The world before the flood was very different. Many of the fossil creatures we have as fossils from the flood are much larger than the same creatures alive today. I have had several individuals challenge my statements about this so I have had two experts provide citations from typical geology texts.
Fossil Gigantism by Bob Gentet. When I first took Historical Geology in the spring of 1960, we used the book Historical Geology (Second Edition) by Carol O. Dunbar; John Wiley & Sons, Inc. New York, London, 1960 edition. On pages 237 in the chapter on the Pennsylvanian Period, the following is said:
"The insects of this time were truly remarkable for their great size. Out of four hundred forms known from Lower and Middle Pennsylvanian strata, more than a score exceeded 4 inches in length, six attained nearly 8 inches, and three exceeded a foot, the average length being about 2 inches. The largest of all was a dragonflylike type found in the Coal Measures of Belgium, which had a wing spread of 29 inches (Fig. 192). No period since has produced insects so large. Most of these insects were of strange primitive stocks not exactly like any of the modern orders. Cockroaches, however, were very like the living ones, only larger, and so common that the period has sometimes been called the Age of Cockroaches (fig. 195). Several of the Pennsylvanian species achieved a length of 3 or 4 inches.
"The presence of several hundred species of insects in the Pennsylvanian makes their sudden appearance at this time the more remarkable. The [begin page 238] diversity of the forms represented implies a long antecedent evolution whose record may yet be found in Mississippian if not in "Devonian rocks.
"Scorpions, remarkably like modern ones in size and structure, occur with the insect fossils. Spiders (Fig. 196) likewise occur, though none of the fossils shows clear evidence of spinnerets, and it may be that these early forms did not make webs. Centipedes (or myriapods) of several kinds are known, the largest of which, found at Mazon Creek, Illinois, had a length of 12 inches.
"Land snails were first discovered in the famous Joggins section of Nova Scotia, where they were associated with the skeletons of Amphibia. Both had taken refuge in standing hollow stumps that were overwhelmed by floods and buried by sand and mud. Land snails are extremely rate fossils in the Paleozoic rocks, however, and all are small".
1. Levin, H.L. 1992. The Earth Through Time. Fourth edition. Saunders College Publishing. New York. p. 406.
"Carboniferous strata contain a slightly better record of insects, including giant dragonflies with wingspans of over 70 cm (2 feet). Cockroaches that reached lengths of 10 cm crept about among the rotting vegetation."
2. Dunbar, C.O., and K.M. Waage. 1969. Historical Geology. Third edition. John Wiley and Sons. p. 283.
"The insects were many and varied but nearly all belonged to primitive, extinct orders. Among the most common and the most familiar kinds were primitive cockroaches, most of which were larger than their living descendants. One species attained a length of about 4 inches. Close relatives of the modern dragonflies were also common and exceptionally large. One species found in the Coal Measures of Belgium had a wing span of about 29 inches. The insects generally were large. Out of some 400 known species more than a score exceeded 6 inches and three exceeded a foot in length. No other period has produced insects so large."