中生代鸟类牙齿的退化及其可忽略的体重效应（英文）  

Negligible effect of tooth reduction on body mass in Mesozoic birds

作　　者：周亚纯 舒柯文 张福成 ZHOU Ya-Chun;Corwin SULLIVAN;ZHANG Fu-Cheng(Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences,Institute of VertebratePaleontology and Paleoanthropology,Chinese Academy of Sciences,Beijing 100044,China;University of Chinese Academy of Sciences,Beijing 100049,China;Department of Biological Sciences,University of Alberta Edmonton,Alberta T6G 2E9,Canada;Philip J.Currie Dinosaur Museum Wembley,Alberta T0H 3S0,Canada;Institute of Geology and Paleontology,Linyi University Linyi,Shandong 276000,China)

机构地区：[1]中国科学院古脊椎动物与古人类研究所,中国科学院脊椎动物演化与人类起源重点实验室,北京100044 [2]中国科学院大学,北京100049 [3]加拿大阿尔伯塔大学生命科学学院,埃德蒙顿T6G2E9 [4]加拿大菲利普·柯瑞恐龙博物馆,温布利T6G2E9 [5]临沂大学地质与古生物研究所,山东临沂276000

出　　处：《古脊椎动物学报》2019年第1期38-50,共13页Vertebrata Palasiatica

基　　金：临沂大学人才项目;国家自然科学基金基础科学中心项目(批准号:41688103);加拿大自然科学与工程研究委员会(编号:RGPIN-2017-06246);阿尔伯塔大学启动基金资助~~

摘　　要：牙齿退化是中生代鸟类演化的一个重要过程,牙齿总重综合了牙齿大小和数量的信息,研究这一特征的演化趋势,有助于深入地分析中生代鸟类牙齿退化的原因和方式。然而,现生鸟类均不具齿,无法为研究中生代鸟类的牙齿重量提供参考。除鸟类外的现生脊椎动物中,鳄类与鸟类的亲缘关系最近,且牙齿形态、着生和替换方式与后者相似,因此可为估算中生代鸟类牙齿重量提供参考模型。对从8件现生暹罗鳄标本采得的31枚牙齿进行了形态和重量测量,基于缩放比例原理建立多组回归方程,依此方程对牙齿和齿列保存较完整的中生代鸟类标本进行了牙齿总重估计。结果表明多数中生代鸟类牙齿总重普遍占体重比例极小,据此推测其对飞行的影响可忽略不计,减轻体重的自然选择压力可能不是造成中生代鸟类牙齿退化的主要原因。中生代鸟类牙齿总重的多样性可能反映了其食性和取食行为的差异。Tooth reduction and loss was an important evolutionary process in Mesozoic birds.Analysis of evolutionary trends in the total mass of the dentition,a function of tooth size and tooth number,has the potential to shed light on the evolutionary pattern of tooth reduction and loss,and on the causes of this pattern.Because modern birds lack teeth,however,they cannot provide the basis for a model that would allow estimation of tooth masses in their Mesozoic counterparts.We selected the teeth of crocodilians as analogues of those in Mesozoic birds because the former are the closest living relatives of the latter,and the two groups are similar in tooth morphology,tooth implantation,and tooth replacement pattern.To estimate tooth masses in Mesozoic birds,we formulated four regression equations relating tooth mass to various linear dimensions,which were measured in 31 intact isolated teeth from eight individual crocodiles(Crocodylus siamensis).The results for Mesozoic birds show that dental mass as a proportion of body mass was negligible,at least from the perspective of flight performance,suggesting that selection pressure favoring body mass reduction was probably not the primary driver of tooth reduction or loss.Variations in dental mass among Mesozoic birds may reflect the different foods they ate,and the different types of feeding behavior they displayed.

关 键 词：中生代鸟类 牙齿退化 牙齿重量 体重 取食行为 

分 类 号：Q915.865[天文地球—古生物学与地层学]