Mexcala smaragdina

Mexcala smaragdina is a jumping spider that was first described by the arachnologists Wanda Wesołowska and Glavis B. Edwards in 2012.^[1] They allocated the species to the genus Mexcala, first raised by George and Elizabeth Peckham in 1902.^[2] The genus was a member of the tribe Heliophaninae alongside Pseudicius and Cosmophasis, which was absorbed into Chrysillini by Wayne Maddison in 2015.^[3][4] The tribe is a member of the clade Saltafresia within the subfamily Salticoida.^[5] A year later, in 2016, Jerzy Prószyński allocated the genus to the Heliophanines group of genera, which was named after the genus Heliophanus. The genera share characteristics, including having a rather uniform, mainly dark appearance.^[6]

Like all Mexcala spiders, the species is slender and medium-sized.^[7] The male has a cephalothorax that is typically 2.5 mm (0.098 in) long and typically 1.8 mm (0.071 in) wide. The medium-high carapace is dark brown and covered in short delicate hairs that have an intense green-metallic shine. The eye field is black with long bristles near the eyes. The clypeus is dark and very low. The chelicerae have short spiky bristles.^[8] The spider has a black labium and sternum.^[9] The abdomen is typically 2.7 mm (0.11 in) long and typically 1.7 mm (0.067 in) wide.^[8] It is ovoid and shiny black, clothed in dark hairs that, like those covering the carapace, have a greenish golden shine. The underside is dark. The spinnerets are dark grey. The spider has long thin legs, the front ones generally black and the rearmost brown. The pedipalps are bulbous and the palpal bulb oval. The spider has a wide tibial apophysis that has a curved end. The embolus is shaped like a hook and fixed to the tegulum.^[4][9] The copulatory organs are similar to Mexcala caerulea, but the embolus is shorter. The spider is otherwise most easily identified compared to others in the genus by the greenish shine on its body, after which it is named.^[8] The female has not been described.^[1]