Plagiosauridae, 1919

Nonsrirach, Thanit, Manitkoon, Sita & Lauprasert, Komsorn, 2021, First occurrence of brachyopid temnospondyls in Southeast Asia and review of the Mesozoic amphibians from Thailand, Fossil Record 24 (1), pp. 33-47 : 35-36

Plagiosauridae indet.

Reference material

TF 1453 ( Fig. 2e–f ), a dermal bone ( Suteethorn et al., 1988).

Formation/age

Huai Hin Lat Formation (Carnian–Norian).

Locality and sediment

Outcrop near the Chulabhorn Dam, Kon San District , Chaiyaphum Province. The outcrop is located in the upper part of the Huai Hin Lat Formation ( Suteethorn et al., 1988). The specimen was embedded in a block of carbonaceous black shale rock .

Description

The specimen TF 1453, approximately 22 mm wide and 25 mm long, shows a peculiar ornamentation consisting of tubercles or pustules on its ventral surface. Dorsally, the surface shows some faint radiating grooves and ridges. Based on its ornamentation, TF 1453 was interpreted as a dermal bone fragment of a temnospondyl and was assigned to Plagiosauridae . A comparable ornamentation is observed in Middle to Late Triassic Plagiosauridae , e.g., Gerrothorax pulcherrimus and Plagioscutum ochevi from Europe ( Shishkin, 1986; Warren and Snell, 1991; Suteethorn et al., 1988; Jenkins et al., 2008).

Figures

Figure 2. Triassic amphibian remains from Thailand. A replica skull of Cyclotosaurus cf. posthumus (D.M.R. Ch.D 001) in dorsal (a), palatal (b), and posterior views (c). A reconstruction of Thai Cyclotosauridae (d). A dermal bone of Plagiosauroidea indet. (TF 1453) in ventral (e) and dorsal (f) views. A reconstruction of Thai Plagiosauroidea (g). Reconstruction images (d, g) are not to scale (drawn by Sita Manitkoon).