最近對始新世原始靈長類Darwinius（或稱“Ida”）的介紹引起了一陣騷動，因為有人稱它是一個曾經(jīng)“缺失的環(huán)節(jié)”,，接近包括人類在內(nèi)的類人猿（高等靈長類）的祖先,。古生物學(xué)家對此有所擔(dān)心，因為很少有人認(rèn)為Darwinius所屬的已滅絕的類別（即adapoids）接近類人猿,。
現(xiàn)在,，Erik Seiffert及其同事介紹了一個在埃及新發(fā)現(xiàn)的距今已有3700萬年的adapoid（被命名為Afradapis）的頜骨和牙齒。雖然詳細(xì)的系統(tǒng)發(fā)生分析表明,，這一新形式（同Darwinius一樣）與類人猿只是有遠(yuǎn)親關(guān)系,，但它的確有幾個能夠說明趨同進(jìn)化的特征?？赡艿那闆r是,，Darwinius 和Afradapis都是一個類別中的成員，這個類別在始新世中期趨同進(jìn)化出一些與類人猿相似的適應(yīng)性特征,，但它們在始新世晚期和漸新世早期最終被真正的類人猿取代了,。（生物谷Bioon.com）
生物谷推薦原始出處：
Nature 461, 1118-1121 (22 October 2009) | doi:10.1038/nature08429
Convergent evolution of anthropoid-like adaptations in Eocene adapiform primates
Erik R. Seiffert1, Jonathan M. G. Perry2, Elwyn L. Simons3 & Doug M. Boyer4
1 Department of Anatomical Sciences, Stony Brook University, Stony Brook, New York 11794-8081, USA
2 Department of Anatomy, Midwestern University, Downers Grove, Illinois 60515, USA
3 Division of Fossil Primates, Duke Lemur Center, 1013 Broad Street, Durham, North Carolina 27705, USA
4 Department of Ecology & Evolution, Stony Brook University, Stony Brook, New York 11794-5245, USA
5 Correspondence to: Erik R. Seiffert1 Correspondence and requests for materials should be addressed to E.R.S.
Adapiform or 'adapoid' primates first appear in the fossil record in the earliest Eocene epoch (55 million years (Myr) ago), and were common components of Palaeogene primate communities in Europe, Asia and North America1. Adapiforms are commonly referred to as the 'lemur-like' primates of the Eocene epoch, and recent phylogenetic analyses have placed adapiforms as stem members of Strepsirrhini2, 3, 4, a primate suborder whose crown clade includes lemurs, lorises and galagos. An alternative view is that adapiforms are stem anthropoids5. This debate has recently been rekindled by the description of a largely complete skeleton of the adapiform Darwinius 6, from the middle Eocene of Europe, which has been widely publicised as an important 'link' in the early evolution of Anthropoidea7. Here we describe the complete dentition and jaw of a large-bodied adapiform (Afradapis gen. nov.) from the earliest late Eocene of Egypt (37 Myr ago) that exhibits a striking series of derived dental and gnathic features that also occur in younger anthropoid primates—notably the earliest catarrhine ancestors of Old World monkeys and apes. Phylogenetic analysis of 360 morphological features scored across 117 living and extinct primates (including all candidate stem anthropoids) does not place adapiforms as haplorhines (that is, members of a Tarsius–Anthropoidea clade) or as stem anthropoids, but rather as sister taxa of crown Strepsirrhini; Afradapis and Darwinius are placed in a geographically widespread clade of caenopithecine adapiforms that left no known descendants. The specialized morphological features that these adapiforms share with anthropoids are therefore most parsimoniously interpreted as evolutionary convergences. As the largest non-anthropoid primate ever documented in Afro-Arabia, Afradapis nevertheless provides surprising new evidence for prosimian diversity in the Eocene of Africa, and raises the possibility that ecological competition between adapiforms and higher primates might have played an important role during the early evolution of stem and crown Anthropoidea in Afro-Arabia.
