Development and evolution of the gynoecium in Myrteae (Myrtaceae)

2014 ◽  
Vol 62 (4) ◽  
pp. 335 ◽  
Author(s):  
Rafael R. Pimentel ◽  
Natália P. Barreira ◽  
Diego P. Spala ◽  
Nathane B. Cardim ◽  
Marcelo C. Souza ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Floral Anatomy ◽  
Structural Diversity ◽  
Morphological Characters ◽  
Fleshy Fruit ◽  
South American ◽  
Transmission Electron ◽  
History Of ◽  
Ovule Number ◽  
Development And Evolution

Characters of the gynoecium are considered potentially significant for the systematics of Myrtaceae. However, only two such characters – ovule number and placentation – have been addressed from an evolutionary perspective. Colleter presence in flowers is a synapomorphy of Myrtales; however, no morphological and histochemical descriptions of such structures have been done in Myrtaceae. Here we analysed the ontogeny and anatomy of the gynoecium combined with the ontogeny, anatomy, ultrastructure, and histochemistry of the colleters to study the evolution of these characters and map their states in the Myrteae phylogenetic tree. Our findings may help elucidate the evolutionary history of this tribe of fleshy-fruit producers so important towards maintaining ecological balance in the rainforest. Floral anatomy and ontogeny were analysed using light microscopy. Colleter samples were processed using standard methods for light and transmission electron microscopy. The main metabolites in colleters were detected via histochemistry. To map character states the program Mesquite version 2.71 was used. The morphological characters of the South American Myrteae here analysed provided an overview of the evolution of gynoecium – with cauline or carpellate placenta – and of colleters, as well as synapomorphies for the clades Plinia + Myrcia and Eugenia + Pimenta. The presence of two integuments in the ovules associated with sclereids and colleters in the gynoecium and the young fleshy fruit assures the efficient dispersal of their seeds. Our findings regarding gynoecium structural diversity of the tribe Myrteae give a new insight on their morphologically uniform flowers.

scholarly journals Current perspectives on the evolution of birds

2008 ◽  
Vol 77 (2) ◽  
pp. 109-116 ◽  
Author(s):  
Per G.P. Ericson
Keyword(s):  
Evolutionary History ◽  
Genetic Data ◽  
Morphological Characters ◽  
Current Understanding ◽  
Sources Of Information ◽  
Theropod Dinosaurs ◽  
History Of ◽  
Evolution Of Birds ◽  
The Many ◽  
Rapid Radiations

The paper summarizes the current understanding of the evolution and diversification of birds. New insights into this field have mainly come from two fundamentally different, but complementary sources of information: the many newly discovered Mesozoic bird fossils and the wealth of genetic analyses of living birds at various taxonomic levels. The birds have evolved from theropod dinosaurs from which they can be defined by but a few morphological characters. The early evolutionary history of the group is characterized by the extinctions of many major clades by the end of the Cretaceous, and by several periods of rapid radiations and speciation. Recent years have seen a growing consensus about the higher-level relationships among living birds, at least as can be deduced from genetic data.

A new feather mite species of the genus Neumannella Trouessart, 1916 (Analgoidea, Dermoglyphidae) from the Red-winged Tinamou Rhynchotus rufescens (Temminck, 1815) (Aves, Tinamiformes) with remarks to the evolution of host-parasite associations of the genus

2014 ◽  
Vol 59 (2) ◽  
Author(s):  
Jacek Dabert
Keyword(s):  
New Species ◽  
Evolutionary History ◽  
Morphological Characters ◽  
Mite Species ◽  
Feather Mite ◽  
History Of ◽  
Host Parasite ◽  
Reconciliation Method ◽  
A New Species ◽  
Mite Family

AbstractNeumannella skorackii, a new species of the feather mite family Dermoglyphidae (Acari, Astigmata) is described from the Red-winged Tinamou Rhynchotus rufescens (Temminck, 1815) (Aves, Tinamiformes) from Paraguay and a key to all known species of the genus is provided. The phylogenetic relationships (MP analysis of 25 morphological characters) between Neumannella species along with the evolutionary history of host-parasite associations revealed by Jungle reconciliation method are reconstructed. Relatively low cospeciation contribution to the recent host-parasite associations is discovered.

scholarly journals Floral-oil-producing Plantaginaceae species: geographical distribution, pollinator rewards and interactions with oil-collecting bees

2013 ◽  
Vol 13 (4) ◽  
pp. 77-89 ◽  
Author(s):  
Aline Cristina Martins ◽  
Isabel Alves-dos-Santos
Keyword(s):  
Geographical Distribution ◽  
Evolutionary History ◽  
Neotropical Region ◽  
South American ◽  
Oil Glands ◽  
Especial Case ◽  
History Of ◽  
Plant Families ◽  
Floral Oil ◽  
Pollinator Rewards

Floral oils as reward to pollinators occur in eleven plant families and appeared at least 28 times in the evolutionary history of flowering plants. They are produced in epithelial or tricomatic glands and collected by oil bee visitors. The present paper focuses on floral-oil-producing species of Plantaginaceae, a Neotropical group namely Angelonia clade. This group comprises around 40 described species in the genera Angelonia, Basistemon, Monttea, Monopera and the oil-less Melosperma. We present a revision of all species of the Angelonia clade, their geographical distribution, resources offered to pollinators and records of flower visitors, especially oil-collecting bees. These plants rely only on oil-collecting species in the tribe Centridini and Tapinotaspidini for a successful pollination, being the interaction between both partners an especial case of bee/flower adaptation in Neotropical region. Some bee species depend only on the oil of Plantaginaceae flowers to survive, while others can collect on several floral oil sources. The pollinating bees explore the oil glands located in sacs using specialized hairs in the forelegs. With this study, we hope to inspire further research relating to this fascinating group of plants, in which most species are rare and occur in highly endangered habitats in South American open vegetation biomes.

scholarly journals The unexpected survival of an ancient lineage of anseriform birds into the Neogene of Australia: the youngest record of Presbyornithidae

2016 ◽  
Vol 3 (2) ◽  
pp. 150635 ◽  
Author(s):  
Vanesa L. De Pietri ◽  
R. Paul Scofield ◽  
Nikita Zelenkov ◽  
Walter E. Boles ◽  
Trevor H. Worthy
Keyword(s):  
Evolutionary History ◽  
South Australia ◽  
First Record ◽  
South American ◽  
Crown Group ◽  
Term Survival ◽  
Skeletal Morphology ◽  
Ancient Lineage ◽  
History Of

Presbyornithids were the dominant birds in Palaeogene lacustrine assemblages, especially in the Northern Hemisphere, but are thought to have disappeared worldwide by the mid-Eocene. Now classified within Anseriformes (screamers, ducks, swans and geese), their relationships have long been obscured by their strange wader-like skeletal morphology. Reassessment of the late Oligocene South Australian material attributed to Wilaru tedfordi , long considered to be of a stone-curlew (Burhinidae, Charadriiformes), reveals that this taxon represents the first record of a presbyornithid in Australia. We also describe the larger Wilaru prideauxi sp. nov. from the early Miocene of South Australia, showing that presbyornithids survived in Australia at least until ca 22 Ma. Unlike on other continents, where presbyornithids were replaced by aquatic crown-group anatids (ducks, swans and geese), species of Wilaru lived alongside these waterfowl in Australia. The morphology of the tarsometatarsus of these species indicates that, contrary to other presbyornithids, they were predominantly terrestrial birds, which probably contributed to their long-term survival in Australia. The morphological similarity between species of Wilaru and the Eocene South American presbyornithid Telmabates antiquus supports our hypothesis of a Gondwanan radiation during the evolutionary history of the Presbyornithidae. Teviornis gobiensis from the Late Cretaceous of Mongolia is here also reassessed and confirmed as a presbyornithid. These findings underscore the temporal continuance of Australia’s vertebrates and provide a new context in which the phylogeny and evolutionary history of presbyornithids can be examined.

Description of Metchnikovella spiralis sp. n. (Microsporidia: Metchnikovellidae), with notes on the ultrastructure of metchnikovellids

Parasitology ◽  
2014 ◽  
Vol 141 (8) ◽  
pp. 1108-1122 ◽  
Author(s):  
Y. Y. SOKOLOVA ◽  
G. G. PASKEROVA ◽  
Y. M. ROTARI ◽  
E. S. NASSONOVA ◽  
A. V. SMIRNOV
Keyword(s):  
Life Cycle ◽  
Evolutionary History ◽  
White Sea ◽  
Parasitophorous Vacuole ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Transmission Electron Microscopy Study ◽  
Transmission Electron ◽  
History Of ◽  
A New Species

SUMMARYThe present paper reports results of a transmission electron microscopy study of a new metchikovellid microsporidium. It was isolated from gregarines Polyrhabdina sp. inhabiting guts of polychaetes Pygospio elegans sampled at the White Sea silt littoral zone. Free sporogony (FS) occurred in the life cycle of the microsporidium alongside sac-bound sporogony (BS). Free spores resided in a parasitophorous vacuole and were of typical metchnikovellidean structure, uninucleate and oblong. They measured on sections 2·0–3·2×1·3–1·9 μm. The life cycle included pre-sporogonial stages represented by dikaryotic cells and 4-nucleate cells with coupled nuclei. A multinucleate sporogonial plasmodium of FS split in numerous (>10) sporoblasts. In BS segregation of sporoblasts occurred within thick-walled cysts by internal budding. Spore sacs of this microsporidium, measuring on average 11·6×4·7 μm, were limited by a thick electron-dense wall, externally ornamented with spirally wound cords of dense material. These oval spore sacs contained eight barrel-shaped spores, comparable in size and ultrastructure to FS spores. Ultrastructure of both types of spores and intracellular development of the new microsporidium and Metchnikovella spp. were similar, suggesting they belong to the same genus. In this paper we describe a new species Metchnikovella spiralis and discuss morphology of metchnikovellids in the context of putative evolutionary history of Microsporidia.

Systematics of Senecio section Crociseris (Compositae, Senecioneae)

Phytotaxa ◽  
2015 ◽  
Vol 211 (1) ◽  
pp. 1 ◽  
Author(s):  
JOEL CALVO ◽  
INÉS ÁLVAREZ ◽  
CARLOS AEDO
Keyword(s):  
Central Asia ◽  
Evolutionary History ◽  
Morphological Characters ◽  
The Other ◽  
Distribution Maps ◽  
History Of ◽  
Perennial Herbs ◽  
First Time ◽  
Northwestern Africa ◽  
Shape And Size

The complexity of the evolutionary history of Senecio is reflected in its conflicted taxonomy. Within this genus, Senecio section Crociseris (Compositae, Senecioneae), a group of perennial herbs distributed in Europe, western and Central Asia, and northwestern Africa, was not fully revised. A worldwide revision of this section recognizing 28 species and eight subspecies is presented here. The main morphological characters revealed as useful for distinguishing between species are the number and shape of supplementary and involucral bracts, synflorescence architecture, indumentum, and the shape and size of leaves and achenes. In this new taxonomic treatment S. provincialis and S. lagascanus have been segregated from S. doronicum, within which three subspecies are recognized (S. doronicum subsp. orientalis is validly published herein). On the other hand, S. ruthenensis from France and S. lusitanicus from Portugal have been synonymized to S. lagascanus, as well as S. ovatifolius, S. pisidicus, and S. tmoleus from Anatolia to S. kolenatianus, S. olympicus, and S. castagneanus respectively, S. bertramii from Lebanon to S. cilicius, and S. delbesianus from Syria to S. racemosus subsp. racemosus. Sixty eight names are lectotypified, the names S. barrelieri, S. pyrenaicus, and S. scopolii are neotypified, and one epitype is designated for the name S. perralderianus. Descriptions and distribution maps are provided for all the species included, as well as an identification key. Nine species are illustrated for the first time.

Where Fossils Dare and Males Matter: combined morphological and molecular analysis untangles the evolutionary history of the spider ant genus Leptomyrmex Mayr (Hymenoptera : Dolichoderinae)

2017 ◽  
Vol 31 (6) ◽  
pp. 765 ◽  
Author(s):  
Phillip Barden ◽  
Brendon Boudinot ◽  
Andrea Lucky
Keyword(s):  
Evolutionary History ◽  
Morphological Evolution ◽  
Sister Group ◽  
Morphological Characters ◽  
Fossil Material ◽  
First Case ◽  
History Of ◽  
The Impact ◽  
Surprising Discovery

The distinctive ant genus Leptomyrmex Mayr, 1862 had been thought to be endemic to Australasia for over 150 years, but enigmatic Neotropical fossils have challenged this view for decades. The present study responds to a recent and surprising discovery of extant Leptomyrmex species in Brazil with a thorough evaluation of the Dominican Republic fossil material, which dates to the Miocene. In the first case study of direct fossil inclusion within Formicidae Latreille, 1809, we incorporated both living and the extinct Leptomyrmex species. Through simultaneous analysis of molecular and morphological characters in both Bayesian and parsimony frameworks, we recovered the fossil taxon as sister-group to extant Leptomyrmex in Brazil while considering the influence of taxonomic and character sampling on inferred hypotheses relating to tree topology, biogeography and morphological evolution. We also identified potential loss of signal in the binning of morphological characters and tested the impact of parameterisation on divergence date estimation. Our results highlight the importance of securing sufficient taxon sampling for extant lineages when incorporating fossils and underscore the utility of diverse character sources in accurate placement of fossil terminals. Specifically, we find that fossil placement in this group is influenced by the inclusion of male-based characters and the newly discovered Neotropical ‘Lazarus taxon’.

Evolutionary History of the South American Mistletoe Tripodanthus (Loranthaceae) Using Nuclear and Plastid Markers

2012 ◽  
Vol 37 (1) ◽  
pp. 218-225 ◽  
Author(s):  
Guillermo C. Amico ◽  
Romina Vidal-Russell ◽  
Miguel A. Garcia ◽  
Daniel L. Nickrent
Keyword(s):  
Evolutionary History ◽  
South American ◽  
The South ◽  
History Of ◽  
Plastid Markers ◽  
History Of The South

Xenacoelomorpha Nervous Systems

2017 ◽  
Author(s):  
Pedro Martínez ◽  
Volker Hartenstein ◽  
Simon G. Sprecher
Keyword(s):  
Gene Networks ◽  
Parallel Evolution ◽  
Evolutionary Process ◽  
Morphological Characters ◽  
Nervous Systems ◽  
Transmission Electron ◽  
Unique System ◽  
Changing Roles ◽  
History Of ◽  
The Many

The emergence and diversification of bilateral animals are among the most important transitions in the history of life on our planet. A proper understanding of the evolutionary process will derive from answering such key questions as, how did complex body plans arise in evolutionary time, and how are complex body plans “encoded” in the genome? the first step is focusing on the earliest stages in bilaterian evolution, probing the most elusive organization of the genomes and microscopic anatomy in basally branching taxa, which are currently assembled in a clade named Xenacoelomorpha. This enigmatic phylum is composed of three major taxa: acoel flatworms, nemertodermatids, and xenoturbellids. Interestingly, the constituent species of this clade have an enormously varied set of morphologies; not just the obvious external features but also their tissues present a high degree of constructional variation. This interesting diversity of morphologies (a clear example being the nervous system, with animals showing different degrees of compaction) provides a unique system in which to address outstanding questions regarding the parallel evolution of genomes and the many morphological characters encoded by them. A systematic exploration of the anatomy of members of these three taxa, employing immunohistochemistry, in situ hybridization, and high-throughput transmission electron microscopy, will provide the reference framework necessary to understand the changing roles of genes and gene networks during the evolution of xenacoelomorph morphologies and, in particular, of their nervous systems.

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