Abello María Alejandra, De Los Reyes Martín, Candela Adriana Magdalena, Pujos Francois, Voglino Damián, Quispe Bernardino Mamani
Laboratorio de Sistemática y Biología Evolutiva (LASBE), Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata. Paseo del Bosque s/n, B1900FWA, La Plata, Argentina.; Email:
División Paleontología Vertebrados, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata. Paseo del Bosque, B1900FWA La Plata, Argentina.; Email:
Zootaxa. 2015 Mar 24;3937(1):147-60. doi: 10.11646/zootaxa.3937.1.7.
A new species of sparassocynid marsupial, Sparassocynus maimarai n. sp. from the late Miocene of Maimará Formation (Jujuy Province, Argentina) is described from a left mandibular fragment with a complete p2-m4 series. It differs from the remaining species of the genus S. bahiai (Montehermosan-late Miocene/early Pliocene-of Buenos Aires Province, Argentina) and S. derivatus (Chapadmalalan and Marplatan-Pliocene of Buenos Aires Province) by its smaller size, the relatively longer m1 with respect to the m4, the presence of a lingual cingulum extended between para- and metaconid on the m1-3, and its more robust entoconids. As part of this study the taxonomic status of Sparassocynus heterotopicus (Montehermosan, Umala, Bolivia; Pliocene) was reviewed concluding that this taxon should be referred to as 'Sparassocynus' heterotopicus and considered a Didelphoidea of uncertain affinities. Sparassocynus maimarai n. sp. is the oldest records of the genus, adding new information to evaluate the origins and early diversification of sparassocynids. Sparassocynus maimarai n. sp. was recovered with precise stratigraphic control, highlighting its potential biostratigraphic significance to the temporal correlations between Maimará Formation and other Mio-Pliocene stratigraphic units from the northwestern Argentina.
一种新的袋鼬科有袋动物——来自阿根廷胡胡伊省迈马腊组晚中新世的迈马腊袋鼬（Sparassocynus maimarai n. sp.），依据一块带有完整p2 - m4齿列的左下颌骨碎片进行描述。它与袋鼬属的其他物种，即阿根廷布宜诺斯艾利斯省蒙特埃尔莫桑 - 晚中新世/早上新世的巴伊亚袋鼬（S. bahiai）和布宜诺斯艾利斯省查帕德马拉兰阶和马尔普拉坦阶 - 上新世的衍生袋鼬（S. derivatus）不同，其体型较小，相对于m4而言m1相对较长，在m1 - 3上存在延伸至副尖和后尖之间的舌侧齿带，且其下内尖更粗壮。作为本研究的一部分，对异位袋鼬（Sparassocynus heterotopicus，来自玻利维亚乌马拉蒙特埃尔莫桑阶，上新世）的分类地位进行了重新审视，得出该分类单元应被称为“异位袋鼬”，并被认为是亲缘关系不确定的负鼠总科动物。迈马腊袋鼬（Sparassocynus maimarai n. sp.）是该属最古老的记录，为评估袋鼬科的起源和早期分化增添了新信息。迈马腊袋鼬（Sparassocynus maimarai n. sp.）是在精确的地层控制下发现的，突出了其对迈马腊组与阿根廷西北部其他中新世 - 上新世地层单元之间时间对比的潜在生物地层学意义。
