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Àngel H. Luján - One of the best experts on this subject based on the ideXlab platform.
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revision of Varanus marathonensis squamata varanidae based on historical and new material morphology systematics and paleobiogeography of the european monitor lizards
PLOS ONE, 2018Co-Authors: Andrea Villa, Juan Abella, David M. Alba, Sergio Almécija, Arnau Bolet, George D. Koufos, Fabien Knoll, Àngel H. LujánAbstract:Monitor lizards (genus Varanus) inhabited Europe at least from the early Miocene to the Pleistocene. Their fossil record is limited to about 40 localities that have provided mostly isolated vertebrae. Due to the poor diagnostic value of these fossils, it was recently claimed that all the European species described prior to the 21st century are not taxonomically valid and a new species, Varanus amnhophilis, was erected on the basis of fragmentary material including cranial elements, from the late Miocene of Samos (Greece). We re-examined the type material of Varanus marathonensis Weithofer, 1888, based on material from the late Miocene of Pikermi (Greece), and concluded that it is a valid, diagnosable species. Previously unpublished Iberian material from the Aragonian (middle Miocene) of Abocador de Can Mata (Valles-Penedes Basin, Barcelona) and the Vallesian (late Miocene) of Batallones (Madrid Basin) is clearly referable to the same species on a morphological basis, further enabling to provide an emended diagnosis for this species. Varanus amnhophilis appears to be a junior subjective synonym of V. marathonensis. On the basis of the most complete fossil Varanus skeleton ever described, it has been possible to further resolve the internal phylogeny of this genus by cladistically analyzing 80 taxa coded for 495 morphological and 5729 molecular characters. Varanus marathonensis was a large-sized species distributed at relatively low latitudes in both southwestern and southeastern Europe from at least MN7+8 to MN12. Our cladistic analysis nests V. marathonensis into an eastern clade of Varanus instead of the African clade comprising Varanus griseus, to which it had been related in the past. At least two different Varanus lineages were present in Europe during the Neogene, represented by Varanus mokrensis (early Miocene) and V. marathonensis (middle to late Miocene), respectively.
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Snouts of extant Varanus species showing the maxillary morphology in dorsal and right lateral view.
2018Co-Authors: Andrea Villa, Juan Abella, David M. Alba, Sergio Almécija, Arnau Bolet, George D. Koufos, Fabien Knoll, Àngel H. Luján, Jorge Morales, Josep M. RoblesAbstract:(A, B) Varanus ornatus (Daudin, 1803) ZFMK 14889. (C, D) Varanus komodoensis Ouwens, 1912 ZFMK 64998. (E, F) Varanus griseus (Daudin, 1803) SMF 32911. (G, H) Varanus bengalensis (Daudin, 1802) SMF 63456. Note in all cases the absence of a lateral sulcus along the edge of the narial aperture. In V. ornatus and V. komodoensis there is no hint of medial expansion of the medial edge of the maxilla (no medial concavity along the medial edge of the maxilla in dorsal view), whereas in V. griseus and V. bengalensis a sort of expansion is mostly located in the area anterior to the facial process (presence of a variably developed concavity). Among the four species here depicted, V. ornatus is the only one that bears blunt, molariform teeth. Scale bars equal 10 mm.
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Majority-rule consensus tree based on the results of analysis 1A.
2018Co-Authors: Andrea Villa, Juan Abella, David M. Alba, Sergio Almécija, Arnau Bolet, George D. Koufos, Fabien Knoll, Àngel H. Luján, Jorge Morales, Josep M. RoblesAbstract:The position of Varanus marathonensis (as scored from information provided by the specimen from Batallones and the type of Varanus amnhophilis; this OTU is named “Vmarathonensis Vamnhophilis” in figures of the supplementary information) inside the Indo-Asian A group and as sister species to the IndoVaranus subgenus is supported by 85% of the MPTs. Numbers in the time scale represent million years ago.
Andrea Villa - One of the best experts on this subject based on the ideXlab platform.
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revision of Varanus marathonensis squamata varanidae based on historical and new material morphology systematics and paleobiogeography of the european monitor lizards
PLOS ONE, 2018Co-Authors: Andrea Villa, Juan Abella, David M. Alba, Sergio Almécija, Arnau Bolet, George D. Koufos, Fabien Knoll, Àngel H. LujánAbstract:Monitor lizards (genus Varanus) inhabited Europe at least from the early Miocene to the Pleistocene. Their fossil record is limited to about 40 localities that have provided mostly isolated vertebrae. Due to the poor diagnostic value of these fossils, it was recently claimed that all the European species described prior to the 21st century are not taxonomically valid and a new species, Varanus amnhophilis, was erected on the basis of fragmentary material including cranial elements, from the late Miocene of Samos (Greece). We re-examined the type material of Varanus marathonensis Weithofer, 1888, based on material from the late Miocene of Pikermi (Greece), and concluded that it is a valid, diagnosable species. Previously unpublished Iberian material from the Aragonian (middle Miocene) of Abocador de Can Mata (Valles-Penedes Basin, Barcelona) and the Vallesian (late Miocene) of Batallones (Madrid Basin) is clearly referable to the same species on a morphological basis, further enabling to provide an emended diagnosis for this species. Varanus amnhophilis appears to be a junior subjective synonym of V. marathonensis. On the basis of the most complete fossil Varanus skeleton ever described, it has been possible to further resolve the internal phylogeny of this genus by cladistically analyzing 80 taxa coded for 495 morphological and 5729 molecular characters. Varanus marathonensis was a large-sized species distributed at relatively low latitudes in both southwestern and southeastern Europe from at least MN7+8 to MN12. Our cladistic analysis nests V. marathonensis into an eastern clade of Varanus instead of the African clade comprising Varanus griseus, to which it had been related in the past. At least two different Varanus lineages were present in Europe during the Neogene, represented by Varanus mokrensis (early Miocene) and V. marathonensis (middle to late Miocene), respectively.
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Snouts of extant Varanus species showing the maxillary morphology in dorsal and right lateral view.
2018Co-Authors: Andrea Villa, Juan Abella, David M. Alba, Sergio Almécija, Arnau Bolet, George D. Koufos, Fabien Knoll, Àngel H. Luján, Jorge Morales, Josep M. RoblesAbstract:(A, B) Varanus ornatus (Daudin, 1803) ZFMK 14889. (C, D) Varanus komodoensis Ouwens, 1912 ZFMK 64998. (E, F) Varanus griseus (Daudin, 1803) SMF 32911. (G, H) Varanus bengalensis (Daudin, 1802) SMF 63456. Note in all cases the absence of a lateral sulcus along the edge of the narial aperture. In V. ornatus and V. komodoensis there is no hint of medial expansion of the medial edge of the maxilla (no medial concavity along the medial edge of the maxilla in dorsal view), whereas in V. griseus and V. bengalensis a sort of expansion is mostly located in the area anterior to the facial process (presence of a variably developed concavity). Among the four species here depicted, V. ornatus is the only one that bears blunt, molariform teeth. Scale bars equal 10 mm.
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Majority-rule consensus tree based on the results of analysis 1A.
2018Co-Authors: Andrea Villa, Juan Abella, David M. Alba, Sergio Almécija, Arnau Bolet, George D. Koufos, Fabien Knoll, Àngel H. Luján, Jorge Morales, Josep M. RoblesAbstract:The position of Varanus marathonensis (as scored from information provided by the specimen from Batallones and the type of Varanus amnhophilis; this OTU is named “Vmarathonensis Vamnhophilis” in figures of the supplementary information) inside the Indo-Asian A group and as sister species to the IndoVaranus subgenus is supported by 85% of the MPTs. Numbers in the time scale represent million years ago.
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the last european varanid demise and extinction of monitor lizards squamata varanidae from europe
Journal of Vertebrate Paleontology, 2017Co-Authors: Georgios L Georgalis, Andrea Villa, Massimo DelfinoAbstract:ABSTRACTRemains of a varanid lizard from the middle Pleistocene of the Tourkobounia 5 locality near Athens, Greece are described. The new material comprises cranial elements only (one maxilla, one dentary, and one tooth) and is attributed to Varanus, the genus to which all European Neogene varanid occurrences have been assigned. Previously, the youngest undisputed varanid from Europe had been recovered from upper Pliocene sediments. The new Greek fossils therefore constitute the youngest records of this clade from the continent. Despite being fragmentary, this new material enhances our understanding of the cranial anatomy of the last European monitor lizards and is clearly not referable to the extant Varanus griseus or Varanus niloticus, the only species that could be taken into consideration on a present-day geographic basis. However, these fossils could represent a survivor of the monitor lizards of Asian origin that inhabited Europe during the Neogene.Citation for this article: Georgalis, G. L., A. Vil...
Ornjira Prakhongcheep - One of the best experts on this subject based on the ideXlab platform.
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Additional file 9: Figure S5. of Lack of satellite DNA species-specific homogenization and relationship to chromosomal rearrangements in monitor lizards (Varanidae, Squamata)
2017Co-Authors: Ornjira Prakhongcheep, Kazumi Matsubara, Watcharaporn Thapana, Aorarat Suntronpong, Worapong Singchat, Khampee Pattanatanang, Rattanin Phatcharakullawarawat, Narongrit Muangmai, Surin Peyachoknagul, Tariq EzazAbstract:Statistical parsimony network of VSAREP subfamily III constructed from all VSAREP sequence units of Varanus acanthurus (VAC), V. dumerilii (VDU), and V. bengalensis (VBE). (TIFF 1141 kb
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Additional file 8: Figure S4. of Lack of satellite DNA species-specific homogenization and relationship to chromosomal rearrangements in monitor lizards (Varanidae, Squamata)
2017Co-Authors: Ornjira Prakhongcheep, Kazumi Matsubara, Watcharaporn Thapana, Aorarat Suntronpong, Worapong Singchat, Khampee Pattanatanang, Rattanin Phatcharakullawarawat, Narongrit Muangmai, Surin Peyachoknagul, Tariq EzazAbstract:Statistical parsimony network of VSAREP subfamily II constructed from all VSAREP sequence units of Varanus rosenbergi (VRO), V. komodoensis (VKO), V. acanthurus (VAC), and V. salvadorii (VSALV). (TIFF 7049 kb
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Additional file 1: Table S1. of Lack of satellite DNA species-specific homogenization and relationship to chromosomal rearrangements in monitor lizards (Varanidae, Squamata)
2017Co-Authors: Ornjira Prakhongcheep, Kazumi Matsubara, Watcharaporn Thapana, Aorarat Suntronpong, Worapong Singchat, Khampee Pattanatanang, Rattanin Phatcharakullawarawat, Narongrit Muangmai, Surin Peyachoknagul, Tariq EzazAbstract:Fluorescence in situ hybridization mapping used randomly selected VSAREP clones from each VSAREP subfamily isolated from genomic DNA of three Australian varanids (Varanus acanthurus, V. gouldii, and V. rosenbergi). (DOC 35Â kb
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Additional file 7: Figure S3. of Lack of satellite DNA species-specific homogenization and relationship to chromosomal rearrangements in monitor lizards (Varanidae, Squamata)
2017Co-Authors: Ornjira Prakhongcheep, Kazumi Matsubara, Watcharaporn Thapana, Aorarat Suntronpong, Worapong Singchat, Khampee Pattanatanang, Rattanin Phatcharakullawarawat, Narongrit Muangmai, Surin Peyachoknagul, Tariq EzazAbstract:Statistical parsimony network of VSAREP subfamily I constructed from all VSAREP sequence units of Varanus gouldii (VGO) and V. rosenbergi (VRO). (TIFF 813 kb
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Additional file 10: Figure S6. of Lack of satellite DNA species-specific homogenization and relationship to chromosomal rearrangements in monitor lizards (Varanidae, Squamata)
2017Co-Authors: Ornjira Prakhongcheep, Kazumi Matsubara, Watcharaporn Thapana, Aorarat Suntronpong, Worapong Singchat, Khampee Pattanatanang, Rattanin Phatcharakullawarawat, Narongrit Muangmai, Surin Peyachoknagul, Tariq EzazAbstract:Statistical parsimony network of VSAREP subfamily IV constructed from all VSAREP sequence units of Varanus salvator macromaculatus (VSA(M)) comprising VSAREP1 and VSAREP2, V. salvator sulfur (VSA(S)), V. salvator ziegleri (VSA(Z)), V. nebulosus (VNE), and V. rudicollis (VRU). (TIFF 2542 kb
Akihiko Koga - One of the best experts on this subject based on the ideXlab platform.
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highly species specific centromeric repetitive dna sequences in lizards molecular cytogenetic characterization of a novel family of satellite dna sequences isolated from the water monitor lizard Varanus salvator macromaculatus platynota
Journal of Heredity, 2013Co-Authors: Nampech Chaiprasertsri, Ornjira Prakhongcheep, Surin Peyachoknagul, Yoshinobu Uno, Sudarath Baicharoen, Saranon Charernsuk, Chizuko Nishida, Yoichi Matsuda, Akihiko KogaAbstract:Two novel repetitive DNA sequences, VSAREP1 and VSAREP2, were isolated from the water monitor lizard (Varanus salvator macromaculatus, Platynota) and characterized using molecular cytogenetics. The respective lengths and guanine-cytosine (GC) contents of the sequences were 190 bp and 57.5% for VSAREP1 and 185 bp and 59.7% for VSAREP2, and both elements were tandemly arrayed as satellite DNA in the genome. VSAREP1 and VSAREP2 were each located at the C-positive heterochromatin in the pericentromeric region of chromosome 2q, the centromeric region of chromosome 5, and 3 pairs of microchromosomes. This suggests that genomic compartmentalization between macro- and microchromosomes might not have occurred in the centromeric repetitive sequences of V. salvator macromaculatus. These 2 sequences did only hybridize to genomic DNA of V. salvator macromaculatus, but no signal was observed even for other squamate reptiles, including Varanus exanthematicus, which is a closely related species of V. salvator macromaculatus. These results suggest that these sequences were differentiated rapidly or were specifically amplified in the V. salvator macromaculatus genome.
Sergio Almécija - One of the best experts on this subject based on the ideXlab platform.
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revision of Varanus marathonensis squamata varanidae based on historical and new material morphology systematics and paleobiogeography of the european monitor lizards
PLOS ONE, 2018Co-Authors: Andrea Villa, Juan Abella, David M. Alba, Sergio Almécija, Arnau Bolet, George D. Koufos, Fabien Knoll, Àngel H. LujánAbstract:Monitor lizards (genus Varanus) inhabited Europe at least from the early Miocene to the Pleistocene. Their fossil record is limited to about 40 localities that have provided mostly isolated vertebrae. Due to the poor diagnostic value of these fossils, it was recently claimed that all the European species described prior to the 21st century are not taxonomically valid and a new species, Varanus amnhophilis, was erected on the basis of fragmentary material including cranial elements, from the late Miocene of Samos (Greece). We re-examined the type material of Varanus marathonensis Weithofer, 1888, based on material from the late Miocene of Pikermi (Greece), and concluded that it is a valid, diagnosable species. Previously unpublished Iberian material from the Aragonian (middle Miocene) of Abocador de Can Mata (Valles-Penedes Basin, Barcelona) and the Vallesian (late Miocene) of Batallones (Madrid Basin) is clearly referable to the same species on a morphological basis, further enabling to provide an emended diagnosis for this species. Varanus amnhophilis appears to be a junior subjective synonym of V. marathonensis. On the basis of the most complete fossil Varanus skeleton ever described, it has been possible to further resolve the internal phylogeny of this genus by cladistically analyzing 80 taxa coded for 495 morphological and 5729 molecular characters. Varanus marathonensis was a large-sized species distributed at relatively low latitudes in both southwestern and southeastern Europe from at least MN7+8 to MN12. Our cladistic analysis nests V. marathonensis into an eastern clade of Varanus instead of the African clade comprising Varanus griseus, to which it had been related in the past. At least two different Varanus lineages were present in Europe during the Neogene, represented by Varanus mokrensis (early Miocene) and V. marathonensis (middle to late Miocene), respectively.
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Snouts of extant Varanus species showing the maxillary morphology in dorsal and right lateral view.
2018Co-Authors: Andrea Villa, Juan Abella, David M. Alba, Sergio Almécija, Arnau Bolet, George D. Koufos, Fabien Knoll, Àngel H. Luján, Jorge Morales, Josep M. RoblesAbstract:(A, B) Varanus ornatus (Daudin, 1803) ZFMK 14889. (C, D) Varanus komodoensis Ouwens, 1912 ZFMK 64998. (E, F) Varanus griseus (Daudin, 1803) SMF 32911. (G, H) Varanus bengalensis (Daudin, 1802) SMF 63456. Note in all cases the absence of a lateral sulcus along the edge of the narial aperture. In V. ornatus and V. komodoensis there is no hint of medial expansion of the medial edge of the maxilla (no medial concavity along the medial edge of the maxilla in dorsal view), whereas in V. griseus and V. bengalensis a sort of expansion is mostly located in the area anterior to the facial process (presence of a variably developed concavity). Among the four species here depicted, V. ornatus is the only one that bears blunt, molariform teeth. Scale bars equal 10 mm.
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Majority-rule consensus tree based on the results of analysis 1A.
2018Co-Authors: Andrea Villa, Juan Abella, David M. Alba, Sergio Almécija, Arnau Bolet, George D. Koufos, Fabien Knoll, Àngel H. Luján, Jorge Morales, Josep M. RoblesAbstract:The position of Varanus marathonensis (as scored from information provided by the specimen from Batallones and the type of Varanus amnhophilis; this OTU is named “Vmarathonensis Vamnhophilis” in figures of the supplementary information) inside the Indo-Asian A group and as sister species to the IndoVaranus subgenus is supported by 85% of the MPTs. Numbers in the time scale represent million years ago.
