Morohasaurus
Morohasaurus is an extinct genus of cf. monstersaurian squamates know from a single left dentary from the Early Cretaceous (?Albian) Ohyamashimo Formation of the Sasayama Group in Tamba City, Hyogo Prefecture, Japan. The type and only species is Morohasaurus kamitakiensis.
| Morohasaurus Temporal range: Albian? | |
|---|---|
| Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Squamata |
| Clade: | Monstersauria |
| Genus: | †Morohasaurus Ikeda et al., 2021 |
| Type species | |
| †Morohasaurus kamitakiensis Ikeda et al., 2021 | |
As of 2021, Ikeda et al. place this taxon a conferatur within Monstersauria based on general synapomorphies but without performing a phylogenetic analysis. The unique characters described in the paper to distinguish Morohasaurus kamitakiensis as a valid species include "the sinuous posteroventral rim of the dentary with a large U-shaped upper notch and small V-shaped lower notch, posteroventral corner of intramandibular septum with a weakly pointed eminence projecting posteriorly, and unicuspid, curved trenchant teeth with distinct blade-like carinae on their mesial and distal sides without grooves or serrations." If its presumed affinities are correct, Morohasaurus represents the oldest known monstersaurian to date.