scholarly journals Postcranial anatomy and histology of Seymouria, and the terrestriality of seymouriamorphs

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8698
Author(s):  
Kayla D. Bazzana ◽  
Bryan M. Gee ◽  
Joseph J. Bevitt ◽  
Robert R. Reisz
Keyword(s):  
Computed Tomography ◽  
Life History ◽  
Medullary Cavity ◽  
Early Permian ◽  
Evolutionary Trajectory ◽  
Histological Data ◽  
History Of ◽  
Postcranial Anatomy ◽  
Neutron Computed Tomography

Seymouria is the best known of the seymouriamorphs, a group of Permo-Carboniferous reptiliomorphs with both terrestrial and aquatic taxa. The majority of research on Seymouria has focused on cranial anatomy, with few detailed descriptions or illustrations of the postcrania. We utilized neutron computed tomography (nCT) and histological sampling to provide updated, detailed figures that clarify details of the postcranial anatomy and to assess the development and histology of Seymouria through specimens from the early Permian Richards Spur locality. The correlation of morphological and histological data indicate rapid metamorphosis in this terrestrially capable stem amniote, with the youngest specimen being postmetamorphic despite being distinctly younger than premetamorphic individuals of Discosauriscus, the only other seymouriamorph to have been histologically sampled. The microanatomical data (e.g., semi-open medullary cavity) also substantiate the hypothesis that Seymouria was terrestrial based on interpretation of external features, although the persistence of a modestly developed medullary spongiosa in comparison to either Discosauriscus or to other co-occurring terrestrial tetrapods suggests additional nuances that require further exploration. In the absence of clearly recognizable postmetamorphic stages in several seymouriamorph taxa, it is difficult to determine the evolutionary trajectory of terrestriality within the clade. Our analysis provides the first histological characterization of the life history of Seymouria and highlights the need for further study of seymouriamorph ontogeny.

The amphibamiform Nanobamus macrorhinus from the early Permian of Texas

2019 ◽  
Vol 94 (2) ◽  
pp. 366-377 ◽  
Author(s):  
Bryan M. Gee ◽  
Robert R. Reisz
Keyword(s):  
Phylogenetic Analysis ◽  
Evolutionary History ◽  
Phylogenetic Position ◽  
Early Permian ◽  
Larval Form ◽  
Terrestrial Environments ◽  
History Of ◽  
Insight Into

AbstractNanobamus macrorhinus Schoch and Milner, 2014 is a small amphibamiform temnospondyl from the early Permian Arroyo Formation of Texas. It is most readily characterized by an elongate and partially subdivided naris. This condition is superficially reminiscent of that seen in the coeval trematopids, the group to which N. macrorhinus was originally referred to under an interpretation of the holotype as a larval form. This was discounted by later workers, but the amphibamiform affinities of the specimen were not formalized until recently. The specimen has never been described in the context of its amphibamiform affinities and remains poorly characterized, never having been sampled in a phylogenetic analysis. Here we present a complete, updated osteological description of N. macrorhinus, including an improved characterization of its unique mosaic of plesiomorphic and apomorphic features and clarification of the taxon's autapomorphies. Our analysis of the taxon's phylogenetic position within Amphibamiformes shows that N. macrorhinus was recovered as diverging after basal amphibamiforms, e.g., the micropholids, and before derived amphibamiforms, e.g., the amphibamids. This is supported by the unique mixture of retained plesiomorphies, e.g., nonforeshortened postparietals and an oval choana, and apomorphies, e.g., a narrow interorbital region and slender palatal rami of the pterygoid. These results reflect the complexity of terrestrial amphibamiform diversity and provide further insight into the evolutionary history of the lissamphibian stem in terrestrial environments.

NEMATODE PARASITES FROM TURKISH VERTEBRATES: AN ANNOTATED LIST

1960 ◽  
Vol 38 (5) ◽  
pp. 949-963 ◽  
Author(s):  
G. A. Schad ◽  
R. E. Kuntz ◽  
W. H. Wells
Keyword(s):  
Life History ◽  
Crocidura Russula ◽  
Nematode Parasites ◽  
Annotated List ◽  
History Of ◽  
Taxonomic Characterization

An annotated list of nematodes recovered from 35 species of Turkish vertebrates is presented. In addition to information enabling improved taxonomic characterization of several species, the annotations describe Heligmosomum sp., a parasite of Crocidura russula, and discuss the value of the dorsal ray in distinguishing between species of the Heligmosomidae. Observations are made on the parasitic stages in the life history of Angusticaecum holopterum and their distribution in the host. Notes are given on the recognition of the genus Pseudophysaloptera, and the male of Rictularia proni is described.

scholarly journals Postcrania of large dissorophid temnospondyls from Richards Spur, Oklahoma

Fossil Record ◽  
2018 ◽  
Vol 21 (1) ◽  
pp. 79-91 ◽  
Author(s):  
Bryan M. Gee ◽  
Robert R. Reisz
Keyword(s):  
Taxonomic Diversity ◽  
Pelvic Girdle ◽  
Pectoral Girdle ◽  
Early Permian ◽  
Karst System ◽  
Trunk Region ◽  
Anterior Trunk ◽  
Posterior Trunk ◽  
Postcranial Anatomy

Abstract. The early Permian karst system near Richards Spur, Oklahoma preserves a diverse assemblage of terrestrial dissorophoid temnospondyls. Here we report the presence of a large-bodied dissorophine dissorophid that is represented by an articulated anterior trunk region, including a partial pectoral girdle, a ribcage characterized by extremely developed uncinate processes, and a rare, completely articulated pes. This represents the first documentation of the clade at the locality. Previously, dissorophids were represented only by the eucacopine Cacops. A complete pelvic girdle with hindlimbs is also referred to Cacops and represents the first material of the posterior trunk region to be described from the genus at Richards Spur. These specimens expand the taxonomic diversity known from the site and provide significant, well-preserved postcranial material that improves the characterization of dissorophid postcranial anatomy.

scholarly journals Computed tomography in the diagnosis of steroidal hepatopathy in a dog: case report

2011 ◽  
Vol 63 (1) ◽  
pp. 36-39 ◽  
Author(s):  
D.C Oliveira ◽  
L.A.V.S Costa ◽  
B.F Lopes ◽  
A.B Lanis ◽  
D.C Borlini ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Hepatic Injury ◽  
Imaging Technique ◽  
Helical Computed Tomography ◽  
Hepatic Glycogen ◽  
Hounsfield Units ◽  
Presumptive Diagnosis ◽  
History Of ◽  
Yorkshire Terrier

It is reported a case of an eight-year-old Yorkshire Terrier dog, with a history of prolonged use of prednisone in a dosage of 1mg/kg of body weight each 24 hours during two years. The helical computed tomography revealed hepatomegaly associated to a hyperattenuation of the parenchyma, with a radiodensity value of 82.55 Hounsfield units (HU). The spleen presented a mean radiodensity of 57.17HU, and a radiodensity difference of 25.38HU was observed between the two organs. Based on the history and findings of imaging technique, it was determined the presumptive diagnosis of steroidal hepatopathy compatible with accumulation of hepatic glycogen. It was concluded that computed tomography enabled the characterization of hepatic injury and the presumed diagnosis of steroidal hepatopathy

Characterization of the life history of Bangia fuscopurpurea (Bangiaceae, Rhodophyta) in connection with its cultivation in China

Aquaculture ◽  
2008 ◽  
Vol 278 (1-4) ◽  
pp. 101-109 ◽  
Author(s):  
Wen-jun Wang ◽  
Jian-yi Zhu ◽  
Pu Xu ◽  
Jian-rong Xu ◽  
Xiang-zhi Lin ◽  
...  
Keyword(s):  
Life History ◽  
History Of ◽  
Bangia Fuscopurpurea

scholarly journals Isolation and characterization of microsatellite markers from the RAD sequence of two temperate liana species: Euonymus fortunei (Celastraceae) and Schizophragma hydrangeoides (Hydrangeaceae)

2017 ◽  
Vol 66 (1) ◽  
pp. 40-42
Author(s):  
Hideki Mori ◽  
Saneyoshi Ueno ◽  
Asako Matsumoto ◽  
Kentaro Uchiyama ◽  
Takashi Kamijo ◽  
...  
Keyword(s):  
Life History ◽  
Microsatellite Markers ◽  
Sequence Data ◽  
Life History Strategy ◽  
The Public ◽  
Isolation And Characterization ◽  
Expected Heterozygosity ◽  
Euonymus Fortunei ◽  
History Of

Abstract Clonal reproduction of lianas is a common but important life history strategy. It is necessary to evaluate the clonal structure of liana species because clonal ability is potentially a major determinants distribution pattern of lianas. Therefore, we developed 10 microsatellite markers for Euonymus fortunei and Schizophragma hydrangeoides respectively from genomic sequences obtained from double-digest restriction site associated DNA (ddRAD). The sequence data of the developed markers were deposited on the public database. The expected heterozygosity (HE) of E. fortunei and S. hydrangeoides ranged from 0.727 to 0.847 with an average of 0.766, and from 0.734 to 0.924 with an average of 0.812, respectively. All loci were under HWE except for a locus of S. hydrangeoides (sh07). These markers should contribute to the understanding of the life history of temperate liana species.

scholarly journals Life History of the Oldest Lentivirus: Characterization of ELVgv Integrations in the Dermopteran Genome

2016 ◽  
Vol 33 (10) ◽  
pp. 2659-2669 ◽  
Author(s):  
Tomáš Hron ◽  
Helena Farkašová ◽  
Abinash Padhi ◽  
Jan Pačes ◽  
Daniel Elleder
Keyword(s):  
Life History ◽  
History Of

Studies on Demodex folliculorum Simon (1842). I. Life history

Parasitology ◽  
1961 ◽  
Vol 51 (1-2) ◽  
pp. 181-192 ◽  
Author(s):  
S. G. Spickett
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Life Span ◽  
Statistical Methods ◽  
Skin Surface ◽  
Birkbeck College ◽  
Demodex Folliculorum ◽  
Histological Data ◽  
History Of

1. Histological data are given about the location and frequency of the different stages of the life history of D. folliculorum in the pilo-sebaceous apparatus of man. These data are examined statistically and the relative durations of each stage and their movements in the follicle are deduced from them.2. A method of in vitro culture is described and data are given about the longevity of the various stages of the life history.3. Experiments on the behaviour of the different motile stages of the mite are described. It is concluded that the deutonymph is the distributive stage, and that distribution occurs over the skin surface.4. The life history is reconstructed by a synthesis of the evidence presented. The life-cycle lasts approximately 14½ days, the life span of each stage of it being: ovum 60 hr., larva 36 hr., protonymph 72 hr., deutonymph 60 hr., adult 120 hr. Interval between copulation and oviposition 12 hr.This work was largely carried out in the Department of Pathology of the Institute of Dermatology, London, and I wish to thank the Director of Pathology, Dr J. O. Oliver, for making available to me the facilities of his department, and for his advice and interest during the progress of the work. The photographs were prepared by Mr R. H. Lunnan of the Photographic Department of the Institute of Dermatology. I am indebted to the Dean of the Institute of Dermatology for permission to publish the photographs.I am grateful to Mr T. E. Hughes of the Department of Zoology, Birkbeck College, University of London, for his advice at all times, and to Miss Hilda Davies of the Department of Statistics, University of Sheffield, for help with statistical methods and to Mr W. Moseley, who prepared the text figures.Finally, I wish to express my thanks to Professor I. Chester Jones and Dr E. T. B. Francis of the Department of Zoology, University of Sheffield, for reading the manuscript and for their help in its preparation.

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