The entrance of sin into the world allowed Satan to corrupt humans and other living creatures. Now we have leaves changed to thorns, teeth changed to poison fangs, genes changed into viruses and useful bacteria into disease producers. Satan corrupted some of the reptiles God originally created into the bizarre creatures we call dinosaurs. God chose not to save them at the time of the Flood. Perhaps God also saw that feeble post-flood humans would not be able to control such large animals. Thus, we suggest that God preserved the air-breathing, land animals, except the very large animals and the corrupted ones.