Triadobatrachus (’triple frog’) represents the first known member of the frog and salamander lineage.
Triadobatrachus lives much like our timeline’s modern amphibians, and could even hop like a frog. However, the distinctive fused ring of bones formed from a frog’s collarbone, sternum and ribcage that grants a frog the ability to land would come much later, making every escape attempt a clumsy crash landing.
Triadobatrachus, like most amphibians, cannot endure the presence of saltwater, and needs fresh water in order to properly respirate.
In our timeline, triadobatrachus would be the ancestor of Prosalirus, the first true frog, The divergent effects of the Amphiterra timeline would manifest subtly at first, instead evolving into the Common Eofrog (Novabatrachus vulgaris), which would not seem totally unfamiliar to a visitor from our timeline.