Papers by Carolina Vieytes
A new caviomorph rodent, Dudumus ruigomezi, gen. et sp. nov., is described from the Sarmiento For... more A new caviomorph rodent, Dudumus ruigomezi, gen. et sp. nov., is described from the Sarmiento Formation,
Trelew Member (early Miocene), of the Argentinian Patagonia. This new taxon is represented by upper and lower cheek
teeth, mandible, and maxillary remains. It is characterized by retention of deciduous premolar, and low-crowned and terraced
lower and upper cheek teeth with well-differentiated cusps, as in Caviocricetus lucasi; uppermolariforms with themesolophule
and metacone fused with the posterior-most crest, as in C. lucasi; lower molars with lingual cusp enlarged and metalophulid
II longer in m2 than in m1and m3, as in Prospaniomys priscus; and dp4 with metalophulid I separated from the metaconid
and a spur projecting posterolingually from the posterior wall of metalophulid I, between the protoconid and anteroconid.
The incisor enamel microstructure is derived, with the interprismatic matrix perpendicular (at a right angle) to the prisms,
as in other octodontoids. A cladistic analysis corroborates that D. ruigomezi represents an octodontoid rodent with unusual
tooth morphology. This analysis demonstrates that the early evolutionary history of Octodontoidea was characterized by
the differentiation of successive lineages that survived until the early or middle Miocene, with no direct relationships with
modern Octodontidae and Echimyidae. This analysis also suggests that fossil taxa previously classified as octodontoids are
instead more closely related to the other caviomorph rodents.
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Papers by Carolina Vieytes
Trelew Member (early Miocene), of the Argentinian Patagonia. This new taxon is represented by upper and lower cheek
teeth, mandible, and maxillary remains. It is characterized by retention of deciduous premolar, and low-crowned and terraced
lower and upper cheek teeth with well-differentiated cusps, as in Caviocricetus lucasi; uppermolariforms with themesolophule
and metacone fused with the posterior-most crest, as in C. lucasi; lower molars with lingual cusp enlarged and metalophulid
II longer in m2 than in m1and m3, as in Prospaniomys priscus; and dp4 with metalophulid I separated from the metaconid
and a spur projecting posterolingually from the posterior wall of metalophulid I, between the protoconid and anteroconid.
The incisor enamel microstructure is derived, with the interprismatic matrix perpendicular (at a right angle) to the prisms,
as in other octodontoids. A cladistic analysis corroborates that D. ruigomezi represents an octodontoid rodent with unusual
tooth morphology. This analysis demonstrates that the early evolutionary history of Octodontoidea was characterized by
the differentiation of successive lineages that survived until the early or middle Miocene, with no direct relationships with
modern Octodontidae and Echimyidae. This analysis also suggests that fossil taxa previously classified as octodontoids are
instead more closely related to the other caviomorph rodents.
Trelew Member (early Miocene), of the Argentinian Patagonia. This new taxon is represented by upper and lower cheek
teeth, mandible, and maxillary remains. It is characterized by retention of deciduous premolar, and low-crowned and terraced
lower and upper cheek teeth with well-differentiated cusps, as in Caviocricetus lucasi; uppermolariforms with themesolophule
and metacone fused with the posterior-most crest, as in C. lucasi; lower molars with lingual cusp enlarged and metalophulid
II longer in m2 than in m1and m3, as in Prospaniomys priscus; and dp4 with metalophulid I separated from the metaconid
and a spur projecting posterolingually from the posterior wall of metalophulid I, between the protoconid and anteroconid.
The incisor enamel microstructure is derived, with the interprismatic matrix perpendicular (at a right angle) to the prisms,
as in other octodontoids. A cladistic analysis corroborates that D. ruigomezi represents an octodontoid rodent with unusual
tooth morphology. This analysis demonstrates that the early evolutionary history of Octodontoidea was characterized by
the differentiation of successive lineages that survived until the early or middle Miocene, with no direct relationships with
modern Octodontidae and Echimyidae. This analysis also suggests that fossil taxa previously classified as octodontoids are
instead more closely related to the other caviomorph rodents.