Darwinists maintain that reptiles are descended from amphibians. Yet just as they cannot corroborate the claim that amphibians have a common forerunner, so are they unable to substantiate the claim that reptiles are descended from amphibians. Many scientists are well aware of this. For example, Robert L. Carroll, author of the book Problems of the Origins of Reptiles, writes: "Unfortunately not a single specimen of an appropriate reptilian ancestor is known prior to the appearance of true reptiles. The absence of such ancestral forms leaves many problems of the amphibian-reptilian transition unanswered." (Robert L. Carroll, "Problems of the Origin of Reptiles," Biological Reviews of the Cambridge Philosophical Society, Vol. 44, No. 3, July 1969, p. 393) The 65-million-year-old crocodile fossil pictured is proof that crocodiles are not descended from any supposed ancestor, but have always existed as crocodiles, remaining unchanged over tens of millions of years.