Thorellius, : Gonzalez-Santillan and Prendini, 2013

González-Santillán, Edmundo & Prendini, Lorenzo, 2018, Systematic Revision Of The North American Syntropine Vaejovid Scorpion Genera Balsateres, Kuarapu, And Thorellius, With Descriptions Of Three New Species, Bulletin of the American Museum of Natural History 2018 (420), pp. 1-1 : 26

KEY TO IDENTIFICATION OF THE SPECIES OF THORELLIUS

1. Pedipalp chela carinae granular and immaculate to faintly infuscate; fixed and movable fingers, proximal notch deep; fixed finger, medial lobe pronounced...............................2

– Pedipalp chela carinae smooth and densely infuscate; fixed and movable fingers, proximal notch shallow; fixed finger, medial lobe weak ................................. T. yuyuawi , sp. nov.

2. Pedipalp chela manus ventral retrolateral, ventral retrosubmedian, ventral median, and ventral prosubmedian carinae sparsely granular to smooth; patella retrolateral dorsosubmedian and retrolateral median carinae vestigial, comprising few scattered fine or coarse granules...............................................3

– Pedipalp chela manus ventral retrolateral, ventral retrosubmedian, ventral median, and ventral prosubmedian carinae densely granular; patella retrolateral dorsosubmedian and retrolateral median carinae partially developed, densely granular............................ ........................................... T. wixarika , sp. nov.

3. Metasomal segments I and II, ventral submedian carinae granular; segments I–V, dorsal and ventral intercarinal surfaces immaculate ............................................ T. tekuani , sp. nov.

– Metasomal segments I and II, ventral submedian carinae smooth; segments I–V, dorsal and ventral intercarinal surfaces faintly infuscate ….....................................................4

4. Pedipalp chelae markedly incrassate; carinae broad and irregularly granular; movable finger with a pair of prolateral denticles at seventh position ............................. T. intrepidus

– Pedipalp chelae slightly incrassate; carinae slender and mostly moniliform, movable finger with a single prolateral denticle at seventh position ........................... T. cristimanus