| Juchuysillu | |
|---|---|
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | †Notoungulata |
| Family: | †Interatheriidae |
| Genus: | †Juchuysillu Croft & Anaya, 2020 |
| Species: | †J. arenalesensis |
| Binomial name | |
| †Juchuysillu arenalesensis Croft & Anaya,2020 | |
Juchuysillu is anextinctgenus ofinteratheriidnotoungulate. It lived from the Early to the MiddleMiocene, and its fossils have been found inBolivia.[1]
This animal would have been vaguely similar to a present-dayguinea pig, and must not have been much over a kilogram in weight.Juchuysillu is known only from sparse fossil remains comprising jaws and jaws with teeth, but from comparison with some similar and better known animals such asCochilius,Interatherium andProtypotherium, it is possible to speculate on its appearance.Juchuysillu was distinguished from related genera mainly by its tiny size, but mainly by a unique combination of dentition characters: weak grooves were present on the upper third and fourthpremolar, themolars were in descending order from first to third and trapezoidal in shape, and the lower third molar lacked a buccal talon groove.[1]
Juchuysillu arenalesensis was first described in 2020, based on fossil remains found in theNazareno Formation in southernBolivia, dating to the Early to Middle Miocene. Another specimen attributed to the same species comes from theCerdas area, in Bolivia, in somewhat more recent deposits.Juchuysillu is a representative of theInteratheriidae, a family of typothere notoungulates comprising forms of varied size and appearance. Specifically,phylogenetic analyses would showJuchuysillu in an ancestral position relative to several species of interatheriids such asMiocochilius anomopodus,Caenophilus tripartitus, Miocochilius federicoi and various species ofProtypotherium (including the well-knownP. australe), but more derived thanProtypotherium sinclairi.[1]
