許多先前的研究將恐龍在進化上的成功歸因于它們比其它種系所有的“優(yōu)越性”,，但是研究人員現(xiàn)在說,，它們也許僅僅是因為幸運而取得了進化上的成功。相關(guān)論文發(fā)表在9月12日的《科學》（Science）雜志上,。
Stephen Brusatte及其同事對化石記錄進行了研究,，以決定恐龍與主要競爭者鑲嵌踝類初龍在三疊紀的晚期一同進化時它們之間的相互關(guān)系。他們的發(fā)現(xiàn)披露,，與普遍認為的相反,，恐龍并非通過生境和資源競爭而取代了初龍成為這個星球上占統(tǒng)治地位的物種。相反,，研究人員顯示,，恐龍與初龍是同時進化的,，在恐龍存在的頭3 千萬年間，它們所占有的生境是相同的,。這些結(jié)論意味著初龍更可能是因為意外而滅絕,，而不是因為競爭性替代的結(jié)果?？铸埐⒎侨缭S多人所認為的注定會取得進化上的成功，它們可能是2 次大規(guī)模物種消亡事件中的幸運受益者,。（生物谷Bioon.com）
生物谷推薦原始出處：
Science,，Vol. 321. no. 5895, pp. 1485 - 1488，Stephen L. Brusatte,，Graeme T. Lloyd
Superiority, Competition, and Opportunism in the Evolutionary Radiation of Dinosaurs
Stephen L. Brusatte,* Michael J. Benton, Marcello Ruta, Graeme T. Lloyd
The rise and diversification of the dinosaurs in the Late Triassic, from 230 to 200 million years ago, is a classic example of an evolutionary radiation with supposed competitive replacement. A comparison of evolutionary rates andmorphological disparity of basal dinosaurs and their chief "competitors," the crurotarsan archosaurs, shows thatdinosaurs exhibited lower disparity and an indistinguishable rate of character evolution. The radiation of Triassic archosaurs as a whole is characterized by declining evolutionary rates and increasing disparity, suggesting a decoupling of character evolution from body plan variety. The results strongly suggest that historical contingency, rather than prolonged competition or general "superiority," was the primary factor in the rise of dinosaurs.
