''Alcidedorbignya'' is an extinct pantodont mammal known from the

Early Paleocene The Danian is the oldest age or lowest stage of the Paleocene Epoch or Series, of the Paleogene Period or System, and of the Cenozoic Era or Erathem. The beginning of the Danian (and the end of the preceding Maastrichtian) is at the Cretaceous� ...

( Tiupampan SALMA, ) Santa Lucia Formation (, paleocoordinates ) at Tiupampa near Mizque, Cochabamba,

Bolivia , image_flag = Bandera de Bolivia (Estado).svg , flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center , flag_alt2 = 7 × 7 square p ...

. Following a naming convention established by pioneering Argentine palaeontologist Florentino Ameghino (i.e. combining the first name and surname of a prominent scientist), the genus name honours French naturalist

Alcide d'Orbigny Alcide Charles Victor Marie Dessalines d'Orbigny (6 September 1802 – 30 June 1857) was a French naturalist who made major contributions in many areas, including zoology (including malacology), palaeontology, geology, archaeology and anthropol ...

Description

Estimated 25 cm head-body length and 500 grams, this was a small squirrel sized animal, terrestrial with possible scansorial habits, and either herbivorous or omnivorous. ''Alcidedorbignya'' is one of the oldest and most primitive of the pantodonts and the only pantodont genus known from South America. Not only have some scientists questioned the age of the type locality, instead advocating an Asian origin for the pantodonts, ''Alcidedorbignya'''s bare existence obscures the origins of the already enigmatic pantodonts. Taxonomic similarities indicate that there was a mammalian interchange between North and South America during the early Paleocene, and the North American pantodont ''

Pantolambda ''Pantolambda'' (Greek: "all" (pantos), "lambda" (lambda), in a reference to the shape of upper premolars, similar to the Greek letter lambda) is an extinct genus of Paleocene pantodont mammal. ''Pantolambda'' lived during the middle Paleocene, a ...

'' is a potential descendant of ''Alcidedorbignya''. ''Alciddedorbignya'' is known from several specimens of upper and lower dentitions, including juveniles. P^3–4 have V-shaped ectolophs (ridges on the crowns), indicating it was a primitive pantodont. Other molar characteristics makes it unique among pantodonts. On the molars, the paracone and metacone are separated and not connate as in ''

Bemalambda ''Bemalambda'' is an extinct mammal, belonging to the pantodonts. It lived in the lower-middle Paleocene (about 63–58 million years ago) and the fossil remains have been found in China. Description It was a medium-size animal, and could rea ...

'' and '' Harpyodus''. As in these two genera, there is neither a mesostyle on M^1–2 nor a strongly V-shaped centocrista as in eupantodonts (all later pantodonts). It is still unclear which the primitive condition is in pantodont upper dentition, and the position of ''Alcidedorbignya'' near the base of the clade remain unresolved.

References

Bibliography

* * * * * * {{Taxonbar, from=Q15732309 Pantodonts Paleocene mammals of South America Tiupampan Paleogene Bolivia Fossils of Bolivia Santa Lucía Formation Fossil taxa described in 1987 Prehistoric mammal genera