Letters ‘Unfossilized’ Books, Green Forest, AR, 1998. This book these [dinosaur nests and eggs, is an adventure story of our trip and not a some of which contain embryos] in scientific report of the bones. Alaskan dinosaur a catastrophic framework suggests 2. Davies, K.L., Duck-bill dinosaurs (Hadro- that perhaps female dinosaurs bones? sauridae, Ornithischia) from the North Slope of Alaska, J. Paleontology 61(1):198–200, retained their eggs within their 1987. bodies until the eggs were almost Recently, I have been barraged ready to hatch, as some modern with a number of inquires about the 3. Brouwers, E.M., Clemens, W.A., Spicer, R.A., Ager, T.A., Carter, L.D. and Sliter, W.V., reptiles do (Goin et al. 1978). dinosaur bones I collected from the Dinosaurs on the North Slope of Alaksa: high When the season for egg-laying North Slope of Alaska in 1994.1 The latitude, latest Cretaceous environments, Sci- arrived, they would search for a literature reported that the preservation ence 237:1608–1610, 1987. place to build a nest. The land of the bones was ‘remarkable’.2,3 This 4. See <www.ak.blm.gov/ak930/akdino.html>. led many, including myself, to believe surface during the flood was not that the bones were ‘unfossilized’. all underwater all the time (as Many (but not all) of the bones we evidenced by the numerous animal collected were very lightweight, which Dinosaur eggs tracks on mudflat environments), seemed to confirm this hypothesis. so the dinosaurs built nests on It was our hope, because of the and the post-Flood an exposed surface and laid their ‘remarkable’ preservation, that these eggs. The next inflow of sediments bones might contain some ancient boundary catastrophically buried the nests organic molecules. To date, our tests (nests of eggs would be well- have not been able to confirm the Andrew Sibley has suggested preserved only by rapid burial). ‘unfossilized’ hypothesis. Twenty the possibility that pregnant female ... This could happen repeatedly, of the bone samples were analyzed dinosaurs could have postponed laying resulting in several levels of nests in Russia for collagen. Only four their eggs until days/weeks into the in the same geographic area. This showed positive results. We became Genesis Flood, by which time the story certainly should not be suspicious of these results when we embryos would have been well- taken as a final answer, but it is a were not able to confirm them with developed.1 He cites the Komodo hypothesis to be tested.’3 tests made by other labs. One report monitor as an example of a reptile We have ample means for from a reputable laboratory in the that can breed during the heat of the ‘testing’ the hypothesis that female United States told us the samples they summer, but can withhold laying its dinosaurs may have held their eggs tested were ‘extremely degraded’. eggs until cooler months, such as almost to maturity before depositing Some of the bones have also been September. He also points out that them on newly-exposed Flood tested for DNA. The results were if eggs are withheld for too long they sediments, even though the testing inconclusive. From our results thus develop a second shell, suffocating the cannot be accomplished with live far, the bones should not be referred embryo. This may serve as a parallel dinosaurs naturally. The reference to to as ‘unfossilized’. to dinosaurs, whose eggs on rare Goin et al. in Brand’s quotation above The Bureau of Land Management occasions have been found with double is probably to either or both of the reports4 that the Alaskan bones are shells. According to Sibley, dinosaurs following two passages: fossilized, but all of their pore spaces would have withheld their eggs until ‘Usually the young of amphibians have not been filled in with rock, suitable times during the Flood when hatch after the eggs have been making many of them lightweight. they could walk out on freshly exposed laid and the animals are said to be They also report that no DNA had been land and lay their eggs—eggs that oviparous. Rarely, however, the discovered in the bones, but because would be close to maturity. This they eggs are retained in the body of of their condition, they might be good could do repeatedly, accounting for the female while they pass through candidates for it. Until further testing eggs at different stratigraphic levels. their embryonic development and can prove otherwise, the Alaskan More recently, Walter R. Barnhart has the young are “born alive.” If the dinosaur bones should be referred to likewise hypothesized that ‘embryo developing embryo in the mother’s as ‘fossilized’. development may have been already body is nourished entirely by food well underway when some dinosaur stored in the yolk of the egg, the John H. Whitmore eggs were deposited’.2 animal is ovoviviparous.’4 Cedarville, Ohio One of the first creationists to ‘Most reptiles are oviparous. UNITED STATES of AMERICA suggest that dinosaur eggs may have Some lizards and snakes are References reached near maturity within the ovoviviparous, with the eggs uteruses of females is Leonard Brand, hatching either in the oviduct or 1. Davis, B., Liston, M. and Whitmore, J., The who wrote: just after they are laid. ... Eggs of Great Alaskan Dinosaur Adventure, Master ‘One hypothesis for interpreting some colubrid snakes, examined at 66 TJ 19(3) 2005 Letters ovideposition The warmth of the dinosaur would take mother’s body from heat generated by place very early extensive swimming or track-making in embryonic during the Flood likewise could mean development at that their eggs would not have been the latest. One held for very long in the mother’s body. should also Additionally, as Sibley points out, if keep in mind eggs are held for very long in a mother that all modern Komodo’s body, then a second layer is analogs cited deposited on the eggshell. The extreme in creationist rarity of second layers on dinosaur eggs l i t e r a t u r e proves that most dinosaur eggs were (Sibley and deposited in a fairly short period after B r a n d , f o r their formation in the female’s body. Photo by Sasan <www.sxc.hu> example) refer Moreover, the extreme rarity Most reptiles are oviparous, with their young hatching outside their body to ectotherms, of dinosaur eggs discovered within after the eggs have been laid. or cold-blooded fossilized dinosaur skeletons argues vertebrates, against the idea that gravid female the time of deposition, contained such as amphibians, turtles, snakes, and dinosaurs were carrying their eggs embryos ranging from 15 to 55 lizards. Dinosaurs most likely were not for weeks or even months during the mm in length. Such eggs may ectotherms, and some have suggested Flood, otherwise one should find eggs not hatch for two or three months. they were endotherms, or warm- within, or near to, articulated dinosaur Alligator eggs also seem to go blooded creatures.7 Possibly, though, skeletons buried suddenly in a watery through some development in the they were at an intermediate state catastrophe.11 Eggs would have no oviduct before deposition. This between ectothermy and endothermy. time to be ejected! The first conclusive is also true for some of the spiny Recent evidence from growth discovery of dinosaur eggs within lizards (Sceloporus).’5 lines in tyrannosaur bones offers a dinosaur skeleton has now been Do the above examples confirmation that dinosaur metabolism reported in 2005.12 provide modern analogs for the extinct was midway between that of modern Significantly, only two eggs dinosaurs and their reproductive birds and reptiles.8 This has important were found in the cloacal area of an behaviour? The answer is found when implications on whether dinosaur oviraptosaurian dinosaur, suggesting one considers the relationship between eggs were retained for very long that dinosaurs had two oviducts as in egg-shell thickness and the degree of within the living females. The great modern crocodiles, but did not retain development that takes place in the egg number of dinosaur tracks and the a whole clutch of eggs in their uterus prior to egg laying, or ovideposition, as length of trackways indicate that a prior to laying, as do modern reptiles illustrated in the following quote: large amount of metabolic heat would and amphibians. Elsewhere, two ‘The extent of gas exchange may have been generated within the bodies clutches of oviraptosaurian dinosaurs explain the amount of development of these large creatures, which would have been discovered with an adult that occurs prior to oviposition in be detrimental to any embryos within atop the clutches, each clutch having reptilian eggs (Andrews 2000). eggs. Jerry Bergman has recently at least fifteen eggs. If eggs were laid Turtles and crocodilians have highlighted findings showing that only two at a time, which is more like thick eggshells and oviposit at birds could not retain their eggs for a all modern birds that lay just one egg the gastrula and neurula stages, long duration in their bodies because until another is produced, then the egg- respectively. On the other hand, the warmth of the exercising mother laying process happened over a period most squamates have relatively thin would have led either to death or to of a few days and not all at once. This eggshells and oviposit when 25 to deformation in the young.9 The body would be comparable to ostriches that 40 percent of development has been temperature of birds ranges between lay one egg every two days until the completed (Shine 1983a, DeMarco 40° C and 41° C in most cases.