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Christiane Denys - One of the best experts on this subject based on the ideXlab platform.
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systematics and evolution of the Meriones shawii grandis complex rodentia gerbillinae during the late quaternary in northwestern africa exploring the role of environmental and anthropogenic changes
Quaternary Science Reviews, 2017Co-Authors: Emmanuelle Stoetzel, Thomas Cucchi, Raphael Cornette, Aude Lalis, Violaine Nicolas, Christiane DenysAbstract:Abstract Rodents of the Meriones shawii/grandis complex have been attested to in North Africa since the Middle Pleistocene and are abundant in archaeological sites. Today, they are widely spread and represent a major pest to local human populations. This complex, therefore, represents an accurate model for investigating the roles of climate change and human impact in shaping Quaternary faunal diversity and distribution. Many gray areas still exist regarding the systematics, ecology and geographical distribution of this complex, for both present and past populations. The purpose of this study is to compare modern genotyped and fossil Meriones specimens in order to 1) clarify the current systematics and distribution of the Meriones populations of the shawii/grandis complex, 2) document the taxonomic diversity in fossil Meriones from northwestern Africa, and 3) track their phenotypic and biogeographic evolution through time. To answer these questions we used geometric morphometrics on skulls (landmarks) and first upper molars (landmarks and sliding landmarks). We evidenced the existence of two morpho-groups within the M. shawii/grandis complex, with a clear geographic pattern ( M. grandis in Morocco vs. M. shawii in Algeria and Tunisia). Currently only one morpho-group, attributed to M. grandis , seems to exist in Morocco, with a small overlap with M. shawii in the most eastern part of the country. However, according to fossil data, M. shawii was also present in Atlantic Morocco during the Late Pleistocene. We have also highlighted the impact of Holocene climate change and habitat anthropization on this arid adapted group. During the Middle Holocene, a major climatic event (last interglacial optimum) seems to have induced a demographic collapse in Moroccan populations and the disappearance of the shawii clade from Morocco (except in the most eastern areas). Both species then re-expanded, benefitting from the increasing aridity and the new ecological niche driven by agriculture dispersal from the Neolithic onwards.
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Systematics and evolution of the Meriones shawii/grandis complex (Rodentia, Gerbillinae) during the Late Quaternary in northwestern Africa: Exploring the role of environmental and anthropogenic changes
Quaternary Science Reviews, 2017Co-Authors: Emmanuelle Stoetzel, Thomas Cucchi, Raphael Cornette, Aude Lalis, Violaine Nicolas, Christiane DenysAbstract:Rodents of the Meriones shawii/grandis complex have been attested to in North Africa since the Middle Pleistocene and are abundant in archaeological sites. Today, they are widely spread and represent a major pest to local human populations. This complex, therefore, represents an accurate model for investigating the roles of climate change and human impact in shaping Quaternary faunal diversity and distribution. Many gray areas still exist regarding the systematics, ecology and geographical distribution of this complex, for both present and past populations. The purpose of this study is to compare modern genotyped and fossil Meriones specimens in order to 1) clarify the current systematics and distribution of the Meriones populations of the shawii/grandis complex, 2) document the taxonomic diversity in fossil Meriones from northwestern Africa, and 3) track their phenotypic and biogeographic evolution through time. To answer these questions we used geometric morphometrics on skulls (landmarks) and first upper molars (landmarks and sliding landmarks). We evidenced the existence of two morpho-groups within the M. shawii/grandis complex, with a clear geographic pattern (M. grandis in Morocco vs. M. shawii in Algeria and Tunisia). Currently only one morpho-group, attributed to M. grandis, seems to exist in Morocco, with a small overlap with M. shawii in the most eastern part of the country. However, according to fossil data, M. shawii was also present in Atlantic Morocco during the Late Pleistocene. We have also highlighted the impact of Holocene climate change and habitat anthropization on this arid adapted group. During the Middle Holocene, a major climatic event (last interglacial optimum) seems to have induced a demographic collapse in Moroccan populations and the disappearance of the shawii clade from Morocco (except in the most eastern areas). Both species then re-expanded, benefitting from the increasing aridity and the new ecological niche driven by agriculture dispersal from the Neolithic onwards.
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Evolution morphologique des crânes et dents de Meriones (Rodentia: Gerbillinae) actuels et fossiles du Maroc
2014Co-Authors: Emmanuelle Stoetzel, Thomas Cucchi, Raphael Cornette, Roland Nespoulet, Christiane DenysAbstract:Certaines zones d’ombre subsistent encore concernant la systématique et l’évolution de certains rongeurs nord-africains non-sahariens. C’est notamment le cas du complexe shawii-grandis au sein du genre Meriones (Muridae, Gerbillinae). Très largement répartis dans les zones bioclimatiques semi-arides et arides du nord du Maghreb, ces rongeurs sont aujourd’hui considérés comme d’importants ravageurs de cultures et vecteurs de maladies transmissibles à l’homme. Actuellement, une seule espèce, M. shawii, est officiellement reconnue pour ce complexe au Maghreb. Mais sur la base d’analyses de distances (mesures externes et crâniennes), certains auteurs semblent distinguer deux formes, principalement par leur taille : une grande forme rapportée à grandis, et une forme plus petite rapportée à shawii. Cependant leur statut taxonomique ainsi que leur distribution géographique en Afrique du Nord restent encore discutés, et rien n’est connu sur d’éventuelles différences éco-éthologiques entre ces deux formes (comportement, habitat, régime alimentaire). Concernant le registre fossile de la fin du Quaternaire, toutes les Mériones de morphologie « moderne » ont été attribuées à M. shawii sans étude plus approfondie. Le site archéologique d’El Harhoura 2, situé dans la région côtière de Rabat-Témara au Maroc, a livré un matériel microfaunique exceptionnellement abondant, riche en restes osseux et dentaires de M. cf. shawii. La séquence étudiée couvre les derniers 100 000 ans, permettant de suivre l’évolution de ce taxon sur une longue période de temps caractérisée par plusieurs changements paléoenvironnementaux. Afin d’éclairer la question du statut taxonomique du complexe shawii-grandis, et d’aider à une meilleure connaissance de son évolution dans le temps et de sa distribution géographique actuelle, nous avons appliqué des méthodes de morphométrie géométrique 2D sur les molaires de différentes populations fossiles et actuelles du Maghreb. Les molaires sont en effet les éléments les plus abondants en contexte fossile, et comme aucune analyse de ce type n’a été entreprise précédemment sur les molaires de Mériones, nous avons choisi d’utiliser à la fois des points repères homologues (landmarks) et des semi-landmarks pour obtenir un maximum d’informations aussi bien sur le contour que sur le dessin de la surface occlusale. Nous avons ainsi pu comparer des conditions anciennes « naturelles » (Pléistocène supérieur – Holocène moyen) uniquement soumises aux variations environnementales, avec des habitats actuels naturels ou fortement impactés par les activités humaines. En effet, les Mériones du complexe shawii-grandis sont aujourd’hui très fortement inféodées aux champs cultivés et aux friches avoisinantes, témoignant d’une adaptation récente à l’anthropisation des milieux. Nous avons pu intégrer aux analyses morphométriques des spécimens ayant fait également l’objet d’analyses génétiques, afin de comparer les différents scénarios au niveau taxonomique et populationnel. Les analyses sont encore en cours, mais les premiers résultats confirmeraient l’existence de deux groupes de taille et de conformation structurés géographiquement, avec des spécimens de grande taille à l’Ouest (Maroc) correspondant à priori à M. grandis, et des spécimens de plus petite taille à l’Est (Algérie, Tunisie) correspondant à priori à M. shawii. De plus, ces groupes morphologiques semblent correspondre à deux grands clades génétiques mis en évidence récemment au Maroc et en Algérie. Ces deux formes semblent présentes dans le matériel fossile marocain, en proportions variables tout au long de la séquence archéologique d’El Harhoura 2.
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Stable isotope analysis of modern small mammals from Morocco: implications for reconstructing palaeoenvironment and palaeoclimate
2014Co-Authors: Amy Jeffrey, Christiane Denys, Emmanuelle Stoetzel, Julia Lee-thorpAbstract:Small mammal remains from archaeological sites provide an excellent tool for reconstructing palaeoenvironment and palaeoclimate as they are abundant in the archaeological record, have small home ranges and prefer specific habitats. In this study we evaluate the stable carbon and oxygen isotope composition of small mammal teeth as a reflection of local climate and environmental conditions, with the aim of assessing their use as a terrestrial proxy climate record in North Africa. Modern Gerbillus, Meriones and Mus teeth and bones, collected from mesic, semi-arid and arid environments across Morocco, were analysed for their δ13C and δ 18O, and δ 13C and δ 15N composition respectively. The results show oxygen isotopes in Gerbillus and Meriones tooth enamel are sensitive to changes in rainfall and relative humidity, with mammal teeth in more arid sites displaying higher oxygen isotope values relative to sites located in the mesic coastal zone. This is best explained by small mammals strong reliance on plant water, hence their bodywater and tooth enamel is highly sensitive to evaporative enrichment in plants under xeric conditions. The carbon isotopes in the Gerbillus and Meriones tooth enamel display greater isotopic variability and likely reflect the vegetation within the mammal’s microhabitat. In Gerbillus, Meriones and Mus δ 15N appears insensitive to changes in aridity. Based on isotopic comparisons between individual Gerbillus and Meriones molar and incisor teeth, we find that molar teeth should be used in palaeoenvironmental reconstructions because these teeth consistently reflect the spring/summer breeding season. In contrast, incisors, which form continuously throughout the year, show increased isotopic variability in the proxy record. From this study we conclude that both oxygen and carbon isotopes in small mammal teeth are sensitive to environmental conditions in North Africa.
Emmanuelle Stoetzel - One of the best experts on this subject based on the ideXlab platform.
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systematics and evolution of the Meriones shawii grandis complex rodentia gerbillinae during the late quaternary in northwestern africa exploring the role of environmental and anthropogenic changes
Quaternary Science Reviews, 2017Co-Authors: Emmanuelle Stoetzel, Thomas Cucchi, Raphael Cornette, Aude Lalis, Violaine Nicolas, Christiane DenysAbstract:Abstract Rodents of the Meriones shawii/grandis complex have been attested to in North Africa since the Middle Pleistocene and are abundant in archaeological sites. Today, they are widely spread and represent a major pest to local human populations. This complex, therefore, represents an accurate model for investigating the roles of climate change and human impact in shaping Quaternary faunal diversity and distribution. Many gray areas still exist regarding the systematics, ecology and geographical distribution of this complex, for both present and past populations. The purpose of this study is to compare modern genotyped and fossil Meriones specimens in order to 1) clarify the current systematics and distribution of the Meriones populations of the shawii/grandis complex, 2) document the taxonomic diversity in fossil Meriones from northwestern Africa, and 3) track their phenotypic and biogeographic evolution through time. To answer these questions we used geometric morphometrics on skulls (landmarks) and first upper molars (landmarks and sliding landmarks). We evidenced the existence of two morpho-groups within the M. shawii/grandis complex, with a clear geographic pattern ( M. grandis in Morocco vs. M. shawii in Algeria and Tunisia). Currently only one morpho-group, attributed to M. grandis , seems to exist in Morocco, with a small overlap with M. shawii in the most eastern part of the country. However, according to fossil data, M. shawii was also present in Atlantic Morocco during the Late Pleistocene. We have also highlighted the impact of Holocene climate change and habitat anthropization on this arid adapted group. During the Middle Holocene, a major climatic event (last interglacial optimum) seems to have induced a demographic collapse in Moroccan populations and the disappearance of the shawii clade from Morocco (except in the most eastern areas). Both species then re-expanded, benefitting from the increasing aridity and the new ecological niche driven by agriculture dispersal from the Neolithic onwards.
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Systematics and evolution of the Meriones shawii/grandis complex (Rodentia, Gerbillinae) during the Late Quaternary in northwestern Africa: Exploring the role of environmental and anthropogenic changes
Quaternary Science Reviews, 2017Co-Authors: Emmanuelle Stoetzel, Thomas Cucchi, Raphael Cornette, Aude Lalis, Violaine Nicolas, Christiane DenysAbstract:Rodents of the Meriones shawii/grandis complex have been attested to in North Africa since the Middle Pleistocene and are abundant in archaeological sites. Today, they are widely spread and represent a major pest to local human populations. This complex, therefore, represents an accurate model for investigating the roles of climate change and human impact in shaping Quaternary faunal diversity and distribution. Many gray areas still exist regarding the systematics, ecology and geographical distribution of this complex, for both present and past populations. The purpose of this study is to compare modern genotyped and fossil Meriones specimens in order to 1) clarify the current systematics and distribution of the Meriones populations of the shawii/grandis complex, 2) document the taxonomic diversity in fossil Meriones from northwestern Africa, and 3) track their phenotypic and biogeographic evolution through time. To answer these questions we used geometric morphometrics on skulls (landmarks) and first upper molars (landmarks and sliding landmarks). We evidenced the existence of two morpho-groups within the M. shawii/grandis complex, with a clear geographic pattern (M. grandis in Morocco vs. M. shawii in Algeria and Tunisia). Currently only one morpho-group, attributed to M. grandis, seems to exist in Morocco, with a small overlap with M. shawii in the most eastern part of the country. However, according to fossil data, M. shawii was also present in Atlantic Morocco during the Late Pleistocene. We have also highlighted the impact of Holocene climate change and habitat anthropization on this arid adapted group. During the Middle Holocene, a major climatic event (last interglacial optimum) seems to have induced a demographic collapse in Moroccan populations and the disappearance of the shawii clade from Morocco (except in the most eastern areas). Both species then re-expanded, benefitting from the increasing aridity and the new ecological niche driven by agriculture dispersal from the Neolithic onwards.
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Evolution morphologique des crânes et dents de Meriones (Rodentia: Gerbillinae) actuels et fossiles du Maroc
2014Co-Authors: Emmanuelle Stoetzel, Thomas Cucchi, Raphael Cornette, Roland Nespoulet, Christiane DenysAbstract:Certaines zones d’ombre subsistent encore concernant la systématique et l’évolution de certains rongeurs nord-africains non-sahariens. C’est notamment le cas du complexe shawii-grandis au sein du genre Meriones (Muridae, Gerbillinae). Très largement répartis dans les zones bioclimatiques semi-arides et arides du nord du Maghreb, ces rongeurs sont aujourd’hui considérés comme d’importants ravageurs de cultures et vecteurs de maladies transmissibles à l’homme. Actuellement, une seule espèce, M. shawii, est officiellement reconnue pour ce complexe au Maghreb. Mais sur la base d’analyses de distances (mesures externes et crâniennes), certains auteurs semblent distinguer deux formes, principalement par leur taille : une grande forme rapportée à grandis, et une forme plus petite rapportée à shawii. Cependant leur statut taxonomique ainsi que leur distribution géographique en Afrique du Nord restent encore discutés, et rien n’est connu sur d’éventuelles différences éco-éthologiques entre ces deux formes (comportement, habitat, régime alimentaire). Concernant le registre fossile de la fin du Quaternaire, toutes les Mériones de morphologie « moderne » ont été attribuées à M. shawii sans étude plus approfondie. Le site archéologique d’El Harhoura 2, situé dans la région côtière de Rabat-Témara au Maroc, a livré un matériel microfaunique exceptionnellement abondant, riche en restes osseux et dentaires de M. cf. shawii. La séquence étudiée couvre les derniers 100 000 ans, permettant de suivre l’évolution de ce taxon sur une longue période de temps caractérisée par plusieurs changements paléoenvironnementaux. Afin d’éclairer la question du statut taxonomique du complexe shawii-grandis, et d’aider à une meilleure connaissance de son évolution dans le temps et de sa distribution géographique actuelle, nous avons appliqué des méthodes de morphométrie géométrique 2D sur les molaires de différentes populations fossiles et actuelles du Maghreb. Les molaires sont en effet les éléments les plus abondants en contexte fossile, et comme aucune analyse de ce type n’a été entreprise précédemment sur les molaires de Mériones, nous avons choisi d’utiliser à la fois des points repères homologues (landmarks) et des semi-landmarks pour obtenir un maximum d’informations aussi bien sur le contour que sur le dessin de la surface occlusale. Nous avons ainsi pu comparer des conditions anciennes « naturelles » (Pléistocène supérieur – Holocène moyen) uniquement soumises aux variations environnementales, avec des habitats actuels naturels ou fortement impactés par les activités humaines. En effet, les Mériones du complexe shawii-grandis sont aujourd’hui très fortement inféodées aux champs cultivés et aux friches avoisinantes, témoignant d’une adaptation récente à l’anthropisation des milieux. Nous avons pu intégrer aux analyses morphométriques des spécimens ayant fait également l’objet d’analyses génétiques, afin de comparer les différents scénarios au niveau taxonomique et populationnel. Les analyses sont encore en cours, mais les premiers résultats confirmeraient l’existence de deux groupes de taille et de conformation structurés géographiquement, avec des spécimens de grande taille à l’Ouest (Maroc) correspondant à priori à M. grandis, et des spécimens de plus petite taille à l’Est (Algérie, Tunisie) correspondant à priori à M. shawii. De plus, ces groupes morphologiques semblent correspondre à deux grands clades génétiques mis en évidence récemment au Maroc et en Algérie. Ces deux formes semblent présentes dans le matériel fossile marocain, en proportions variables tout au long de la séquence archéologique d’El Harhoura 2.
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Stable isotope analysis of modern small mammals from Morocco: implications for reconstructing palaeoenvironment and palaeoclimate
2014Co-Authors: Amy Jeffrey, Christiane Denys, Emmanuelle Stoetzel, Julia Lee-thorpAbstract:Small mammal remains from archaeological sites provide an excellent tool for reconstructing palaeoenvironment and palaeoclimate as they are abundant in the archaeological record, have small home ranges and prefer specific habitats. In this study we evaluate the stable carbon and oxygen isotope composition of small mammal teeth as a reflection of local climate and environmental conditions, with the aim of assessing their use as a terrestrial proxy climate record in North Africa. Modern Gerbillus, Meriones and Mus teeth and bones, collected from mesic, semi-arid and arid environments across Morocco, were analysed for their δ13C and δ 18O, and δ 13C and δ 15N composition respectively. The results show oxygen isotopes in Gerbillus and Meriones tooth enamel are sensitive to changes in rainfall and relative humidity, with mammal teeth in more arid sites displaying higher oxygen isotope values relative to sites located in the mesic coastal zone. This is best explained by small mammals strong reliance on plant water, hence their bodywater and tooth enamel is highly sensitive to evaporative enrichment in plants under xeric conditions. The carbon isotopes in the Gerbillus and Meriones tooth enamel display greater isotopic variability and likely reflect the vegetation within the mammal’s microhabitat. In Gerbillus, Meriones and Mus δ 15N appears insensitive to changes in aridity. Based on isotopic comparisons between individual Gerbillus and Meriones molar and incisor teeth, we find that molar teeth should be used in palaeoenvironmental reconstructions because these teeth consistently reflect the spring/summer breeding season. In contrast, incisors, which form continuously throughout the year, show increased isotopic variability in the proxy record. From this study we conclude that both oxygen and carbon isotopes in small mammal teeth are sensitive to environmental conditions in North Africa.
Raphael Cornette - One of the best experts on this subject based on the ideXlab platform.
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systematics and evolution of the Meriones shawii grandis complex rodentia gerbillinae during the late quaternary in northwestern africa exploring the role of environmental and anthropogenic changes
Quaternary Science Reviews, 2017Co-Authors: Emmanuelle Stoetzel, Thomas Cucchi, Raphael Cornette, Aude Lalis, Violaine Nicolas, Christiane DenysAbstract:Abstract Rodents of the Meriones shawii/grandis complex have been attested to in North Africa since the Middle Pleistocene and are abundant in archaeological sites. Today, they are widely spread and represent a major pest to local human populations. This complex, therefore, represents an accurate model for investigating the roles of climate change and human impact in shaping Quaternary faunal diversity and distribution. Many gray areas still exist regarding the systematics, ecology and geographical distribution of this complex, for both present and past populations. The purpose of this study is to compare modern genotyped and fossil Meriones specimens in order to 1) clarify the current systematics and distribution of the Meriones populations of the shawii/grandis complex, 2) document the taxonomic diversity in fossil Meriones from northwestern Africa, and 3) track their phenotypic and biogeographic evolution through time. To answer these questions we used geometric morphometrics on skulls (landmarks) and first upper molars (landmarks and sliding landmarks). We evidenced the existence of two morpho-groups within the M. shawii/grandis complex, with a clear geographic pattern ( M. grandis in Morocco vs. M. shawii in Algeria and Tunisia). Currently only one morpho-group, attributed to M. grandis , seems to exist in Morocco, with a small overlap with M. shawii in the most eastern part of the country. However, according to fossil data, M. shawii was also present in Atlantic Morocco during the Late Pleistocene. We have also highlighted the impact of Holocene climate change and habitat anthropization on this arid adapted group. During the Middle Holocene, a major climatic event (last interglacial optimum) seems to have induced a demographic collapse in Moroccan populations and the disappearance of the shawii clade from Morocco (except in the most eastern areas). Both species then re-expanded, benefitting from the increasing aridity and the new ecological niche driven by agriculture dispersal from the Neolithic onwards.
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Systematics and evolution of the Meriones shawii/grandis complex (Rodentia, Gerbillinae) during the Late Quaternary in northwestern Africa: Exploring the role of environmental and anthropogenic changes
Quaternary Science Reviews, 2017Co-Authors: Emmanuelle Stoetzel, Thomas Cucchi, Raphael Cornette, Aude Lalis, Violaine Nicolas, Christiane DenysAbstract:Rodents of the Meriones shawii/grandis complex have been attested to in North Africa since the Middle Pleistocene and are abundant in archaeological sites. Today, they are widely spread and represent a major pest to local human populations. This complex, therefore, represents an accurate model for investigating the roles of climate change and human impact in shaping Quaternary faunal diversity and distribution. Many gray areas still exist regarding the systematics, ecology and geographical distribution of this complex, for both present and past populations. The purpose of this study is to compare modern genotyped and fossil Meriones specimens in order to 1) clarify the current systematics and distribution of the Meriones populations of the shawii/grandis complex, 2) document the taxonomic diversity in fossil Meriones from northwestern Africa, and 3) track their phenotypic and biogeographic evolution through time. To answer these questions we used geometric morphometrics on skulls (landmarks) and first upper molars (landmarks and sliding landmarks). We evidenced the existence of two morpho-groups within the M. shawii/grandis complex, with a clear geographic pattern (M. grandis in Morocco vs. M. shawii in Algeria and Tunisia). Currently only one morpho-group, attributed to M. grandis, seems to exist in Morocco, with a small overlap with M. shawii in the most eastern part of the country. However, according to fossil data, M. shawii was also present in Atlantic Morocco during the Late Pleistocene. We have also highlighted the impact of Holocene climate change and habitat anthropization on this arid adapted group. During the Middle Holocene, a major climatic event (last interglacial optimum) seems to have induced a demographic collapse in Moroccan populations and the disappearance of the shawii clade from Morocco (except in the most eastern areas). Both species then re-expanded, benefitting from the increasing aridity and the new ecological niche driven by agriculture dispersal from the Neolithic onwards.
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Evolution morphologique des crânes et dents de Meriones (Rodentia: Gerbillinae) actuels et fossiles du Maroc
2014Co-Authors: Emmanuelle Stoetzel, Thomas Cucchi, Raphael Cornette, Roland Nespoulet, Christiane DenysAbstract:Certaines zones d’ombre subsistent encore concernant la systématique et l’évolution de certains rongeurs nord-africains non-sahariens. C’est notamment le cas du complexe shawii-grandis au sein du genre Meriones (Muridae, Gerbillinae). Très largement répartis dans les zones bioclimatiques semi-arides et arides du nord du Maghreb, ces rongeurs sont aujourd’hui considérés comme d’importants ravageurs de cultures et vecteurs de maladies transmissibles à l’homme. Actuellement, une seule espèce, M. shawii, est officiellement reconnue pour ce complexe au Maghreb. Mais sur la base d’analyses de distances (mesures externes et crâniennes), certains auteurs semblent distinguer deux formes, principalement par leur taille : une grande forme rapportée à grandis, et une forme plus petite rapportée à shawii. Cependant leur statut taxonomique ainsi que leur distribution géographique en Afrique du Nord restent encore discutés, et rien n’est connu sur d’éventuelles différences éco-éthologiques entre ces deux formes (comportement, habitat, régime alimentaire). Concernant le registre fossile de la fin du Quaternaire, toutes les Mériones de morphologie « moderne » ont été attribuées à M. shawii sans étude plus approfondie. Le site archéologique d’El Harhoura 2, situé dans la région côtière de Rabat-Témara au Maroc, a livré un matériel microfaunique exceptionnellement abondant, riche en restes osseux et dentaires de M. cf. shawii. La séquence étudiée couvre les derniers 100 000 ans, permettant de suivre l’évolution de ce taxon sur une longue période de temps caractérisée par plusieurs changements paléoenvironnementaux. Afin d’éclairer la question du statut taxonomique du complexe shawii-grandis, et d’aider à une meilleure connaissance de son évolution dans le temps et de sa distribution géographique actuelle, nous avons appliqué des méthodes de morphométrie géométrique 2D sur les molaires de différentes populations fossiles et actuelles du Maghreb. Les molaires sont en effet les éléments les plus abondants en contexte fossile, et comme aucune analyse de ce type n’a été entreprise précédemment sur les molaires de Mériones, nous avons choisi d’utiliser à la fois des points repères homologues (landmarks) et des semi-landmarks pour obtenir un maximum d’informations aussi bien sur le contour que sur le dessin de la surface occlusale. Nous avons ainsi pu comparer des conditions anciennes « naturelles » (Pléistocène supérieur – Holocène moyen) uniquement soumises aux variations environnementales, avec des habitats actuels naturels ou fortement impactés par les activités humaines. En effet, les Mériones du complexe shawii-grandis sont aujourd’hui très fortement inféodées aux champs cultivés et aux friches avoisinantes, témoignant d’une adaptation récente à l’anthropisation des milieux. Nous avons pu intégrer aux analyses morphométriques des spécimens ayant fait également l’objet d’analyses génétiques, afin de comparer les différents scénarios au niveau taxonomique et populationnel. Les analyses sont encore en cours, mais les premiers résultats confirmeraient l’existence de deux groupes de taille et de conformation structurés géographiquement, avec des spécimens de grande taille à l’Ouest (Maroc) correspondant à priori à M. grandis, et des spécimens de plus petite taille à l’Est (Algérie, Tunisie) correspondant à priori à M. shawii. De plus, ces groupes morphologiques semblent correspondre à deux grands clades génétiques mis en évidence récemment au Maroc et en Algérie. Ces deux formes semblent présentes dans le matériel fossile marocain, en proportions variables tout au long de la séquence archéologique d’El Harhoura 2.
Thomas Cucchi - One of the best experts on this subject based on the ideXlab platform.
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systematics and evolution of the Meriones shawii grandis complex rodentia gerbillinae during the late quaternary in northwestern africa exploring the role of environmental and anthropogenic changes
Quaternary Science Reviews, 2017Co-Authors: Emmanuelle Stoetzel, Thomas Cucchi, Raphael Cornette, Aude Lalis, Violaine Nicolas, Christiane DenysAbstract:Abstract Rodents of the Meriones shawii/grandis complex have been attested to in North Africa since the Middle Pleistocene and are abundant in archaeological sites. Today, they are widely spread and represent a major pest to local human populations. This complex, therefore, represents an accurate model for investigating the roles of climate change and human impact in shaping Quaternary faunal diversity and distribution. Many gray areas still exist regarding the systematics, ecology and geographical distribution of this complex, for both present and past populations. The purpose of this study is to compare modern genotyped and fossil Meriones specimens in order to 1) clarify the current systematics and distribution of the Meriones populations of the shawii/grandis complex, 2) document the taxonomic diversity in fossil Meriones from northwestern Africa, and 3) track their phenotypic and biogeographic evolution through time. To answer these questions we used geometric morphometrics on skulls (landmarks) and first upper molars (landmarks and sliding landmarks). We evidenced the existence of two morpho-groups within the M. shawii/grandis complex, with a clear geographic pattern ( M. grandis in Morocco vs. M. shawii in Algeria and Tunisia). Currently only one morpho-group, attributed to M. grandis , seems to exist in Morocco, with a small overlap with M. shawii in the most eastern part of the country. However, according to fossil data, M. shawii was also present in Atlantic Morocco during the Late Pleistocene. We have also highlighted the impact of Holocene climate change and habitat anthropization on this arid adapted group. During the Middle Holocene, a major climatic event (last interglacial optimum) seems to have induced a demographic collapse in Moroccan populations and the disappearance of the shawii clade from Morocco (except in the most eastern areas). Both species then re-expanded, benefitting from the increasing aridity and the new ecological niche driven by agriculture dispersal from the Neolithic onwards.
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Systematics and evolution of the Meriones shawii/grandis complex (Rodentia, Gerbillinae) during the Late Quaternary in northwestern Africa: Exploring the role of environmental and anthropogenic changes
Quaternary Science Reviews, 2017Co-Authors: Emmanuelle Stoetzel, Thomas Cucchi, Raphael Cornette, Aude Lalis, Violaine Nicolas, Christiane DenysAbstract:Rodents of the Meriones shawii/grandis complex have been attested to in North Africa since the Middle Pleistocene and are abundant in archaeological sites. Today, they are widely spread and represent a major pest to local human populations. This complex, therefore, represents an accurate model for investigating the roles of climate change and human impact in shaping Quaternary faunal diversity and distribution. Many gray areas still exist regarding the systematics, ecology and geographical distribution of this complex, for both present and past populations. The purpose of this study is to compare modern genotyped and fossil Meriones specimens in order to 1) clarify the current systematics and distribution of the Meriones populations of the shawii/grandis complex, 2) document the taxonomic diversity in fossil Meriones from northwestern Africa, and 3) track their phenotypic and biogeographic evolution through time. To answer these questions we used geometric morphometrics on skulls (landmarks) and first upper molars (landmarks and sliding landmarks). We evidenced the existence of two morpho-groups within the M. shawii/grandis complex, with a clear geographic pattern (M. grandis in Morocco vs. M. shawii in Algeria and Tunisia). Currently only one morpho-group, attributed to M. grandis, seems to exist in Morocco, with a small overlap with M. shawii in the most eastern part of the country. However, according to fossil data, M. shawii was also present in Atlantic Morocco during the Late Pleistocene. We have also highlighted the impact of Holocene climate change and habitat anthropization on this arid adapted group. During the Middle Holocene, a major climatic event (last interglacial optimum) seems to have induced a demographic collapse in Moroccan populations and the disappearance of the shawii clade from Morocco (except in the most eastern areas). Both species then re-expanded, benefitting from the increasing aridity and the new ecological niche driven by agriculture dispersal from the Neolithic onwards.
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Evolution morphologique des crânes et dents de Meriones (Rodentia: Gerbillinae) actuels et fossiles du Maroc
2014Co-Authors: Emmanuelle Stoetzel, Thomas Cucchi, Raphael Cornette, Roland Nespoulet, Christiane DenysAbstract:Certaines zones d’ombre subsistent encore concernant la systématique et l’évolution de certains rongeurs nord-africains non-sahariens. C’est notamment le cas du complexe shawii-grandis au sein du genre Meriones (Muridae, Gerbillinae). Très largement répartis dans les zones bioclimatiques semi-arides et arides du nord du Maghreb, ces rongeurs sont aujourd’hui considérés comme d’importants ravageurs de cultures et vecteurs de maladies transmissibles à l’homme. Actuellement, une seule espèce, M. shawii, est officiellement reconnue pour ce complexe au Maghreb. Mais sur la base d’analyses de distances (mesures externes et crâniennes), certains auteurs semblent distinguer deux formes, principalement par leur taille : une grande forme rapportée à grandis, et une forme plus petite rapportée à shawii. Cependant leur statut taxonomique ainsi que leur distribution géographique en Afrique du Nord restent encore discutés, et rien n’est connu sur d’éventuelles différences éco-éthologiques entre ces deux formes (comportement, habitat, régime alimentaire). Concernant le registre fossile de la fin du Quaternaire, toutes les Mériones de morphologie « moderne » ont été attribuées à M. shawii sans étude plus approfondie. Le site archéologique d’El Harhoura 2, situé dans la région côtière de Rabat-Témara au Maroc, a livré un matériel microfaunique exceptionnellement abondant, riche en restes osseux et dentaires de M. cf. shawii. La séquence étudiée couvre les derniers 100 000 ans, permettant de suivre l’évolution de ce taxon sur une longue période de temps caractérisée par plusieurs changements paléoenvironnementaux. Afin d’éclairer la question du statut taxonomique du complexe shawii-grandis, et d’aider à une meilleure connaissance de son évolution dans le temps et de sa distribution géographique actuelle, nous avons appliqué des méthodes de morphométrie géométrique 2D sur les molaires de différentes populations fossiles et actuelles du Maghreb. Les molaires sont en effet les éléments les plus abondants en contexte fossile, et comme aucune analyse de ce type n’a été entreprise précédemment sur les molaires de Mériones, nous avons choisi d’utiliser à la fois des points repères homologues (landmarks) et des semi-landmarks pour obtenir un maximum d’informations aussi bien sur le contour que sur le dessin de la surface occlusale. Nous avons ainsi pu comparer des conditions anciennes « naturelles » (Pléistocène supérieur – Holocène moyen) uniquement soumises aux variations environnementales, avec des habitats actuels naturels ou fortement impactés par les activités humaines. En effet, les Mériones du complexe shawii-grandis sont aujourd’hui très fortement inféodées aux champs cultivés et aux friches avoisinantes, témoignant d’une adaptation récente à l’anthropisation des milieux. Nous avons pu intégrer aux analyses morphométriques des spécimens ayant fait également l’objet d’analyses génétiques, afin de comparer les différents scénarios au niveau taxonomique et populationnel. Les analyses sont encore en cours, mais les premiers résultats confirmeraient l’existence de deux groupes de taille et de conformation structurés géographiquement, avec des spécimens de grande taille à l’Ouest (Maroc) correspondant à priori à M. grandis, et des spécimens de plus petite taille à l’Est (Algérie, Tunisie) correspondant à priori à M. shawii. De plus, ces groupes morphologiques semblent correspondre à deux grands clades génétiques mis en évidence récemment au Maroc et en Algérie. Ces deux formes semblent présentes dans le matériel fossile marocain, en proportions variables tout au long de la séquence archéologique d’El Harhoura 2.
Violaine Nicolas - One of the best experts on this subject based on the ideXlab platform.
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Systematics and evolution of the libyan jird based on molecular and morphometric data
Journal of Zoological Systematics and Evolutionary Research, 2020Co-Authors: Malahat Dianat, Jamshid Darvish, Mansour Aliabadian, Roohollah Siahsarvie, Boris Krystufek, Violaine NicolasAbstract:The libyan jird is one of the most widely distributed species among wild rodents, with its range extending from Morocco to China. Fifteen subspecies were described but their validity and the phylogenetic relationships among them are uncertain. Based on a comprehensive sampling, this study aims to define subspecies limits within Meriones libycus and to discuss the factors driving subspecific diversification. We used an integrative approach combining molecular (Cytochrome b and Cytochrome Oxidase Subunit 1 genes) and geometric morphometric data. Genetic data allowed us to identify three allopatric lineages within M. libycus: Western lineage in North Africa, Central lineage in Saudi Arabia, Jordan, and Syria, and Eastern lineage in Iran, Afghanistan, and China. These three lineages can also be differentiated based on skull morphology. Our results support the existence of at least three subspecies within the libyan jird: Meriones libycus libycus, M. l. syrius, and Meriones libycus erythrourus. Based on our divergence time estimates, all divergence events within M. libycus probably occurred during the Pleistocene, after 1.597 Ma. Quaternary climate fluctuations in the Sinai Peninsula explain the differentiation between the African M. l. libycus and the Levant‐Arabian M. l. syrius. The differentiation of M. l. syrius with respect to the eastern M. l. erythrourus is putatively linked to the climatic fluctuations and tectonic activity of the Zagros Mountains and/or the Mesopotamia Plain of Iraq during the Pleistocene.
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systematics and evolution of the Meriones shawii grandis complex rodentia gerbillinae during the late quaternary in northwestern africa exploring the role of environmental and anthropogenic changes
Quaternary Science Reviews, 2017Co-Authors: Emmanuelle Stoetzel, Thomas Cucchi, Raphael Cornette, Aude Lalis, Violaine Nicolas, Christiane DenysAbstract:Abstract Rodents of the Meriones shawii/grandis complex have been attested to in North Africa since the Middle Pleistocene and are abundant in archaeological sites. Today, they are widely spread and represent a major pest to local human populations. This complex, therefore, represents an accurate model for investigating the roles of climate change and human impact in shaping Quaternary faunal diversity and distribution. Many gray areas still exist regarding the systematics, ecology and geographical distribution of this complex, for both present and past populations. The purpose of this study is to compare modern genotyped and fossil Meriones specimens in order to 1) clarify the current systematics and distribution of the Meriones populations of the shawii/grandis complex, 2) document the taxonomic diversity in fossil Meriones from northwestern Africa, and 3) track their phenotypic and biogeographic evolution through time. To answer these questions we used geometric morphometrics on skulls (landmarks) and first upper molars (landmarks and sliding landmarks). We evidenced the existence of two morpho-groups within the M. shawii/grandis complex, with a clear geographic pattern ( M. grandis in Morocco vs. M. shawii in Algeria and Tunisia). Currently only one morpho-group, attributed to M. grandis , seems to exist in Morocco, with a small overlap with M. shawii in the most eastern part of the country. However, according to fossil data, M. shawii was also present in Atlantic Morocco during the Late Pleistocene. We have also highlighted the impact of Holocene climate change and habitat anthropization on this arid adapted group. During the Middle Holocene, a major climatic event (last interglacial optimum) seems to have induced a demographic collapse in Moroccan populations and the disappearance of the shawii clade from Morocco (except in the most eastern areas). Both species then re-expanded, benefitting from the increasing aridity and the new ecological niche driven by agriculture dispersal from the Neolithic onwards.
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Systematics and evolution of the Meriones shawii/grandis complex (Rodentia, Gerbillinae) during the Late Quaternary in northwestern Africa: Exploring the role of environmental and anthropogenic changes
Quaternary Science Reviews, 2017Co-Authors: Emmanuelle Stoetzel, Thomas Cucchi, Raphael Cornette, Aude Lalis, Violaine Nicolas, Christiane DenysAbstract:Rodents of the Meriones shawii/grandis complex have been attested to in North Africa since the Middle Pleistocene and are abundant in archaeological sites. Today, they are widely spread and represent a major pest to local human populations. This complex, therefore, represents an accurate model for investigating the roles of climate change and human impact in shaping Quaternary faunal diversity and distribution. Many gray areas still exist regarding the systematics, ecology and geographical distribution of this complex, for both present and past populations. The purpose of this study is to compare modern genotyped and fossil Meriones specimens in order to 1) clarify the current systematics and distribution of the Meriones populations of the shawii/grandis complex, 2) document the taxonomic diversity in fossil Meriones from northwestern Africa, and 3) track their phenotypic and biogeographic evolution through time. To answer these questions we used geometric morphometrics on skulls (landmarks) and first upper molars (landmarks and sliding landmarks). We evidenced the existence of two morpho-groups within the M. shawii/grandis complex, with a clear geographic pattern (M. grandis in Morocco vs. M. shawii in Algeria and Tunisia). Currently only one morpho-group, attributed to M. grandis, seems to exist in Morocco, with a small overlap with M. shawii in the most eastern part of the country. However, according to fossil data, M. shawii was also present in Atlantic Morocco during the Late Pleistocene. We have also highlighted the impact of Holocene climate change and habitat anthropization on this arid adapted group. During the Middle Holocene, a major climatic event (last interglacial optimum) seems to have induced a demographic collapse in Moroccan populations and the disappearance of the shawii clade from Morocco (except in the most eastern areas). Both species then re-expanded, benefitting from the increasing aridity and the new ecological niche driven by agriculture dispersal from the Neolithic onwards.