Phylogenetic relationships of captorhinomorph reptiles

1986 ◽  
Vol 23 (3) ◽  
pp. 402-418 ◽  
Author(s):  
M. J. Heaton ◽  
R. R. Reisz

The Captorhinomorpha consists of two families, the Captorhinidae and the Protorothyrididae. The distribution of morphological character states of the skeleton permits reevaluation of currently accepted theories of the relationships of captorhinomorph reptiles. Identification of characters states that are primitive for reptiles (amniotes) has been made through outgroup comparison. The Captorhinidae, Protorothyrididae, and Diapsida form a natural group that share such derived characters as reduced supratemporal, reduced tabular, narrow supraoccipital with anteriorly directed crista alaris, loss of supratemporal–postorbital contact, loss of opisthotic–tabular contact, and loss of the medial centralia pedis. These shared derived character states indicate that captorhinomorphs are not the sister taxon of all other reptiles but are advanced relative to pelycosaurs, pareiasaurs, and procolophonids. Protorothyridids share with diapsids such derived characters as short postorbital region of the skull, keeled anterior presacral pleurocentra, slender limbs, and long, slender feet. This distribution of character states indicates that protorothyridids are more closely related to diapsids than either of these taxa is to captorhinids.The morphological pattern of small, lightly built, agile insectivores, represented by protorothyridids and early diapsids, is no longer considered to be the primitive amniote condition. Available evidence indicates that the most primitive amniote adaptation was, instead, that of a small, relatively slow carnivore that probably fed on primitive, terrestrial annelids and arthropods.

2015 ◽  
Vol 97 (2) ◽  
pp. 394-404 ◽  
Author(s):  
Juan F. Díaz-Nieto ◽  
Sharon A. Jansa ◽  
Robert S. Voss

Abstract Morphological character data are inadequate to resolve the evolutionary relationships of the didelphid genus Chacodelphys , which previous phylogenetic analyses have alternatively suggested might be the sister taxon of Lestodelphys and Thylamys (tribe Thylamyini) or of Monodelphis (tribe Marmosini) in the subfamily Didelphinae. Because fresh material of Chacodelphys is unavailable, we extracted DNA from microscopic fragments of soft tissue adhering to the 95-year-old holotype skull of C. formosa. Phylogenetic analyses of the resulting sequence data convincingly resolve Chacodelphys as the sister taxon of Cryptonanus , a genus with which it had not previously been thought to be closely related. This novel clade ( Chacodelphys + Cryptonanus ) belongs to an unnamed thylamyine lineage with Gracilinanus and Lestodelphys + Thylamys , but relationships among these taxa remain to be convincingly resolved. Los análisis basados en caracteres morfológicos han sido inadecuados para resolver las relaciones evolutivas del género marsupial didélfido Chacodelphys . Previos análisis filogenéticos han sugerido como hipótesis alternativas que Chacodelphys sea el grupo hermano de Lestodelphys y Thylamys (tribu Thylamyini) o de Monodelphis (tribu Marmosini), todos estos géneros pertenecientes a la subfamilia Didelphinae. Debido a la ausencia de material fresco de Chacodelphys , extrajimos ADN de fragmentos microscópicos de tejido adherido al cráneo de 95 años del holotipo de C. formosa . Análisis filogenéticos de las secuencias obtenidas resuelven convincentemente la posición filogenética de Chacodelphys como el taxón hermano de Cryptonanus , un género con el cual nunca antes se había pensado que estuviera cercanamente relacionado. Aunque reconocemos a este nuevo clado ( Chacodelphys + Cryptonanus ) junto con Gracilinanus y Lestodelphys + Thylamys pertenecientes a un linaje sin nombre, las relaciones entre estas taxa siguen sin estar convincentemente resueltas.


2019 ◽  
Vol 94 (2) ◽  
pp. 202-216
Author(s):  
Valerio Gennari ◽  
Roberto Rettori

AbstractAmong Permian smaller foraminifers, the genus Dagmarita is one of the most studied due to its worldwide distribution. The detailed study of the Zal (NW Iran) and Abadeh (Central Iran) stratigraphic sections led to redescription of the genus Dagmarita and its taxonomic composition. In Dagmarita, a peculiar generic morphological character, represented by a secondary valvular projection, has been detected for the first time among globivalvulinid foraminifers. The phylogeny of Dagmarita, and in particular its ancestor Sengoerina, is discussed and the new species, D. ghorbanii n. sp. and D. zalensis n. sp., are introduced. Analogies and differences among all the species belonging to Dagmarita are highlighted and morphological features of the new taxa are shown in 3D reconstructions, useful for understanding differently oriented sections of the specimens in thin section.UUID: http://zoobank.org/3d8eb14c-7757-4cbd-877c-4bacd2d156da


2019 ◽  
Vol 94 (3) ◽  
pp. 568-579
Author(s):  
Alexander O. Averianov

AbstractKazachostylops occidentalis Nesov, 1987b, based on partial maxilla and dentary from the upper Paleocene Zhylga locality in South Kazakhstan, is redescribed. A new phylogenetic hypothesis of Arctostylopida is proposed based on phylogenetic analysis of 26 characters and 17 taxa. Kazachostylops is recovered as a sister taxon to the Arctostylopinae, the advanced clade of Asian and North American arctostylopids characterized by pseudohypocone on upper molars and reduced trigonid of lower molars, with the ectolophid being attached labial on the trigonid. Kazachostylops differs from more basal arctostylopids (Asiostylops, Allostylops, Bothriostylops, and Wanostylops) by higher-crowned molars, M1–3 metaconule absent, m1–3 entoconid connected with ectolophid by entolophid, and m2 wider than m1 and m3. Principal component analyses of the upper and lower dentition of arctostylopids show great distinctness of Kazachostylops from other members of the group. The arctostylopid taxa are reviewed, and the new genus Enantiostylops is erected for ‘Sinostylops’ progressus Tang and Yan, 1976 from the lower Eocene of China, because of uniquely concave parastylar area on upper molars.UUID: http://zoobank.org/a46d8f29-fd73-4e59-88dc-fcc55b12d1d3


2000 ◽  
Vol 77 (12) ◽  
pp. 1790-1800 ◽  
Author(s):  
Alexandra Riethmüller ◽  
Michael Weiß ◽  
Franz Oberwinkler

To reveal phylogenetic relationships within the Peronosporomycetes (Oomycetes), we sequenced a part of the nuclear rDNA coding for the ribosomal large subunit of 46 Peronosporomycetes species and one representative of the Xanthophyta. The main emphasis of our study was put on the phylogenetic relationships within the Saprolegniomycetidae. We supplemented our data with a sequence of Phytophthora megasperma Drechsler from GenBank. Two sets of sequences were analysed using the neighbor-joining method, statistically supported by the bootstrap method, as well as the maximum parsimony method. Our results are well compatible with the tripartite subclassification of the Peronosporomycetes into Saprolegniomycetidae, Rhipidiomycetidae and Peronosporomycetidae, as well as with the placement of the orders Saprolegniales and Leptomitales in the Saprolegniomycetidae. Pachymetra chaunorhiza Croft & Dick, which has been placed in the Sclerosporales, was grouped within the Saprolegniales. Within the Peronosporomycetidae, the orders Peronosporales and Pythiales could not be separated. There are indications that Phytophthora de Bary and the Peronosporales form a common natural group. The genus Achlya Nees proved to be a heterogeneous group.


Phytotaxa ◽  
2020 ◽  
Vol 436 (3) ◽  
pp. 283-292 ◽  
Author(s):  
YONG-FU LI ◽  
MIN ZHANG ◽  
XIAN-RONG WANG ◽  
STEVEN PAUL SYLVESTER ◽  
QI-BAI XIANG ◽  
...  

Osmanthus (Oleaceae) is considered one of the most confusing genera with regards to circumscription and phylogenetic placement of taxa within the subtribe Oleinae of Oleaceae, with controversies mainly focused on the attribution of section Leiolea. In the present study, we analyzed 71 samples that represent the broad taxonomic, biogeographic, and morphological patterns in the subtribe Oleinae. Based on concatenation of four plastid genes (trnL-F, trnT-L, trnS-G, and matK) and comparison with the ITS region, Bayesian Inference, Maximum Likelihood and Maximum Parsimony phylogenies were inferred. Morphological character traits and geographical distributions of taxa were also studied. These results provide strong support for the segregation of the Leiolea clade (Osmanthus marginatus, O. matsumuranus and O. minor) of sect. Leiolea from Osmanthus. Therefore, the Leiolea clade is instated as the new genus Chengiodendron, with a taxonomic treatment provided. This study provides a clearer understanding of the phylogenetic relationships of genera in the subtribe Oleinae.


2016 ◽  
Vol 50 (1) ◽  
pp. 71-84 ◽  
Author(s):  
S. J. Rahmat ◽  
I. Koretsky

Abstract The Devinophoca emryi material from the early Badenian, early Middle Miocene (16.26–14.89 Ma) presents mixed cranial and especially postcranial characters with the three extant phocid subfamilies (Cystophorinae, Monachinae and Phocinae), as well as unique postcranial characters not seen in any taxa. These distinguishing characters (i. e. well-outlined, large oval facet on greater tubercle of humerus; broader width between the head and lesser tubercle of humerus; femoral proximal epiphysis larger than distal; thin innominate ilium that is excavated on ventral surface) demonstrate that this material belongs to a recently described species (D. emryi). During ecomorphotype analyses, fossil humerus and femur bones were directly associated with their corresponding mandible to reveal associations based on Recent morphological analogues. Strong correlation between ecomorphotypes and postcranial morphology supports placement of this material to D. emryi and not its sister taxon, D. claytoni. The previously described skull, mandible and teeth and postcranial bones described herein were discovered at the same locality during excavations at the base of the Malé Karpaty Mountains (Slovakia), at the junction of the Morava and Danube rivers. The geological age of D. emryi and the presence of mixed characters strongly suggest that this species was an early relative to the ancestor of seals, possibly being a terminal branch of the phocid tree. This material allows for emended diagnoses of the species, updated assessments of geographical distribution and provides further material for clarification of controversial phylogenetic relationships in Phocidae.


2020 ◽  
Vol 18 (2) ◽  
Author(s):  
Pedro Senna Bittencourt ◽  
Valéria Nogueira Machado ◽  
Bruce Gavin Marshall ◽  
Tomas Hrbek ◽  
Izeni Pires Farias

ABSTRACT Neon tetras (Paracheirodon spp.) are three colorful characid species with a complicated taxonomic history, and relationships among the species are poorly known. Molecular data resolved the relationships among the three neon tetras, and strongly supported monophyly of the genus and its sister taxon relationship to Brittanichthys. Additionally, the sister-taxon relationship of the rummy-nose tetras Hemigrammus bleheri and Petitella georgiae was strongly supported by molecular and morphological data. Therefore, we propose to transfer the rummy-nose tetras H. bleheri and H. rhodostomus to the genus Petitella. Furthermore, Petitella georgiae is likely to be a species complex comprised of at least two species.


2021 ◽  
Vol 9 ◽  
Author(s):  
Juan C. Cisneros ◽  
Paula Dentzien-Dias ◽  
Heitor Francischini

Provelosaurus americanus is the only known representative of the Pareiasauria in the Americas. This mid-size pareiasaur from the Rio do Rasto Formation of southern Brazil has been traditionally considered to be related to smaller forms from the South African Karoo known as the “dwarf pareiasaurs” of Lopingian age. P. americanus, however, co-existed with dinocephalians, which indicates a Guadalupian age. New fossils provide a nearly complete osteological account that forms the basis for a revised diagnosis and a test of phylogenetic relationships of P. americanus. Our results offer further support to the hypothesis that the Brazilian pareiasaur is the sister taxon of the Karoo “dwarf pareiasaurs,” being the earliest member of this group and one of the oldest pareiasaurs known so far. This is reinforced by a radiometric dating of the Morro Pelado Member of the Rio do Rasto Formation. In addition, the association of four individuals of various ontogenetic stages at the type locality supports some degree of social behavior in P. americanus.


2014 ◽  
Vol 62 (3) ◽  
pp. 362-373 ◽  
Author(s):  
Anna Karnkowska ◽  
Matthew S. Bennett ◽  
Donovan Watza ◽  
Jong Im Kim ◽  
Bożena Zakryś ◽  
...  

2001 ◽  
Vol 49 (5) ◽  
pp. 463 ◽  
Author(s):  
Antoine Campeau-Péloquin ◽  
John A. W. Kirsch ◽  
Mark D. B. Eldridge ◽  
François-Joseph Lapointe

DNA/DNA hybridisation analysis was undertaken to resolve the phylogenetic relationships within the chromosomally diverse genus Petrogale. Excepting P. concinna, all full species and three subspecies of P. lateralis were examined; all but four of these 16 taxa were labeled, as were four outgroup species. While demonstrating the ability of the technique to resolve relationships at the species level, our study confirmed that divergence of Petrogale species is recent and occurred during the late Pliocene to mid-Pleistocene. Our data placed the first division within Petrogale species between the monophyletic brachyotis group and the paraphyletic xanthopus plus lateralis/penicillata groups, the latter including P. rothschildi; the subspecies P. l. purpureicollisappears to be intermediate between thelateralis and thepenicillata complexes. However, our data could not resolve most relationships amongst the eastern Petrogale radiation, except for a probable grouping of the species P. herberti,P. inornata,P. penicillata, andP. sharmani. Finally, our results support recent suggestions that Dendrolagus rather than Thylogaleis the sister taxon to Petrogale.


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