Phylogeny and Rates of Character Evolution Among Ringtail Possums (Pseudocheiridae, Marsupialia)

1993 ◽  
Vol 41 (3) ◽  
pp. 273 ◽  
Author(s):  
MS Springer
Keyword(s):  
Plant Material ◽  
Biochemical Analysis ◽  
Sister Taxon ◽  
Phylogenetic Position ◽  
Rates Of Evolution ◽  
Process Plant ◽  
Extant Species ◽  
Dollo Parsimony ◽  
Pseudocheirus Peregrinus ◽  
Cladistic Analyses

A total of 47 craniodental characters seen in fossil and extant ringtail possums (Pseudocheiridae: Marsupialia) were examined using Wagner, Camin-Sokal, and Dollo parsimony. All extant species form a clade to the exclusion of Miocene genera. Hemibelideus and Petauroides are sister taxa, as are Petropseudes and Pseudochirops. All species of Pseudocheirus are united together, except Pseudocheirus peregrinus, the phylogenetic position of which is uncertain on the basis of craniodental information. Overall, the agreement between cladistic analyses of craniodental characters and biochemical analysis is excellent, although the latter provide much stronger evidence that P. peregrinus is a sister taxon to other Pseudocheirus species. Rates of evolution of craniodental characters are highest in the Pseudochirops-Petropseudes lineage, where widening of the molars, elaboration of cusps and conules, accentuation of cristae and cristids, and the development of highly crenulated enamel create a dental battery that is better equipped to process plant material. Pseudocheirus displays the least modification of the presumed primitive dental condition.

The phylogenetic position of the tuatara, Sphenodon (Sphenodontida, Amniota), as indicated by cladistic analysis of the ultrastructure of spermatozoa

1992 ◽  
Vol 335 (1274) ◽  
pp. 207-219 ◽  
Keyword(s):  
Cladistic Analysis ◽  
Sister Group ◽  
Sister Taxon ◽  
Phylogenetic Position ◽  
Sister Group Relationship ◽  
Usual Concept ◽  
Cladistic Analyses ◽  
Relationship Of

Sphenodon has traditionally been regarded as a little changed survivor of the Permo-Triassic thecodont or eosuchian ‘stem reptiles’ but has alternatively been placed in the Lepidosauria as the plesiomorphic or even apomorphic sister-taxon of the squamates. A cladistic analysis of 16 characters from spermatozoal ultrastructure of Sphenodon and other amniotes unequivocally confirms its exceedingly primitive status. The analysis suggests that monotremes are the sister-group of birds; squamates form the sister-group of a bird + monotreme clade while the three sister-groups successively below the bird + monotreme + squa- mate assemblage are the caiman, the tuatara and the outgroup (turtles). The monotreme + bird couplet, supports the concept of the Haemothermia, but can only be regarded heuristically. The usual concept of mammals as a synapsid-derived outgroup of all other extant amniotes is not substantiated spermatologically. All cladistic analyses made, and a separate consideration of apomorphies, indicate that Sphenodon is spermatologically the most primitive amniote, excepting the Chelonia. It is advanced (apomorphic) for the amniotes in only two of the 16 spermatozoal characters considered. A close, sister-group relationship of Sphenodon with squamates is not endorsed.

scholarly journals The tetrapod Caerorhachis bairdi Holmes and Carroll from the Lower Carboniferous of Scotland

2001 ◽  
Vol 92 (3) ◽  
pp. 229-261 ◽  
Author(s):  
Marcello Ruta ◽  
Andrew R. Milner ◽  
Michael I. Coates
Keyword(s):  
Sister Taxon ◽  
Phylogenetic Position ◽  
Lower Carboniferous ◽  
Stem Group ◽  
Cladistic Analyses ◽  
Early Tetrapods

ABSTRACTThe tetrapod Caerorhachis bairdi, probably from the Pendleian Limestone Coal Group in the Scottish Midland Valley, is rediagnosed and redescribed, and its affinities are discussed. Caerorachis was originally interpreted as a temnospondyl amphibian, based on characters that are now regarded as primitive for tetrapods, or of uncertain polarity. Several features of Caerorhachis (e.g. gastrocentrous vertebrae, curved trunk ribs, reduced dorsal iliac blade, L-shaped tarsal intermedium) are observed in certain primitive amniotes. In particular, Caerorhachis resembles ‘anthracosaurs’, generally considered to be among the most primitive of stem-group amniotes.The phylogenetic position of Caerorhachis is considered in the light of recently published cladistic analyses of Palaeozoic tetrapods. Most analyses place Caerorhachis at the base of, or within, ‘anthracosaurs’. When multiple, equally parsimonious solutions are found, its ‘anthracosaur’ affinities are shown in at least some trees, and are supported by several informative and, generally, highly consistent characters. Alternative phylogenetic placements (e.g. sister taxon to temnospondyls) are usually less well corroborated.If the fundamental evolutionary split of most early tetrapods into stem-group lissamphibians (e.g. temnospondyls) and stem-group amniotes (e.g. ‘anthracosaurs’) is accepted, then the revised interpretation of Caerprhachis sheds light on near-ancestral conditions for Amniota.

scholarly journals Phylogenetic relationships of the European newts (genus Triturus) tested with mitochondrial DNA sequence data

1999 ◽  
Vol 68 (2) ◽  
pp. 73-81 ◽  
Author(s):  
I. Zajc ◽  
J.W. Arntzen
Keyword(s):  
Mitochondrial Dna ◽  
Sequence Data ◽  
A Priori ◽  
Strong Support ◽  
Species Group ◽  
Rrna Genes ◽  
Sister Taxon ◽  
Phylogenetic Position ◽  
12S Rrna ◽  
16S Rrna Sequence

European newts (genus Triturus) are widely studied, but their phylogeny is not yet unambiguously resolved. Fragments of mitochondrial DNA experiencing different rates of evolution (the ATPase and 12S rRNA genes) were sequenced in order to test a phylogenetic hypothesis derived from biochemical and behavioral data. Well-supported branches of the existing phylogeny gained support in our study. The monophyletic origin of the hypothesized T. boscai – T. italicus clade remained ambiguous, whereas strong support was gained for the sister-taxon relationship of T. vulgaris and T. montandoni. The position of T. vittatus as a sister taxon to the T. marmoratus species group was also supported. The phylogenetic position of T. alpestris could not be clarified. With an in-group taxon sampling denser than in previous molecular phylogenetic studies and under the a priori selection of species from the genera Cynops, Neurergus and Paramesotriton as out-groups, the monophyly of Triturus was strongly supported. It cannot be excluded, however, that the presumed out-group actually belongs to the in-group, rendering Triturus paraphyletic as was concluded from recently published 12S and 16S rRNA sequence data.

scholarly journals New data from Monoplacophora and a carefully-curated dataset resolve molluscan relationships

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Kevin M. Kocot ◽  
Albert J. Poustka ◽  
Isabella Stöger ◽  
Kenneth M. Halanych ◽  
Michael Schrödl
Keyword(s):  
Mixture Models ◽  
Strong Support ◽  
Housekeeping Genes ◽  
Data Matrix ◽  
Quality Data ◽  
Sister Taxon ◽  
Phylogenetic Position ◽  
Morphological Studies ◽  
Homogeneous Models ◽  
Molluscan Evolution

AbstractRelationships among the major lineages of Mollusca have long been debated. Morphological studies have considered the rarely collected Monoplacophora (Tryblidia) to have several plesiomorphic molluscan traits. The phylogenetic position of this group is contentious as morphologists have generally placed this clade as the sister taxon of the rest of Conchifera whereas earlier molecular studies supported a clade of Monoplacophora + Polyplacophora (Serialia) and phylogenomic studies have generally recovered a clade of Monoplacophora + Cephalopoda. Phylogenomic studies have also strongly supported a clade including Gastropoda, Bivalvia, and Scaphopoda, but relationships among these taxa have been inconsistent. In order to resolve conchiferan relationships and improve understanding of early molluscan evolution, we carefully curated a high-quality data matrix and conducted phylogenomic analyses with broad taxon sampling including newly sequenced genomic data from the monoplacophoran Laevipilina antarctica. Whereas a partitioned maximum likelihood (ML) analysis using site-homogeneous models recovered Monoplacophora sister to Cephalopoda with moderate support, both ML and Bayesian inference (BI) analyses using mixture models recovered Monoplacophora sister to all other conchiferans with strong support. A supertree approach also recovered Monoplacophora as the sister taxon of a clade composed of the rest of Conchifera. Gastropoda was recovered as the sister taxon of Scaphopoda in most analyses, which was strongly supported when mixture models were used. A molecular clock based on our BI topology dates diversification of Mollusca to ~546 MYA (+/− 6 MYA) and Conchifera to ~540 MYA (+/− 9 MYA), generally consistent with previous work employing nuclear housekeeping genes. These results provide important resolution of conchiferan mollusc phylogeny and offer new insights into ancestral character states of major mollusc clades.

SYNOPSIS OF THE NEOTROPICAL GENUS OZAENA OLIVIER: CLASSIFICATION AND RECONSTRUCTED EVOLUTIONARY HISTORY (COLEOPTERA: CARABIDAE: OZAENINI)

1990 ◽  
Vol 122 (5) ◽  
pp. 779-815 ◽  
Author(s):  
George E. Ball ◽  
Danny Shpeley
Keyword(s):  
South America ◽  
Sister Group ◽  
Structural Features ◽  
Character Evolution ◽  
Type Locality ◽  
Sister Taxon ◽  
Fore Tibia ◽  
Sensilla Basiconica ◽  
Extant Species ◽  
And Shifts

AbstractDescriptions and illustrations of structural features of adults, a key, and chorological data provide the basis for characterizing the genus Ozaena Olivier and classifying the 10 included species, two of which are new: O. maxi (type locality: Iracubo, CAYENNE), and O. manu (type locality: Manu National Park, Madre de Dios Province, PERU). With a geographical range that extends from ca. 30°S to 30°N in the New World, all species of Ozaena occur in cis-Andean South America, only two ranging farther north: O. dentipes Olivier, to Panama; and O. lemoulti Bänninger to southern Arizona, USA. A reconstructed phylogeny postulates the following: the genus Platycerozaena Bänninger as the sister-group of Ozaena, together these genera comprising the Ozaena genus-group; within Ozaena, the O. dentipes group as sister-taxon of the O. lemoulti + convexa groups; within the O. dentipes group, O. maxi as sister-taxon of O. linearis Bänninger + dentipes; within the O. lemoulti group, the sequence O. ecuadorica Bänn. (O. elavata Bänn. [O. lemoulti + martinezi Ogueta]); and within the O. convexa group, O. grossa Bänn. as sister-taxon of O. convexa Bänn. + manu. Character evolution involves losses, gains, and shifts, in about equal numbers. Convergence is relatively rare, involving only three of 35 characters. The predominant mode of character evolution is simple, with few examples of sequential changes sustained through several speciation events. Basic modifications in evolution of the ground-plan of the Ozaena genus-group include reduction or loss (for example, tactile sense organs, antennal cleaner of the fore tibia, and adhesive vestiture of the male fore tarsi), and enhancement or gain (for example, scale-like sensilla basiconica on pronotum and elytra, concentration of sensilla basiconica in groups on the antennomeres, particularly antennomere 11). Within Ozaena, many modifications to the antennae and mouthparts indicate the importance of these organs to evolution of the group.Based on phylogenetic relationships and the distribution pattern of the extant species, a reconstructed geographical history of Ozaena postulates the following: first, a vicariance event in South America separating the ancestral stock of Ozaena into a northern vicar that gave rise to the O. dentipes group, and a southern vicar that gave rise to the O. lemoulti and convexa groups; followed by cycles of range expansion and contraction that allowed for differentiation of successive stocks of species. The temporal range for these speciation events is estimated to extend over a period of about 12 million years, or from the latter part of the Miocene epoch to the Recent. The most recent speciation events are estimated to be of Pliocene age.Based on lack of differentiation of South American and Middle American representatives of O. dentipes and O. lemoulti respectively, and extent of range in Middle America, these two species are postulated to be relatively recent invaders of the latter area, with O. dentipes being the more recent to arrive.

scholarly journals Slowly but surely: gradual diversification and phenotypic evolution in the hyper-diverse tree fern family Cyatheaceae

2019 ◽  
Vol 125 (1) ◽  
pp. 93-103
Author(s):  
Oriane Loiseau ◽  
Anna Weigand ◽  
Sarah Noben ◽  
Jonathan Rolland ◽  
Daniele Silvestro ◽  
...  
Keyword(s):  
Species Richness ◽  
Taxonomic Diversity ◽  
Tree Fern ◽  
Rates Of Evolution ◽  
Extant Species ◽  
The Family ◽  
History Of ◽  
Rapid Diversification ◽  
The Tropics ◽  
Diverse Groups

Abstract Background and Aims The tremendously unbalanced distribution of species richness across clades in the tree of life is often interpreted as the result of variation in the rates of diversification, which may themselves respond to trait evolution. Even though this is likely a widespread pattern, not all diverse groups of organisms exhibit heterogeneity in their dynamics of diversification. Testing and characterizing the processes driving the evolution of clades with steady rates of diversification over long periods of time are of importance in order to have a full understanding of the build-up of biodiversity through time. Methods We studied the macroevolutionary history of the species-rich tree fern family Cyatheaceae and inferred a time-calibrated phylogeny of the family including extinct and extant species using the recently developed fossilized birth–death method. We tested whether the high diversity of Cyatheaceae is the result of episodes of rapid diversification associated with phenotypic and ecological differentiation or driven by stable but low rates of diversification. We compared the rates of diversification across clades, modelled the evolution of body size and climatic preferences and tested for trait-dependent diversification. Key Results This ancient group diversified at a low and constant rate during its long evolutionary history. Morphological and climatic niche evolution were found to be overall highly conserved, although we detected several shifts in the rates of evolution of climatic preferences, linked to changes in elevation. The diversification of the family occurred gradually, within limited phenotypic and ecological boundaries, and yet resulted in a remarkable species richness. Conclusions Our study indicates that Cyatheaceae is a diverse clade which slowly accumulated morphological, ecological and taxonomic diversity over a long evolutionary period and provides a compelling example of the tropics as a museum of biodiversity.

Anatomy and morphology of Cremnothamnus (Asteraceae) a new genus for Helichrysum thomsonii

1994 ◽  
Vol 7 (6) ◽  
pp. 569 ◽  
Author(s):  
CF Puttock
Keyword(s):  
New Genus ◽  
Sister Taxon ◽  
General Morphology ◽  
Cladistic Analyses

The stem and cypsela anatomy, and the general morphology of Helichrysum thomsonii F.Muel1. (Ozothamnus thomsonii (F.Muell.) Paul G. Wilson) are investigated. Cladistic analyses indicate that Helichrysum thomsonii is not closely related to the four genera to which it has been previously associated (Basedowia, Helichrysum, Lawrencella and Ozothamnus), but is a likely sister taxon of Argyroglottis, Bracteantha and the rest of the Angianthinae. A new genus, Cremnothamnus Puttock, is proposed for Helichrysum thomsonii.

A new species of Lepidophyma (Squamata: Xantusiidae) from San Luis Potosí, México, with notes on its physiological ecology

Zootaxa ◽  
2021 ◽  
Vol 4949 (1) ◽  
pp. 115-130
Author(s):  
DIEGO M. ARENAS-MORENO ◽  
FRANCISCO J. MUÑOZ-NOLASCO ◽  
ADÁN BAUTISTA-DEL MORAL ◽  
LUIS A. RODRÍGUEZ-MIRANDA ◽  
SAÚL F. DOMÍNGUEZ-GUERRERO ◽  
...  
Keyword(s):  
New Species ◽  
Natural History ◽  
Water Loss ◽  
Taxonomic Status ◽  
Thermal Parameters ◽  
Morphological Data ◽  
Sister Taxon ◽  
Activity Period ◽  
Phylogenetic Position ◽  
A New Species

In recent years, there has been an increase in the descriptions of members of the lizard genus Lepidophyma. Herein, we describe a new species of Lepidophyma from the Huasteca Potosina region of Mexico, previously confused with L. gaigeae, from which it differs in lacking parietal spot, among other characteristics. We inferred its phylogenetic position and provide information on its thermal and hydric physiology, as well as on some other aspects of natural history. Molecular and morphological data supported the independent taxonomic status of the new species, indicating its placement as the sister taxon of L. gaigeae and a wide morphological separation between these species. Lepidophyma lusca sp. nov. has a diurnal-crepuscular activity period and occurs at lower elevations than L. gaigeae. Also, the new species differ from its sister taxon in its physiology, as reflected by its tendency toward higher thermal parameters and water loss rates. With the description of L. lusca sp. nov., the number of species in the genus Lepidophyma rises to 21. 

Revision of the genus Lisposoma Lawrence, 1928 (Scorpiones: Bothriuridae)

2003 ◽  
Vol 34 (3) ◽  
pp. 241-264 ◽  
Author(s):  
Lorenzo Prendini
Keyword(s):  
South America ◽  
New Records ◽  
Conservation Status ◽  
Morphological Data ◽  
Phylogenetic Position ◽  
Generic Diagnosis ◽  
Distribution Map ◽  
Present Contribution ◽  
Cladistic Analyses

AbstractThe endemic Namibian genus Lisposoma Lawrence, 1928, comprising two described species, represents one of two basal African genera in the Gondwanan family Bothriuridae Simon, 1880. All other, more derived genera of Bothriuridae occur in South America, India and Australia. Although the phylogenetic position of Lisposoma has become an increasingly contentious subject, three cladistic analyses based on morphological data have confirmed that it is a basal bothriurid. In view of those findings, the present contribution serves to revise the generic diagnosis of Lisposoma, last revised by Lamoral (1979), who placed the genus in the Scorpionidae Latreille, 1802 and constructed his diagnosis accordingly. A considerable number of new specimens, many representing new records for the two species of Lisposoma, have also accumulated since Lamoral's (1979) revision. These new data justify the provision of revised diagnoses and descriptions for the two species, together with a key to their identification, brief summaries of their ecology and conservation status, and a distribution map plotting all known locality records.

scholarly journals A duplicate gene rooting of seed plants and the phylogenetic position of flowering plants

2010 ◽  
Vol 365 (1539) ◽  
pp. 383-395 ◽  
Author(s):  
Sarah Mathews ◽  
Mark D. Clements ◽  
Mark A. Beilstein
Keyword(s):  
Sequence Data ◽  
Duplicate Gene ◽  
Molecular Data ◽  
Flowering Plants ◽  
Phylogenetic Position ◽  
Molecular Evidence ◽  
Dna Sequence Data ◽  
Extant Species ◽  
Statistical Support ◽  
Origin Of Angiosperms

Flowering plants represent the most significant branch in the tree of land plants, with respect to the number of extant species, their impact on the shaping of modern ecosystems and their economic importance. However, unlike so many persistent phylogenetic problems that have yielded to insights from DNA sequence data, the mystery surrounding the origin of angiosperms has deepened with the advent and advance of molecular systematics. Strong statistical support for competing hypotheses and recent novel trees from molecular data suggest that the accuracy of current molecular trees requires further testing. Analyses of phytochrome amino acids using a duplicate gene-rooting approach yield trees that unite cycads and angiosperms in a clade that is sister to a clade in which Gingko and Cupressophyta are successive sister taxa to gnetophytes plus Pinaceae. Application of a cycads + angiosperms backbone constraint in analyses of a morphological dataset yields better resolved trees than do analyses in which extant gymnosperms are forced to be monophyletic. The results have implications both for our assessment of uncertainty in trees from sequence data and for our use of molecular constraints as a way to integrate insights from morphological and molecular evidence.

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