Known from Early Paleocene fossils in Bolivia,
with a phylogenetic genesis in the early Jurassic, Pucadelphys andinus (Figs. 1-3), nests in the large reptile tree (LRT, 1870+ taxa) just prior to the extant arboreal didelphid, Caluromys (Figs. 3-4). These taxa nest as omnivores between the largely herbivorous marsupials and the largely carnivorous marsupials, not far from the omnivorous ancestors of placentals.
35 partial skeletons are known
from mouse-like Pucadelphys, dying en masse within ten feet of each other, perhaps during a flash flood. This was originally considered odd because usually marsupials are territorial and isolated from one another (kangaroos are exceptions to this trend). Twelve are female. Six are male with larger heads and larger canines. Five were juveniles. Ladeveze et al. 2011 concluded, “the early Palaeocene P. andinus population at Tiupampa was a socially interacting group, characterized by gregariousness, male–male competition and polygyny.”
Later, Astúa et al. 2015
reported the first evidence of gregarious denning in didelphids supported by photos (Fig. 2)
Pucadelphys phylogenetics are rather difficult to find. Pucadelphys is al so close to Caluromys geographically. Prepubes are present on both taxa.
Astúa D et al. 2015. First evidence of gregarious denning in opossums (Didelphimorphia, Didelphidae), with notes on their social behaviour. Biol. Lett. 11: 20150307.
Ladeveze S, de Muizon C, Beck R, Germain D and Cespedes-Paz R 2011. Earliest evidence of mammalian social behaviour in the basal Tertiary of Bolivia Nature, 474, 83-86 DOI: 10.1038/nature09987
Marshall LG and De Muizon C 1988. The Dawn of the Age of Mammals in South America. National Geographic Research 4:23-55.
Marshall LG, de Muizon C and Sigogneau-Russsell D 1995. Pucadelphys andinus (Marsupialia, Mammalia) from the early Paleocene of Bolivia. Part I: The locality of Tiupampa: age, taphonomy and mammal fauna. Mémoires du Muséum national d’histoire naturelle 165: 11–20.
Please Help Support BeforeitsNews by trying our Natural Health Products below!
Order by Phone at 888-809-8385 or online at https://mitocopper.com M - F 9am to 5pm EST
Order by Phone at 888-388-7003 or online at https://www.herbanomic.com M - F 9am to 5pm EST
Order by Phone at 888-388-7003 or online at https://www.herbanomics.com M - F 9am to 5pm EST
Humic & Fulvic Trace Minerals Complex - Nature's most important supplement! Vivid Dreams again!
HNEX HydroNano EXtracellular Water - Improve immune system health and reduce inflammation
Ultimate Clinical Potency Curcumin - Natural pain relief, reduce inflammation and so much more.
Oxy Powder - Natural Colon Cleanser! Cleans out toxic buildup with oxygen!
Nascent Iodine - Promotes detoxification, mental focus and thyroid health.
Smart Meter Cover - Reduces Smart Meter radiation by 96%! (See Video)