scholarly journals The first Miocene fossils of Lacerta cf.trilineata(Squamata, Lacertidae) with a comparative study of the main cranial osteological differences in green lizards and their relatives

2019 ◽  
Author(s):  
Andrej Čerňanský ◽  
Elena V. Syromyatnikova
Keyword(s):  
Comparative Study ◽  
Late Miocene ◽  
Fossil Record ◽  
Calibration Point ◽  
Lizard Species ◽  
Podarcis Muralis ◽  
Modern Species ◽  
Zootoca Vivipara ◽  
Morphological Differences ◽  
Important Evidence

AbstractWe here describe the first fossil remains of a green lizardof theLacertagroup from the late Miocene (MN 13) of the Solnechnodolsk locality in southern European Russia. This region of Europe is crucial for our understanding of the paleobiogeography and evolution of these middle-sized lizards. Although this clade has a broad geographical distribution across the continent today, its presence in the fossil record has only rarely been reported. In contrast to that, the material described here is abundant, consists of a premaxilla, maxillae, frontals, parietals, jugals, quadrate, pterygoids, dentaries and vertebrae. The comparison of these elements to all extant green lizard species shows that these fossils are indistinguishable fromLacerta trilineata. Thus, they form the first potential evidence of the occurrence of this species in the Miocene. This may be also used as a potential calibration point for further studies. Together with other lizard fossils, Solnechnodolsk shows an interesting combination of survivors and the dawn of modern species. This locality provides important evidence for the transition of an archaic Miocene world to the modern diversity of lizards in Europe. In addition, this article represents a contribution to the knowledge of the comparative osteological anatomy of the selected cranial elements in lacertid. This study gives special emphasis to the green lizards, but new data are also presented for related taxa, e.g.,Timon lepidus, Podarcis muralisorZootoca vivipara. Although the green lizards include several cryptic species for which determination based on isolated osteological material would be expected to be difficult, our comparisons show several important morphological differences.

scholarly journals A comparative study of Pleurosigma subrectum and P. acus (Bacillariophyta)

Phytotaxa ◽  
2015 ◽  
Vol 207 (3) ◽  
pp. 273
Author(s):  
FRITHJOF A.S. STERRENBURG ◽  
STUART R. STIDOLPH ◽  
EUGENIA A. SAR ◽  
Ines Sunesen
Keyword(s):  
Comparative Study ◽  
Original Data ◽  
Type Material ◽  
Diatom Species ◽  
Morphological Differences ◽  
Sem Investigation ◽  
Made In

In continuation of an earlier paper on Pleurosigma species with an (almost) non-sigmoid valve and raphe sternum, a comparative study was made in LM and SEM of Pleurosigma subrectum and P. acus. For P. subrectum, slides and a subsample of the type material were examined. For P. acus no unmounted material permitting SEM investigation is extant; a sample containing specimens fully matching the type in LM was therefore used as epitype material for SEM. The original data on striation of P. acus are emended. No morphological differences indicating separate specific status of these two taxa were observed and P. acus is therefore here designated a heterotypic synonym of P. subrectum. From the data now available, this is a very widely distributed species. The study demonstrates the indispensable role of collections for investigations on the diversity and distribution of diatom species.

Morphological differences in lower facial third soft tissues in children with and without gingival smile: A cross-sectional comparative study

2018 ◽  
Vol 9 (4) ◽  
pp. e12364
Author(s):  
Oscar Zapata-Noreña ◽  
Diana M. Barbosa-Lis ◽  
Lucia V. Bernal ◽  
Laura C. Tamayo ◽  
Juliana Bustamante
Keyword(s):  
Comparative Study ◽  
Soft Tissues ◽  
Cross Sectional ◽  
Morphological Differences

scholarly journals Unsupervised learning of satellite images enhances discovery of late Miocene fossil sites in the Urema Rift, Gorongosa, Mozambique

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11573
Author(s):  
João d’Oliveira Coelho ◽  
Robert L. Anemone ◽  
Susana Carvalho
Keyword(s):  
Unsupervised Learning ◽  
Late Miocene ◽  
Fossil Record ◽  
Satellite Images ◽  
Near Infrared ◽  
Rift System ◽  
East African Rift System ◽  
Coastal Forests ◽  
Hominin Evolution ◽  
Fossil Site

Background Paleoanthropological research focus still devotes most resources to areas generally known to be fossil rich instead of a strategy that first maps and identifies possible fossil sites in a given region. This leads to the paradoxical task of planning paleontological campaigns without knowing the true extent and likely potential of each fossil site and, hence, how to optimize the investment of time and resources. Yet to answer key questions in hominin evolution, paleoanthropologists must engage in fieldwork that targets substantial temporal and geographical gaps in the fossil record. How can the risk of potentially unsuccessful surveys be minimized, while maximizing the potential for successful surveys? Methods Here we present a simple and effective solution for finding fossil sites based on clustering by unsupervised learning of satellite images with the k-means algorithm and pioneer its testing in the Urema Rift, the southern termination of the East African Rift System (EARS). We focus on a relatively unknown time period critical for understanding African apes and early hominin evolution, the early part of the late Miocene, in an overlooked area of southeastern Africa, in Gorongosa National Park, Mozambique. This clustering approach highlighted priority targets for prospecting that represented only 4.49% of the total area analysed. Results Applying this method, four new fossil sites were discovered in the area, and results show an 85% accuracy in a binary classification. This indicates the high potential of a remote sensing tool for exploratory paleontological surveys by enhancing the discovery of productive fossiliferous deposits. The relative importance of spectral bands for clustering was also determined using the random forest algorithm, and near-infrared was the most important variable for fossil site detection, followed by other infrared variables. Bands in the visible spectrum performed the worst and are not likely indicators of fossil sites. Discussion We show that unsupervised learning is a useful tool for locating new fossil sites in relatively unexplored regions. Additionally, it can be used to target specific gaps in the fossil record and to increase the sample of fossil sites. In Gorongosa, the discovery of the first estuarine coastal forests of the EARS fills an important paleobiogeographic gap of Africa. These new sites will be key for testing hypotheses of primate evolution in such environmental settings.

First fossil record of a nymph (Ephemeroptera, Teloganellidae) from the Indian subcontinent

Zootaxa ◽  
2020 ◽  
Vol 4838 (1) ◽  
pp. 137-142
Author(s):  
PRIYA AGNIHOTRI ◽  
KAJAL CHANDRA ◽  
ANUMEHA SHUKLA ◽  
HUKAM SINGH ◽  
RAKESH C. MEHROTRA
Keyword(s):  
Fossil Record ◽  
Indian Subcontinent ◽  
Early Eocene ◽  
Lignite Mine ◽  
Modern Species ◽  
The Family ◽  
Mayfly Nymph ◽  
Modern Genus ◽  
First Time ◽  
A New Species

A fossil of a mayfly nymph that shows similarities with the modern genus Teloganella Ulmer, 1939 of the family Teloganellidae is recorded for the first time from the Indian subcontinent. It is systematically described from the Gurha lignite mine of Bikaner, Rajasthan which belongs to the Palana Formation (late Paleocene-early Eocene). As assignment of the fossil to a modern species of Teloganella is difficult due to indistinguishable location of gills in the impression, a new species, Teloganella gurhaensis Agnihotri et al., sp. nov. is instituted to include this fossil naiad resembling the extant Teloganella. 

Spatiotemporal palaeodiversity patterns of modern crocodiles (Crocodyliformes: Eusuchia)

2019 ◽  
Vol 189 (2) ◽  
pp. 635-656 ◽  
Author(s):  
Ane De Celis ◽  
Iván Narváez ◽  
Francisco Ortega
Keyword(s):  
South America ◽  
Least Squares ◽  
Late Miocene ◽  
North American ◽  
Fossil Record ◽  
Generalized Least Squares ◽  
Global Scale ◽  
Biotic Factors ◽  
Species Dynamics ◽  
Over Time

Abstract Eusuchia is a crocodyliform clade with a rich and diverse fossil record dating back to the Mesozoic. There are several recent studies that analyse crocodyliform palaeodiversity over time, but none of them focuses exclusively on eusuchians. Thus, we estimated subsampled eusuchian palaeodiversity species dynamics over time not only at a global scale, but also by continents and main crocodylian lineages (Alligatoroidea, Crocodyloidea and Gavialoidea). These estimates reveal complex spatiotemporal palaeodiversity patterns, in which two maxima can be detected: the first during the Palaeocene and the second, which is also the biggest, in the middle-late Miocene. The Palaeocene shift is related to a North American alligatoroid diversification, whereas the middle–late Miocene maximum is related to a diversification of the three main Crocodylia lineages in Gondwanan land masses, but especially in South America. Additionally, a model-based study using generalized least squares was carried out to analyse the relationships between different abiotic and sampling proxies and eusuchian palaeodiversity. The results show that palaeotemperature is the most important factor amongst the analysed proxies, in accordance with previous studies. However, the results suggest that, along with palaeotemperature, other abiotic and/or biotic factors might also be driving eusuchian palaeodiversity dynamics.

scholarly journals Comparative Histomorphology of the Ovary and the Oviduct in Rabbits and Pigeons

2018 ◽  
Vol 35 (04) ◽  
pp. 242-245
Author(s):  
Helga Ishaya ◽  
Imelda Omaga ◽  
Nathan Dibal ◽  
Martha Attah
Keyword(s):  
Comparative Study ◽  
Microscopic Study ◽  
Evolutionary Relationship ◽  
Left Ovary ◽  
Yolk Granules ◽  
Parenchyma Cells ◽  
Compact Body ◽  
Morphological Differences ◽  
Mode Of Development ◽  
Domestic Pigeons

Introduction Knowledge of the evolutionary relationship between different classes of vertebrates can be obtained through a comparative study of their structures, forms, functions, and of the mode of development of the structures. Birds and mammals are vertebrates with different modes of reproduction, that is, oviparity in birds and viviparity in mammals. The aim of the present study is to compare the histomorphology of the ovaries and of the oviducts/uterine tubes in rabbits and pigeons. The present study highlights the histological and morphological differences that bring about the production of eggs in birds and the production of fully developed fetuses in mammals. Materials and Methods Five rabbits and five domestic pigeons were anesthetized with chloroform and sacrificed. The ovaries and the oviducts/uterine tubes were dissected and fixed in Bouin fluid and processed for a light microscopic study. Results The result showed paired ovaries and uterine tubes in rabbits that unite at the isthmus to form a single uterus that opens into the vagina, with only the left ovary and oviduct appearing as a compact body with distinct infundibulum, magnum, isthmus, uterus and vagina in pigeons. Photomicrographs of the ovaries of rabbits showed parenchyma cells with primary follicles, while the ovaries of pigeons showed developing follicles and yolk granules. Both the oviducts of rabbits and of pigeons showed a highly folded mucosa with a thick muscular wall. Conclusion The differences observed in the structures of the ovaries and of the oviducts of rabbits and pigeons might be due to their different reproductive functions in parturition (viviparity and oviparity, respectively).

Cellulose Derivatives Based Membranes for Biomedical Applications

2015 ◽  
Vol 638 ◽  
pp. 27-30 ◽  
Author(s):  
Stefan Ioan Voicu ◽  
Alexandru Muhulet ◽  
Iulian Antoniac ◽  
Marijana Simina Corobea
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Comparative Study ◽  
Biomedical Applications ◽  
Cellulose Derivatives ◽  
Hydrodynamic Behavior ◽  
Flow Rates ◽  
Cellulose Acetate Membranes ◽  
Morphological Differences ◽  
Scanning Electron

This paper presents a comparative study of cellulose acetate membranes, respectively nitrocellulose membranes, synthesized under the same conditions for the retention of proteins from aqueous solutions. It has also been studied the hydrodynamic behavior of the membranes, measuring water, respectively ethanol flow rates, and the retention of proteins. The membranes have been characterized by scanning electron microscopy in order to study the morphological differences.

scholarly journals Early Late Miocene Murine Rodents from the Upper Part of the Nagri Formation, Siwalik Group, Pakistan, with a new fossil calibration point for the Tribe Apodemurini (Apodemus/Tokudaia)

2017 ◽  
Vol 73 (1-2) ◽  
pp. 197-212 ◽  
Author(s):  
Yuri Kimura ◽  
Lawrence J. Flynn ◽  
Louis L. Jacobs
Keyword(s):  
Late Miocene ◽  
Middle Miocene ◽  
Northern Pakistan ◽  
Calibration Point ◽  
Fossil Calibration ◽  
Murine Rodents ◽  
Siwalik Group ◽  
Fossil Genus ◽  
Early Late ◽  
A New Species

Abstract The early late Miocene is an interval of increased diversification for murine rodents. Whereas the genus Progonomys became widespread throughout Eurasia by 10 Ma, it appears from the known paleontological record that southern Asia is the arena of evolution and diversification at the base of the Murinae. The Siwalik fossil record of the Potwar Plateau in northern Pakistan preserves fossil evidence relevant to unraveling this history. Murine rodents are recorded there throughout the middle Miocene, and diversification began in Siwalik assemblages before 11 Ma. The well-established Progonomys and Karnimata lineages were already present between 11 and 10 Ma, and these represent extant murine crown groups. Here we document diversity in Siwalik murines dating to 10.5 to 10.1 Ma, and clarify their recognition by naming a new species of Karnimata and referring specimens of Progonomys from this interval to P. hussaini. In addition, we define at least two other uncommon murine species that coexist with them. One of these is an early record of Parapodemus, a fossil genus of Tribe Apodemurini, which constitutes a calibration point for the Apodemus/Tokudaia split. Together, these fossil taxa provide further evidence bearing on the major split among murines leading to the clades Murini and Arvicanthini.

scholarly journals The phylogeny and systematics of Xiphosura

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10431
Author(s):  
James C. Lamsdell
Keyword(s):  
Fossil Record ◽  
Evolutionary History ◽  
Phylogenetic Analyses ◽  
Systematic Revision ◽  
Ecological History ◽  
Living Fossils ◽  
Modern Species ◽  
The Matrix ◽  
History Of ◽  
Taxonomic Framework

Xiphosurans are aquatic chelicerates with a fossil record extending into the Early Ordovician and known from a total of 88 described species, four of which are extant. Known for their apparent morphological conservatism, for which they have gained notoriety as supposed ‘living fossils’, recent analyses have demonstrated xiphosurans to have an ecologically diverse evolutionary history, with several groups moving into non-marine environments and developing morphologies markedly different from those of the modern species. The combination of their long evolutionary and complex ecological history along with their paradoxical patterns of morphological stasis in some clades and experimentation among others has resulted in Xiphosura being of particular interest for macroevolutionary study. Phylogenetic analyses have shown the current taxonomic framework for Xiphosura—set out in the Treatise of Invertebrate Paleontology in 1955—to be outdated and in need of revision, with several common genera such as Paleolimulus Dunbar, 1923 and Limulitella Størmer, 1952 acting as wastebasket taxa. Here, an expanded xiphosuran phylogeny is presented, comprising 58 xiphosuran species as part of a 158 taxon chelicerate matrix coded for 259 characters. Analysing the matrix under both Bayesian inference and parsimony optimisation criteria retrieves a concordant tree topology that forms the basis of a genus-level systematic revision of xiphosuran taxonomy. The genera Euproops Meek, 1867, Belinurus König, 1820, Paleolimulus, Limulitella, and Limulus are demonstrated to be non-monophyletic and the previously synonymized genera Koenigiella Raymond, 1944 and Prestwichianella Cockerell, 1905 are shown to be valid. In addition, nine new genera (Andersoniella gen. nov., Macrobelinurus gen. nov., and Parabelinurus gen. nov. in Belinurina; Norilimulus gen. nov. in Paleolimulidae; Batracholimulus gen. nov. and Boeotiaspis gen. nov. in Austrolimulidae; and Allolimulus gen. nov., Keuperlimulus gen. nov., and Volanalimulus gen. nov. in Limulidae) are erected to accommodate xiphosuran species not encompassed by existing genera. One new species, Volanalimulus madagascarensis gen. et sp. nov., is also described. Three putative xiphosuran genera—Elleria Raymond, 1944, Archeolimulus Chlupáč, 1963, and Drabovaspis Chlupáč, 1963—are determined to be non-xiphosuran arthropods and as such are removed from Xiphosura. The priority of Belinurus König, 1820 over Bellinurus Pictet, 1846 is also confirmed. This work is critical for facilitating the study of the xiphosuran fossil record and is the first step in resolving longstanding questions regarding the geographic distribution of the modern horseshoe crab species and whether they truly represent ‘living fossils’. Understanding the long evolutionary history of Xiphosura is vital for interpreting how the modern species may respond to environmental change and in guiding conservation efforts.

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