Brain Evolution and Archaeopteryx

Abstract

THE brain of Archaeopteryx lithographica, the earliest fossil bird, is known from a natural endocranial cast exposed in the famous specimen on display at the British Museum (Natural History). Edinger¹ and de Beer² have agreed that its brain was “similar in type and structure to that of reptiles and different from that of all other known birds” (ref. 2, page 13). Through the courtesy of Dr H. W. Ball, keeper of palaeontology at the museum, I have been able to examine a copy of the endocast prepared by de Beer. I agree that the brain differed from that of known birds, but it seems to me clearly avian in external form and intermediate between bird and reptile brains with respect to size. The new interpretation of Archaeopteryx results from the discovery of the true midline suture of the skull a few millimetres away from the line that has until now been thought to be the midline.