Cretaceous temnospondyls

Koolasuchus is an extinct genus of brachyopoid temnospondyl in the family Chigutisauridae. Fossils have been found in Victoria, Australia and date back to 125-120 million years ago during the Barremian and Aptian stages of the Early Cretaceous, making Koolasuchus the youngest known temnospondyl. It is known from several fragments of the skull and other bones such as vertebrae, ribs, and pectoral elements. The type species Koolasuchus cleelandi was named in 1997. K. cleelandi was adopted as the fossil emblem for the state of Victoria, Australia on 13 January 2022.

The Stereospondyli are a group of extinct temnospondyl amphibians that existed primarily during the Mesozoic period. They are known from all seven continents and were common components of many Triassic ecosystems, likely filling a similar ecological niche to modern crocodilians prior to the diversification of pseudosuchian archosaurs.

Brachyopoidea is a superfamily of temnospondyls that lived during the Mesozoic. It contains the families Brachyopidae and Chigutisauridae. The earliest records of brachyopids are from the Lower Triassic in Australia. The latest-surviving member of the superfamily is the chigutisaurid Koolasuchus from the Early Cretaceous of Australia.

Trematosauria is one of two major groups of temnospondyl amphibians that survived the Permian-Triassic extinction event, the other (according to Yates and Warren 2000) being the Capitosauria. The trematosaurs were a diverse and important group that included many medium-sized to large forms that were semi-aquatic to fully aquatic. The group included long-snouted forms such as the trematosauroids and short, broad-headed forms such as the metoposaurs. Although most groups did not survive beyond the Triassic, one lineage, the brachyopoids, continued until the Cretaceous period. Trematosauria is de

right|thumb|Arenaerpeton|Arenaerpeton supinatus (specimen AM F125866) from the [[Sydney Basin]]