Platynota
| Platynota Temporal range: Late Cretaceous - Holocene, 80–0 Ma |
|
|---|---|
 |
|
| Sand goanna (Varanus gouldii) | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Squamata |
| Clade: | Pythonomorpha |
| Clade: |
Platynota Duméril and Bibron, 1839 |
| Subgroups | |
Platynota is a group of anguimorph lizards and thus belongs to the order Squamata of the class Reptilia. Since it was named in 1839, it has included several groups, including monitor lizards, snakes, mosasaurs, and helodermatids. Its taxonomic use still varies, as it is sometimes considered equivalent to the group Varanoidea and other times viewed as a distinct group. It is phylogenetically defined as a clade containing Varanidae (the monitor lizards) and Helodermatidae (the beaded lizard and Gila monster). It also includes many extinct species.
Many skeletal features support the grouping of monitor lizards, helodermatids, and several extinct species in Platynota. All platynotans have a hinged upper jaw with widely spaced teeth, each having a large base, that erupt from behind existing teeth. The teeth are plicidentine, meaning that they have highly folded layers of dentine in their centers. Many have fused frontal and nasal bones on the top of their skulls (in other lizards, these bones are separated into pairs). Some platynotan features that are not seen in the skeleton, and therefore only known from living species, include a deeply forked tongue and a venom gland called the gland of Gabe.
Platynota was first used as a superfamily of anguimorph lizards. In 1923, Charles Lewis Camp included the groups Varanoidea and Mosasauroidea, or monitor lizards and mosasaurs (a group of large marine reptiles from the Cretaceous). A close relationship between mosasaurs and snakes, which together formed the group Pythonomorpha, gained favor in the following years. Consequently, some researchers also included snakes within Platynota.
...
Wikipedia