“假磨楔式”：一个概念的发展历史(英文)

PSEUDOTRIBOSPHENIC:THE HISTORY OF A CONCEPT

大多数情况下古生物学是事后解释的科学,也就是说,在大多数情况下它的中心任务是解释存在的资料。古生物学成为预测科学的一个罕见的实例见诸于"假磨楔式"这个概念的发展历史中。根据一个假磨楔式哺乳动物的单个齿骨上的下臼齿结构,推测出当时尚不知道的上臼齿结构。随后,被认为很可能属于假磨楔式哺乳动物的单个上臼齿以及更晚的一件具有咬合在一起的上下臼齿的标本的发现证实了最初的假设。磨楔式臼齿结构作为哺乳动物历史中一个关键的创新结构,本身相当复杂。假磨楔式概念的被接受在认识磨楔式臼齿结构方面具有重要意义,这个结构可能发生不止一次。"假磨楔式"这个术语最初提出之后,随着它的使用,一些后来的研究者的用法严重偏离了它的本义。这一术语既被用来描述并不以原始定义的假磨楔式方式咬合的柱齿兽类牙齿,也被用于描述明显属于原始定义的磨楔式而不是假磨楔式牙齿。结果是古生物学界对其定义的理解变得更不准确,这个概念的实用性因此大大削弱。所以,回归最初的定义是合适的。

Palaeontology is for the most part a postdictive science.That is,its central task is for the most part to explain existing data.A rare instance of palaeontology being a predictive science is to be found in the history of the development of the pseudotribosphenic concept.Based on the structure of the lower molars in a single dentary of a pseudotribosphenic mammal,the structure of the then unknown upper molars was hypothesized.The subsequent discovery first of an isolated upper molar regarded as likely to be a pseudotribosphenic mammal and later,a specimen of a pseudotribosphenic mammal with its upper and lower molars in occlusion,rigorously corroborated the original hypothesis.The acceptance of the pseudotribosphenic concept was instrumental in the recognition that the tribosphenic condition,a key innovation in the history of mammals,could well have arisen more than once,despite its complexity.Living languages evolve through time.As the term ＂pseudotribosphenic＂ was utilised after being originally coined,its usage by some subsequent workers departed significantly from the original concept.The term has been used both to describe teeth of docodonts which do not occlude in the pseudotribosphe-nic manner as originally defined as well as teeth that were clearly tribosphenic as that term was originally defined rather than pseudotribosphenic.As a result,its definition as understood by the paleontological community became less precise,and thus the utility of the concept was significantly reduced.Consequently,a return to the original definition would be appropriate.