Noun
opisthosoma (plural opisthosomas or opisthosomata)
(zoology) The posterior abdomen of the chelicerates
The mouth is between segments two and three. citation The opisthosoma consists of twelve or fewer segments that originally formed two groups, a mesosoma of seven segments and a metasoma of five, terminating with a telson or spike. Source: Internet
The body of a scorpion is divided into two parts ( tagmata ): the head ( cephalothorax ) and the abdomen ( opisthosoma ), which is subdivided into a broad anterior ( mesosoma ), or preabdomen, and a narrow taillike posterior ( metasoma ), or postabdomen. Source: Internet