scholarly journals Molecular evidence and marine snake origins

2005 ◽  
Vol 1 (2) ◽  
pp. 227-230 ◽  
Author(s):  
Michael S.Y Lee

A molecular phylogeny was used to refute the marine scenario for snake origins. Nuclear gene sequences suggested that snakes are not closely related to living varanid lizards, thus also apparently contradicting proposed relationships between snakes and marine mosasaurs (usually considered to be varanoids). However, mosasaurs share derived similarities with both snakes and living varanids. A reanalysis of the morphological data suggests that, if the relationships between living taxa are constrained to the proposed molecular tree, with fossil forms allowed to insert in their optimal positions within this framework, mosasaurs cluster with snakes rather than with varanids. Combined morphological and molecular analyses also still unite marine lizards with snakes. Thus, the molecular data do not refute the phylogenetic evidence for a marine origin of snakes.

2021 ◽  
Vol 80 (2) ◽  
Author(s):  
Duilio Iamonico

Habrosia (Sagineae, Caryophyllaceae) is a genus that includes only H. spinuliflora, a species occurring in Iran, Iraq, Syria, Lebanon, and Turkey (Irano-Turanian floristic chorological element). Based on the available molecular data published in 2011, Habrosia appears to be nested in a Minuartia-clade, which includes taxa currently recognized under the genus Sabulina. Consequently, Habrosia should be treated as a genus to be included in Sabulina. However, the molecular tree published in 2011 considered only 9 Sabulina members whereas, according to the current concept, Sabulina is a genus comprising about 65 species. Unfortunately, the molecular phylogeny including a larger Sabulina sample published in 2014 did not include H. spinuliflora and the taxonomic position of Habrosia remains, therefore, uncertain. With the aim of verifying the correct position of Habrosia in the tribe Sagineae with respect to its relationship to Sabulina, a comprehensive molecular investigation based on ITS sequences, linked to detailed morphological data, is presented. The results obtained revealed that Habrosia is not part of Sabulina. A detailed description of H. spinuliflora, its ecological preference, and a distribution map are provided. Eventually, the name Arenaria spinulifolia (basionym of H. spinuliflora) is lectotypified on a specimen preserved at G (barcode G00212963).


2008 ◽  
Vol 98 (5) ◽  
pp. 499-507 ◽  
Author(s):  
H.C. Zhang ◽  
G.X. Qiao

AbstractThree traditional tribes of Fordini, Pemphigini and Eriosomatini comprise Pemphiginae, and there are two subtribes in Fordini and Pemphigini, respectively. Most of the species in this subfamily live heteroecious holocyclic lives with distinct primary host specificity. The three tribes of Pemphigini (except Prociphilina), Eriosomatini and Fordini use three families of plants, Salicaceae (Populus), Ulmaceae (Ulums) and Anacardiaceae (Pistacia and Rhus), as primary hosts, respectively, and form galls on them. Therefore, the Pemphigids are well known as gall makers, and their galls can be divided into true galls and pseudo-galls in type. We performed the first molecular phylogenetic study of Pemphiginae based on molecular data (EF-1α sequences). Results show that Pemphiginae is probably not a monophylum, but the monophyly of Fordini is supported robustly. The monophyly of Pemphigini is not supported, and two subtribes in it, Pemphigina and Prociphilina, are suggested to be raised to tribal level, equal with Fordini and Eriosomatini. The molecular phylogenetic analysis does not show definite relationships among the four tribes of Pemphiginae, as in the previous phylogenetic study based on morphology. It seems that the four tribes radiated at nearly the same time and then evolved independently. Based on this, we can speculate that galls originated independently four times in the four tribes, and there is no evidence to support that true galls are preceded by pseudo-galls, as in the case of thrips and willow sawflies.


Zootaxa ◽  
2004 ◽  
Vol 634 (1) ◽  
pp. 1 ◽  
Author(s):  
Oscar Arribas ◽  
Salvador Carranza

Iberolacerta cyreni martinezricai is elevated to the species level (I. martinezricai) based on both morphological and molecular data. The phylogenetic analysis using two mitochondrial and one nuclear gene shows I. martinezricai is more closely related to I. monticola than to I. cyreni. A multivariate analysis of the morphological data also supports the affinities between I. martinezricai and I. monticola but, at the same time, clearly indicates that I. martinezricai is morphologically distinct from both I. monticola and I. cyreni. The molecular data suggests I. cyreni and the clade formed by I. monticola + I. martinezricai split approximately 6.1 Mya, during the Mesinian Salinity Crisis, when climatic conditions around the Mediterranean area changed dramatically as a result of the desiccation of the Mediterranean Sea. Separation between I. martinezricai and I. monticola occurred approximately 2 Mya but, with at least two equally plausible alternative hypotheses, their biogeography is still unclear. New data on the habitat and distribution of I. martinezricai indicates its distribution area is very small (12 15 km 2 ), and that it lives in a climatically extreme habitat for this kind of mountain species. As a result of that and the low numbers of individuals, I. martinezricai is considered here as Critically Endangered.


2011 ◽  
Vol 43 (4) ◽  
pp. 345-356 ◽  
Author(s):  
Damien ERTZ ◽  
Frank BUNGARTZ ◽  
Paul DIEDERICH ◽  
Leif TIBELL

AbstractBased on morphological, anatomical, chemical, ecological and molecular evidence, Blarneya is synonymized here with Tylophoron. The molecular phylogeny derived from sequences obtained from sporodochia of Blarneya places this genus, described to accommodate an anamorphic lichen with white cushion-shaped sporodochia, within Tylophoron. This conclusion is further supported by the discovery of Tylophoron-type ascomata emerging directly from thalli with Blarneya-type sporodochia and producing identical hyaline conidia. In one specimen pycnidia were also observed. This represents a surprising variety of morphologically different conidiomata. A different anamorphic type was previously reported from Tylophoron, and this is confirmed here by molecular analysis for T. moderatum: besides thalli with ascomata this species has anamorphic thalli with an irregularly delimited brown sporodochial felt and brown conidia. Ascomata are not known from these entirely anamorphic thalli, whereas they do occur infrequently in Tylophoron species with Blarneya-type sporodochia. A key to all currently accepted species of Tylophoron is provided. In addition to the corticolous Tylophoron hibernicum, confined to humid forests, two saxicolous species with Blarneya-type sporodochia are described here as new: T. galapagoense, known only from Galapagos, differs from T. hibernicum by a thicker, more compact, beige rather than white, more strongly C+ red thallus, growing below sheltered rock overhangs in dry forests; T. stalactiticum has a C− thallus with stipitate, white, C+ red sporodochia; the species is known only from a single locality in Tenerife, on a large slope with volcanic boulders.


Zootaxa ◽  
2017 ◽  
Vol 4242 (2) ◽  
pp. 313
Author(s):  
MAURICIO RIVERA-CORREA ◽  
CARLOS JIMÉNEZ-RIVILLAS ◽  
JUAN M. DAZA

Pristimantis, distributed throughout the New World tropics, is the most speciose vertebrate genus. Pristimantis presents an enormous morphological diversity and is currently divided into several demonstrably non-monophyletic phenetic species groups. With the purpose of increasing our understanding of Pristimantis systematics, we present the first phylogenetic analysis using molecular evidence to test the monophyly and infer evolutionary relationships within the Pristimantis leptolophus group, an endemic group of frogs from the highlands of the Colombian Andes. Our phylogenetic reconstruction recovers the group as monophyletic with high support, indicating general concordance between molecular data and morphological data. In addition, we describe a new polymorphic species lacking conspicuous tubercles, a regular attribute among species of the P. leptolophus species group and endemic from the Páramo de Sonsón complex (Antioquia, Colombia). The phylogenetic position of the new species is inferred and other systematic implications in the light of our results are discussed. 


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.


MycoKeys ◽  
2020 ◽  
Vol 63 ◽  
pp. 163-172
Author(s):  
Xiao-Lan He ◽  
Egon Horak ◽  
Di Wang ◽  
Tai-Hui Li ◽  
Wei-Hong Peng ◽  
...  

Entoloma subgenus Claudopus is widely distributed, yet the taxonomy and systematics of its species are still poorly documented. In the present study, more than forty collections of Claudopus were gathered in China and subsequently analysed, based on morphological and molecular data. The results revealed first a high level of species diversity of Claudopus in China and second, there is a wide ecological range regarding the substrates and the habitats ranging from temperate, tropical to subalpine locations. Based on morphological and molecular evidence, five novel species from China are proposed, viz. E. conchatum, E. flabellatum, E. gregarium, E. pleurotoides and E. reductum. Molecular phylogeny of Entoloma s.l. was also reconstructed, based on 187 representatives of Entoloma s.l. by employing the combined ITS, LSU, mtSSU and RPB2 sequences. Ten monophyletic clades (Claudopus, Leptonia, Nolanea, Cuboid-spored Inocephalus, “Alboleptonia”, Cyanula, Pouzarella, Rhodopolia, Prunuloides and Rusticoides) were recovered, while 13 taxa could not be placed in any defined clades. The results confirmed that Claudopus in a traditional morphological sense is not monophyletic and the Rusticoides-group, previously considered within Claudopus, formed a separate clade; but section Claudopus and relatives of E. undatum belong to a distinctive monophyletic group. Despite some monophyletic groups in Entoloma s.l. being distinctive in both morphology and molecular phylogeny, they were still treated as subgenera of Entoloma s.l. temporarily, because accepting them as genera will make Entoloma s.l. paraphyletic.


MycoKeys ◽  
2019 ◽  
Vol 61 ◽  
pp. 1-26
Author(s):  
Xiao-Lan He ◽  
Egon Horak ◽  
Di Wang ◽  
Tai-Hui Li ◽  
Wei-Hong Peng ◽  
...  

Entoloma subgenus Claudopus is widely distributed, yet the taxonomy and systematics of its species are still poorly documented. In the present study, more than forty collections of Claudopus were gathered in China and subsequently analysed, based on morphological and molecular data. The results revealed first a high level of species diversity of Claudopus in China and second, there is a wide ecological range regarding the substrates and the habitats ranging from temperate, tropical to subalpine locations. Based on morphological and molecular evidence, five novel species from China are proposed, viz. E. conchatum, E. flabellatum, E. gregarium, E. pleurotoides and E. reductum. Molecular phylogeny of Entoloma s.l. was also reconstructed, based on 187 representatives of Entoloma s.l. by employing the combined ITS, LSU, mtSSU and RPB2 sequences. Ten monophyletic clades (Claudopus, Leptonia, Nolanea, Cuboid-spored Inocephalus, “Alboleptonia”, Cyanula, Pouzarella, Rhodopolia, Prunuloides and Rusticoides) were recovered, while 13 taxa could not be placed in any defined clades. The results confirmed that Claudopus in a traditional morphological sense is not monophyletic and the Rusticoides-group, previously considered within Claudopus, formed a separate clade; but section Claudopus and relatives of E. undatum belong to a distinctive monophyletic group. Despite some monophyletic groups in Entoloma s.l. being distinctive in both morphology and molecular phylogeny, they were still treated as subgenera of Entoloma s.l. temporarily, because accepting them as genera will make Entoloma s.l. paraphyletic.


2020 ◽  
Vol 71 (4) ◽  
pp. 518 ◽  
Author(s):  
Douglas Bearham ◽  
Myrto Robert ◽  
Jennifer A. Chaplin ◽  
Glenn I. Moore ◽  
David V. Fairclough ◽  
...  

The discovery and identification of species is fundamental to the documentation, conservation and management of biodiversity. The taxonomy of the antitropical Pseudocaranx dentex complex (Carangidae) is confused and inconsistently reported. Previous morphological analyses concluded that this complex consisted of three species, namely P. sp. ‘dentex’, P. georgianus and P. dinjerra, in Australian waters. This study used genetic (COI sequence) and morphological data to evaluate the validity of this conclusion. The COI data showed the presence of three discrete lineages within this complex, which appear to correspond to the above-mentioned three species. They also suggested that P. sp. ‘dentex’ is closely related to, and possibly the same species as, P. dentex from southern Africa and the Mediterranean Sea. Also, the extent of morphological and geographical overlap between P. georgianus and P. dinjerra was greater than previously documented which, uncorrected, could lead to identification errors and present challenges for monitoring and management of harvested stocks of these species. By answering important taxonomic questions, our results will facilitate the proper interpretation of the results of past studies and the design of future studies of the P. dentex complex. They have also highlighted the value of molecular data for identifying species in morphologically conservative taxa.


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