae, Spinuligerae, and Virgatae; however, morphological and molecular circumscriptions within each section lack clarity. In this study, we analyzed three distinct markers to establish phylogenetic relationships among Hypnea species. To assign each species to the correct section, morphological data were obtained from original descriptions, reference literature, and comparisons with type/topotype and herbaria specimens. Our analyses recovered robust phylogenies for the genus and provided new insights on the taxonomic status and relationships among and within Hypnea species. The combination of three genetic markers increased the resolution and support, resulting in the largest and best-resolved phylogeny of the genus to date. Single and combined analyses revealed that the three sections of the genus Hypnea are taxonomically irrelevant, as currently recognized. Morphological differences are not associated with monophyletic groups and similarities among clades could be better explained by convergent evolution in thallus habit.


2020 ◽  
Vol 51 (1) ◽  
pp. 81-138
Author(s):  
Fábio G.L. Oliveira ◽  
Nikolas G. Cipola ◽  
Eduardo A.B. Almeida

Nine new species of the collembolan genus Salina MacGillivray from South America are described and illustrated. Two Neotropical species were recorded for the first time from Brazil: S. dedoris Mari-Mutt and S. tristani Denis. Salina was previously known to occur in three Brazilian states, and this is now updated to include 19 states with 12 recorded species. A new proposal of morphological character description and illustration, and an identification key for the celebensis group are provided. A hypothesis for the phylogenetic relationships among 34 species of Salina (about 50% of the 72 described species) allowed three main pursuits: (a) a reevaluation of Salina species groups; (b) the first explicit interpretation of how morphological characters of these springtails may have changed during the course of the diversification of the taxon; and (c) an evaluation of the historical biogeographic connections of Salina, with an emphasis on the celebensis group distribution to the New World.


2021 ◽  
Author(s):  
Congcong Du ◽  
Jing CHen ◽  
Liyun Jiang ◽  
Gexia Qiao

Abstract As the second largest and most diverse group in the superfamily Aphidoidea, the phylogeny of drepanosiphine aphids sensu lato (s.l.) is critical for discussing the evolution of aphids. However, the taxa composition and phylogenetic relationships of drepanosiphine aphids s.l. have not been fully elucidated to date. In this study, based on total-evidence analyses combining 4 molecular genes (3 mitochondrial, COI, tRNA-Leu/COII, and CytB; 1 nuclear, EF-1ɑ) and 64 morphological and biological characteristics, the phylogeny of this group was reconstructed for the first time at the subfamily level using different datasets, parsimonies and model-based methods. All of our phylogenetic inferences clearly indicated that the drepanosiphine aphids s.l. was not a monophyletic group and seemed to support the division of the drepanosiphine aphids s.l. into different groups classified at the subfamily level. Calaphidinae was also not a monophyletic group, and Saltusaphidinae was nested within this subfamily. Drepanosiphinae was not clustered with Chaitophorinae, which was inconsistent with the previous hypothesis of a close relationship between them, illustrating that their phylogeny remains controversial. Overall, some groups of drepanosiphine aphids s.l., including Phyllaphidinae, Macropodaphidinae, Pterastheniinae, Lizeriinae, Drepanosiphinae, Spicaphidinae, Saltusaphidinae, and Calaphidinae, clustered together and might constitute the actual drepanosiphine aphids s.l. To a certain extent, our results clarified the phylogenetic relationships among drepanosiphine aphids s.l. and confirmed their taxonomic status as subfamilies.


2019 ◽  
Vol 67 (3) ◽  
pp. 162
Author(s):  
Barry J. Richardson

Phylogenetic relationships and estimated dates of origin, plus distributional, ecological and morphological data for salticid genera were used to examine a series of hypotheses related to the evolution of the Australian salticid fauna. Though independent, the time patterns of evolution of genera in Australia and South America were similar, while that for Northern Hemisphere taxa differed. In each case the production of new genera occurred during the warmer parts of the mid Tertiary but not during cooler and drier times. Asian elements entered Australia as early as 31 million years ago, long before the collision of the Australasian and Asian continental plates. Endemic and derivatives of Asian genera were similarly distributed across Australian biomes. However, arriving taxa were more successful when conditions matched their mesic origins (tropical), but less so when different (temperate). While endemic genera often extended their ranges into drier environments by increasing the number of species, recent arrivals did so by extending the range of individual species. Maximum Parsimony analyses of a range of presumed adaptive, morphological and ecological characters showed these did not reflect genus-level processes; however, the analysis did show all endemic genera had mesic origins.


Entomologia ◽  
2013 ◽  
pp. e4 ◽  
Author(s):  
H. Pohl ◽  
R.G. Beutel

The history of the phylogenetic placement of the parasitic insect order Strepsiptera is outlined. The first species was described in 1793 by P. Rossi and assigned to the hymenopteran family Ichneumonidae. A position close to the cucujiform beetle family Rhipiphoridae was suggested by several earlier authors. Others proposed a close relationship with Diptera or even a group Pupariata including Diptera, Strepsiptera and Coccoidea. A subordinate placement within the polyphagan series Cucujiformia close to the wood-associated Lymexylidae was favored by the coleopterist R.A. Crowson. W. Hennig considered a sistergroup relationship with Coleoptera as the most likely hypothesis but emphasized the uncertainty. Cladistic analyses of morphological data sets yielded very different placements, alternatively as sistergroup of Coleoptera, Antliophora, or all other holometabolan orders. Results based on ribosomal genes suggested a sistergroup relationship with Diptera (Halteria concept). A clade Coleopterida (Strepsiptera and Coleoptera) was supported in two studies based on different combinations of protein coding nuclear genes. Analyses of data sets comprising seven or nine genes (7 single copy nuclear genes), respectively, yielded either a subordinate placement within Coleoptera or a sistergroup relationship with Neuropterida. Several early hypotheses based on a typological approach − affinities with Diptera, Coleoptera, a coleopteran subgroup, or Neuropterida − were revived using either a Hennigian approach or formal analyses of morphological characters or different molecular data sets. A phylogenomic approach finally supported a sistergroup relationship with monophyletic Coleoptera.


2021 ◽  
Author(s):  
Jack Oyston ◽  
Mark Wilkinson ◽  
Marcello Ruta ◽  
Matthew Wills

Abstract Phylogenetic relationships are inferred principally from two classes of data: morphological and molecular. Most current phylogenies of extant taxa are inferred from molecules, and when morphological and molecular trees conflict the latter are often preferred. Although supported by simulations, the superiority of molecular trees has never been assessed empirically. Here we test phylogenetic accuracy using two independent data sources: biogeographical distributions and fossil first occurrences. For 48 pairs of morphological and molecular trees, we show that molecular trees are, on average, significantly more biogeographically congruent than their morphological counterparts. We also report an increase in the biogeographical congruence of phylogenies over research time. We find no significant differences in stratigraphical congruence between morphological and molecular trees. These findings have implications for understanding homoplasy in morphological data sets, the utility of morphology as a test of molecular hypotheses, and the difficulty of analysing fossil groups for which molecular data are unavailable.


2015 ◽  
Vol 145 (3-4) ◽  
pp. 283-301 ◽  
Author(s):  
David Cannatella

Published data from DNA sequences, morphology of 11 extant and 15 extinct frog taxa, and stratigraphic ranges of fossils were integrated to open a window into the deep-time evolution of Xenopus. The ages and morphological characters of fossils were used as independent datasets to calibrate a chronogram. We found that DNA sequences, either alone or in combination with morphological data and fossils, tended to support a close relationship between Xenopus and Hymenochirus, although in some analyses this topology was not significantly better than the Pipa + Hymenochirus topology. Analyses that excluded DNA data found strong support for the Pipa + Hymenochirus tree. The criterion for selecting the maximum age of the calibration prior influenced the age estimates, and our age estimates of early divergences in the tree of frogs are substantially younger than those of published studies. Node-dating and tip-dating calibrations, either alone or in combination, yielded older dates for nodes than did a root calibration alone. Our estimates of divergence times indicate that overwater dispersal, rather than vicariance due to the splitting of Africa and South America, may explain the presence of Xenopus in Africa and its closest fossil relatives in South America.


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