According to the evolutionary narrative, life supposedly began as single-celled creatures that slowly became multicellular animals and plants. Through time, these evolved into a plethora of marine invertebrates (animals without a backbone), such as trilobites and sea stars. Over many more millions of years, invertebrates evolved into the first vertebrates—the fish. From these came amphibians like frogs, and eventually, fully terrestrial animals. But did these early four-limbed animals, known as tetrapods, really transition from fins to limbs?^1,2

Recently unearthed crocodile-like fossils have devastated the long-held conventional assumption about how animals supposedly adapted to a terrestrial environment.³ At Mazon Creek, a fossil deposit located outside of Chicago, researchers found fossilized juvenile tetrapods called embolomeres that didn’t meet conventional expectations.

Conventional scientists have heavily relied on metamorphosis, the process of abrupt morphological changes in animals, to explain the transition of various creatures from living in water to living on land. But the baby embolomeres lacked any indication of this. Despite being only a few weeks old when they were overcome by sediments and buried, they showed no larval stage, external gills, or other anticipated features, causing the researchers to admit that the story of metamorphosis “doesn’t work anymore, it’s dust in the wind.”^3,4 They even go so far as to say their discovery “rewrites decades of scientific understanding of early tetrapod evolution.”³

The development of embolomeres instead appears to be much more direct—they simply grow from a smaller to bigger version of themselves without a detectable metamorphic stage. Not surprisingly, this is comparable to development in the mammals, birds, and reptiles of today. The lack of significant metamorphosis has been observed across several other fossil groups as well.

Arjan Mann, a coauthor of the study, made a final comment that creationists applaud: “I think the take home message of this study is that we should always challenge conventional wisdom in science, especially when these older ideas do not have substantial backing.”⁵ Would that also include the philosophy of naturalism masquerading as science?

References

1. Sherwin, F. 2013. Paleontology’s Pelvic Puzzle. Acts & Facts. 42 (5): 16.
2. Sherwin, F. Was a Fossil “Fish-Hand” Discovered? Creation Science Update. Posted on ICR.org June 21, 2020.
3. Field Museum. Fossilized Babies of Ancient Crocodile-Like Predators Uproot Understanding of How Animals Adapted to the Land. Phys.org. Posted on phys.org June 18, 2026.
4. Pardo, J. D. and A. Mann. 2026. Direct Development of Stem Tetrapods Across the Fin-to-Limb Transition. Science. 392 (6804): 1292–1296.
5. Pester, P. ‘A Completely Different Story’: 300 Million-Year-Old Fossils Reveal the First Vertebrate Land Dwellers Weren’t What We Thought, Researchers Claim. Live Science. Posted on livescience.com June 19, 2026.

* Dr. Sherwin is a science news writer at the Institute for Creation Research. He earned an M.A. in invertebrate zoology from the University of Northern Colorado and received an honorary doctorate of science from Pensacola Christian College.