Mantodea(praying mantises)is a group of exclusively predatory insects,which,together with nonraptorial blattodeans(cockroaches and termites)and groups exclusively found in the fossil record,form the group Dictyoptera....Mantodea(praying mantises)is a group of exclusively predatory insects,which,together with nonraptorial blattodeans(cockroaches and termites)and groups exclusively found in the fossil record,form the group Dictyoptera.A central characteristic of Mantodea is the specialization of their first pair of legs as raptorial grasping appendages,but the evolution from walking to raptorial legs is not yet fully understood.Here,we trace the evolution of the raptorial appendages in Dictyoptera through time using a morphometric(morphospaces)approach.We also describe two new mantodean nymphs preserved in amber from the Cretaceous and Eocene,which expand the scarce mantodean fossil record.Blattodean and mantodean appendages appear distinct in morphospace,but several appendages of fossil non-mantodeans can be considered raptorial,providing a potential transitional link between walking and raptorial morphotypes.Therefore,we discuss potential mantodean affinities for other predatory fossil dictyopterans.We examine changes across extant mantodeans,characterized by a straightening of the tibia especially associated with the rise of the diversification of the Mantidea and discuss whether a thickening of the femur could reflect an early adaptation to cursorial hunting.展开更多
Sexual size dimorphism （SSD） is widespread among diverse animal taxa and has attracted the attention of evolutionary biologists for over a century. SSD is likely to be adaptive and the result of divergent selection ...Sexual size dimorphism （SSD） is widespread among diverse animal taxa and has attracted the attention of evolutionary biologists for over a century. SSD is likely to be adaptive and the result of divergent selection on different size optima for males and females, given their different roles in reproduction. The developmental trajectory leading to SSD may help us to understand how selection acts on male and female size. Here, we describe the growth and development of two Australian praying mantids, Pseudomantis albofimbriata and Hierodula majuscula including the number of moults, time to adulthood, size at each moult, and the degree of SSD. While both species exhibit the common pattern of female-biased SSD, the number of moults required for individuals to reach adulthood differed between males and females and between species. Despite their larger adult size, P. albofimbriata females require fewer moults and less time than males to reach adulthood, but are significantly larger than males from the second instar onwards. In contrast, H. majuscula males reached adulthood in fewer moults, and less time than females, however males and females did not differ in size until females went through their final moult into adulthood. H. majuscula also required more time and more moults to reach adulthood than 17. albofimbriata. We discuss these different developmental pathways in light of the existing knowledge of reproductive biology for each species. We also suggest that these differences may relate to the different phenologies that occur in strongly seasonal temperate environments compared with those in the tropics. This study provides evidence that SSD can result from two different patterns of growth and development in closely related species.展开更多
基金support in the frame of a Lichtenberg professorship and the German Research Foundation(DFG HA 6300/6-1)performed at the Imaging Center of the Department of Biology,University of Greifswald(DFG INST 292/119-1 FUGGDFG INST 292/120-1 FUGG).
文摘Mantodea(praying mantises)is a group of exclusively predatory insects,which,together with nonraptorial blattodeans(cockroaches and termites)and groups exclusively found in the fossil record,form the group Dictyoptera.A central characteristic of Mantodea is the specialization of their first pair of legs as raptorial grasping appendages,but the evolution from walking to raptorial legs is not yet fully understood.Here,we trace the evolution of the raptorial appendages in Dictyoptera through time using a morphometric(morphospaces)approach.We also describe two new mantodean nymphs preserved in amber from the Cretaceous and Eocene,which expand the scarce mantodean fossil record.Blattodean and mantodean appendages appear distinct in morphospace,but several appendages of fossil non-mantodeans can be considered raptorial,providing a potential transitional link between walking and raptorial morphotypes.Therefore,we discuss potential mantodean affinities for other predatory fossil dictyopterans.We examine changes across extant mantodeans,characterized by a straightening of the tibia especially associated with the rise of the diversification of the Mantidea and discuss whether a thickening of the femur could reflect an early adaptation to cursorial hunting.
文摘Sexual size dimorphism （SSD） is widespread among diverse animal taxa and has attracted the attention of evolutionary biologists for over a century. SSD is likely to be adaptive and the result of divergent selection on different size optima for males and females, given their different roles in reproduction. The developmental trajectory leading to SSD may help us to understand how selection acts on male and female size. Here, we describe the growth and development of two Australian praying mantids, Pseudomantis albofimbriata and Hierodula majuscula including the number of moults, time to adulthood, size at each moult, and the degree of SSD. While both species exhibit the common pattern of female-biased SSD, the number of moults required for individuals to reach adulthood differed between males and females and between species. Despite their larger adult size, P. albofimbriata females require fewer moults and less time than males to reach adulthood, but are significantly larger than males from the second instar onwards. In contrast, H. majuscula males reached adulthood in fewer moults, and less time than females, however males and females did not differ in size until females went through their final moult into adulthood. H. majuscula also required more time and more moults to reach adulthood than 17. albofimbriata. We discuss these different developmental pathways in light of the existing knowledge of reproductive biology for each species. We also suggest that these differences may relate to the different phenologies that occur in strongly seasonal temperate environments compared with those in the tropics. This study provides evidence that SSD can result from two different patterns of growth and development in closely related species.
