What critical pelvic feature defines Xiaosaurus's placement within the Ornithischia?
Answer
The pubis bone points backward
The definitive characteristic placing *Xiaosaurus* within the Ornithischia, or bird-hipped dinosaurs, relates directly to the orientation of its pelvic structure. Specifically, the pubis bone is oriented backward, pointing toward the tail. This configuration is structurally similar to the arrangement found in modern birds, although this parallel evolution occurred independently in birds. This foundational hip structure is considered essential because it establishes the lineage for the unique method of gut processing utilized by later ornithischians for efficiently digesting tough vegetation. Examining this pelvic blueprint is fundamental to tracing the evolutionary path of this entire branch of dinosaurs.
Related Questions
What is the approximate typical length estimate given for an adult Xiaosaurus?From which specific geological location were Xiaosaurus specimens recovered?What critical pelvic feature defines Xiaosaurus's placement within the Ornithischia?What geological period dates the Xiaosaurus fossils found in the Lufeng Formation?What mode of locomotion is suggested for the physical structure of Xiaosaurus's limbs?How many incomplete skeletons form the basis for the known anatomy of Xiaosaurus?Who formally named and described the genus Xiaosaurus in 1973?Which ornithischian group is Xiaosaurus tentatively assigned to, leading to taxonomic debate?What is the meaning of the name Xiaosaurus?Compared to later ceratopsians or ankylosaurs, what key aspect characterizes the primitive physical makeup of Xiaosaurus?