Background: The lava mouse, Malpaisomys insularis, was endemic to the Eastern Canary islands and became extinct at the beginning of the 14th century when the Europeans reached the archipelago. ...Studies to determine Malpaisomys' phylogenetic affinities, based on morphological characters, remained inconclusive because morphological changes experienced by this insular rodent make phylogenetic investigations a real challenge. Over 20 years since its first description, Malpaisomys' phylogenetic position remains enigmatic. Methodology/Principal Findings: In this study, we resolved this issue using molecular characters. Mitochondrial and nuclear markers were successfully amplified from subfossils of three lava mouse samples. Molecular phylogenetic reconstructions revealed, without any ambiguity, unsuspected relationships between Malpaisomys and extant mice (genus Mus, Murinae). Moreover, through molecular dating we estimated the origin of the Malpaisomys/mouse clade at 6.9 Ma, corresponding to the maximal age at which the archipelago was colonised by the Malpaisomys ancestor via natural rafting. Conclusion/Significance: This study reconsiders the derived morphological characters of Malpaisomys in light of this unexpected molecular finding. To reconcile molecular and morphological data, we propose to consider Malpaisomys insularis as an insular lineage of mouse.
Background: The lava mouse, Malpaisomys insularis, was endemic to the Eastern Canary islands and became extinct at the beginning of the 14th century when the Europeans reached the archipelago. ...Studies to determine Malpaisomys' phylogenetic affinities, based on morphological characters, remained inconclusive because morphological changes experienced by this insular rodent make phylogenetic investigations a real challenge. Over 20 years since its first description, Malpaisomys' phylogenetic position remains enigmatic. Methodology/Principal Findings: In this study, we resolved this issue using molecular characters. Mitochondrial and nuclear markers were successfully amplified from subfossils of three lava mouse samples. Molecular phylogenetic reconstructions revealed, without any ambiguity, unsuspected relationships between Malpaisomys and extant mice (genus Mus, Murinae). Moreover, through molecular dating we estimated the origin of the Malpaisomys/mouse clade at 6.9 Ma, corresponding to the maximal age at which the archipelago was colonised by the Malpaisomys ancestor via natural rafting. Conclusion/Significance: This study reconsiders the derived morphological characters of Malpaisomys in light of this unexpected molecular finding. To reconcile molecular and morphological data, we propose to consider Malpaisomys insularis as an insular lineage of mouse.
Boltimys broomi gen. nov., sp. nov., a Muridae of uncertain affinity in the Early Pliocene of South Africa.
Boltimys broomi gen. nov., sp. nov. is reported from the Early Pliocene fauna of Waypoint ...160, a fossiliferous locality in the area of Bolt's Farm (Province of Gauteng) near Krugersdorp in South Africa. The occlusal surface of the jugal teeth is characterized by a basin-shaped aspect due to the coalescence of the cusps which make the lobes of the molars. An accessory inner cusp is present on the first and second upper molars. A faint longitudinal crest is present only in the first lower molar. The new rodent is tentatively referred to the subfamily Myocricetodontinae.
Boltimys broomi gen. nov., sp. nov. (Rodentia, Muridae) a été trouvé dans la faune d'âge Pliocène inférieur du site Waypoint 160, zone fossilifère de Bolt's Farm (Province de Gauteng) près de Krugersdorp en Afrique du Sud. La surface occlusale des dents jugales est caractérisée par une morphologie en bassin résultant de la confluence des tubercules principaux qui constituent les lobes des dents. Un tubercule accessoire interne est observé aux première et deuxième molaires supérieures. Une crête longitudinale, faible, n'est présente qu'à la première molaire inférieure. Ce nouveau rongeur est rapporté provisoirement à la sous-famille des Myocricetodontinae.
Histoire récente de l'ours brun au Maghreb Hamdine, Watik; Thévenot, Michel; Michaux, Jacques
Comptes rendus de l'Académie des sciences, Série III, Sciences de la vie,
7/1998, Letnik:
321, Številka:
7
Journal Article
Bones of the brown bear (
Ursus arctos, Mammalia, Carnivora) found in a cave of the Akouker massif (Djurdjura, Algeria) have been dated according to the
14C method as belonging to the historical ...times (420–600 A.D.). The bone and teeth measurements correspond to a small-sized animal, the smallest ever found in the Maghreb. A review of fossil bears in the Quaternary faunas of North Africa clearly shows that the area of distribution, which was initially wide, shrank at the end of the Upper Pleistocene. The bears had temporarily taken to mountainous areas difficult to access. The bone remains discovered up to now prove that the brown bear was represented by individuals or populations showing a large diversity of size.
Des ossements d'ours brun (
Ursus arctos, Mammalia, Carnivora) trouvés dans une grotte du massif de l'Akouker (Djurdjura, Algérie) ont été datés par la méthode
14C de l'époque historique (420 à 600 A.D.). Les mensurations des os et des dents indiquent un animal de taille modeste, le plus petit à ce jour au Maghreb. Une revue des ours fossiles des faunes quaternaires du nord de l'Afrique montre que l'aire de répartition d'abord très vaste s'est réduite à la fin du Pléistocène supérieur, les ours ayant trouvé refuge momentanément dans les régions montagneuses difficiles d'accès. Les pièces trouvées montrent que l'ours brun était représenté par des individus ou des populations caractérisés par une forte diversité de taille.
The Vitrolles-Couperigne locality has yielded an almost complete skeleton of
Rhabdodon priscus. Until now, this taxon was only represented by sparse and fragmentary remains. The flora and fauna ...associated to the
R. priscus remains are briefly described. The position of the locality in the Late Cretaceous stratigraphy of Provence is discussed on the basis of dinosaur eggshell biostratigraphy. New data concerning some hitherto unknown anatomical features of the
R. priscus permit discussion of its systematical position within the dinosaurs.
Le gisement de Vitrolles-Couperigne a livré la presque totalité d'un squelette de
Rhabdodon priscus. Ce taxon n'était jusqu'ici représenté que par des restes isolés et fragmentaires. Divers éléments de la flore et de la faune associés sont sommairement décrits. La position du site dans la stratigraphie du Crétacé supérieur de Provence est discutée à partir d'une biostratigraphie basée sur les coquilles d'œufs de dinosaures. De nouvelles données anatomiques du squelette de
R. priscus permettent de préciser sa position systématique au sein des dinosaures.
