Ceratopsia is among the most extensively studied groups of dinosaurs. However, research on ceratopsian osteohistology remains extremely limited, leaving significant gaps in our understanding of their growth rates, growth patterns, and life histories. This study presents a detailed histological analysis of the fibulae and ribs from two Liaoceratops yanzigouensis specimens (IVPP V18616 and V17910). V18616 was identified as a juvenile, estimated to be less than one year old, while V17910 was classified as a subadult, at least three years of age. The results indicate that Liaoceratops experienced rapid growth during its juvenile stage, with fibrolamellar bone dominating the cortical bone. By the subadult stage, the growth rate had gradually slowed. This study also highlights the importance of standardized sampling protocols, as evidenced by the rib sections. The feasibility of conducting comparative studies is constrained by the non-standardized sampling locations. The presence of LAGs (Lines of Arrested Growth) in V17910 suggests that Liaoceratops had a cyclical, interrupted growth pattern. In contrast to the continuous growth seen in chasmosaurinae, early-diverging neoceratopsians may have predominantly experienced cyclic growth interruptions.
