Table 1.

List of maxillary, mandibular, and dental characters and their expressions in Au. afarensis, Au. bahrelghazali, K. platyops, and Au. deyiremeda, with Au. anamensis as the outgroup

Characteristic	Au. anamensis	Au. afarensis	Au. bahrelghazali	K. platyops	Au. deyiremeda
Maxilla
Subnasal prognathism*	Strong	Strong	–	Weak	Moderate
Nasoalveolar clivus transverse contour	Slightly convex	Convex	–	Flat	Convex
Anterior zygomatic origin	M1	M1 or posterior	–	P4	P4/M1
Mandible
Symphyseal inclination	Strong	Variable†	Weak	–	Variable
Genioglossal fossa position/depth	Low/deep	Low/variable	High/shallow	–	Variable/variable
Mandibular corpus robusticity‡	Narrow	Broad	–	–	Very broad
Lateral corpus hollow	Absent	Present	–	–	Less defined
Anterior ascending ramus origin	M1/M2	M1/M2	–	–	P4/M1
Dentition
Maxillary molar size	Large	Large	–	Small	Small
Enamel thickness	Intermediate-thin	Thick	Intermediate-thin§	Thick	Very thick¶
P3 metaconid size	Small/absent	Small	Large	–	Small

Data compiled from refs. 12, 14, 15, 17, 24, 25, 44, 56, 58, 64.

^*As measured by the subnasal angle (nasospinale-prosthion to postcanine alveolar plane).

^†Individuals from the geologically younger sections in the Hadar Formation (e.g., A.L. 288-1, A.L. 444-2) have symphyses that are almost vertical.

^‡Quantified by the corpus robusticity index [(corpus breadth/corpus height) × 100], taken at the M₁ level.

^§Qualitative observations of line drawings reported in ref. 64.

^¶M² relative enamel thickness exceeds P. robustus mean.