Solved after 140 years: the identity of the millipede Polydesmus cavicola Packard, 1877, and proposal of Packardesmus n. gen. (Diplopoda: Polydesmida: Macrosternodesmidae) Author Shear, William A. Author Shelley, Rowland M. text Zootaxa 2019 2019-02-20 4559 2 384 390 journal article 27454 10.11646/zootaxa.4559.2.11 a7e06f14-dd95-4c3a-bbf6-eda7e97bd236 1175-5326 2626944 A2F6F333-A5F9-40EE-A4FF-60C2647CF07F Family Macrosternodesmidae Brölemann 1916 Shear & Shelley (2006) and Shear & Reddell (2017) provided a modern diagnosis of this family, particularly regarding the North American components. The family incorporates two subfamilies, Macrosternodesminae and Nearctodesminae ( Shear & Reddell 2017 ). Aside from four species in Europe, the Macrosternodesminae consists mostly of small, pallid species from the central and southern Rocky Mountains and the arid Southwest, including southern California, Arizona and Nevada ( Shear & Shelley 2006 , 2007 , 2008 ); while species of the genus Chaetaspis Bollman, 1884 are found in forested habitats and caves east of the Mississippi River. Many of these species are known only from caves and are likely relicts of a cooler, wetter climate in the region. The subfamily Nearctodesminae (revised by Shelley 1994 ) occurs in the Pacific Northwest, with isolated single species in Illinois and Mexico . They are much larger ( 10–35 mm long) and often pigmented with brown, pink, red or orange; while they may occur in caves as accidentals, none of the species are known exclusively from underground habitats.