Underwater faunal assemblages: radiocarbon dates and late Quaternary vertebrates from Cold Lake, Alberta and Saskatchewan, Canada

Abstract

Late Quaternary faunal remains from three underwater settings in Cold Lake, Alberta and Saskatchewan, Canada, include at least 13 vertebrate taxa consistent with assemblages that postdate the Last Glacial Maximum (LGM). Seven new radiocarbon dates range from 10 350 ± 40 to 161 ± 23 years BP and provide insight into the post-LGM biotic history of east-central Alberta and west-central Saskatchewan. The presence of an essentially modern large mammal biota is suggested for the mid-Holocene, and possibly earlier, if the absence of extinct or extirpated taxa in association with Late Pleistocene Bison at the Alberta–Saskatchewan site is meaningful. Taphonomically, some of the remains suggest deposition in open environments during the Holocene, possibly when lake levels were lower. The recovery of late Quaternary faunal remains from a present-day lacustrine setting is novel, and suggests that similar records may occur in other lakes in western Canada, including those in areas with scarce Quaternary vertebrate records.

Practice and prospects in underwater palaeontology

“…For example, on the Yucatan peninsula, Pleistocene sites were unknown until the exploration of sinkholes because the thick limestone bedrock combined with the extremely low topographic relief that limited sediment deposition, dense vegetation, and the high rates of precipitation and humic acids are otherwise unconducive to fossil preservation (González González et al, 2008). Similarly, underwater lake deposits could be an important source of fossils in North America where dense vegetation, moist sediments, and acidic soils inhibit good preservation of bone (Jass et al, 2018). Areas that would benefit from exploration of underwater settings, such as the flooded Sunda shelf in Island Southeast Asia, and otherwise fossil-poor landscapes such as those present in the Yucatan, should be made a priority for future research efforts in this field.…”

“…While deposits in caves, and to a lesser extent sinkholes, can occur in both phreatic and vadose environments, those on the continental shelf will almost always occur in a terrestrial or semi-terrestrial environment first. In a similar scenario, fossils recovered from lake settings may be the result of changes in lake levels resulting in flooding near-shore, terrestrial depositional environments (Jass et al, 2018). Thus, continental shelf deposits, and to a lesser extent lacustrine deposits, are dictated primarily by their geographical location rather than their geological context, the latter of which can encompass any sedimentary environment likely to preserve fossils.…”

“…Thus, continental shelf deposits, and to a lesser extent lacustrine deposits, are dictated primarily by their geographical location rather than their geological context, the latter of which can encompass any sedimentary environment likely to preserve fossils. The recovery of marine vertebrates in shallow offshore settings (Noakes et al, 2009) and those deposited in lakes by falling through ice (Jass et al, 2018) are probably rare exceptions to the major underwater deposit types.…”

Conservation of Subfossil Bones from a Lacustrine Setting: Uncontrolled and Controlled Drying of Late Quaternary Vertebrate Remains from Cold Lake, Western Canada

“…The majority of the remains are from large ungulates, including bison (Bison sp. ), elk (Cervus elaphus), and moose (Alces alces), but bones and teeth of smaller animals were also recovered (Caldwell et al 2016;Jass et al 2014Jass et al , 2018. The taxonomic composition of the fauna and radiocarbon dating of a sample of specimens indicate an age range of late Pleistocene to late Holocene (Caldwell et al 2016, Jass et al 2018.…”

“…), elk (Cervus elaphus), and moose (Alces alces), but bones and teeth of smaller animals were also recovered (Caldwell et al 2016;Jass et al 2014Jass et al , 2018. The taxonomic composition of the fauna and radiocarbon dating of a sample of specimens indicate an age range of late Pleistocene to late Holocene (Caldwell et al 2016, Jass et al 2018. The faunal record of the region during this time frame is scant, and the Cold Lake collection fills an important gap in the Quaternary record of east-central Alberta and west-central Saskatchewan (Caldwell et al 2016;Jass et al 2014Jass et al , 2018.…”