“It has been argued that dinosaurs did not die out, but just evolved wings and flew away. At a certain level, this reasoning is sound.... Birds, as a group, did descend from dinosaurs and ... all 8,600 species of birds living today carry some inheritance from their reptilian ancestors.” Has BeensTodayCertainDiesSoundLevelsGroupsBirdWingsSpeciesReasoningAncestorInheritanceFlewDinosaurs Author:David M. Raup
“The charge that the construction of the geologic scale involves circularity has a certain amount of validity. ...Thus, the procedure is far from ideal and the geologic ranges are constantly being revised (usually extended) as new occurrences are found.” CertainFoundAmountIdealsScalesRangeConstructionProceduresValidityCircularity Author:David M. Raup
