Endothiodon Owen 1876

The humeri, radii, and tibiae of specimens SAM-PK- 5605 and SAM-PK-K6618 were available for thin sectioning. The cortical thickness values of the

Values of the Diictodon elements were taken from Ray & Chinsamy (2004), and those of L. declivis SAM-PK-11184 and SAM-PK-K8013, and L. murrayi SAM-PK-K8 were taken from Ray et al. (2005). Juvenile = 0–30% adult, subadult = 30–80% adult, adult = 80–100% adult.

elements from SAM-PK-5605 all exceed 30%, with the tibia having the greatest value (48%; Table 2). The bone tissue of the elements from this specimen consists of highly vascularized (14% for the humerus) uninterrupted fibrolamellar bone (Fig. 2E). The vascular canals form a mixture of longitudinal primary osteons and a subreticular network, and there is no decrease in vascularization towards the periphery in any of these elements. Enlarged channels, however, such as those seen in Eodicynodon, are not observed. The humerus, radius, and tibia of SAM-PK-K6618 also consist of fibrolamellar bone, but annuli (sometimes multiple) interrupt the bone tissue in all elements (Fig. 2F). The vascular canals are arranged as longitudinal primary osteons, with short anastomoses. The canals are smaller and less dense compared to the elements belonging to SAM-PK-5605. There is a decrease in vascularization and parallelfibred bone appears towards the periphery of the humerus (SAM-PK-K6618a). Prominent Sharpey’s fibres were observed in radius SAM-PK-K6618b.