Diet and environment of Mylodon darwinii based on pollen of a Late-Glacial coprolite from the Mylodon Cave in southern Chile

Bas Van Geel,Jacqueline F.N Van Leeuwen,Kees Nooren,Dick Mol,Natasja Den Ouden,Pim W.O Van Der Knaap,Frederik V Seersholm,Alba Rey-Iglesia,Eline D Lorenzen

doi:10.1016/j.revpalbo.2021.104549

Abstract

We studied the pollen content of a well-preserved coprolite of a Late-Glacial giant ground sloth (Mylodon darwinii) from the Mylodon Cave, province Última Esperanza, southern Chile. The specimen was obtained in 1909 and has been stored in a museum in the Netherlands since. It was radiocarbon dated to 13,140 ± 55 BP (15,927–15,522 cal BP), which fits with other radiocarbon dates showing the early Late-Glacial presence of M. darwinii in the province Última Esperanza. Contemporaneous oxygen isotope data from Antarctic EPICA Dome C indicates that our Mylodon specimen lived during a warming phase of the Late-Glacial, ca. 1000 years before the start of the Antarctic Cold Reversal. We compared our pollen data with pollen records showing contemporaneous regional vegetation and discuss the uncertainties in the interpretation of pollen spectra from faeces. To expand on the pollen data, we tested ancient DNA preservation in the sample; we sequenced ~9.4 million DNA reads and found that the concentration of ancient plant DNA is below detectable levels. Pollen analysis confirms earlier findings that the Mylodon was a grazer, but the discovery of large amounts of Fragaria and Azorella pollen in the faeces may indicate that Mylodon was also able to select and consume specific plants, and therefore could also be regarded as a selective feeder.

Highlights

The Late-Glacial climate history as based on Greenland ice cores differs from Antarctic data, and we compare the age interval of our South American coprolite with the chronological and climatological records of the Antarctic EPICA Dome C (Jouzel et al, 2007; Pedro et al, 2015)
Based on the oxygen isotope curves and our radiocarbon date, we conclude (Fig. 2) that the M. darwinii faeces specimen was deposited during an early Late-Glacial warming phase, about 1000 years before the start of the Antarctic Cold Reversal
A well-preserved Late-Glacial coprolite of the giant ground sloth Mylodon darwinii, which was obtained more than 110 years ago from the Mylodon Cave in southern Chile, was successfully studied for pollen

Summary

Introduction

The Naturalis Biodiversity Center in Leiden, the Netherlands, hosts an extraordinary collection of Pleistocene mammal bones and other remains from southern South America. The Dutch biologist Jan Herman Kruimel (1885–1916) obtained this collection in 1909, including bones, skin fragments, and coprolites (fossilised faeces), in Punta Arenas in South Chile. The cave is in the southern part of Chile (province Última Esperanza; coordinates 51°33′49′′S, 72°37′07′′′W) 160 m above sea level, and 24 km from Puerto Natales (Fig. 1). It is situated in the Benítez mountain, north of the Strait of Magellan that separates the island Tierra del Fuego from mainland South America. The entrance of the cave is 170 m wide, 30 m high, and the cave is 270 m deep

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