On the Supposed Presence of Miocene Tayassuidae and Dromomerycinae (Mammalia, Cetartiodactyla) in South America

Abstract

The earliest record of North American mammals in South America is significant for constraining the timing of intercontinental faunal interchange. At present, the oldest securely dated remains of a North American terrestrial mammal in South America pertain to a late Miocene procyonid; a few other North American mammal groups are present in late Miocene and early Pliocene outcrops in South America, but most are not recorded until the late Pliocene or Pleistocene, after the complete emergence of the Panamanian Isthmus. This long-established pattern has recently been called into question by reports of a proboscidean, two tayassuids, and a dromomerycine cervoid in supposed late Miocene deposits of Peruvian Amazon. In this contribution, we analyze the taxonomic identities and stratigraphic provenances of the tayassuid and dromomerycine fossils in detail. We conclude that these specimens are not distinguishable from modern tayassuids (Tayassu pecari and Dicotyles tajacu) and cervids, and that previous taxonomic identifications are based on misinterpretation of characters or inadequate specimens. In addition, there is insufficient evidence to support a late Miocene age for these terrestrial cetartiodactyl fossils; the stratigraphic provenance of the specimens is highly dubious, and the fossils are likely Quaternary in age.

The Late Miocene mammals from the Humahuaca Basin (northwestern Argentina) provide new evidence on the initial stages of the Great American Biotic Interchange

“…However, these records have been questioned from systematic and stratigraphic points of view (Gasparini et al . 2021; Alberdi & Prado 2022).…”

Out of Africa: A New Afrotheria Lineage Rises From Extinct South American Mammals

“…Moreover, the record of some mammals of Holarctic origins in the Miocene of Amazon led to an alternative hypothesis to explain their arrival into South America, across GAARlandia (Agnolin et al, 2019). Nevertheless, both the Miocene age and taxonomic validity of these records had been questioned, and they might represent Pleistocene ordinary taxa (Mothé and Avilla, 2015;Gasparini et al, 2021).…”

Georeferencing fossiliferous localities from Solimões and Acre Basins (Brazil) - what we know so far about Solimões Formation and future perspectives

“…The giant-sloths (Megatheriidae), were registered in two localities, one for each taxon: Megatherium sp and Nothropus priscus. The Palaeomerycidae species Surameryx acrensis were recorded in one locality (however, this taxon needs a reappraisal to confirm their taxonomic validity (Perini et al 2016, Gasparini et al 2021)), as well as the Tayassuidae Sylvochoerus woodburnei (this taxon also has your doubtful taxonomic and stratigraphic (Perini et al 2016, Gasparini et al 2021). Tapirus sp (Tapiridae) were found in six localities (figure 4).…”