傳統(tǒng)觀念認(rèn)為，恐龍只會(huì)在白天活動(dòng),，美國(guó)研究人員14日公布的研究成果挑戰(zhàn)了這一觀念,。他們完成的一項(xiàng)對(duì)相關(guān)動(dòng)物眼睛形狀所做的研究顯示，恐龍中也有“夜貓子”,。
加利福尼亞大學(xué)戴維斯分校的研究人員對(duì)164種現(xiàn)存哺乳動(dòng)物,、爬行動(dòng)物和鳥(niǎo)類(lèi)的眼睛進(jìn)行了分析，并判定了其活動(dòng)模式與眼睛結(jié)構(gòu)的關(guān)系,。這些動(dòng)物的活動(dòng)模式分為白天型,、夜間型、24小時(shí)中隨時(shí)活動(dòng)的無(wú)定時(shí)型,。研究人員發(fā)現(xiàn),，白天活動(dòng)的動(dòng)物的眼部鞏膜環(huán)開(kāi)口較小，而夜間活動(dòng)的動(dòng)物開(kāi)口較大,。
研究人員接著分析了來(lái)自33種恐龍的化石,，并根據(jù)它們的眼睛結(jié)構(gòu)特征來(lái)推斷其活動(dòng)模式。他們發(fā)現(xiàn),，翼龍等飛行動(dòng)物大多在白天活動(dòng),，食肉恐龍大多在夜間活動(dòng),，有些可能在夜間還很活躍，而食草恐龍大多是無(wú)定時(shí)活動(dòng)的動(dòng)物,。
據(jù)研究人員介紹,，因電影《侏羅紀(jì)公園》而名聲大噪的速龍很可能就是“夜貓子”,，而兇猛的食肉動(dòng)物霸王龍是否夜間活動(dòng)目前仍無(wú)法下結(jié)論,，因?yàn)槠裆形闯鐾帘４嫱旰玫陌酝觚堁鄄炕?/p>
上述研究成果15日發(fā)表在美國(guó)新一期《科學(xué)》雜志上。（生物谷Bioon.com）
生物谷推薦原文出處：
Science, 14 April 2011 DOI: 10.1126/science.1200043
Nocturnality in Dinosaurs Inferred from Scleral Ring and Orbit Morphology
Lars Schmitz and Ryosuke Motani
Variation in daily activity patterns facilitates temporal partitioning of habitat and resources among species. Knowledge of temporal niche partitioning in paleobiological systems has been limited by the difficulty of obtaining reliable information about activity patterns from fossils. On the basis of an analysis of scleral ring and orbit morphology in 33 archosaurs, including dinosaurs and pterosaurs, we show that the eyes of Mesozoic archosaurs were adapted to all major types of diel activity (that is, nocturnal, diurnal, and cathemeral) and provide concrete evidence of temporal niche partitioning in the Mesozoic. Similar to extant amniotes, flyers were predominantly diurnal; terrestrial predators, at least partially, nocturnal; and large herbivores, cathemeral. These similarities suggest that ecology drives the evolution of diel activity patterns.
