Evidence for the diet and habitat of two late Pleistocene mastodons from the Midwest, USA

Abstract

We analyzed intestinal contents of two late-glacial mastodons preserved in lake sediments in Ohio (Burning Tree mastodon) and Michigan (Heisler mastodon). A multi-proxy suite of macrofossils and microfossils provided unique insights into what these individuals had eaten just before they died and added significantly to knowledge of mastodon diets. We reconstructed the mastodons’ habitats with similar multi-proxy analyses of the embedding lake sediments. Non-pollen palynomorphs, especially spores of coprophilous fungi differentiated intestinal and environmental samples. The Burning Tree mastodon gut sample originates from the small intestine. The Heisler mastodon sample is part of the large intestine to which humans had added clastic material to anchor parts of the carcass under water to cache the meat. Both carcasses had been dismembered, suggesting that the mastodons had been hunted or scavenged, in line with other contemporaneous mastodon finds and the timing of early human incursion into the Midwest. Both mastodons lived in mixed coniferous-deciduous late-glacial forests. They browsed tree leaves and twigs, especially Picea. They also ate sedge-swamp plants and drank the lake water. Our multi-proxy estimates for a spring/summer season of death contrast with autumn estimates derived from prior tusk analyses. We document the recovered fossil remains with photographs.

American mastodon mitochondrial genomes suggest multiple dispersal events in response to Pleistocene climate oscillations

“…American mastodons ( Mammut americanum ) were an iconic part of wooded and swampy habitats in Pleistocene North America 22 – 24 , with remains recovered from the Central American subtropics to the Arctic latitudes of Alaska and Yukon 20 , 25 . Stable isotope data, dental morphology, and microwear analyses reveal some regional and chronological variation or flexibility in diet, although C 3 woody browse vegetation (e.g., spruce trees) seems to have been preferred 25 – 28 . Like most proboscideans, the mastodon was a keystone species and served an important role in maintaining the integrity and diversity of its preferred habitats 25 , 29 , 30 .…”

On the Use of Spores of Coprophilous Fungi Preserved in Sediments to Indicate Past Herbivore Presence

“…Based on this principle, SCF found in sedimentary samples have been used to indicate the presence vs. absence, or trends of density changes, of herbivores in the past [13,15,20,21]. In particular, SCF have been extensively used to trace back the presence of large herbivores during the Pleistocene and Holocene; for example, in North America, researchers have used SCF to create records of mass megaherbivore extinctions at the end of the last ice age [13,14,18,19,[22][23][24].…”

Red Panda feces from Eastern Himalaya as a modern analogue for palaeodietary and palaeoecological analyses

“…This information helps to establish the species relationship with surrounding vegetation and climate of the region. Earlier studies examining both coprolites and modern dung have enhanced our understanding about the palaeodietary preferences of extinct species from different parts of the world and at different intervals of geological time 13 , 15 – 19 .…”