Revisiting proboscidean phylogeny and evolution through total evidence and palaeogenetic analyses including Notiomastodon ancient DNA

Sina Baleka,Luciano Varela,P Sebastián Tambusso,Johanna L.A Paijmans,Dimila Mothé,Thomas W Stafford,Richard A Fariña,Michael Hofreiter

doi:10.1016/j.isci.2021.103559

Abstract

SummaryThe extinct Gomphotheriidae is the only proboscidean family that colonized South America. The phylogenetic position of the endemic taxa has been through several revisions using morphological comparisons. Morphological studies are enhanced by paleogenetic analyses, a powerful tool to resolve phylogenetic relationships; however, ancient DNA (aDNA) preservation decreases in warmer regions. Despite the poor preservation conditions for aDNA in humid, sub-tropical climates, we recovered ∼3,000 bp of mtDNA of Notiomastodon platensis from the Arroyo del Vizcaíno site, Uruguay. Our calibrated phylogeny places Notiomastodon as a sister taxon to Elephantidae, with a divergence time of ∼13.5 Ma. Additionally, a total evidence analysis combining morphological and paleogenetic data shows that the three most diverse clades within Proboscidea diverged during the early Miocene, coinciding with the formation of a land passage between Africa and Eurasia. Our results are a further step toward aDNA analyses on Pleistocene samples from subtropical regions and provide a framework for proboscidean evolution.

Highlights

Proboscidea Illiger, 1811 is a mammalian order that includes the extant elephants (Elephas Linnaeus, 1758, and Loxodonta Anonymous, 1827) and a great diversity of extinct species (Shoshani and Tassy, 2005; Gheerbrant and Tassy, 2009)
Morphological studies are enhanced by paleogenetic analyses, a powerful tool to resolve phylogenetic relationships; ancient DNA preservation decreases in warmer regions
We present almost 3,000 base pairs of mitochondrial ancient DNA obtained from a specimen of N. platensis from Uruguay (Figure 1) and reconstruct a molecular phylogeny using these

Summary

Introduction

Proboscidea Illiger, 1811 is a mammalian order that includes the extant elephants (Elephas Linnaeus, 1758, and Loxodonta Anonymous, 1827) and a great diversity of extinct species (Shoshani and Tassy, 2005; Gheerbrant and Tassy, 2009). The second radiation took place during the early Miocene, with the diversification of ‘‘Gomphotheriidae’’ Hay, 1922, (used sensu lato throughout the text, indicated by brackets) Mammutidae Hay, 1922, and Stegodontidae Osborn, 1918, a family within the Elephantoidea. The last radiation took place during the late Miocene/ early Pliocene and resulted in the diversification of Elephantidae Gray (1821), as well part of the superfamily Elephantoidea, including the living elephants (Shoshani and Tassy, 1996; Gheerbrant and Tassy, 2009)

Objectives

Results

Conclusion