Papachacra (Miocene of Bolivia)

Where: Tarija, Bolivia (21.9° S, 65.2° W: paleocoordinates 22.2° S, 62.0° W)

• coordinate stated in text

• small collection-level geographic resolution

When: Serravallian (13.8 - 11.6 Ma)

• The tuff was analyzed at the Laboratory for Argon Geochronology at the University of California, Santa Barbara using two methods: 40Ar/39Ar dating of plagioclase, which yielded an estimated age of 12.32 ± 0.14 Ma, and U-Pb dating of individual zircon crystals, which yielded two populations with ages of 12.35 ± 0.15 Ma and 13.00 ± 0.15 Ma. The close concor- dance between the 40Ar/39Ar date and that of the younger population of zircons strongly suggests the sampled tuff is approximately 12.35 Ma (and that the older zircons were reworked from older tuffs in the area).

• bed-level stratigraphic resolution

Environment/lithology: terrestrial; poorly lithified tuff

• reworked ash fall tuff.

Size class: macrofossils

Primary reference: D. Brandoni, A. A. Carlini, F. Anaya, P. Gans, and D. A. Croft. 2018. New Remains of Megathericulus patagonicus Ameghino, 1904 (Xenarthra, Tardigrada) from the Serravallian (Middle Miocene) of Bolivia; Chronological and Biogeographical Implications. Journal of Mammalian Evolution 25:327-337 [P. Mannion/M. Kouvari]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 197501: authorized by Philip Mannion, entered by Miranta Kouvari on 14.11.2018

Creative Commons license: CC BY (attribution)

Taxonomic list

• The UATF-V-001414 specimen was collected in situ, as was a sample from a nearby (2 m dis- tant) reworked ash fall tuff from the same stratigraphic level as the fossil.
Mammalia
 Megatherioidea - Megatheriidae
Megathericulus patagonicus Ameghino 1904 edentate
UATF-V-001414