Rosa Rubicondior: Creationism Refuted - How The Survivors of a Mass Extinction Evolved Into Dinosaurs

Triassic reptiles took 10,000 mile trips through “hellish” conditions, study suggests - University of Birmingham

Contrary to the child-like naivety and carefully cultivated ignorance of creationists, Earth is not — and never has been — a paradise perfectly designed for life, let alone tailor-made for humans. In reality, the vast majority of Earth's history — around 99.9975% of it — took place long before creationists believe the planet even existed, during which time the environment has frequently become so hostile that mass extinctions wiped out the majority of living species. Life as we know it today descends from the lucky few that managed to survive and adapt to radically altered conditions.

One of the most devastating of these extinction events was the end-Permian climate catastrophe, during which one group of reptiles — the archosauromorphs — managed to endure. From this resilient lineage emerged the dinosaurs, who would go on to dominate the planet until they too were annihilated by a cataclysmic meteor impact 66 million years ago.

While palaeontologists have long known about the survival and evolutionary significance of archosauromorphs, a lingering mystery remained: how did they manage to disperse across vast "dead zones" of the tropics, where temperatures were thought to be lethally high? A new study by researchers from the University of Birmingham and the University of Bristol has now shed light on this question. Their findings have been published, open access, in Nature Ecology & Evolution.

The End-Permian Mass Extinction.

Also known as: The Great Dying
When: ~252 million years ago (end of the Permian Period)
Duration: Estimated to have occurred over ~60,000 years (some evidence suggests even more rapidly)
Species lost: ~90–96% of marine species, ~70% of terrestrial vertebrates, and numerous plant and insect species
Cause:

Massive volcanic activity in what is now Siberia (Siberian Traps)
Release of vast amounts of CO₂ and methane
Global warming of 8–10°C
Ocean acidification and anoxia (loss of oxygen in oceans)
Collapse of food webs

Significance:

Largest mass extinction event in Earth’s history
Cleared ecological space, allowing for the rise of new groups — including the ancestors of dinosaurs
Profoundly reshaped ecosystems, paving the way for the Mesozoic Era

Aftermath:

Ecosystems took millions of years to recover
Dominant survivor groups included certain amphibians, synapsids (proto-mammals), and the ancestors of modern reptiles (archosauromorphs)

The research is also summarised in a news release from the University of Birmingham.

Triassic reptiles took 10,000 mile trips through “hellish” conditions, study suggests
First study to consider how ancient reptiles dispersed across the Earth after end-Permian mass extinction
The forerunners of dinosaurs and crocodiles in the Triassic period were able to migrate across areas of the ancient world deemed completely inhospitable to life, new research suggests.

In a paper published in Nature Ecology and Evolution, researchers from the University of Birmingham and University of Bristol have used a new method of geographical analysis to infer how these ancestral reptiles, known as archosauromorphs, dispersed following one of the most impactful climate events the Earth has ever seen, the end-Permian mass extinction.

The first archosauromorphs, some resembling modern reptiles and many times smaller than familiar dinosaurs, were previously believed to only survive in certain parts of the globe due to extreme heat across the tropics, viewed by many palaeontologists as a dead zone, in the earliest Triassic.

Our results suggest that these reptiles were much hardier to the extreme climate of the Pangaean tropical dead zone, able to endure these hellish conditions to reach the other side of the world.

Dr Joseph Flannery-Sutherland, corresponding author
School of Geography, Earth and Environmental Science
University of Birmingham, Birmingham, UK.

By developing a new modelling technique based on landscape reconstructions and evolutionary trees, the team of researchers have been able to discover clues about how these reptiles moved around the world during the Triassic period, following the mass extinction where more than half of land-based animals and 81% of marine life died.

The archosauromorphs that survived the extinction event rose to prominence in Earth’s ecosystems in the Triassic, leading to the evolution of dinosaurs. The team now suggest that their later success was in part due to their ability to migrate up to 10,000 miles across the tropical dead zone to access new ecosystems.

Amid the worst climatic event in Earth’s history, where more species died than at any period since, life still survived. We know that archosauromorphs as a group managed to come out of this event and over the Triassic period became one of the main players in shaping life thereafter.

Gaps in their fossil record have increasingly begun to tell us something about what we weren’t seeing when it comes to these reptiles. Using our modelling system, we have been able to build a picture of what was happening to the archosauromorphs in these gaps and how they dispersed across the ancient world. This is what led us to call our method TARDIS, as we were looking at terrains and routes directed in space-time.

Our results suggest that these reptiles were much hardier to the extreme climate of the Pangaean tropical dead zone, able to endure these hellish conditions to reach the other side of the world. It’s likely that this ability to survive the inhospitable tropics may have conferred an advantage that saw them thrive in the Triassic world.

Dr Joseph Flannery-Sutherland.

The evolution of life has been controlled at times by the environment, but it is difficult to integrate our limited and uncertain knowledge about the ancient landscape with our limited and uncertain knowledge about the ecology of extinct organisms. But by combining the fossils with reconstructed maps of the ancient world, in the context of evolutionary trees, we provide a way of overcoming these challenges.

Professor Michael J. Benton, senior author
School of Earth Sciences
University of Bristol, Bristol, UK.

Publication:

Flannery-Sutherland, J.T., Elsler, A., Farnsworth, A. et al.
Landscape-explicit phylogeography illuminates the ecographic radiation of early archosauromorph reptiles. Nat Ecol Evol (2025). https://doi.org/10.1038/s41559-025-02739-y

Technical details appear in the team's open access paper in Nature Ecology & Evolution

Abstract
Spatial incompleteness in the fossil record severely diminishes the observed ecological and geographic ranges of clades. The biological processes shaping species distributions and richness through time, however, also operate across geographic space and so clade biogeographic histories can indicate where their lineages must have successfully dispersed through these sampling gaps. Consequently, these histories are powerful, yet untapped tools for quantifying their unobserved ecographic diversity. Here, we couple phylogeographic modelling with a landscape connectivity approach to reconstruct the origins and dispersal of Permian–Triassic archosauromorph reptiles. We recover substantial ecographic diversity from the gaps in their fossil record, illuminating the cryptic first 20 million years of their evolutionary history, a peak in climatic disparity in the earliest Triassic period, and dispersals through the Pangaean tropical dead zone which contradict its perception as a hard barrier to vertebrate movement. This remarkable tolerance of climatic adversity was probably integral to their later evolutionary success.

Main
Changing climate across space and through time is a fundamental control on the dispersal, extinction and divergence processes that shape species distributions and diversity patterns^1,2,3. Fossil record incompleteness, however, severely challenges climate-driven palaeobiological narratives by simultaneously distorting their observed stratigraphic durations, geographic ranges and environmental tolerances in deep time^1,4,5. In the face of these spatiotemporal gaps, palaeontologists have explored extrapolative statistical techniques, such as species distribution modelling and ancestral state estimation, to reconstruct deep-time geographic ranges and climatic tolerances. Their use is limited, however, if fossil data are insufficient to adequately characterize a clade’s climate space occupancy (climatic niche)^{6,7,8,9,10,11,12}. Climate space occupancy, however, is inextricably linked to the biogeographic distribution (biotope) of a clade through time^13,14, including within spatial gaps in the fossil record where they may never be sampled, but through which they must have successfully dispersed. Here, we posit that this ecographic reciprocity between niche and biotope, known as Hutchinson’s duality^15,16, makes the phylogeographic history of a clade an informative, yet underappreciated, tool for inferring ancestral climatic tolerances on the basis of how those spatial relationships are embedded within, and connected through, climate space.

We explore the use of Hutchinson’s duality for reconstructing clade ecographic diversity using the phylogeographic history of early archosauromorph reptiles. Archosauromorphs (including crocodiles and birds today, as well as the dinosaurian ancestors of the latter) have shown immense taxonomic and ecomorphological diversity across the terrestrial, freshwater and marine realms from the Triassic period to the present^{17,18,19,20,21}. Most of their diversity is contained within the bird-line and crocodile-line crown groups (Archosauria) but was founded on the initial adaptive radiation of early-diverging archosauromorphs. Following their cryptic origin in the Middle Permian, archosauromorphs entered a host of ecological niches left vacant by the end-Permian mass extinction²² before explosive diversification of the crown groups during the Carnian Pluvial Episode in the Late Triassic²³. In turn, the success of avemetatarsalians (bird-line) compared to pseudosuchians (crocodile-line) has been attributed to their capacity to tolerate a much wider range of climatic conditions^10,24. These scenarios, however, are based on inferences from their sporadically sampled fossil record and early-diverging phylogenetic relationships. Further, although early archosauromorph phylogeny is broadly well-resolved^25,26,27, recent fossil discoveries and re-analysis of enigmatic taxa with modern imaging techniques have spurred revisions to placements of many early avemetatarsalian clades^{27,28,29,30,31,32,33,34,35,36}. Consequently, archosauromorph biogeographic origins and ecographic patterns remain incompletely understood, making them an ideal case study for this work.

To reconstruct early archosauromorph ecographic diversity, we couple Bayesian phylogeographic inference of their origins with an approach for inferring spatially explicit dispersal routes based on landscape connectivity^37,38,39 termed TARDIS (terrains and routes directed in space–time). TARDIS represents palaeogeographic surfaces and their substantial changes in topography and continental configuration as a flexibly weighted spatiotemporal graph. We estimate the dispersal routes between ancestor and descendant locations in space and time within this graph as least-cost paths whose geometries provide conservative, yet highly informative estimates of the lineage geographic distributions necessitated by their phylogeographic history. These paths then permit measurement of the environmental conditions that clades must have tolerated during dispersal, including through spatial gaps in their fossil record. As spatially resolved climate data based on lithological proxies are also afflicted by geographic incompleteness in the wider geological record, we instead leverage climate reconstructions from recent advances in deep-time earth system modelling^2,40,41. By connecting the fragmented portions of the early archosauromorph fossil record through unsampled regions of geographic space, we transform inaccessible portions of their biogeographic history into rich sources of data on the breadth of their occupied climate space (climatic disparity), enabling us to estimate the tempo and mode of their early climatic evolution in unprecedented detail.

Flannery-Sutherland, J.T., Elsler, A., Farnsworth, A. et al.
Landscape-explicit phylogeography illuminates the ecographic radiation of early archosauromorph reptiles. Nat Ecol Evol (2025). https://doi.org/10.1038/s41559-025-02739-y

Copyright: © 2025 The authors.
Published by Springer Nature Ltd. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)

Apart from the rather inconvenient fact that this mass extinction occurred long before creationists believe the Earth even existed, there’s plenty here for them to try to ignore or misrepresent. Chief among these is the unmistakable evidence that a major environmental shift led to a profound change in the evolutionary trajectory of life — not through divine intervention, but through extinction and natural selection, clearing the ecological stage for new forms to emerge.

Then there is the conspicuous absence of any indication that the scientists involved in this research are on the verge of abandoning the Theory of Evolution. Nowhere in their findings is there a hint that they are ready to exchange a robust, evidence-based framework for a supernatural explanation based on unevidenced assumptions and creationist dogma.

And finally, the data speak plainly against the fantasy of a benevolently fine-tuned Earth. Far from being an idealised paradise crafted with life in mind, the planet’s natural environment has, time and again, become so hostile that only a handful of species — those fortunate enough to possess the right adaptations — were able to endure.

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