
Figure 1. Three-dimensional models derived from µCT scan data of Zanycteris paleocenus (AMNH 17180) with descriptions and orientations of skeletal elements organized from left to right. (a) Cranium in dorsal and ventral views with basicranial region transparent showing original position of digitally extracted bones. Box illustrates left upper molars rotated into occlusal view with distolingual basin (asterisk) and postprotocingulum (arrow). (b) Three-dimensional model of right petrosal in ventral view, composite line drawing incorporating preserved morphology from right and left petrosal, and composite line drawing with major neurovascular structures; (c) R partial ectotympanic in oblique posterior and ventral view; (d) R partial alisphenoid/basisphenoid in lateral and ventral view. Scale bars, 1 mm. Abbreviations: C = upper canine; C a = upper canine alveolus; M = upper molar; P a = upper premolar alveolus.
The only certainty in science is that there are no certainties in science.
Unlike religions which provide unreasonable certainty in the absence of evidence and call it 'faith', science provides reasonable uncertainty and provisional opinion pending further evidence.
This was illustrated a couple of days ago by a paper published in Royal Society Biology Letters, which describes the reclassification of a middle Palaeocene placental mammal, known to science as a picrodontid, and known only from a partial cranium, some teeth and pieces of jawbone. This was discovered about 100 years ago and 50 years ago was classified as an early primate, in other words, close to the remote placental common ancestor of all the apes, monkeys, lemurs, tree shrews, etc.
Just to remind creationists: the middle Palaeocene lasted from about 66 million years before the mythical 'Creation Week' to 56 million years before the mythical creation of the Universe. It began a few million years after the non-avian dinosaurs all went extinct.