The lesser Egyptian jerboa Jaculus jaculus, is a member of the subfamily Dipodinae, known to have a number of subspecies. Previous studies of J. jaculus from North Africa found various morphological forms of unknown t...The lesser Egyptian jerboa Jaculus jaculus, is a member of the subfamily Dipodinae, known to have a number of subspecies. Previous studies of J. jaculus from North Africa found various morphological forms of unknown taxonomic status, which are frequently grouped into two taxa： J. jaculus and J. deserti. We assessed the taxonomic status of this taxon in Tunisia using allozymic （phylogenetic analysis of 23 genetic loci encoding 16 enzymatic proteins） and morphological （multivariate analysis of 13 craniodental characters） analyses of 136 J. jaculus specimens collected from seven localities within its distribution range. Allozymic analysis clearly indicated the existence of two distinct groups of J. jaculus, with a mean genetic distance （D） value of 0.99 and FΩ=0.52. Individuals within the two groups did not show any obvious geographical structuration, even within the Matmata locality which represents the meeting point for the two groups where they were found in sympatry. Additionally, morphometric analysis of 13 craniodental characters was clearly separated the two groups. These results were obtained over a very restricted area of the total distribution of J. jaculus and strongly suggest the occurrence of two separate and often sympatric species within the currently accepted J.jaculus in Tunisia： J.jaculus and J. deserti展开更多
Recent phylogenetic studies amended the taxonomy of three-toed jerboas(subfamily Dipodinae),including raising subspecies to full species.Here,we use geometric morphometrics to compare scaled-shape differences in dipod...Recent phylogenetic studies amended the taxonomy of three-toed jerboas(subfamily Dipodinae),including raising subspecies to full species.Here,we use geometric morphometrics to compare scaled-shape differences in dipodine crania while considering their revised taxonomy.We sampled Dipus deasyi,D.sagitta halli,D.s.sowerbyi,Jaculus blanfordi blanfordi,J.hirtipes,J.jaculus,J.loftusi,J.orientalis gerboa,J.o.mauritanicus,and Stylodipus andrewsi.Crania were not sexually dimorphic.Common allometry explained some of the shape variation,for example,reduced braincases in larger specimens.Most operational taxonomic unit pairs differed in both size and shape.Dipus and Stylodipus clustered together based on their cranial shape.Jaculus differed from the aforementioned genera by its larger tympanic bulla,broader braincase,larger infraorbital foramen,along with reduced molars and rostra.Jaculus orientalis differed from other Jaculus by its broader face versus reduced cranial vault.Jaculus blanfordi(subgenus Haltomys)resembles members of the subgenus Jaculus more than its consubgener(J.orientalis).Jaculus loftusi,previously considered a synonym of J.jaculus,clearly differed from the latter by its shorter rostrum,smaller infraorbital foramen,and more caudolaterally expanded tympanic bulla.Jaculus hirtipes,another recent synonym of J.jaculus,resembled J.blanfordi more in scaled cranial shape than it did J.jaculus.Dipus sagitta halli and D.s.sowerbyi were indistinguishable,but they clearly differed from D.deasyi(recently raised to full species)with the latter having a larger molar row,more inflated tympanic bulla,and shorter,slenderer rostrum.Ecological explanations for detected cranial shape differences are considered,including diet and habitat(particularly substrate).展开更多
文摘The lesser Egyptian jerboa Jaculus jaculus, is a member of the subfamily Dipodinae, known to have a number of subspecies. Previous studies of J. jaculus from North Africa found various morphological forms of unknown taxonomic status, which are frequently grouped into two taxa： J. jaculus and J. deserti. We assessed the taxonomic status of this taxon in Tunisia using allozymic （phylogenetic analysis of 23 genetic loci encoding 16 enzymatic proteins） and morphological （multivariate analysis of 13 craniodental characters） analyses of 136 J. jaculus specimens collected from seven localities within its distribution range. Allozymic analysis clearly indicated the existence of two distinct groups of J. jaculus, with a mean genetic distance （D） value of 0.99 and FΩ=0.52. Individuals within the two groups did not show any obvious geographical structuration, even within the Matmata locality which represents the meeting point for the two groups where they were found in sympatry. Additionally, morphometric analysis of 13 craniodental characters was clearly separated the two groups. These results were obtained over a very restricted area of the total distribution of J. jaculus and strongly suggest the occurrence of two separate and often sympatric species within the currently accepted J.jaculus in Tunisia： J.jaculus and J. deserti
文摘Recent phylogenetic studies amended the taxonomy of three-toed jerboas(subfamily Dipodinae),including raising subspecies to full species.Here,we use geometric morphometrics to compare scaled-shape differences in dipodine crania while considering their revised taxonomy.We sampled Dipus deasyi,D.sagitta halli,D.s.sowerbyi,Jaculus blanfordi blanfordi,J.hirtipes,J.jaculus,J.loftusi,J.orientalis gerboa,J.o.mauritanicus,and Stylodipus andrewsi.Crania were not sexually dimorphic.Common allometry explained some of the shape variation,for example,reduced braincases in larger specimens.Most operational taxonomic unit pairs differed in both size and shape.Dipus and Stylodipus clustered together based on their cranial shape.Jaculus differed from the aforementioned genera by its larger tympanic bulla,broader braincase,larger infraorbital foramen,along with reduced molars and rostra.Jaculus orientalis differed from other Jaculus by its broader face versus reduced cranial vault.Jaculus blanfordi(subgenus Haltomys)resembles members of the subgenus Jaculus more than its consubgener(J.orientalis).Jaculus loftusi,previously considered a synonym of J.jaculus,clearly differed from the latter by its shorter rostrum,smaller infraorbital foramen,and more caudolaterally expanded tympanic bulla.Jaculus hirtipes,another recent synonym of J.jaculus,resembled J.blanfordi more in scaled cranial shape than it did J.jaculus.Dipus sagitta halli and D.s.sowerbyi were indistinguishable,but they clearly differed from D.deasyi(recently raised to full species)with the latter having a larger molar row,more inflated tympanic bulla,and shorter,slenderer rostrum.Ecological explanations for detected cranial shape differences are considered,including diet and habitat(particularly substrate).
