Tropidophis, Bibron, 1840

Ortega-Andrade, H. Mauricio, Bentley, Alexander, Koch, Claudia, Yánez-Muñoz, Mario H. & Entiauspe-Neto, Omar M., 2022, A time relic: a new species of dwarf boa, Tropidophis Bibron, 1840 (Serpentes: Amerophidia), from the Upper Amazon Basin, European Journal of Taxonomy 854 (1), pp. 1-107 : 30

Dichotomous key for Tropidophis on mainland South America

(* = Species likely not from mainland South America) († = Species with confirmed records from the Andes mountain range)

1. Dorsal rows conspicuously keeled, interparietals present, lateral stripes present .............................. ............................................................................................... T. taczanowskyi (Steindachner, 1880) †

– Not as above ..................................................................................................................................... 2

2. Dorsal pattern with large spots,> 40 subcaudals,> 200 ventrals ......... T. battersbyi Laurent, 1949 *

– Dorsal pattern with small spots, <40 subcaudals, usually <200 ventrals ....................................... 3

3. Contact between parietals present .................................................................................................... 4

– Contact between parietals absent ...................................................... T. grapiuna Curcio et al., 2012

4. Subcaudals fewer than 30 ................................................................. T. preciosus Curcio et al., 2012

– Subcaudals higher than 30 ................................................................................................................ 5

5. Ventrals in males 164–178, in females 167–183, body spots in six rows, bright colored tail ............ ...................................................................................... T. paucisquamis (Müller in Schenkel, 1901)

– Ventrals in the single male 162, in the single female 156, body spots not in rows, tail uniformly colored ......................................................................................................... T. cacuangoae sp. nov. †