Positive Evidence | |||
---|---|---|---|
Morphological Feature | Hypothesis of character evolution | Alternative hypothesis | Reference |
Teeth that are superficially attached to the jaw | Apomorphy of Lepidosauria | – | [54] |
Pleurodont teeth | Apomorphy of Squamata | – | [55] |
Fused postnatal premaxilla | Apomorphy of Squamata | – | |
≥5 premaxillary tooth positions | Apomorphy of Pleurodonta within crown Iguania, independently acquired in Hydrosaurus and Japalura | – | |
5–6 premaxillary tooth positions | Independently derived in Phrynosomatidae, Iguanidae, and Opluridae + Leiosauridae + Hoplocercidae | – | |
Anterior premaxillary foramina (across Squamata) | Independently derived in Iguania, Anguimorpha, Cordylidae + Gerrhosauridae, Amphisbaenia | Independently derived in Iguania + Anguimorpha, Cordylidae + Gerrhosauridae, Amphisbaenia | |
Anterior premaxillary foramina (within Phrynosomatidae) | Apomorphy of sand lizards within crown Phrynosomatidae, independently derived in Uta | Apomorphy of Phrynosomatidae, secondarily lost in Sceloporus, Urosaurus, and Petrosaurus | [15], this paper |
Anterior face of the premaxilla and nasal process form a flat anterior face | Apomorphy of sand lizards within crown Phrynosomatidae | – | This paper |
Rectangular body of premaxilla | Apomorphy of sand lizards within crown Phrynosomatidae | – | This paper |
Posterodorsally directed nasal process | Apomorphy of sand lizards within crown Phrynosomatinae | – | This paper |
Isoceles triangle-shaped nasal process | Independently acquired apomorphy of Uma and of Holbrookia | Apomorphy of sand lizards, lost in Callisaurus and Cophosaurus | This paper |
Anterior foramen on the nasal process | Independently acquired apomorphy of Uma and of Callisaurus | Apomorphy of sand lizards, lost in Holbrookia and Cophosaurus | This paper |
Relatively wide nasal process (dependent on shape of premaxilla) | Present only in Uma within sand lizard clade | – | [28] |
Relatively square body of premaxilla | Apomorphy of Uma | – | This paper |
Negative Evidence | |||
 5–6 premaxillary tooth positions | ≥7 premaxillary tooth positions is an apomorphy of Anguimorpha and of Cordylidae + Gerrhosauridae (see text for exceptions) | – | |
 Posterodorsally directed nasal process | Apomorphy of sand lizards, absent in Amphisbaenia | – | [57] |
 Anterior face of the premaxilla and nasal process form a flat anterior surface | Apomorphy of sand lizards, absent in Iguanidae, Hoplocercidae, Cordylidae + Gerrhosauridae | – | [15] |
 Rectangular body of premaxilla | Apomorphy of sand lizards, absent in Opluridae + Leiosauridae | – | This paper |
 Unicuspid teeth | The presence of multicuspid premaxillary teeth is an apomorphy of Iguanidae (see text for exceptions) | – | [63] |