Leposternon

Ribeiro, Siria, Santos-Jr, Alfredo P. & Zaher, Hussam, 2015, A new species of Leposternon Wagler, 1824 (Squamata, Amphisbaenia) from northeastern Argentina, Zootaxa 4034 (2), pp. 309-324 : 321

Key to the species of the genus Leposternon

1. Precloacals pores present.............................................................................. 2

- Precloacals pores absent............................................................................... 5

2. Dorsal postpectoral half-annuli less than 402, ventral postpectoral half-annuli less than 400......................... 3

- Dorsal postpectoral half-annuli equal or greater than 403, ventral postpectoral half-annuli equal or greater than 408........................................................................................... Leposternon maximus

3. 3/3 infralabials; lateral malar present and distinct from major infralabials........................................ 4

- 2/2 infralabials; lateral malar absent, probably fused with larger infralabials.................... Leposternon cerradensis

4. Rostronasal and azygous shields in contact; prefrontals and azygous length representing more than 35% of head length; seven teeth in the premaxilla; three or four teeth in each maxilla; six teeth in each dentary............ Leposternon kisteumacheri

- Rostronasal and azygous shields separated; prefrontals relatively small, with lengths representing less than 29% of head length; azygous relatively small, with length representing less 28% of head length; one tooth in the premaxilla; two teeth in each maxilla; five teeth in each dentary................................................. Leposternon polystegum

5. Supraocular shields absent, azygous and frontals not distinct, probably fused..................................... 6

- Supraocular shields present, azygous shield distinct of the frontal shields........................................ 7

6. Equal or greater than 340 dorsal and 330 ventral postpectoral half-annuli; 1/1 supralabials, temporals distinct............................................................................................. Leposternon octostegum

- Less than 340 dorsal and 330 ventral postpectoral half-annuli; 2/2 supralabials, temporals not distinct, probably fused....................................................................................... Leposternon scutigerum

7. 1/1 or 2/2 supralabials.................................................................................. 8

- 3/3 supralabials................................................................... Leposternon infraorbitale

8. 1/1 or 2/2 infralabials................................................................................. 9

- 3/3 infralabials......................................................................... Leposternon bagual

9. Parietals distinct; prefrontals representing more than 28% of the head length; azygous representing less than 58% of head width........................................................................ Leposternon microcephalum

- Parietals not distinct, probably fused with frontals; prefrontals representing less than 27% of head length; azygous relatively large, representing more than 58% of head width........................................... Leposternon wuchereri