Anura

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 : 38

Anura indet.

Reference material

SHM-PT 529 ( Fig. 4a–b ) and SHM-PT 530 ( Fig. 4c–d ), humeri; SHM-HY 231 ( Fig. 4e–f ), pelvic girdle ( Srisuk, 2002, 2005).

Formation/age

Sao Khua Formation (Lower Cretaceous).

Locality and sediment

The humeri (SHM-PT 529 and SHM-PT 530) were collected in a road cut outcrop near Phu Phan Thong village, Muang District, Nong Bua Lamphu Province. These fossils were embedded in a pale olive fine-grained siltstone ( Srisuk, 2002).

The pelvic girdle (SHM-HY 231) was discovered in a road cut outcrop near the Huai Lao Yang reservoir road, Nong Bua Lamphu Province. The outcrop is formed by reddish-brown micaceous siltstones and lime-nodule conglomerates ( Srisuk, 2005).

Description

The left (SHM-PT 529) and right humeri (SHM-PT 530) are represented by their distal parts. They are elongated with a slender shaft, slightly curved in lateral view, with rounded capitulum.

The partial pelvic girdle (SHM-HY 231) consists of parts of the ischium, pubis, and acetabulum, while the ilium shaft is not preserved. The acetabular fossa is nearly circular with a posteriorly widened acetabular rim. The base of the ilium shaft has a triangular cross section. These features are reminiscent of an anuran amphibian, but the taxonomic identification of these incomplete specimens is difficult.

Figures

Figure 4. Cretaceous anuran remains from Thailand: left humerus, SHM-PT 529 in ventral (a) and medial view (b); right humerus, SHM-PT 530 in ventral (c) and medial view (d). Partial pelvic girdle, SHM-HY 231 in dorsal (e) and lateral view (f) (after Srisuk, 2002, 2005). Reconstruction of Thai anuran (g) is not to scale (drawn by Sita Manitkoon). Abbreviations: act, acetabulum; acr, acetabulum rim; cap, capitulum; ect, ectepicondyle; ent, entepicondyle; isc, ischium; pu, pubis.