The Bible matter-of-factly states that humans living before and shortly after the Genesis Flood had centuries-long lifespans (Genesis 5 and 11). Yet the Bible gives no indication that this remarkable longevity was supernatural. If such human longevity was indeed natural, then early animals likely also had very long lifespans, since almost any conceivable cause for greater human longevity (fewer DNA mutations, a more optimal environment, etc.) would also have affected the animals. This would include birds, and a new proposal for why fossil birds lost their teeth is consistent with longer pre-Flood lifespans.

Direct and indirect evidence already published in the conventional scientific literature shows that fossil clams and oysters, sharks, crocodilians, and some small mammals lived much longer than comparable creatures today.¹ Also, generally, larger animals live longer than smaller animals, and long-lived animals take longer to mature than shorter-lived animals.²

At least some fossil birds were much larger than today’s birds.³ And most of today’s birds take a few weeks to months to reach adulthood,⁴ yet multiple fossil birds took several years to do so.⁵ Such delayed maturation is consistent with longer bird lifespans, and it may help creationists explain why some fossil birds had teeth, though true teeth are not present in any of today’s birds.

Yang and Sander suggested that teeth are absent in today’s birds because they take less time to hatch than fossil birds.⁶ Tooth growth in some extant reptiles doesn’t even start until at least 40% of the incubation time has elapsed, and embryonic bird teeth may follow a similar development schedule. If so, today’s birds may lack teeth because they hatch too quickly for teeth to form. Therefore, teeth could be indirect evidence that fossil birds had longer incubation times. And since longer-lived creatures often take longer to mature than shorter-lived animals, both before and after birth or hatching,⁷ this could be more evidence that fossil birds had longer lifespans than today’s birds.

Evolutionary scientists claim fossil birds inherited their teeth from reptile ancestors but eventually lost them through mutations and natural selection. But there could be another explanation. Teeth are useful but not absolutely necessary structures. Perhaps there are coded instructions within a bird’s genome or other non-genetic information that instruct the embryo not to begin tooth formation when teeth are not an adaptive priority and/or when the anticipated incubation time is too short to complete the tooth formation process. Rather, instructions optimize the developing embryo to give higher priority to more essential structures and functions. This could be another example of adaptation guided by continuous environmental tracking.⁸

Bible-believing Christians should be encouraged by this. Delayed maturation and larger body sizes in at least some fossil birds are consistent with the Bible’s testimony of greater longevity on the pre-Flood earth. And the evolutionary lens is not the only, nor often the best, one through which one can interpret scientific data. Living things, and even their fossils, confirm Scripture and testify to Jesus’ engineering genius.

References

1. Hebert, J. 2025. Croc Fossils Hint at Extreme Longevity. Acts & Facts. 54 (2): 18.
2. Hebert, L. III. 2023. Allometric and Metabolic Scaling: Arguments for Design . . . and Clues to Explaining Pre-Flood Longevity? Proceedings of the International Conference on Creationism. 9, article 18.
3. Burakoff, M. Terror Birds, Giga-Geese, and the Oldest Birds of Prey? 2024’s Fascinating Avian Fossil Finds. Audubon Magazine. Posted on audubon.org December 20, 2024, accessed October 17, 2025.
4. Canoville, A. A. et al. 2022. New Comparative Data on the Long Bone Microstructure of Large Extant and Extinct Flightless Birds. Diversity. 14 (298): 26.
5. Padian, K. 2023. 25th Anniversary of the First Known Feathered Dinosaurs. Nature. 613 (7943): 251–252.
6. Yang, T.-R. and P. M. Sander. 2018. The Origin of the Bird’s Beak: New Insights from Dinosaur Incubation Periods. Biology Letters. 14 (5): 1–5.
7. Ricklefs, R. E. 2010. Life-History Connections to Rates of Aging in Terrestrial Vertebrates. PNAS. 107 (22): 10,314–10,319.
8. Guliuzza, R. J. 2023. Continuous Environmental Tracking: An Engineering-Based Model of Adaptation. Acts & Facts. 52 (6): 22–23.

* Dr. Hebert is a research scientist at the Institute for Creation Research and earned his Ph.D. in physics from the University of Texas at Dallas.

Stage image: The famous bird Archaeopteryx had teeth
Stage image credit: James L. Amos, CC BY 1.0, public domain