On the development of surface ornamentation of skull bones in the ontogeny of Early Triassic benthosuchids (Amphibia, Temnospondyli)

摘要

The rate of developmental changes in ornamentation of the dermal skull observed at the submature stages of the trematosauroid Benthosuchus (Amphibia, Temnospondyli) shows a wide range of individual variation divided into two dominant modes. The analysis of this variation based on comparisons within samples of two dermal bones (supratemporal and squamosal) displays that such a bimodality is distinctly expressed at the earliest known growth stage and tends to disappear with age.