Sakkoonidae

Sakkoonidae is an extinct family of salamander-like amphibians known from the fossil record. The family is currently monogeneric, consisting of the genus Sakkoonodon, described from remains recovered in the Sakkoon Formation of Southeast Asia. The name honors the locality that yielded the type material.

Members of Sakkoonidae are characterized by an elongated body, relatively broad skull, and limbs that are reduced compared with related taxa. The preserved skeletons show a mix of aquatic and terrestrial adaptations, including a tail-fin structure in some specimens and a dorsally placed pectoral girdle. Dental features include pointed marginal teeth and a small vomerine tooth series.

Taxonomic placement is uncertain. Sakkoonidae is usually placed within the order Caudata (salamanders), but its exact position—whether as a stem caudatan or a basal member near crown-group Salamandroidea—is debated in recent analyses.

Geological age and distribution: The known material comes from Late Cretaceous to early Paleocene deposits in the Sakkoon Basin, indicating a long temporal range. At present, material is restricted to a single locality, limiting reconstruction of the full diversity of the family.

Palaeoecology: The morphology suggests a semi-aquatic lifestyle in rivers or swamps, feeding on small invertebrates. Reproductive biology is unknown, but many contemporaneous salamander-like taxa laid eggs in water.

Species: The genus Sakkoonodon presently includes two described species, Sakkoonodon primordialis and Sakkoonodon minor. Etymology and discovery: The name combines the locality with the Greek odon, “tooth”; the family was erected based on multiple fragmentary skeletons recovered during surveys in the Sakkoon Formation.