...In a twenty-page review in Social Studies of Science, Jo Wodak and David Oldroyd describe the book's argument: Early paleoanthropologists, in the late nineteenth century and early twentieth, interpreted much empirical information as evidence favoring the existence of human beings in the Tertiary period (about 65.5 million to 2.6 million ago). But starting from about the 1930s, paleoanthropologists turned to the view that human beings first evolved in the next era, the Pleistocene (2.6 million to 11,700 years ago). The older evidence, Cremo and Thompson say, was never shown bad; it was just reinterpreted in such a way as to rule out tertiary humans. So what Cremo and Thompson have done is "comb the early literature in great—indeed impressive—detail"[6]:196 and argue, on the basis of their historical study, "that the old arguments were never satisfactorily disproved and should be reconsidered with open minds".[6]:206–207
...Reviewing the book in the French journal L'anthropologie, paleontologist Marylene Patou-Mathis wrote that the book is "a provocative work that raises the problem of the influence of the dominant ideas of a time period on scientific research. These ideas can compel researchers to publish their analyses according to the conceptions permitted by the scientific community."[8]:159 The evidence Cremo and Thompson bring forward for the very ancient origin of humanity, she wrote, "isn't always convincing (far from it)," but "the documentary richness of this work, more sociological than scientific, isn't to be overlooked."
...Writing in Geoarcheology,[9]:338 anthropologist Kenneth L. Feder said, "While decidedly antievolutionary in perspective, this work is not the ordinary variety of antievolutionism in form, content, or style. In distinction to the usual brand of such writing, the authors use original sources and the book is well written. Further, the overall tone of the work is far superior to that exhibited in ordinary creationist literature. Nonetheless, I suspect that creationism is at the root of the authors' argument, albeit of a sort not commonly seen before."