Morphological variation in the Pennsylvanian horseshoe crab Euproops danae (Meek & Worthen, 1865) (Xiphosurida, Euproopidae) from the lower Mercer Shale, Windber, Pennsylvania, USA

2019 ◽  
Vol 39 (4) ◽  
pp. 396-406 ◽  
Author(s):  
Jessica N Tashman ◽  
Rodney M Feldmann ◽  
Carrie E Schweitzer
Keyword(s):  
Developmental Stage ◽  
Morphological Variation ◽  
Horseshoe Crab ◽  
Ontogenetic Changes ◽  
Strip Mine ◽  
First Time

Abstract Examination of 36 specimens of the Pennsylvanian horseshoe crab Euproops danae (Meek & Worthen, 1865) from a previously unreported occurrence in the lower Mercer Shale exposed in an abandoned strip mine south from Windber, Pennsylvania, USA, document ontogenetic changes in prosomal morphology. Intercardiophthalmic transverse bars become less pronounced as ophthalmic spines become longer in larger, older specimens through approximately seven instar stages. It remains unclear if the presence or absence of ophthalmic spines is taphonomic, regardless of developmental stage. The holotype of E. danae is illustrated photographically for the first time.

Morphological variation in Xenoxybelis boulengeri (Procter, 1923) (Serpentes, Xenodontinae, Philodryadini)

Zootaxa ◽  
2008 ◽  
Vol 1743 (1) ◽  
pp. 53 ◽  
Author(s):  
ANA LÚCIA DA COSTA PRUDENTE ◽  
MÁRCIO ANDRÉ AMORIM DA SILVA ◽  
WÁLDIMA ALVES DA ROCHA ◽  
FRANCISCO LUÍS FRANCO
Keyword(s):  
Morphological Variation ◽  
Rare Species ◽  
Original Description ◽  
External Morphology ◽  
Time Analysis ◽  
Morphometric Characters ◽  
Permit Allocation ◽  
Scientific Collections ◽  
First Time ◽  
Molecular Characters

The genus Xenoxybelis contains two species, X. argenteus and X. boulengeri, characterized by semi-arboreal habits and an extremely thin rostral area, classified in the subfamily Xenodontinae (Colubridae). Xenoxybelis boulengeri is considered a rare species and is poorly represented in scientific collections. Its external morphology is known only from the original description and seven other specimens. In this study, twenty additional specimens were examined from the Brazilian states of Acre, Amazonas and Rondônia. Variation in meristic and morphometric characters are described, and new characters are incorporated in a revised diagnosis of the species. Illustrations and a description of the hemipenes of X. boulengeri are presented for the first time. Analysis of morphological and molecular characters permit allocation of Xenoxybelis to the tribe Phylodryadini, together with Ditaxodon, Philodryas, Pseudablabes and Tropidodryas.

Taxonomic and Nomenclatural notes on Lechenaultia R.Br. (Goodeniaceae)

Brunonia ◽  
1986 ◽  
Vol 9 (1) ◽  
pp. 1 ◽  
Author(s):  
DA Morrison
Keyword(s):  
New Species ◽  
Morphological Variation ◽  
Phylogenetic Relationships ◽  
First Time

There have been a large number of nomenclatural and taxonomic problems within Lechenaultia, and these are resolved here. A total of 24 names are lectotypified, two neotypes are chosen, a series of misapplied names is elucidated, and L. agrostophylla is synonymised under L. filiformis for the first time. As well, L. brevifolia, L. lutescens and L. papillata are described as new species, and the considerable morphological variation within several of the species is reported in detail. The phylogenetic relationships within the genus are also re-appraised, the sectional delimi- tations are re-defined and section Patentes is described as new.

scholarly journals Morphological variability of the nanoplanktonic diatom Thalassiosira laevis from coastal waters of Province of Buenos Aires (Argentina).

2017 ◽  
Vol 52 (4) ◽  
pp. 617-622
Author(s):  
Eugenia A. Sar ◽  
Inés Sunesen
Keyword(s):  
Morphological Variation ◽  
Coastal Waters ◽  
Buenos Aires ◽  
Morphological Variability ◽  
Ultrastructural Analysis ◽  
Marine Waters ◽  
First Time

Morphological variability of the nanoplanktonic diatom Thalassiosira laevis from coastal waters of Province of Buenos Aires (Argentina). Despite the fact that the genus Thalassiosira was previous and extensively studied including ultrastructural analysis of species found in phytoplanktonic samples collected from marine waters of Argentina, nanoplanktonic species have been frequently overlooked. This paper is devoted to show the morphological variation of Thalassiosira laevis, a nanoplanktonic species collected from marine coastal waters of the Province of Buenos Aires, to compare Argentinean material with those from China, Korea and Brazil described in the literature, and to record it for the first time from Argentina.

A new hermit crab species of the Pagurixus anceps group (Crustacea: Decapoda: Anomura: Paguridae) from southern Japan, and supplemental notes on P. patiae Komai, 2006

Zootaxa ◽  
2007 ◽  
Vol 1627 (1) ◽  
pp. 41-51 ◽  
Author(s):  
MASAYUKI OSAWA ◽  
TOMOYUKI KOMAI
Keyword(s):  
New Species ◽  
Morphological Variation ◽  
Hermit Crab ◽  
Dorsal Surface ◽  
Crab Species ◽  
Okinawa Island ◽  
Southern Japan ◽  
Males And Females ◽  
The Right ◽  
First Time

The pagurid hermit crab genus Pagurixus Melin, 1939, currently includes 24 species in the Indo-West Pacific, and recent studies have revealed the richness of this genus in southern Japan, particularly in coral reefs. In this paper, we deal with two species of the genus, P. dissimilis n. sp. described from southern Japan, and the recently described P. patiae Komai, 2006. The new species appears closest to P. nanus Komai & Takada, 2006 in both morphology and coloration in life, but is distinguished from the latter by having a clearly delimited dorsomesial margin of the dactylus of the right cheliped in males and females, a blunt but distinct median crest and a mesial row of small spines on the dorsal surface of the carpus of the male right cheliped, and paired gonopores in females. The newly obtained specimens of P. patiae from Okinawa Island enable us to describe the coloration in life of the species for the first time and to examine morphological variation. Brief notes on the distribution of the Japanese Pagurixus species are also provided.

Taxonomic notes on the genus Paratrechalea Carico, 2005 (Araneae: Trechaleidae: Trechaleinae)

Zootaxa ◽  
2010 ◽  
Vol 2667 (1) ◽  
pp. 43
Author(s):  
ESTEVAM L. CRUZ DA SILVA ◽  
ARNO A. LISE
Keyword(s):  
Morphological Variation ◽  
New Records ◽  
Female Genitalia ◽  
First Time

The male of Paratrechalea longigaster Carico, 2005 and the female of P. julyae Silva & Lise, 2006 are described and illustrated for the first time, and new records provided. Photomicrographs of the female genitalia showing accessory spermathecae for P. ornata (Mello-Leitão, 1943) and P. azul Carico, 2005 as well as the morphological variation of the epigynum in both species are also presented. A previously unreported feature of the male palpus common to both P. azul Carico, 2005 and P. ornata (Mello-Leitão, 1943) is also discussed.

scholarly journals Ontogeny of highly variable ceratitid ammonoids from the Anisian (Middle Triassic)

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10931
Author(s):  
Eva Alexandra Bischof ◽  
Nils Schlüter ◽  
Dieter Korn ◽  
Jens Lehmann
Keyword(s):  
Cross Sections ◽  
Middle Triassic ◽  
Phenotypic Variability ◽  
Taxonomic Diversity ◽  
Ontogenetic Changes ◽  
Knowledge Based ◽  
Ontogenetic Trajectories ◽  
Early Middle Triassic ◽  
First Time ◽  
High Diversity

Ammonoids reached their greatest diversity during the Triassic period. In the early Middle Triassic (Anisian) stage, ammonoid diversity was dominated by representatives of the family Ceratitidae. High taxonomic diversity can, however, be decoupled from their morphologic disparity. Due to its high phenotypic variability, the high diversity of ceratitids of the Anisian of Nevada was initially assumed to be caused by artificial over-splitting. This study aims to contribute data to settle this issue by applying geometric morphometrics methods, using landmarks and semi-landmarks, in the study of ontogenetic cross-sections of ammonoids for the first time. The results reveal that alterations in ontogenetic trajectories, linked to heterochronic processes, lead to the morphologic diversification of the species studied herein. Our knowledge, based on these ontogenetic changes, challenge the traditional treatment of species using solely adult characters for their distinction. This study furthermore demonstrates that the high diversity of the Anisian ammonoid assemblages of Nevada based on the traditional nomenclatoric approach is regarded to be reasonably accurate.

scholarly journals Variation in the skulls of Elgaria and Gerrhonotus (Anguidae, Gerrhonotinae) and implications for phylogenetics and fossil identification

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11602
Author(s):  
David T. Ledesma ◽  
Simon G. Scarpetta ◽  
Christopher J. Bell
Keyword(s):  
Morphological Variation ◽  
Phylogenetic Analyses ◽  
Morphological Features ◽  
Diagnostic Utility ◽  
Extensive Documentation ◽  
Extant Species ◽  
Traditionally Prepared ◽  
X Ray Computed ◽  
Cranial Osteology ◽  
First Time

Background There are limited data on intra- and interspecific osteological variation for many squamate clades. Those data are relevant for phylogenetic analyses that use osteological characters and for apomorphic identifications of fossils. We investigate whether morphological features in the skulls of extant gerrhonotine lizards can be used to distinguish taxa at the species- and genus-level and assess whether newly discovered intra- and interspecific osteological variation alters the utility of previously reported apomorphic features. We examined skulls of species belonging to the gerrhonotine genera Elgaria and Gerrhonotus. These genera contain 17 extant species, but the cranial osteology of only a few species was previously examined. As a result, intra- and interspecific osteological variation of these gerrhonotines is poorly understood. Methods We employed high-resolution x-ray computed tomography (CT) to scan 25 alcohol-preserved specimens. We provide data on the skulls of all eight species of Elgaria, four for the first time, and five species of Gerrhonotus, three for the first time. We examined 3-D reconstructed skulls of the scanned specimens as well as dry, traditionally prepared skeletons (when they were available). Results We found that the purported diagnostic utility of many previously described morphological features is impacted because of substantial morphological variation between and within species. We present an assessment of osteological differences that may be useful to differentiate species of Elgaria and Gerrhonotus, many of which are present on isolated cranial elements commonly recovered as fossils, including the premaxilla, maxilla, parietal, pterygoid, prootic, dentary, and surangular. We demonstrate the importance of documenting patterns of osteological variation using large sample sizes, and the utility of examining disarticulated cranial elements of the squamate skull to identify diagnostic morphology. This study adds to a growing body of literature suggesting that extensive documentation of morphological variation is needed to further our understanding of the phylogenetic and diagnostic utility of morphological features across vertebrate clades. Efforts in that direction likely will benefit from examination of disarticulated skeletal elements.

scholarly journals New record of the rare Gonatopus mariae Martins, Lara, Perioto & Olmi, 2015 (Hymenoptera, Dryinidae) for the state of Espírito Santo, Brazil

Check List ◽  
2019 ◽  
Vol 15 (4) ◽  
pp. 691-964
Author(s):  
André Luis Martins
Keyword(s):  
Morphological Variation ◽  
Rare Species ◽  
New Record ◽  
First Record ◽  
The State ◽  
Distribution Map ◽  
Espírito Santo ◽  
Espirito Santo ◽  
First Time ◽  
Southeastern Region

Gonatopus mariae Martins, Lara, Perioto & Olmi, 2015, described from the state of São Paulo, is recorded for the first time in the state of Espírito Santo, Brazil, representing the first record of the genus and species from the state. The specimen was collected with a Malaise Dossel trap and deposited at the Entomological Collection of the Universidade Federal do Espírito Santo (Brazil). A diagnosis and illustration of this species are presented  demonstrating morphological variation of the type material. A distribution map is also provided. Gonatopus mariae is a rare species and its distribution is probably restricted to the southeastern region of Brazil. 

scholarly journals RNA editing in inflorescences of wild grapevine unveils association to sex and development

2020 ◽  
Author(s):  
Miguel J. N. Ramos ◽  
David Faísca-Silva ◽  
João L. Coito ◽  
Jorge Cunha ◽  
Helena Gomes Silva ◽  
...  
Keyword(s):  
Molecular Biology ◽  
Developmental Stage ◽  
Rna Editing ◽  
Genetic Information ◽  
Perennial Species ◽  
Transcription Level ◽  
Central Dogma ◽  
Wild Grapevine ◽  
First Time

SUMMARYRNA editing challenges the central dogma of molecular biology, by modifying the genetic information at the transcription level. Recent reports, suggesting increased levels of RNA editing in plants, raised questions on the nature and dynamics of such events during development. We here report the occurrence of distinct RNA editing patterns in wild Vitis flowers during development, with twelve possible RNA editing modifications observed for the first time in plants. RNA editing events are gender and developmental stage specific, identical in subsequent years of this perennial species and with distinct nucleotide frequencies neighboring editing sites on the 5’ and 3’ flanks. The transcriptome dynamics unveils a new regulatory layer responsible for gender plasticity enhancement or underling dioecy evolution in Vitis.

Morphological variation in bony structures of Hylaeamys seuanezi (Rodentia, Cricetidae, Sigmodontinae) in Southern Bahia, Brazil

Mammalia ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Franger J. García ◽  
Martín Roberto del Valle Alvarez
Keyword(s):  
Sexual Dimorphism ◽  
Morphological Variation ◽  
Climatic Factors ◽  
Geometric Morphometric ◽  
Average Shape ◽  
Southern Bahia ◽  
Morphological Diagnosis ◽  
Males And Females ◽  
Negative Pressures ◽  
First Time

Abstract Rodents of the genus Hylaeamys, are a group of cryptic species previously included in the Oryzomys capito complex. In Brazil are represented by six species, distributed in different biomes. However, the limits of their geographic distributions and taxonomy have not yet been well defined. In particular, the taxonomy for Hylaeamys seuanezi is unstable. Based on the analysis of bony structures and supported with geometric morphometric techniques, we characterize and compare the average shape from populations in four localities from Southern Bahia, Brazil. We review 145 individuals and we create morphological landmarks in skulls, mandibles, scapulae, and pelvis. In all the structures there were statistically significant differences between populations, in which the average shape from the Igrapiúna population was the most differentiated. Our results also showed differences between the pelvis of males and females, reporting for the first time sexual dimorphism for H. seuanezi. Finally, we provide a morphological diagnosis between the populations and postulate that such differences may be correlated with environmental and climatic factors that could be exerting negative pressures on H. seuanezi; as has been evidenced with other species of rodents and other mammals.

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