Xystodesmidae, Cook, 1895

Riquelme, Francisco & Hernández-Patricio, Miguel, 2018, The millipedes and centipedes of Chiapas amber, Check List 14 (4), pp. 637-646 : 641-642

Xystodesmidae sp. indet.

Referred material. 2 specimens: CPAL.109: adult female, complete specimen ( Fig. 2D–F); MALM.307: juvenile, complete specimen.

Locality. Mexico, Chiapas: Simojovel: Guadalupe Victoria site, 17°07ʹ58ʺ N, 092°48ʹ19ʺ W.

Identification. Body convex and tapering, head without eyes, antennae long and slender, collum smooth, trunk with about 17 rings in CPAL.109 and 20 in MALM.307, dorsally smooth, slightly mineralized in few zones by the fossilization process, paraterga subhorizontal, ozopores are fully visible on rings 5, 12, 13, and partially visible on rings 16, 17 and 18, as seen in a normal formula, epiproct conical with 2 short distal projections, and leg prefemura with short ventrodistal spine, which is clearly seen in the microscope, somewhat blurred in the micrograph due to the opacity of amber. Both specimens CPAL.109 and MALM.307 match Xystodesmidae , so this is the first fos- sil record of the family in Chiapas amber.

Remarks. The extant members of the family Xystodesmidae are recorded in 20 states from the north to the south of the country, including Coahuila, Chiapas, Guerrero, Guanajuato, Hidalgo, Jalisco, Mexico City, Michoacán, Morelos, Nuevo León, Oaxaca, Puebla, San Luis Potosí, Sinaloa, State of Mexico, Tabasco, Tamaulipas, Tlaxcala, Veracruz, and Yucatán ( Bueno-Villegas et al. 2004, Cupul-Magaña et al. 2014, Cortés-Ríos and Gárate-Rodríguez 2017).