Table 2. Selected traits compared among Ctenomys bidaui n. sp., Ctenomys contrerasi contrerasi n. subsp., Ctenomys contrerasi navonae n. subsp., Ctenomys thalesi n. sp., and Ctenomys sericeus.

	C. bidauin. sp. (PVC)	C. c. contrerasin. subsp. (NCR)	C. c. navonaen. subsp. (WCC)	C.thalesin. sp. (SRC)	C. sericeus
Size	medium	small	medium	small	small
Premaxillo-frontal suture	level with naso-frontal suture	sligthly behind the naso-frontal suture	well behind the naso-frontal suture	sligthly behind the naso-frontal suture	well behind the naso-frontal suture
Interparietal	broad and short	fused	fused	fused	fused or indistinct
Zygomatic arches	Robust	thin	moderately robust	thin	moderately robust
Incisive foramina	moderately short and broad	moderately long and narrow	moderately long and narrow	moderately short and narrow	moderately short and broad
Interpremaxillary foramen	large	small	large	small to absent	small to absent
Auditory bullae	inflated and ovate	inflated and pyriform	inflated and pyriform	inflated and pyriform	inflated and pyriform
Paraoccipital processes	quadrate	hook-shaped	hook-shaped	fan-shaped	hook-shaped
2N; FN	48; 72	38; 42 or 52	unknown	28; 40	28-30; 44-46