Biology:Incamys

Incamys is an extinct genus of chinchillid rodent that lived during the Late Oligocene (Deseadan) in what is now South America. Fossils of this genus have been found in the Salla Formation of Bolivia and the Agua de la Piedra and Sarmiento Formations of Argentina. Research on endocasts suggest they were group living using call communication like modern chinchillas.

Taxonomy

Incamys was first described by Hoffstetter and Lavocat, based on remains found in the Salla Formation of Bolivia, with the proposed type species being Incamys bolivianus, referring to the country it was found in. Later, in 1976, a new species was named, I. pretiosus, which was subsequently found to be a junior synonym of the type species. In 2015, Vucetich and colleagues described a new species of Incamys, I. menniorum, from the Sarmiento Formation of Chubut Province, Argentina.

The following cladogram of the Caviomorpha is based on Busker et al. 2020, showing the position of Incamys.

Baluchimyinae Bugtimys zafarullahi         "Phiomorpha"   Phiomys andrewsi     Metaphiomys schaubi           Octodontoidea   Prospaniomys priscus       Myocastor coypus       Echimyidae   Proechimys polioplus       Eumysops laeviplicatus       Kannabaetomys amblyonyx     Echimys chrysurus               Ctenomyidae Ctenomys australis           Plataeomys brevis     Pithanotomys columnaris         Octomys mimax       Octodontomys gliroides       Chasichimys bonaerense     Chasicomys octodontiforme       Acarechimys leucotheae     Acarechimys minutus   Acaremyidae   Acaremys murinus     Galileomys antelucanus     Galileomys baios                             Erethizontoidea   Steiromys detentus     Eosteiromys homogenidens         Dasyproctidae Dasyprocta azarae   Node A     Eoviscaccia frassinettii     Eoviscaccia boliviana     Garridomys curunuquem         Incamys bolivianus         Asteromys bolivianus     Asteromys punctus         Cephalomyidae   Cephalomys ceciae     Cephalomyopsis hypselodontus     Litodontomys chubutensis     Cephalomys arcidens           Scotamys antiquus       Neoepiblemidae Perimys intermedius   Chinchillidae   Lagostomus maximus       Lagidium viscacia     Chinchilla chinchilla         Node B     Banderomys leanzai       Soriamys ganganensis     Soriamys gaimanensis           Luantus propheticus       Guiomys unica       Microcavia australis       Cavia aperea       Galea musteloides     Dolichotis patagonum

Brain endocasts

Research on 30 million-year-old Incamys bolivianus virtual endocasts show they had expanded temporal lobes in the cerebrum and large caudal colliculi in the midbrain, arguing they had enhanced auditory acuity and vocalization. This is consistent with them living in social groups and using calls to communicate with each other, similar to modern chinchillas.

References

Wikidata ☰ Q114351124 entry