Ungar P S, Walker A, Coffing K
Department of Cell Biology and Anatomy, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
Am J Phys Anthropol. 1994 Jun;94(2):165-73. doi: 10.1002/ajpa.1330940202.
This paper details a reanalysis of KNM-LU 335, a hominoid mandibular first molar dated to about 6 Ma from the Lukeino Formation, Kenya. Researchers have argued that this molar closely resembles those of modern chimpanzees and may approximate the ancestral morphotype of humans and chimpanzees. The investigation presented here describes a morphometric study of the Lukeino molar and M1s of Homo sapiens, Pan troglodytes, and early australopithecines. Results indicate that KNM-LU 335 differs from both human and chimpanzee M1s in relative distances (measured in three dimensions) between crown fissure termini. Further, the Lukeino molar shares with early australopithecines a pronounced flaring of the buccal surface of the crown not seen for either modern sample. Results of this study do not exclude KNM-LU 335 as a potential ancestral morphotype for Pan and Homo but provide no evidence that this morphotype resembled modern chimpanzees.
本文详细介绍了对KNM-LU 335的重新分析，这是一枚来自肯尼亚卢克尼奥组、年代约为600万年前的类人猿下颌第一磨牙。研究人员认为，这颗磨牙与现代黑猩猩的磨牙非常相似，可能接近人类和黑猩猩的祖先形态类型。此处进行的调查描述了对卢克尼奥磨牙以及智人、黑猩猩和早期南方古猿的M1的形态测量研究。结果表明，KNM-LU 335在牙冠裂隙末端之间的相对距离（三维测量）上与人类和黑猩猩的M1均有所不同。此外，卢克尼奥磨牙与早期南方古猿一样，牙冠颊面有明显的扩张，而现代样本中均未见到这种情况。本研究结果并不排除KNM-LU 335作为黑猩猩和人类潜在祖先形态类型的可能性，但没有证据表明这种形态类型与现代黑猩猩相似。
