As augmented reality (AR) gains prevalence, various AR exhibits are being installed in science museums. However, few research has thus far examined the extent to which these exhibits can improve visitors' learning. This study qualitatively evaluates the effectiveness of an AR dinosaur exhibit at the Gwacheon National Science Museum in Korea and examines the implications for its improvement. Eight elementary school students experienced the AR dinosaur exhibit, and their reactions were captured by audio and video recordings. Science museum experts were also interviewed to understand the intended affordances of the exhibit. The students' responses to the intended affordances were examined by analyzing their tour of the AR dinosaur exhibit. We found that the exhibit attracted the visitors by catching their attention. However, they did not pay attention to the exhibition's primary purpose of improving scientific understanding or reasoning. Some unintended interactions, unrelated to the intended affordances, also emerged. The limitations of the examined AR dinosaur exhibit suggest implications for improving AR exhibits in the future.