Table 6. Summary of the osteological synapomorphies for the Cyprinodontoidei and Aplocheiloidei and comparisons with †Kenyaichthys gen. et sp. nov. compiled from [1], [3], [48] and [50].

Synapomorphy (author and character number)	Cypr	Apl	†Ken
Posterior indentation of the alveolar arm of premaxilla (vs. absent) ([3]; [48], char. 14)	+	0	0
Dentary deep (vs. slender) ([3]; [48], char. 19)	+	0	0
Head of autopalatinum bent anteriorly, displaced laterally relative to the main axis of the bone (vs. continuous with the main longitudinal axis of the bone) ([48], char. 27)	+	0	I
Metapterygoid absent (vs. present) ([3]; [48], char. 34)	+	0	0
Dorsal hypohyal absent (vs. present) ([3]; [48], char. 41)	+	0	n.a.
First basibranchial absent (vs. present) ([3]; [48], char. 45)	+	0	n.a.
Ventral process of fourth ceratobranchial expanded medially (vs. short) ([48], char. 48)	+	0	n.a.
Ventral process of lateral portion of second epibranchial absent (vs. present) ([48], char. 55)	+	0	n.a.
Second pharyngobranchial expanded ventrally (vs. not expanded) ([48], char. 58)	+	0	n.a.
Lacrimal approximately rectangular (vs. approximately triangular) ([48], char. 71)	+	0	0
Neuroapophyses on the first vertebra separated (vs. united) ([48], char. 96)	+	0	n.a.
Stegural, ventral portion with lateral spine-like process (vs. no spine-like process) ([1], char. 10)	+	0	0
Neural and haemal spines of PU3 wider than spines anterior to PU4 vs. about equal ([1], char. 9) (but see also text)	+	0	P
Dorsal process of maxilla short, anteriorly directed, not parallel to ventral process (vs. long, medially directed or vestigial) ([48], char. 1)	0	+	+
Main axis of the ventral process of maxilla slightly curved, tip directed posteriorly (vs. directed anteriorly) ([48], char. 4)	0	+	n.a.
Coronoid process of anguloarticular reduced (vs. not reduced) ([48], char. 23; [50], char. 7)	0	+	+
Lateral flange of hyomandibula expanded posterodorsally (vs. short) ([48], char. 35)	0	+	n.a.
Anterior portion of basihyal widened (vs. slender) ([48], char. 43)	0	+	n.a.
A distinct anteromedial process on second hypobranchial directed toward second basibranchial (vs. absent) ([48], char. 46)	0	+	n.a.
A distinct posterior process on fourth epibranchial (vs. absent) ([48], char. 57)	0	+	n.a.
Dentition on second pharyngobranchial reduced (vs. not reduced) ([48], char. 59)	0	+	n.a.
Vomerine teeth present (vs. absent) ([3]; [48], char. 60)	0	+	n.a.
Wide process on the anterior portion of lateral ethmoid (vs. narrow or no process) ([48], char. 63)	0	+	n.a.
Neurocranium flattened (vs. not flattened) ([48], char. 66; [50], char. 30)	0	+	+
Dermosphenotic short (vs. elongate or minute) ([48], char. 73)	0	+	n.a.
Medial process of pelvic girdle short (vs. long) ([3]; [48], char. 83)	0	+	+
Distal radial of anal fin with an expanded posteroventral rim (vs. without ventral extensions) ([48], char. 93)	0	+	n.a.
Supraorbital canals open with neuromasts exposed externally (vs. closed) ([3]; [48], char. 98)	0	+	n.a.
Anterior naris opening at the tip of a distinctively cylindrical structure (vs. flat, no fleshy structure or situated on prominent fleshy structure) ([48], char. 100)	0	+	n.a.
20 to 25 radii on anterior abdominal scales (vs. 12 to 16) ([48], char. 105)	0	+	?

+, present;

0, absent;

P, polymorphic; n.a., not applicable; I, intermediate;?, uncertain; Cypr = Cyprinodontoidei; Apl = Aplocheiloidei;

†Ken = †Kenyaichthys.