Relicts of the lost arc: High-throughput sequencing of the Eutrichomyias rowleyi (Aves: Passeriformes) holotype uncovers an ancient biogeographic link between the Philippines and Fiji.

ABSTRACT

Molecular studies have revealed a number of cases in which traditional assessments of evolutionary relationships have been incorrect. This has implications not only for systematics and taxonomy but also for our understanding of how diversity patterns on Earth have been formed. Here, we use high-throughput sequencing technology to obtain molecular data from the holotype specimen of the elusive Eutrichomyias rowleyi, which is endemic to the Indonesian island of Sangihe. We show that E. rowleyi unexpectedly is a member of the family Lamproliidae, which dates back some 20 Million years and only include two other species, Lamprolia victoriae from Fiji and Chaetorhynchus papuensis from New Guinea. Tectonic reconstructions suggest that the Melanesian island arc, which included land masses on the northern edge of the Australian plate (present day New Guinea) stretched as a string of islands from the Philippines (including proto-Sangihe) to Fiji from 25 to 20 My. Consequently, our results are indicative of an ancient distribution along the Melanesian island arc followed by relictualization, which led to members of the Lamproliidae to be distributed on widely separated islands across the Indo-Pacific.