| Basic info | Taxonomic history | Classification | Included Taxa |
| Morphology | Ecology and taphonomy | External Literature Search | Age range and collections |
Taxonomy
Balsayacuy was named by Boivin et al. (2021). Its type is Balsayacuy huallagaensis.
It was assigned to Caviomorpha by Boivin et al. (2021).
It was assigned to Caviomorpha by Boivin et al. (2021).
Species
B. huallagaensis (type species)
Synonymy list
| Year | Name and author |
|---|---|
| 2021 | Balsayacuy Boivin et al. |
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If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.
Diagnosis
| Reference | Diagnosis | |
|---|---|---|
| M. Boivin et al. 2021 | Small-sized rodent characterized by brachydont and bunolophodont teeth. Lower molars with a pseudo-tae- niodont pattern at early stages of wear. Upper teeth with a variable morphology of the lingual protoloph, which can be either complete, reduced to one or two connected or dis- connected crestules (i.e., posterior arm of the protocone or crestule from the labial protoloph-mure junction), or absent, but the pseudo-taeniodont pattern is more frequently pre- sent. Round P4s with a transverse lingual protoloph, and with a connection of its labial structures (i.e., anteroloph, paracone, mesostyle, and posteroloph) at a moderate stage of wear. P4s and upper molars with a frequently incomplete third transverse crest. P4s and M1–2s without metaloph. If it is present, the metaloph is strongly reduced and lingually free on M3s at early stage of wear. M1–2s frequently with a long mesoloph faintly linked to the mesolophular spur or lingually free (the mesophular spur being absent). Acces- sory, thin and short enamel structures (posteroloph spur included) may be present between the third crest and the posteroloph, and connected to either or both transverse crests on upper molars. Differs from Cachiyacuy contamanensis, Eobranisamys, Eosallamys paulacoutoi, and ‘Eosallamys’ simpsoni in having a smaller size. Differs from Canaanimys maquiensis in having more square-shaped M1–2s and from Eobranisamys, Es. paulacoutoi, ‘Es.’ simpsoni, Eoespina, and Pozomys in having more transverse M1–2s. Differs from Cc. contamanensis, Cachiyacuy kummeli, Es. paulacoutoi, ‘Es.’ simpsoni, Eoespina, and Eosachacui in having a higher tendency toward the taeniodonty; and from Eobranisamys and Pozomys in having a lower tendency toward the taeni- odonty. The metaloph is absent on M1–2s of Balsayacuy, differing from the most frequent morphology of this crest in Cc. contamanensis, Canaanimys, Eobranisamys, and Es. paulacoutoi, in which the metaloph is present. Differs from Cc. contamanensis, Cc. kummeli, Cn. maquiensis, Eobranisamys, Es. paulacoutoi, ‘Es.’ simpsoni, Eoespina, and Eosachacui in having a mesoloph more frequently faintly linked to the mesolophular spur or lingually free on M1–2s. It further differs from Cc. kummeli, Eobranisamys, Eoespina, and Pozomys in having more important developed accessory structures between the third crest and the pos- teroloph on some upper molars; from Cc. contamanensis, Eobranisamys, Eoespina, and Es. paulacoutoi in having more rounded P4s; from Cc. contamanensis in having a con- nection of the labial structures (i.e., anteroloph, paracone, mesostyle, and posteroloph) on P4s at an earlier stage of wear; from Eoespina and ‘Es.’ simpsoni in having a trans- verse lingual protoloph on P4s; from Eoespina in having a stronger connection of the labial structures on P4s at mod- erate stage of wear; from Eobranisamys and Eosachacui
in having a complete mure on P4s; from Eosachacui, Es. paulacoutoi, and ‘Es.’ simpsoni in having a reduced third crest; and from Pozomys in having a third crest on P4s. |
Measurements
No measurements are available
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| Source: o = order, subc = subclass, c = class, subp = subphylum | |||||
| References: Nowak 1999, Hendy et al. 2009, Ji et al. 2002, Carroll 1988, Lillegraven 1979 | |||||
Age range: base of the Late/Upper Eocene to the top of the Rupelian or 37.20000 to 28.10000 Ma
Collections (3 total)
| Time interval | Ma | Country or state | Original ID and collection number |
|---|---|---|---|
| Late/Upper Eocene | Peru | B. huallagaensis (207066 207067) | |
| Rupelian | Peru (Departamento de Ucayali) | B. huallagaensis (149523) |