In the last few years, the Quebrada de Los Colorados Formation has become an important middle Eocene fossiliferous
unit in Northwestern Argentina. In this unit, the South American native ungulates were until now only represented
by the order Notoungulata, including one family of Typotheria and three of Toxodontia. In this contribution, we
present a new faunistic assemblage of South American native ungulates, collected from outcrops of the Quebrada
de Los Colorados Formation at Los Cardones National Park, Calchaquí Valleys, Salta Province (Argentina). This
new assemblage is constituted by the following taxa: litoptern Didolodontidae cf. Ernestokokenia sp., Astrapotheria
indet., and notoungulate Notostylopidae Homalostylops sp., a ?Homalostylops sp., typothere “Oldfieldthomasiidae”
Colbertia falui sp. nov., Colbertia lumbrerense, and Colbertia sp. and toxodont “Notohippidae” Pampahippus secundus.
Colbertia falui sp. nov. differs from the other species of Colbertia by the following features: lower cheek teeth
with both more labially angular and oblique trigonid; lower premolars more labio-lingually compressed; with proportionally
larger trigonid, and shorter talonid; ectoflexid transversally deeper; lower molars with a more developed
paralophid, and more expanded metalophid and entoconid; the latter is located in a more mesial position, being closer
to the metaconid; deep and lingually narrower talonid basin; disto-lingual sulcus transversally shallower; more developed
cingulids; and m3 with less lingually projected hypoconulid. This new fauna markedly increases the taxonomic
richness known for this formation since it includes the first mention of notostylopids, “oldfieldthomasiids”, litoptern
didolodontids, and astrapotheres. With the current evidence, we postulate an ungulate migration from Patagonia to
Northwestern Argentina during the Eocene. We also hypothesize that the observed taxonomic differences among the
Quebrada de Los Colorados, Geste, and Lumbrera formations are more probably associated to orogenic factors that
have regulated the faunal dynamic in Northwestern Argentina during the Paleogene than to a differential sampling
effort or taphonomic biases.
Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies
Informacja
SZANOWNI CZYTELNICY!
UPRZEJMIE INFORMUJEMY, ŻE BIBLIOTEKA FUNKCJONUJE W NASTĘPUJĄCYCH GODZINACH:
Wypożyczalnia i Czytelnia Główna: poniedziałek – piątek od 9.00 do 19.00