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C20H22Cu3N8O10, monoclinic, C2/c (no. 15), a = 12.0766(11) Å, b = 16.2778(14) Å, c = 14.7605(13) Å, β = 97.8580(10)∘, V = 2874.4(4) Å3, Z = 4, R gt(F) = 0.0420, wR ref (F 2) = 0.0988, T = 298.15 K.

Two new mealybug species, Paracoccus gillianwatsonae Zhang, sp. nov. and P. wui Zhang, sp. nov., collected from Jiangxi, South China, are described and illustrated based on the morphology of adult females. Paracoccus gillianwatsonae is similar to P. burnerae (Brain, 1915), but it differs in having fewer pairs of cerarii, and in lacking both ventral oral collar tubular ducts on the margins of the head and translucent pores on the hind femur. Paracoccus wui resembles P. keralae Williams, 2004 and P. neocarens (Lit, 1992), but it differs in lacking ventral oral collar tubular ducts on the margins of the head and in having multilocular disc-pores usually in double rows at the posterior edges of abdominal segments V and VI. A key to the Paracoccus species found in China is provided. [ABSTRACT FROM AUTHOR]

C20H22Cu3N8O10, monoclinic, C2/c (no. 15), a = 12.0766(11) Å, b = 16.2778(14) Å, c = 14.7605(13) Å, β = 97.8580(10)∘, V = 2874.4(4) Å3, Z = 4, Rgt(F) = 0.0420, wRref (F2) = 0.0988, T = 298.15 K. [ABSTRACT FROM AUTHOR]

A widely held hypothesis in evolution is that adaptive specialization constrains the potential direction of future evolutionary change and thus may be irreversible, also known as Dollo's law. However, this hypothesis has long been subject to debate in evolutionary biology. Floral specialization is intriguing as it is usually linked to reproductive isolation and could affect speciation. Here, following the discovery of four new taxa, we observed some interesting phenomena of reversal versus specialization in morphology in a clade with the most specialized flowers in the genus Petrocosmea. In the phylogenetic tree based on sequences of multiple DNA regions, the morphological reversals, especially the regain of a long corolla tube, are nested within the branches characteristic of normally specialized flowers with a short corolla tube and highly specialized zygomorphy. Our results indicate that the highly specialized floral organ of this clade is still actively evolving in multiple branches toward specialization while reversals to different ancestral states occur in some branches. Great disturbance of ecological environment is likely a crucial factor affecting trait reversibility, such as the rapid uplift of the Himalayan–Tibetan plateau. The four new taxa are treated herein taxonomically. The flowers of this clade represent an interesting model to explore the genetic basis underlying the evolutionary reversal versus specialization and the interplay between genetic factors and environmental variables. [ABSTRACT FROM AUTHOR]