Mosaiceratops

Mosaiceratops is a new genus of ceratopsian described by Zheng, Jin & Xu in 2015 found in the Xiaguan Formation of Neixiang County. Although phylogenetic analysis have found it to be the most basal neoceratopsian, the authors noted that several features in the premaxilla and nasal bones are shared with the family Psittacosauridae, indicating that neoceratopsians evolved premaxillary teeth twice and that Psittacosauridae is not a primitive family as previously thought

Discovery
Mosaiceratops lived in the upper Cretaceous in what is now the Henan Province of China. The holotype is represented by an incomplete and disarticulated skeleton including pelvis bones and leg bones (femur, tibia, fibula, ischium, ilium, some phalanges and metatarsals, calcaneum and astragalus), 24 vertebrae (3 cervicals, 3 dorsals and 18 caudals), a dorsal rib, a humerus, a radius and the anterior part of an articulated skull with a disarticulated postorbital bone and squamosal. The articulates skull preserves the rostral bone, premaxilla, maxilla, jugal bone, quadratojugal, dentary, surangular, angular bone, the anterior section of the prefrontal bone, and the anterior part of the nasal bone.

Description
Mosaiceratops can be distinguished by multiple autapomorphic features which include: the presence of an evident premaxillar groove between the rostral bone and the maxilla in lateral view, and the elongation of the anterior part of the jugal. In addition, the taxon appears to be different from other neoceratopsians in the width proportion between premaxilla and maxilla, with the former being broader in lateral view. The presence of that trait is plesiomorphic, being shared with Psittacosaurus. But the skull overall is more similar to advanced taxa like Aquilops or Liaoceratops.[1]

In Mosaiceratops, the premaxilla is edentulous, meaning it has a roughened edge.