The vertebrate skull is a complex structure with diverse evolutionary and developmental patterns. Anuran chondrocranial development has been shown to deviate from generalized vertebrate trends, highlighting its evolutionary flexibility. This study investigates the chondrocranial development of Staurois parvus , a ranid frog, to provide insights into larval cranial morphology and developmental sequences. I examined 116 larval specimens (Gosner Stages 19–27) obtained from the Vienna Zoo Schönbrunn. Specimens were preserved, sectioned, and stained using Heidenhain’s trichrome method. High‐resolution imaging and 3D reconstructions were performed, and chondrocranial development was analyzed based on a standardized morphological scoring system. The chondrocranium of S. parvus not only exhibits key ranid features but also reveals unique traits, including the absence of a larval otic process, a distinct suprarostral cartilage configuration, and a consistently present basihyal. The species follows the anuran‐specific mosaic pattern of viscerocranial development, with the ceratohyal forming early. However, its neurocranial development retains ancestral vertebrate characteristics, with early chondrification of the otic capsule, parachordal cartilage, and trabecular cartilage. The findings further challenge the assumed uniformity of vertebrate chondrocranial development. While S. parvus contradicts anuran trends in viscerocranial development, its neurocranial patterning suggests evolutionary conservation. This study provides new insights into anuran cranial development and evolution and underscores the need for further research into the links between chondrocranial development, ecological adaptation, and evolutionary history.
Paul Lukas (Thu,) studied this question.