Some Arthropods In Mid-cretaceous Myanmar Amber Systematics And Ethology

Arthropods are the most diverse group of living animals and occupy almost all ecological niches.The earliest fossil records of arthropods date back to the early Cambrian.Animal behaviors play a crucial role in the evolution process,when the environment and external survival pressure change,the behavior has the potential to induce animal morphological changes.A large number of small arthropods have been preserved in mid-Cretaceous Myanmar amber,and some of them have directly or indirectly preserved some behaviors.In this paper,based on the systematics and ethology of some arthropods in amber,the accurate attribution of behaviors discovered in geological period to the the modern studies of animal behaviour provides an important data base for further exploration of the systematic classification and behavioral evolution of arthropods in the Cretaceous period.In this paper,11 pieces of Myanmar amber with behaviors were studied systematically.14 species of 11 genera(10 new species,1 similar species and 3undefined species)in Hemiptera,Diptera,Blattaria(Insecta)and Trombiculidae(Acari)were described systematically.At the same time,a phylogenetic analysis of 7 species of 4 genera in Atelestidae,Ortheziidae,Cecidomyiidae and Keroplatidae were performed,and their phylogenetic positions in their respective families were determined.In this paper,a systematic study of swarming behavior,parental care,parasitism,stress reaction and mating behavior of different taxa in amber has been performed: 1)The possible swarming behavior,and the courtship pattern of Cretaceous dance fly have been analyzed.2)Based on the previous studies of termites divergence time,it is possible that swarming behavior could result in reproductive isolation,due to early Cryptocercus only with simple social behavior,hence,swarming behavior might lead to possible divergence of termites and play a crucial role in forming social behavior.3)Combined with other fossil records of parental care,this study demonstrates that these significant behavioral and morphological adaptations,associated with considerable parental care behavior,were already well established by the mid-Cretaceous.Parental care behavior has been an important driver for the early radiation of scale insects due to the lack of the most important drivers(flowering plants and ants)for radiation.4)This study demonstrates that matriphagy behavior might exist in Trombellidae larvae based on the damage trace on the dorsal side of the mother mite and the skins molted by the larva mites.The larva mites molted their skins by feeding on their mother's internal organization.5)This study demonstrates that most hosts of Acarina in amber are diptera,and almost all parasitic mites in Cretaceous amber are Leptus,suggesting that Leptus might have been widely distributed in Cretaceous.6)Based on the analysis of the arrangement mode of eggs preserved near the Mosquitoes(Cecidomyiidae and Keroplatidae)in amber,the eggs were laid by female mosquitoes with stress reaction after trapped in resin.7)The mating postures of Atelestidae have beed studied,and the reasons for different mating postures were discussed.In this paper,the published fossil behaviors in geological period are classified into13 categories in the framework of modern studies of animal behaviour,and paleontological behaviors are no longer separated from modern behavioral theory.Within the framework of modern studies of animal behavior,9 categories of behaviors existed in fossils have beed analysed baesd on the frequency and credibility of different behaviors.At the same time,combined with the affinity relationship between behavior and survival in the process of evolution,the driving force of different behavior on evolution is discussed,and confirmed the the important role of behaviors in the process of evolution.