Placing Eophila tellinii (Oligochaeta, Lumbricidae) in a molecular phylogenetic context advances the century-old controversy around the problematic genus

Abstract

The genus Eophila Rosa, 1893 has been one of the most controversial in the taxonomy of Lumbricidae. The most accomplished earthworm experts from the last century accepted, rejected or split it into different genera depending on the studied species or morphological characters. In order to delimit a monophyletic, evolutionary significant Eophila, its type species Eophila tellinii was sequenced for mitochondrial (COI, 16S, tRNAs) and nuclear (28S) markers and included in a molecular phylogenetics context. Its putative close relative Eophila gestroi was also included in the same way, like Pietromodeona janueargenti, an enigmatic Tyrrhenian lumbricid. Bayesian inference and divergence time estimation were used to find the phylogenetic placement of the aforementioned species and to compare the age of the different genus-level clades of Lumbricidae. Eophila tellinii was recovered in a well-supported clade together with Eophila gestroi and Eophila crodabepis, clearly separated from other species previously assigned to the genus. In addition, this clade was found to be of a similar age (around 44 mya) to other studied genera and genus-level clades. The ultrametric tree provided preliminary insight on the paleobiogeography and diversification of the family. Relevant taxa to include in further molecular phylogenetic studies and the necessity of an integrative systematic revision are highlighted by the conclusions of this work.