Overall smaller and distinct from Iguana, the skull of Liushusaurus was lower with smaller upper temporal fenestra. The gracile upper temporal arch was even with the upper margin of the orbit.
The torso was flattened by wide ribs. The vertebral spines were greatly reduced. The tail was relatively shorter. The scapula was relatively short. The hand and foot were similar in size. The ilium had no anterior process. The hind limb, foot and its unguals were relatively smaller.
Similar to the pattern seen in pterosaurs, a size reduction signaled the start of the Scleroglossa, beginning with a sister to Liushusaurus, its most basal member here.
The family tree ot the Lepidosauria, including the Rhynchocephalia, the Tritosauria (including fenestrasaurs and drepanosaurs) and the Squamata (Iguania + Scleroglossa). This tree differs from others in recognizing the Tritosauria, an overlooked third clade of lizards outside the Squamata. A new clade, the Dalinghosauria is here defined as Dalinghosaurus, Iguana, their last common ancestor and all of its descendants. |
