Krishtalka L, Stucky R K, Beard K C
Section of Vertebrate Paleontology, Carnegie Museum of Natural History, Pittsburgh, PA 15213.
Proc Natl Acad Sci U S A. 1990 Jul;87(13):5223-6. doi: 10.1073/pnas.87.13.5223.
Recently obtained material of the early Eocene primate Notharctus venticolus, including two partial skulls from a single stratigraphic horizon, provides the geologically earliest evidence of sexual dimorphism in canine size and shape in primates and the only unequivocal evidence for such dimorphism in strepsirhines. By analogy with living platyrrhines, these data suggest that Notharctus venticolus may have lived in polygynous social groups characterized by a relatively high level of intermale competition for mates and other limited resources. The anatomy of the upper incisors and related evidence imply that Notharctus is not as closely related to extant lemuriform primates as has been recently proposed. The early Eocene evidence for canine sexual dimorphism reported here, and its occurrence in a nonanthropoid, indicates that in the order Primates such a condition is either primitive or evolved independently more than once.
最近获得的始新世早期灵长类动物风氏北方狐猴（Notharctus venticolus）的材料，包括来自单一地层层面的两个部分头骨，提供了灵长类动物犬齿大小和形状两性异形在地质上最早的证据，也是狐猴亚目中这种两性异形的唯一明确证据。通过与现存阔鼻猴类比，这些数据表明风氏北方狐猴可能生活在一夫多妻制的社会群体中，其特征是雄性之间为争夺配偶和其他有限资源的竞争较为激烈。上门齿的解剖结构及相关证据表明，风氏北方狐猴与现存狐猴型灵长类动物的亲缘关系并不像最近所提出的那样密切。此处报道的始新世早期犬齿两性异形的证据，以及它在非类人猿中的出现，表明在灵长目动物中，这种情况要么是原始的，要么是不止一次独立进化而来的。
