coelacanths before
and after the flood
chad arment (2026)
Coelacanth exhibit (Smithsonian Institution Archives)
Coelacanths were a group of lobe-finned fishes known only from the fossil record all over the world, until 1938, when a living species (Latimeria chalumnae) was caught off the east coast of South Africa. This stamped its mark on science as a ‘living fossil’ (or so publicity put it at the time). Within creation science, coelacanths have primarily been discussed either as a ‘living fossil’ or in its relation to secular model theories for fin-to-limb vertebrate development.
The December 1939 news announcement of the discovery of a living coelacanth off South Africa
The use of ‘living fossil’ has in recent years incited pushback from some evolutionists (Casane and Laurenti 2013), while others settle for ‘almost living fossils’ (Cavin and Guinot 2014; Cavin and Alvarez 2022). To an extent, the issue involves whether or not deep time is accepted. For evolutionists, the time frame for fossil coelacanths involves hundreds of millions of years (410-66 mya) with moderate morphological diversification found throughout the Actinistia.
There were many small and moderate-sized coelacanths, but several Jurassic-Cretaceous coelacanths in the Mawsoniidae and Latimeriidae were much larger than the modern Latimeria, which is about 2m in length. Axelrodichthys and Megalocoelacanthus reached 3.5m, while Trachymetopon and Mawsonia reached at least 5m (Cavin et al. 2021a). A few coelacanths demonstrate divergence in physical form, particularly in Devonian-Carboniferous genera. The family Rebellatricidae includes one genus, Rebellatrix, the fork-tailed coelacanth, having a bifurcated caudal fin (Wendruff and Wilson 2012). Strange ‘leaf-shaped,’ eel-like coelacanths are known from the Diplocercidae (Gess and Coates 2015). Foreyia, a latimeriid from Triassic deposits in Switzerland, was an exceptionally strange ‘bloated’ coelacanth, found in the same deposits as a more typical relation, Ticinepomis. (It is possible that a simple heterochronic change in expression of the Pax1/9 gene was responsible for its divergence [Cavin et al. 2017].)
So, evolutionists who are considering the entirety of the class within their worldview will visualize moderate change over millions of years, with the modern coelacanth being the final twig from a Mesozoic branch—one that has significantly adapted physiologically to a unique environment. (Interestingly, within the secular model, several coelacanth genera span tens of millions of years. For example, Mawsonia spans 50 million years stratigraphically, late Jurassic to early late Cretaceous. The lack of significant apparent change inspired the term ‘extinct living fossil’ [Cavin et al. 2021b].)
For creationists, the time frame for fossilization was the single Flood year. Notably, regardless of the moderate diversification within the class as a whole, the modern coelacanth’s body plan is remarkably similar to a wide range of coelacanths both within the Latimeriidae and beyond (possibly back to the Devonian [Zhu et al. 2012]), with genera such as Libys, Megalocoelacanthus, and Swenzia likely being the closest fossil relations to Latimeria (Clement 2005; Dutel et al. 2012; Clement et al. 2024). Still, the ‘living fossil’ concept appears more often in anti-evolution discussions, as it has little bearing on creation biology models.
Libys (top) and Undina (bottom)
Jurassic, Germany
Libys has a similar external appearance
to the modern coelacanths.
(CC BY 4.0 Ferrante et al. 2022)
Within the secular taxonomic hierarchy, coelacanths (class Actinistia) are placed within the Sarcopterygii, a clade of bony fish with muscular lobes supporting their fins. Other sarcopterygians include lungfish (Dipnomorpha) and certain fossil fishes like the ‘earliest’ bony fish Guiyu. Tetrapod vertebrates are also included in the secular model as an offshoot of the Sarcopterygii. Today, secular models place lungfish as the closest living group to the fish-tetrapod transition, though lungfish and coelacanths are both considered sister groups (Zardoya et al. 1998; Amemiya et al. 2013; Zhao et al. 2021).
I should include here a brief note on ‘umbrella taxa’ in creation biology: creation biology is concerned with Created Kinds, not with upper-level taxa that systematize character traits in the secular model. ‘Birds’ (Aves), for example, do not comprise a single Created Kind. Penguins and hummingbirds do not share a common ancestor. So, while it is fine to utilize ‘bird’ as a systematic term, it is not an essentialist or baraminic term. There is no intrinsic value to the term ‘bird’ that makes it sacred. Neither is any other higher-level term, like ‘dinosaur’, ‘fish’, or ‘tetrapod’ intrinsically sacred—mosaic morphologies are found throughout creation, and organisms may be moved from one group to another as new definitions are utilized. So, creationists who get their feathers ruffled by other creationists who incorporate secular higher taxa in publications, are not being better creationists. They are simply being deliberately obtuse.
Osteopleurus newarki
Triassic, Pennsylvania
(Bryant, W. L. 1934, 'New fishes from the
Triassic of Pennsylvania', Proceedings of the
APS, v. 73, pp. 319-26)
Within the class Actinistia, recent character-based phylogenies suggest ten different families of Devonian to Cretaceous coelacanths (plus the modern genus) (Ferrante and Cavin 2025), with a handful of extrafamilial genera. Of these, six mostly Mesozoic coelacanth families are placed within the Coelacanthiformes.
Because only one genus (Latimeria) is found in the Cenozoic, all other coelacanths must have been deposited during the global Flood. (At present, alleged claims of Cenozoic coelacanth fossils have not been confirmed [Schwimmer 2002].) What does that say about the Created Kind for coelacanths? Is the diversity within pre-Flood coelacanths representative of a single kind or multiple kinds? On the one hand, we have no reason to think a Created Kind from the Creation Week (especially fish) would be limited to a single pair, or even a single species. If there is only a single coelacanth kind, there may initially have been multiple families created as part of the fabric of the kind, or a single family that diversified extensively. Alternatively, there may have been intrinsic barriers that bounded multiple Created Kinds for coelacanths, perhaps near the family level. Whichever starting point, the initial fish would have been capable of further diversification as they spread and multiplied to ‘fill the earth’. With about 2,000 years (+/-) between Creation and the Flood, there was plenty of time for diversification, whether into species, genera, or families. It should be no surprise that the Flood’s fossil record shows a diversity of form that preserves both plesiomorphic (‘primitive’) and derived traits (such as the Devonian Shoshonia’s pectoral appendage, compared to the modern Latimeria’s much more derived appendage [Friedman et al. 2007]).
By the time of the Flood, there were at least 46 genera we now find in the fossil record (with likely many more as yet undiscovered). Only one family had a single, small branch that has survived to the present day.
Coelacanths: One Created Kind or Many?
The class Actinistia could be a single Created Kind (monobaraminic) or multiple Created Kinds (polybaraminic).
Coelacanths are found from Devonian through Cretaceous layers, but not randomly. There are certainly taphonomic biases in some regions (Yuan et al. 2025), but there are distinct differences in coelacanth abundance between different deposits around the world. Coelacanthiformes (except for the Permian Coelacanthus) are found in Triassic to Cretaceous layers, while the families outside that group are mostly found in Devonian and Carboniferous layers (with a few genera in Permian or Triassic deposits). While secularists attempt to create a phylogenetic tree that changed over time, focusing on inferred plesiomorphic or derived traits, an argument could also be made from the creation model for ecological partitioning by the Flood. The problem that some creationists get into, however, is when they try to oversimplify ecological zones or biomes in the pre-Flood world with nonsensical concepts like a ‘dinosaur peninsula’. This subject deserves a more serious and thorough examination, but overall, fossil coelacanths were biogeographically diverse. Unlike the modern, deep-water-adapted Latimeria, fossil coelacanths had well-developed lungs and are found fossilized in ‘low-depth palaeoenvironments’ (Cupello et al. 2019). Some Paleozoic coelacanths were freshwater (Smith 1953), while others were shallow marine residents (Clement et al. 2024). Fossilized juveniles suggest that some species utilized brackish estuaries as nursery sites, likely due to higher food availability (Gess and Coates 2015; Cooper 2025). Mesozoic coelacanths could also be found in both marine and freshwater environments (Poyato-Ariza et al. 1998). One Cretaceous site in Spain is a putative fossilized wetland, with a few rare coelacanths (Martín-Abad and Fregenal-Martínez 2021). The Jurassic-Cretaceous giant coelacanths included both marine (Megalocoelacanthus) and freshwater-brackish (Mawsonia) species (Dutel et al. 2014).
The Living Coelacanth, Latimeria
There are currently two living species, the West Indian Ocean coelacanth (Latimeria chalumnae) and the Indonesian coelacanth (Latimeria menadoensis). The secular model suggests that the divergence between the two species occurred when India collided with Eurasia during the Eocene period (Inoue et al. 2005)—that continental collision also fits within a Lower Cenozoic Boundary post-Flood model for creationists. Transposable elements contributed extensively to the species’ divergence (Naville et al. 2015). Separate populations demonstrating deep genetic lineage divergence are also known within each species (Nikaido et al. 2011; Kadarusman et al. 2020), with speculation that there may be as yet undiscovered species.
Coelacanths give live birth to large ‘pups’, which may restrict dispersal over long distances across open water (Holder et al. 1999). They have a slow metabolism, and may be very long-lived, with an estimated lifespan of about 100 years (Mahé et al. 2021). The coelacanths are passive ‘drift-hunters’, aided by a rostral electro-detection organ that helps detect nearby prey by determining “local field intensity, orientation and polarity” (Berquist et al. 2015). Coelacanths are known for occasional head-standing behavior that allows this organ to detect prey under sand or in crevices (Forey 1990).
Latimeria typically inhabits deep (below 150m) caves and caverns along coastal shelves and steep slopes as shelter during the day, and hunts at night even further into the depths, where there is very low prey biomass, apparently able to survive because it has a very low resting metabolism (Fricke and Hissmann 2000). More recently, observations at shallower depths have been reported off Sodwana Bay, South Africa (Sakaue et al. 2021). Frick and Hissmann (2000) suggest that fossil coelacanths adapted to “murky, oxygen-deficient, shallow-water habitats which were food limited,” then were forced by competition with ray-finned fishes to deeper depths. Wen et al. (2013) suggested that this ability to inhabit anoxic environments offered survival bias during the secular model’s assumed ‘end-Permian mass extinction’. But for the creation model, might it not suggest a reason for low coelacanth survival through and after the Flood?
Physiological adaptations to deep-water habitat in the modern species include visual pigment mutations to provide the coelacanths with optimum sensitivity deep underwater (Yokoyama and Tada 2000), a fatty organ-vestigial single lung pairing that maintains buoyancy and hydrostatic pressure via large lipid deposits throughout the body (Lauridsen et al. 2022), and reduced skeletal ossification along with more skeletal cartilage persisting into the adult stage (Meunier et al. 2019). Many fossil coelacanths had a well-developed calcified lung (Cupello et al. 2019), and were probably bi-modal breathers, while modern coelacanths only breathe through their gills. Those gills are relatively inefficient, but the modern species’ low metabolism means less oxygen is required.
references
Amemiya, C. T., et al. 2013. The African coelacanth genome provides insights into tetrapod evolution. Nature 496: 311-6.
Berquist, R. M., et al. 2015. The coelacanth rostral organ is a unique low-resolution electro-detector that facilitates the feeding strike. Scientific Reports 5: 8962.
Casane, D., and P. Laurenti. 2013. Why coelacanths are not ‘living fossils’. Bioessays 35: 332-338.
Cavin, L., and N. Alvarez. 2022. Why coelacanths are almost “living fossils”? Frontiers in Ecology and Evolution 10: 896111.
Cavin, L., and G. Guinot. 2014. Coelacanths as “almost living fossils”. Frontiers in Ecology and Evolution 2: 49.
Cavin, L., et al. 2017. Heterochronic evolution explains novel body shape in a Triassic coelacanth from Switzerland. Scientific Reports 7: 13695.
Cavin, L., et al. 2021a. Giant Mesozoic coelacanths (Osteichthyes, Actinistia) reveal high body size disparity decoupled from taxic diversity. Scientific Reports 11: 11812.
Cavin, L., et al. 2021b. The first late Cretaceous mawsoniid coelacanth (Sarcopterygii: Actinistia) from North America: Evidence of a lineage of extinct ‘living fossils’. PLoS ONE 16(11): e0259292.
Clement, A. M., et al. 2024. A late Devonian coelacanth reconfigures actinistian phylogeny, disparity, and evolutionary dynamics. Nature Communications 15: 7529.
Clement, G. 2005. A new coelacanth (Actinistia, Sarcopterygii) from the Jurassic of France, and the question of the closest relative fossil to Latimeria. Journal of Vertebrate Paleontology 25(3): 481-491.
Cooper, J. A. 2025. A rare fossil juvenile coelacanth may shine a light on a successful survival strategy across deep time. Historical Biology https://doi.org/10.1080/08912963.2025.2572891
Cupello, C., et al. 2019. The long-time adaptation of coelacanths to moderate deep water: Reviewing the evidence. Bulletin of the Kitakyushu Museum of Natural History and Human History, Series A 17: 29-35.
Dutel, H., et al. 2012. The giant Cretaceous coelacanth (Actinistia, Sarcopterygii) Megalocoelacanthus dobiei
Schwimmer, Stewart & Williams, 1994, and its bearing on Latimerioidei interrelationships. PLoS ONE 7(11): e49911.
Dutel, H., et al. 2014. A giant marine coelacanth from the Jurassic of Normandy, France. Journal of Vertebrate Paleontology 34(5): 1239-1242.
Ferrante, C., and L. Cavin. 2023. Early Mesozoic burst of morphological disparity in the slow-evolving coelacanth fish lineage. Scientific Reports 13: 11356.
Ferrante, C., and L. Cavin. 2025. A deep dive into the coelacanth phylogeny. PLoS One 20(6): e0320214.
Ferrante, C., U. Menkveld-Gfeller, and L. Cavin. 2022. The first Jurassic coelacanth from Switzerland. Swiss Journal of Palaeontology 141(15): 1-20.
Forey, P. L. 1990. An extraordinary blue fish. Endeavour, N.S. 14(1): 8-13.
Fricke, H., and K. Hissmann. 2000. Feeding ecology and evolutionary survival of the living coelacanth Latimeria chalumnae. Marine Biology 136: 379-386.
Friedman, M., M. I. Coates, and P. Anderson. 2007. First discovery of a primitive coelacanth fin fills a major gap in the evolution of lobed fins and limbs. Evolution & Development 9(4): 329-337.
Gess, R. W., and M. I. Coates. 2015. Fossil juvenile coelacanths from the Devonian of South Africa shed light on the order of character acquisition in actinistians. Zoological Journal of the Linnean Society 175: 360-383.
Holder, M. T., et al. 1999. Two living species of coelacanths? PNAS 96(22): 12616-12620.
Inoue, J. G., et al. 2005. The mitochondrial genome of Indonesian coelacanth Latimeria menadoensis (Sarcopterygii: Coelacanthiformes) and divergence time estimation between the two coelacanths. Gene 349: 227-235.
Kadarusman, et al. 2020. A thirteen-million-year divergence between two lineages of Indonesian coelacanths. Scientific Reports 10: 192.
Lauridsen, H., et al. 2022. Buoyancy and hydrostatic balance in a West Indian Ocean coelacanth Latimeria chalumnae. BMC Biology 20: 180.
Mahé, K., B. Ernande, and M. Herbin. 2021. New scale analyses reveal centenarian African coelacanths. Current Biology 31: 3621-3628.
Martín-Abad, H., and M. Fregenal-Martínez. 2021. The ecology of the lower Cretaceous coelacanths from Las Hoyas Konservat-Lagerstätte (Cuenca, Spain): A new insight after the integration of palaeontological and sedimentological data. Spanish Journal of Palaeontology 36(2): 1-13.
Meunier, F. J., C. Cupello, and G. Clement. 2019. The skeleton and the mineralized tissues of the living coelacanths. Bulletin of the Kitakyushu Museum of Natural History and Human History, Series A 17: 37-48.
Naville, M., et al. 2015. The coelacanth: Can a “living fossil” have active transposable elements in its genome? Mobile Genetic Elements 5(4): 55-59.
Nikaido, M., et al. 2011. Genetically distinct coelacanth population off the northern Tanzanian coast. PNAS 108(44): 18009-18013.
Poyato-Ariza, F., et al. 1998. First isotopic and multidisciplinary evidence for nonmarine coelacanths and pycnodontiform fishes: Palaeoenvironmental implications. Palaeogeography, Palaeoclimatology, Palaeoecology 144(1-2): 65-84.
Sakaue, J., et al. 2021. New insights about the behavioral ecology of the coelacanth Latimeria chalumnae video recorded in the absence of humans off South Africa. Frontiers in Marine Science 8: 755275.
Schwimmer, D. R. 2002. Giant fossil coelacanth from the late Cretaceous of the eastern USA. Fernbank Magazine 22(2): 24-30.
Smith, J. L. B. 1953. Problems of the coelacanth. South African Journal of Science 49(9): 279-281.
Wen, W., et al. 2013. Coelacanths from the middle Triassic Luoping Biota, Yunnan, South China, with the earliest evidence of ovoviviparity. Acta Palaeontologica Polonica 58(1): 175-193.
Wendruff, A. J., and M. V. H. Wilson. 2012. A fork-tailed coelacanth, Rebellatrix divaricerca, gen. et sp. nov. (Actinistia, Rebellatricidae, fam. nov.), from the lower Triassic of western Canada. Journal of Vertebrate Paleontology 32(3): 499-511.
Yokoyama, S., and T. Tada. 2000. Adaptive evolution of the African and Indonesian coelacanths to deep-sea environments. Gene 261: 35-42.
Yuan, Z., L. Cavin, and H. Song. 2025. On the incompleteness of the coelacanth fossil record. Fossil Studies 3(10): 1-22.
Zardoya, R., et al. 1998. Searching for the closest living relative(s) of tetrapods through evolutionary analyses of mitochondrial and nuclear data. Molecular Biology and Evolution 15(5): 506-517.
Zhao, L., et al. 2021. Phylogenomics based on transcriptome data provides evidence for the internal phylogenetic relationships and potential terrestrial evolutionary genes of lungfish. Frontiers in Marine Science 8: 724977.
Zhu, M., et al. 2012. Earliest known coelacanth skull extends the range of anatomically modern coelacanths to the early Devonian. Nature Communications 3: 772.
