The Cambrian Burgess Shale–type fossil Lagerstätten play a crutial role in revealing the origin and early evolution of arthropods. Tuzoiidae, one of the important bivalved arthropod groups, occupied a very important ecological niche in the Cambrian marine ecosystem. Here we describe a new taxon, Duplapex anima gen. et. sp. nov., in the family Tuzoiidae, on the basis of four exceptionally preserved specimens from the early Cambrian (Stage 3) Qingjiang biota of Hubei, South China. Duplapex is characterized by an ornament bivalved carapace, the ventral notch (vno) and doublure spine (dsp) of the valve, a pair of compound eyes connected by the fleshy annulated eye stalks. Despite having an unusual morphology for the group, the new taxon is recognized as a tuzoiid arthropod and indicates that these problematic euarthropods possessed a greater degree of morphological disparity than previously considered. D. anima, as well as the new reported Tuzoia. sp. from the Fandian biota, represent the oldest occurrence of Tuzoiidae, extending its stratigraphic range to Cambrian stage 3 and expanding the palaeobiographic distribution of the group to the northern border of Yangtze Platform.Thematic collection: This article is part of the Advances in the Cambrian Explosion collection available at: https://www.lyellcollection.org/cc/advances-cambrian-explosion

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Radiodonta, an extinct stem-euarthropod group, has been considered as the largest predator of Cambrian marine ecosystems. As one of the radiodont-bearing Konservat-Lagerstätten, the Guanshan biota (South China, Cambrian Stage 4) has yielded a diverse assemblage of soft-bodied and biomineralized taxa that are exclusive to this exceptional deposit. “Anomalocaris” kunmingensis, the most abundant radiodont in the Guanshan biota, was originally assigned to Anomalocaris within the Anomalocarididae. Despite this taxon being formally assigned to the family Amplectobeluidae more recently, its generic assignment remains uncertain. Here, we present new materials of “Anomalocaris” kunmingensis from the Guanshan biota, and reveal that the frontal appendages possess two enlarged endites; all endites bear one posterior auxiliary spine and up to four anterior auxiliary spines; three robust dorsal spines and one terminal spine protrude from the distal part. These new observations, allied with anatomical features illustrated by previous studies, allow us to assign this taxon to a new genus, Guanshancaris gen. nov. Brachiopod shell bearing embayed injury and incomplete trilobites, associated with frontal appendages in our specimens, to some extent confirm Guanshancaris as a possible durophagous predator. The distribution of amplectobeluids demonstrates that this group is restricted to Cambrian Stage 3 to Drumian, and occurs across South China and Laurentia within the tropics/subtropics belt. Moreover, the amount and abundance of amplectobeluids evidently decreases after the Early–Middle Cambrian boundary, which indicates its possible preference for shallow water, referring to its paleoenvironmental distribution and may be influenced by geochemical, tectonic, and climatic variation.

To explore the butterfly community composition and its altitude distribution in the Badagongshan National Nature Reserve, we investigated and analyzed the butterfly populations of different habitats at different altitudes, and continuously observed the monthly dynamics of their populations in 2016-2018. In this study, we recorded 6,164 butterfly individuals, belonging to 5 families, 107 genera, and 191 species. The survey results showed that the butterfly individuals recorded in low-altitude (250-450 m) and high-altitude (1,200-1,400 m) habitats were mainly Popilioninae and Pierinae, respectively, but mid-altitude (700-900 m) habitats did not have obvious dominant butterfly groups. Similarity analyses showed that there was a high proportion of common species (> 59%) in each habitat, but the individual distribution of these species in different habitats was different. Seasonal dynamic analyses showed that the butterflies in the Badagongshan were in the rising period from April to June including the species, individuals and diversity indices, usually reaching a peak in July, and then gradually decreasing from August to September. In general, the composition of the butterfly community in the Badagongshan is vertically distributed along the altitude gradient with heterogeneity between high and low altitude habitats and a transitional state at the middle altitude. The butterfly community in the Badagongshan showed consistent seasonal dynamics with a high percentage of •研究报告• 第 8 期 陈梦悦等: 八大公山国家级自然保护区不同生境蝶类群落特征与月动态 951 蝴蝶多样性观测专栏species turnover. High altitude habitats had a shorter active period and higher species turnover than lower altitudes.