Prevosti Francisco J
Cladistics. 2010 Oct;26(5):456-481. doi: 10.1111/j.1096-0031.2009.00298.x.
South America currently possesses a high diversity of canids, comprising mainly small to medium-sized omnivorous species, but in the Pleistocene there were large hypercarnivorous taxa that were assigned to Protocyon spp., Theriodictis spp., Canis gezi, Canis nehringi and Canis dirus. These fossils have never been included in phylogenies based on quantitative cladistics, but hand-constructed cladograms published in the 1980s included some of them in the South American canine clade and others in the Canis clade. In this work, the phylogenetic position of the large extinct South American canids was studied using a large sample of living and extinct canids, as well as different sources of characters (e.g. DNA and 133 osteological characters). The phylogenetic analysis corroborates the inclusion of Theriodictis and Protocyon in the "South American clade", where C. gezi is also included. In addition, the position of C. dirus as a highly derived Canis species is confirmed. The simultaneous analysis supports hypercarnivory having arisen at least three times in Caninae and once in the "South American clade". The combination of the phylogenetic analyses, the fossil record and divergence dates estimated in previous works suggests that at least three or four independent lineages of the "South American clade" invaded South America after the establishment of the Panama bridge around 3 million years ago, plus other events corresponding to the immigration of Urocyon and Canis dirus. © The Willi Hennig Society 2009.
南美洲目前拥有高度多样化的犬科动物,主要包括中小型杂食性物种,但在更新世时期,存在大型超食肉动物类群,它们被归类为原犬属(Protocyon spp.)、恐犬属(Theriodictis spp.)、格氏犬(Canis gezi)、内氏犬(Canis nehringi)和恐狼(Canis dirus)。这些化石从未被纳入基于定量分支系统学的系统发育研究中,但20世纪80年代发表的手工构建的分支图将其中一些归入南美犬科分支,另一些归入犬属分支。在这项研究中,利用大量现存和已灭绝犬科动物样本以及不同的性状来源(如DNA和133个骨骼性状),对已灭绝的大型南美犬科动物的系统发育位置进行了研究。系统发育分析证实了恐犬属和原犬属被纳入“南美分支”,格氏犬也在其中。此外,确认了恐狼作为高度特化的犬属物种的位置。同时分析支持超食肉性在犬亚科中至少独立出现过三次,在“南美分支”中出现过一次。系统发育分析、化石记录以及先前研究中估计的分歧时间相结合表明,在约300万年前巴拿马地峡形成后,“南美分支”中至少有三到四个独立谱系侵入南美洲,另外还有与狐属(Urocyon)和恐狼迁入相关的其他事件。©威利·亨尼希协会2009年。