Rhinatrematidae – Beaked caecilians

Native to equatorial South America; widely regarded as the most basal family of caecilians

Found amidst the leaf litter in the tropical forests of northern South America, the Rhinatrematidae family comprises primitive, medium-sized caecilians commonly referred to as American-tailed caecilians or tailed caecilians. These creatures typically display a grayish or purplish coloration, with some featuring a distinctive yellow lateral stripe.

What sets the Rhinatrematidae family apart is its retention of several primitive characteristics compared to other caecilian families. They have real tails, external gills, and mouths at the end of their heads instead of underneath. These traits suggest they might not be as good at burrowing and might prefer living on land. Their tails are a bit like having a tailbone, unlike most caecilians. This makes them special in the group, and studying these features helps us understand how they live in the tropical forests of northern South America.

Another distinctive trait is their method of reproduction. Unlike most other caecilians, the Rhinatrematidae family lays eggs, and these eggs hatch into free-living larvae. This reproductive strategy contrasts with the more common direct development seen in many caecilian species. The combination of their unique features and reproductive approach adds to the intrigue surrounding the ecological role and evolutionary history of the Rhinatrematidae family in the diverse ecosystems of tropical South American forests.