“The earliest and most primitive known members of every order already have the basic ordinal characters, and in no case is an approximately continuous sequence from one order to another known. In most cases the break is so sharp and the gap so large that the origin of the order is speculative and much disputed.” CharacterOrderKnownBreakCasesMembersGapsPrimitiveFossilsSequence Author:George Gaylord Simpson
“Almost all paleontologists recognize that the discovery of a complete transition is in any case unlikely.” CasesDiscoveryTransitionUnlikely Author:George Gaylord Simpson
