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Marcelo S De La Fuente - One of the best experts on this subject based on the ideXlab platform.
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a new large panchelid turtle pleurodira from the loncoche formation upper campanian lower maastrichtian of the mendoza province argentina morphological osteohistological studies and a preliminary phylogenetic analysis
Cretaceous Research, 2017Co-Authors: Juliana Sterli, Marcelo S De La Fuente, Ignacio Maniel, Juan Marcos Jannello, Bernardo Gonzalez J Riga, Fernando E NovasAbstract:Abstract A new genus and species of panchelid turtle ( Mendozachelys wichmanni gen. et sp. nov.) from the upper Campanian–lower Maastrichtian Loncoche Formation (southern Mendoza Province, Argentina) is described here. This species is represented by only one complete and articulated large specimen (carapace length estimated in 950 mm) that was recovered from tidal flat deposits. A detailed morphological and osteohistological description is made, recognizing autapomorphic characters that allow differentiating this taxon from the rest of extant and extinct panchelids. Osteohistological characters suggest an aquatic to semi-aquatic life style for Mendozachelys wichmanni gen. et sp. nov. Phylogenetic analysis based on morphological data suggested that this new taxon is nested within crown Chelidae. Both phylogenetic signals (morphological and molecular) about the assessment of long-necked chelids monophyly or polyphyly are discussed.
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Shell bone histology of the long-necked chelid Yaminuechelys (Testudines: Pleurodira) from the late Cretaceous—early Palaeocene of Patagonia with comments on the histogenesis of bone ornamentation
The Science of Nature, 2016Co-Authors: Juan Marcos Jannello, Ignacio A. Cerda, Marcelo S De La FuenteAbstract:Yaminuechelys is a long-necked chelid turtle whose remains have been recovered from outcrops of the Santonian-Maastrichtian and Danian of South America. With the purpose of providing data about shell sculpturing origin and palaeoecology, the bone histology of several shell elements (including neural, costal, peripheral and plastral plates) of Yaminuechelys is described herein. Histological analysis reveals that Yaminuechelys shares with Chelidae the presence of interwoven structural fibre bundles in the external cortex, and parallel-fibred bone of the internal cortex. The presence of resorption lines in several samples indicates that the particular ornamentation of the external surfaces originated, at least in part, by focalized resorption and new bone deposition. This mechanism for ornamentation origin and maintenance is here described for the first time in a turtle. Compactness of the shell bones is consistent with an aquatic habitat, which supports previous hypothesis based on palaeoenvironmental and morphological data.
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shell bone histology of the long necked chelid yaminuechelys testudines pleurodira from the late cretaceous early palaeocene of patagonia with comments on the histogenesis of bone ornamentation
Naturwissenschaften, 2016Co-Authors: Marcelo S De La Fuente, Juan Marcos Jannello, Ignacio A. CerdaAbstract:Yaminuechelys is a long-necked chelid turtle whose remains have been recovered from outcrops of the Santonian-Maastrichtian and Danian of South America. With the purpose of providing data about shell sculpturing origin and palaeoecology, the bone histology of several shell elements (including neural, costal, peripheral and plastral plates) of Yaminuechelys is described herein. Histological analysis reveals that Yaminuechelys shares with Chelidae the presence of interwoven structural fibre bundles in the external cortex, and parallel-fibred bone of the internal cortex. The presence of resorption lines in several samples indicates that the particular ornamentation of the external surfaces originated, at least in part, by focalized resorption and new bone deposition. This mechanism for ornamentation origin and maintenance is here described for the first time in a turtle. Compactness of the shell bones is consistent with an aquatic habitat, which supports previous hypothesis based on palaeoenvironmental and morphological data.
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A Review of the Fossil Record of Turtles of the Clade Pan-Chelidae
Bulletin of the Peabody Museum of Natural History, 2016Co-Authors: Ignacio Maniel, Marcelo S De La FuenteAbstract:Abstract Turtles of the total Clade Pan-Chelidae have a relatively poor fossil record, which is completely restricted from the Early Cretaceous to Recent of South America and Australasia. The clade is expected to have formerly inhabited Antarctica as well. The phylogenetic relationships of extant pan-chelids remain poorly resolved, notably because there are conflicting signals between morphological and molecular data. The ecology of fossil pan-chelids appears to have been similar to that of their extant relatives. A taxonomic review of the group concluded that of 45 named taxa, 22 are nomina valida, 6 are nomina invalida and 15 are nomina dubia, whereas the final 2 are rendered non-testudinate through the designation of lectotypes.
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una tortuga Chelidae testudines pleurodira de cuello largo en el grupo neuquen rio negro argentina significado cronologico y paleobiogeografico
Andean Geology, 2010Co-Authors: Marcelo S De La Fuente, Ruben Barbieri, Pablo ChafratAbstract:Diferentes restos de una tortuga Chelidae cuellilarga de la Formacion Anacleto (Santoniano tardio-Campaniano temprano), aflorante en la localidad de Valle de la Luna Rojo, Provincia de Rio Negro, Argentina, son conferidos a la especie Yaminuechelys cf. gasparinii De la Fuente, De Lapparent de Broin y Manera de Bianco, 2001. Ellos representan el registro mas antiguo para el genero y los Chelidae de cuello largo. Se sugiere que el ancestro comun de Yaminuechelys e Hydromedusa habito en Gondwana meridional con anterioridad a la separacion de Australia. La presencia de este taxon en el Cretacico Tardio en Patagonia y algunos de los resultados de los analisis filogeneticos previos apoyan la hipotesis sobre una temprana diferenciacion y diversificacion de los quelidos en dicha region de Gondwana.
Arthur Georges - One of the best experts on this subject based on the ideXlab platform.
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The identity of Chelodina oblonga Gray 1841 (Testudines: Chelidae) reassessed.
Zootaxa, 2020Co-Authors: Glenn Shea, Scott Thomson, Arthur GeorgesAbstract:The identity of Chelodina oblonga has been unclear because it has been variously defined to include populations of snake-necked chelid turtle from the southwest of Western Australia, across northern Australia, Cape York and southern New Guinea in its broadest conception, from just the northern part of this range (northern Australia and New Guinea), or restricted to the southwest corner of Western Australia in its narrowest conception. Uncertainty over the identity of the type specimens has added to the confusion. In this paper, we review the historical data on the extent of the type series of Chelodina oblonga, and its potential provenance, and find evidence that resolves some of the inconsistencies in previous literature on the identification of the type. Our analysis casts doubt on the northern Australian provenance of the type material. Hence, we return the name C. oblonga to the south-western species, in accordance with the genetic evidence for the provenance of the type in the Natural History Museum, London, and the external morphology of the type series. We designate a lectotype for the species, and redefine the subgeneric names that apply to the Australasian genus Chelodina, providing a new subgeneric name for one lineage.
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Mitogenomics of historical type specimens of Australasian turtles: clarification of taxonomic confusion and old mitochondrial introgression
Scientific reports, 2019Co-Authors: Christian Kehlmaier, Xiuwen Zhang, Arthur Georges, Patrick D. Campbell, Scott Thomson, Uwe FritzAbstract:Diagnosability is central to taxonomy as are type specimens which define taxa. New advances in technologies and the discovery of new informative traits must be matched with previous taxonomic decisions based on name-bearing type specimens. Consequently, the challenge of sequencing highly degraded DNA from historical types becomes an inevitability to resolve the very many taxonomic issues arising from, by modern standards, poor historical species descriptions leading to difficulties to assign names to genetic clusters identified from fresh material. Here we apply high-throughput parallel sequencing and sequence baiting to reconstruct the mitogenomes from 18 type specimens of Australasian side-necked turtles (Chelidae). We resolve a number of important issues that have confused the taxonomy of this family, and analyse the mitogenomes of the types and those of fresh material to improve our understanding of the phylogenetic relationships of this morphologically conservative group. Together with previously published nuclear genomic data, our study provides evidence for multiple old mitochondrial introgressions.
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resolution of the enigmatic phylogenetic relationship of the critically endangered western swamp tortoise pseudemydura umbrina pleurodira Chelidae using a complete mitochondrial genome
Molecular Phylogenetics and Evolution, 2017Co-Authors: Xiuwen Zhang, Peter J Unmack, Gerald Kuchling, Yinan Wang, Arthur GeorgesAbstract:Abstract Pseudemydura umbrina is one of the most endangered turtle species in the world, and the imperative for its conservation is its distinctive morphology and relict status among the Chelidae. We use Illumina sequencing to obtain the complete mitogenome for resolving its uncertain phylogenetic position. A novel nuclear paralogue confounded the assembly, and resolution of the authentic mitogenome required further Sanger sequencing. The P. umbrina mitogenome is 16,414 bp comprising 37 genes organized in a conserved pattern for other vertebrates. The nuclear paralogue is 547 bp, 97.8% identity to the corresponding mitochondrial sequence. Particular features of the mitogenome include an nd3 174+1A frameshift, loss of DHC loop in tRNASer (AGN), and a light-strand replication initiation site in Wancy region that extends into an adjacent tRNA gene. Phylogenetic analysis showed that P. umbrina is the monotypic sister lineage to the remaining Australasian Chelidae, a lineage probably dating back to the Cretaceous.
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First record of hatchling overwintering inside the natal nest of a chelid turtle
Australian Journal of Zoology, 2015Co-Authors: Bruno O. Ferronato, John H. Roe, Arthur GeorgesAbstract:Hatchling overwintering inside the natal nest is a strategy used by several Northern Hemisphere species of freshwater turtles. We recorded hatchling overwintering in the nest by Chelodina longicollis (Chelidae) in south-eastern Australia, during three reproductive seasons. Hatchlings spent, on average, 320 days inside the nest from the date eggs were laid until emergence. Some nests were carefully opened adjacent to the nest plug, one during winter and one in spring, to confirm that eggs had hatched and were not in diapause, although we could not precisely confirm hatching dates. Despite our small sample size, we observed a dichotomous overwintering strategy, with hatchlings from one nest emerging in autumn and spending their first winter in the aquatic environment, and hatchlings from three nests overwintering in the nest and emerging in spring. These findings expand the phylogenetic range of turtles exhibiting hatchling overwintering behaviour. Future research should evaluate whether this strategy is widespread among other long-necked turtles in temperate regions and examine physiological mechanisms involved in coping with winter temperatures.
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a complete mitochondrial genome sequence for the australian turtle chelodina longicollis obtained using 454 pyrosequencing
Conservation Genetics Resources, 2014Co-Authors: Xiuwen Zhang, Arthur GeorgesAbstract:The mitochondrial genome of the Australia eastern long-necked turtle Chelodina longicollis is 16,437 bp, containing 37 genes, with overall gene organisation and nucleotide composition typical of mitogenomes of other vertebrates. We identified a presumptive light strand replication initiation site (OL) in the WANCY region, a feature thought to be absent from the side-necked turtles (Pleurodira). The tRNAser2 of C. longicollis lacks a D-arm. This is the fifth mitogenome published for the Pleurodira, the third for the Chelidae and the first turtle mitogenome generated using next-generation sequencing. It will assist the development of primers and strategies for examining mitochondrial variation across the side-necked turtles.
Scott D. Snyder - One of the best experts on this subject based on the ideXlab platform.
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Paradeuterobaris victoriae n. sp. (Digenea: Microscaphidiidae) and Buckarootrema minuta n. sp. (Digenea: Pronocephalidae) from the Victoria River Red-Faced Turtle, Emydura victoriae (Pleurodira: Chelidae) in Australia
Comparative Parasitology, 2015Co-Authors: Scott D. Snyder, Vasyl V TkachAbstract:Abstract Paradeuterobaris victoriae n. sp. (Digenea: Microscaphidiidae) and Buckarootrema minuta n. sp. (Digenea: Pronocephalidae) are described from the Victoria River red-faced turtle, Emydura victoriae (Pleurodira: Chelidae), from the Victoria River, Northern Territory, Australia. Each of the new species is the second known member of a previously monotypic genus. Paradeuterobaris victoriae n. sp. differs from Paradeuterobaris novaguineae in the extent of the vitellarium and ventral glands, the position of the testes, and the presence of numerous uterine loops between the anterior testis and seminal vesicle, among other characters. Buckarootrema minuta n. sp. differs from Buckarootrema goodmani in the relative length of the ceca, the relative position of the gonads and testes, the position of uterine loops, the number of eggs, and overall body size. This work is the first report of any parasite from the Victoria River red-faced turtle and the first report of endohelminths from turtles of Northern Territory.
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aptorchis kuchlingi n sp digenea plagiorchioidea from the oblong turtle chelodina oblonga pleurodira Chelidae in western australia
Comparative Parasitology, 2011Co-Authors: Scott D. Snyder, Vladimirovich Vladimir TkachAbstract:Aptorchis kuchlingi n. sp. is described from the rectum of the oblong turtle, Chelodina oblonga (Pleurodira: Chelidae), in southwest Western Australia. This digenean is morphologically most similar to Aptorchis pearsoni but can be differentiated from the latter species by: a relatively longer cirrus sac in relation to overall body length, a cirrus sac that reaches the ovary, testes that are situated much closer to the cirrus sac and separated from it only by the seminal receptacle, vitellarium that extends anteriorly beyond the ventral sucker, a relatively wider ventral sucker in relation to oral sucker width, and a pharynx equal in size or larger than the oral sucker. Comparison of approximately 2,400 bases of ribosomal DNA (complete internal transcribed spacer (ITS)1 + 5.8S + ITS2, partial 28S) obtained from all 5 known Aptorchis species also suggests a close relationship of the new species with A. pearsoni and strongly supports the status of A. kuchlingi n. sp. as a new species. This is the fourth species of Aptorchis reported from long-necked turtles (Chelodina) and the first species of the genus reported in C. oblonga.
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Aptorchis glandularis N. Sp. (Digenea: Plagiorchioidea) From the Northwestern Red-Faced Turtle, Emydura australis, (Pleurodira: Chelidae) in the Kimberley, Western Australia
The Journal of parasitology, 2008Co-Authors: Vasyl V Tkach, Scott D. SnyderAbstract:Aptorchis glandularis n. sp. is described from the intestine of the northwestern red-faced turtle, Emydura australis (Pleurodira: Chelidae), in the Kimberley, Western Australia. This digenean is morphologically most similar to Aptorchis aequalis but can be differentiated readily from the latter species by the presence of ventral glands arranged in 3 rows. This feature is unique among plagiorhioidean digeneans and resembles the glands observed in some monostome digeneans in Notocotylidae and Microscaphidiidae. Comparison of approximately 2,600 bases of ribosomal DNA (partial 18S, complete ITS1+5.8S+ITS2, partial 28S), obtained from all 5 known Aptorchis species, strongly supports the status of Aptorchis glandularis n. sp. as a new species. Phylogenetic analysis of these sequence data demonstrates 2 strongly supported clades (A. pearsoni + A. megacetabulus) and (A. aequalis + A. glandularis n. sp.), with A. megapharynx representing a separate lineage. This is the first report of an endoparasite from Emydura...
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Choanocotyle platti sp. nov. from the northern long-necked turtle, Chelodina rugosa (Pleurodira, Chelidae) in Australia
Acta Parasitologica, 2007Co-Authors: Vladimirovich Vladimir Tkach, Scott D. SnyderAbstract:Choanocotyle platti sp. nov. (Digenea, Choanocotylidae) is described from the northern long-necked turtle, Chelodina rugosa (Pleurodira, Chelidae) from the Daly and Mary Rivers, Northern Territory, Australia. This is the fifth known member of Choanocotyle. Choanocotyle platti sp. nov. differs from Choanocotyle nematoides Jue Sue et Platt, 1998 and Choanocotyle hobbsi Platt et Tkach, 2003 by smaller body length, larger oral sucker, relatively greater distance between tests, and prepharynx with an infolded posterior region. In addition the new species does not have the looped cirrus sac characteristic of Choanocotyle nematoides . Comparison of sequences of 18S, ITS (ITS1, 5.8S, ITS2) and partial 28S regions of nuclear rDNA among all 3 species strongly supports the status of Choanocotyle platti sp. nov. as a new species.
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aptorchis megacetabulus n sp platyhelminthes digenea from the northern long necked turtle chelodina rugosa pleurodira Chelidae in australia
Journal of Parasitology, 2007Co-Authors: Vladimirovich Vladimir Tkach, Scott D. SnyderAbstract:Aptorchis megacetabulus n. sp. is described from the intestine of the northern long-necked turtle, Chelodina rugosa (Pleurodira: Chelidae), in Northern Territory, Australia. This is the first helminth species reported from C. rugosa. This plagiorchioidean digenean differs from the 3 previously known species of Aptorchis in the relative size of the ventral sucker, overall body proportions, nature of the cirrus sac, and egg size. Comparison of approximately 2,700 bases of ribosomal DNA obtained from all known Aptorchis species strongly supports the status of Aptorchis megacetabulus n. sp. as a new species.
Juan Marcos Jannello - One of the best experts on this subject based on the ideXlab platform.
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a new large panchelid turtle pleurodira from the loncoche formation upper campanian lower maastrichtian of the mendoza province argentina morphological osteohistological studies and a preliminary phylogenetic analysis
Cretaceous Research, 2017Co-Authors: Juliana Sterli, Marcelo S De La Fuente, Ignacio Maniel, Juan Marcos Jannello, Bernardo Gonzalez J Riga, Fernando E NovasAbstract:Abstract A new genus and species of panchelid turtle ( Mendozachelys wichmanni gen. et sp. nov.) from the upper Campanian–lower Maastrichtian Loncoche Formation (southern Mendoza Province, Argentina) is described here. This species is represented by only one complete and articulated large specimen (carapace length estimated in 950 mm) that was recovered from tidal flat deposits. A detailed morphological and osteohistological description is made, recognizing autapomorphic characters that allow differentiating this taxon from the rest of extant and extinct panchelids. Osteohistological characters suggest an aquatic to semi-aquatic life style for Mendozachelys wichmanni gen. et sp. nov. Phylogenetic analysis based on morphological data suggested that this new taxon is nested within crown Chelidae. Both phylogenetic signals (morphological and molecular) about the assessment of long-necked chelids monophyly or polyphyly are discussed.
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Shell bone histology of the long-necked chelid Yaminuechelys (Testudines: Pleurodira) from the late Cretaceous—early Palaeocene of Patagonia with comments on the histogenesis of bone ornamentation
The Science of Nature, 2016Co-Authors: Juan Marcos Jannello, Ignacio A. Cerda, Marcelo S De La FuenteAbstract:Yaminuechelys is a long-necked chelid turtle whose remains have been recovered from outcrops of the Santonian-Maastrichtian and Danian of South America. With the purpose of providing data about shell sculpturing origin and palaeoecology, the bone histology of several shell elements (including neural, costal, peripheral and plastral plates) of Yaminuechelys is described herein. Histological analysis reveals that Yaminuechelys shares with Chelidae the presence of interwoven structural fibre bundles in the external cortex, and parallel-fibred bone of the internal cortex. The presence of resorption lines in several samples indicates that the particular ornamentation of the external surfaces originated, at least in part, by focalized resorption and new bone deposition. This mechanism for ornamentation origin and maintenance is here described for the first time in a turtle. Compactness of the shell bones is consistent with an aquatic habitat, which supports previous hypothesis based on palaeoenvironmental and morphological data.
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shell bone histology of the long necked chelid yaminuechelys testudines pleurodira from the late cretaceous early palaeocene of patagonia with comments on the histogenesis of bone ornamentation
Naturwissenschaften, 2016Co-Authors: Marcelo S De La Fuente, Juan Marcos Jannello, Ignacio A. CerdaAbstract:Yaminuechelys is a long-necked chelid turtle whose remains have been recovered from outcrops of the Santonian-Maastrichtian and Danian of South America. With the purpose of providing data about shell sculpturing origin and palaeoecology, the bone histology of several shell elements (including neural, costal, peripheral and plastral plates) of Yaminuechelys is described herein. Histological analysis reveals that Yaminuechelys shares with Chelidae the presence of interwoven structural fibre bundles in the external cortex, and parallel-fibred bone of the internal cortex. The presence of resorption lines in several samples indicates that the particular ornamentation of the external surfaces originated, at least in part, by focalized resorption and new bone deposition. This mechanism for ornamentation origin and maintenance is here described for the first time in a turtle. Compactness of the shell bones is consistent with an aquatic habitat, which supports previous hypothesis based on palaeoenvironmental and morphological data.
Gertrud Müller - One of the best experts on this subject based on the ideXlab platform.
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New records of helminths in Chelidae freshwater turtles (Testudines) in South America
Revista Brasileira de Zoociências, 2020Co-Authors: Bruna Medeiros Chaviel, Carolina Silveira Mascarenhas, Fabiana Fedatto Bernardon, Marco Antonio Afonso Coimbra, Gertrud MüllerAbstract:Helminthological studies with Chelidae freshwater turtles in South America were conducted in Argentina, Uruguay and Brazil, where nematodes, digeneans and monogeneans were reported. In this context, the study aims to report new cases of gastrointestinal helminth parasites of Acanthochelys spixii, Hydromedusa tectifera, and Phrynops hilarii. A total of 65 hosts from the southern region of Rio Grande do Sul, Brazil, were examined. Seven taxa belonging to Nematoda, Digenea, and Monogenoidea have new cases on hosts Chelidae in South America, as well as a Nematoda and two Digenea have new host cases for Brazil. Thus, the study expands the knowledge about the diversity of helminths and the geographic distribution of taxa associated with Chelidae turtles.
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Nematode parasites of Chelidae (Testudines) from southern Brazil.
Parasitology research, 2013Co-Authors: Carolina Silveira Mascarenhas, Marco Antonio Afonso Coimbra, Jéssica Dias Souza, Gertrud MüllerAbstract:The presence of helminths associated with freshwater turtles is rarely reported. There are no records of nematodes parasitizing Acanthochelys spixii, and for Hydromedusa tectifera, there is only the report of unidentified nematodes found in this species in Argentina. This is the first report of nematodes (Spiroxys contortus and Camallanus sp.) in A. spixii and the first record of Spiroxys contortus and Camallanus sp. in H. tectifera. This is the southernmost record of S . contortus because this nematode was previously recorded only in Mexico.