Rosa Rubicondior: Refuting Creationism - The Mass Extinction 252 Million Years Before 'Creation Week'

Friday, 4 July 2025

Refuting Creationism - The Mass Extinction 252 Million Years Before 'Creation Week'

Pre-extinction tropical rainforest seed fern, Gigantopteris, (giant leaves)

Dr Zhen Xu.

New fossils reveal climate tipping point in most famous mass extinction | University of Leeds

Creationists claim that Earth is only a few thousand years old and that it was created perfectly and finely tuned for life—brought into existence without ancestors, from nothing, by means of supernatural command. Their evidence for this extraordinary claim rests on the beliefs of Bronze Age pastoralists who imagined Earth as small, flat, and covered by a solid dome. These ancient myths were eventually written down, bound up in a book later declared by people with a vested interest, to be divinely inspired and historically accurate.

Science, by contrast, presents a very different picture. Far from being a perfect and finely tuned haven for life, Earth is a dynamic and often hostile planet. Life persists here not because conditions are universally benign, but because a small number of organisms have evolved to thrive within narrow environmental niches. Throughout Earth’s long history, global conditions have periodically tipped into extremes so severe that they triggered mass extinction events. Unlike creationist claims, these conclusions are supported by tangible, testable evidence.

One such event—known as the Great Dying—occurred around 252 million years ago, relatively recent in the planet’s \~4.5 billion-year history. This catastrophe, the most severe extinction event known, was likely triggered by intense volcanic activity that caused a rapid and sustained rise in global temperatures. The resulting climate shift led to the collapse of tropical forests, which in turn reduced the planet’s capacity to absorb atmospheric carbon, driving further warming. This cascade of ecological breakdown led to the loss of most marine species and widespread collapse of terrestrial ecosystems.

The outcome was a planetary heatwave that lasted for approximately five million years.

New evidence for the role of rainforest collapse in both the onset and the recovery from the Great Dying has been presented by an international team of scientists, led by researchers from the University of Leeds and the China University of Geosciences in Wuhan. Their findings are detailed in a recent paper published in Nature Communications and summarised in a news release from the University of Leeds.

What major taxons were lost in the Great Dying and what eventually brought it to an end? The Great Dying, or Permian–Triassic extinction event, occurred around 252 million years ago and was the most catastrophic mass extinction in Earth’s history. It eliminated an estimated 81% of marine species and 70% of terrestrial vertebrate species. Many entire taxonomic groups either disappeared completely or were severely reduced.

Major Taxa Lost in the Great Dying

Marine Groups:

Trilobites – Entirely extinct; this once-diverse and widespread arthropod group never recovered.
Eurypterids (sea scorpions) – Severely reduced and extinct shortly after.
Graptolites – Previously in decline but did not survive the event.
Tabulate and rugose corals – These coral groups, which built extensive reefs, became extinct.
Brachiopods – Many lineages wiped out; some survived but never regained their former diversity.
Bryozoans – Several groups perished; those that survived diversified again later.
Ammonoids – Almost exterminated; a few lineages survived and later re-radiated.
Crinoids – Greatly reduced in diversity.
Foraminifera – Large benthic forms suffered heavily; smaller planktonic forms persisted.
Conodonts – Many species lost; survived but declined thereafter.

Terrestrial Groups:

Therapsids (mammal-like reptiles) – Dominant Permian forms such as dinocephalians and gorgonopsians became extinct; only small groups like cynodonts and dicynodonts survived.
Amphibians (Temnospondyls and others) – Greatly reduced, though some lineages endured.
Insects – Major extinction of insect families, the only known mass extinction event for insects.
Glossopterid flora – The dominant seed ferns in Gondwana were mostly wiped out, drastically changing terrestrial ecosystems.

What Brought the Great Dying to an End?

The end of the extinction event was likely due to a slow process of environmental and ecological stabilisation over millions of years. Key contributing factors included:

Cessation of Siberian Traps Volcanism

The primary trigger of the extinction was the Siberian Traps large igneous province, where vast volcanic eruptions released CO₂, methane, and sulphur compounds.
As this volcanism waned, the influx of greenhouse gases slowed, allowing for gradual climatic recovery.

Ocean Reoxygenation

Anoxic and euxinic (sulphidic) conditions dominated the oceans during the extinction.
As temperatures declined and biological productivity resumed, oxygen began returning to deeper waters, allowing marine life to repopulate.

Recovery of Terrestrial Vegetation

New plant ecosystems, particularly early coniferous forests, began to re-establish and stabilise terrestrial carbon cycling.
This helped draw down atmospheric CO₂ over time and reduce runaway warming.

Evolution of New Ecological Niches

Surviving species began to diversify, filling ecological voids left by the extinction.
This led to the Triassic radiation, setting the stage for new groups such as archosaurs (precursors to dinosaurs, crocodiles, and birds) and early mammals.

New fossils reveal climate tipping point in most famous mass extinction
The collapse of tropical forests during Earth’s most catastrophic extinction event was the primary cause of the prolonged global warming which followed, according to new research.
The Permian–Triassic Mass Extinction – sometimes referred to as the “Great Dying”, happened around 252 million years ago, leading to the massive loss of marine species and significant declines in terrestrial plants and animals.

The event has been attributed to intense global warming triggered by a period of volcanic activity in Siberia, known as the Siberian Traps, but scientists have been unable to pinpoint why super-greenhouse conditions persisted for around five million years afterwards.

Now a team of international researchers led by the University of Leeds and the China University of Geosciences in Wuhan has gathered new data which supports the theory that the demise of tropical forests, and their slow recovery, limited carbon sequestration – a process where carbon dioxide is removed from the atmosphere and held in plants, soils or minerals.

During extensive field studies, the team used a new type of analysis of fossil records as well as clues about past climate conditions found in certain rock formations to reconstruct maps of changes in plant productivity during the Permian–Triassic Mass Extinction.

Their results, published in Nature Communications, show that vegetation loss during the event led to greatly reduced levels of carbon sequestration resulting in a prolonged period where there were high levels of CO².

The causes of such extreme warming during this event have been long discussed, as the level of warming is far beyond any other event. Critically, this is the only high temperature event in Earth’s history in which the tropical forest biosphere collapses, which drove our initial hypothesis. Now, after years of fieldwork, analysis and simulations, we finally have the data which supports it.

Dr Zhen Xu, lead author
School of Earth and Environment
Leeds University, Leeds, UK.

The researchers believe their results reinforce the idea that thresholds, or ‘tipping points’ exist in Earth’s climate-carbon system which, when reached, mean that warming can be amplified.

China is home to the most complete geological record of the Permian-Triassic Mass Extinction and this work leverages an incredible archive of fossil data that has been gathered over decades by three generations of Chinese geologists.

The lead author Dr Zhen Xu is the youngest of these and is continuing the work begun by Professor Hongfu Yin and Professor Jianxin Yu, who are also authors of the study. Since 2016, Zhen and her colleagues have travelled throughout China from subtropical forests to deserts, including visiting areas accessible only by boat or on horseback.

Zhen came to the University of Leeds in 2020 to work with Professor Benjamin Mills on simulating the extinction event and assessing the climate impacts of the loss of tropical vegetation which is shown by the fossil record. Their results confirm that the change in carbon sequestration suggested by the fossils is consistent with the amount of warming that occurred afterwards.

There is a warning here about the importance of Earth’s present day tropical forests. If rapid warming causes them to collapse in a similar manner, then we should not expect our climate to cool to preindustrial levels even if we stop emitting CO². Indeed, warming could continue to accelerate in this case even if we reach zero human emissions. We will have fundamentally changed the carbon cycle in a way that can take geological timescales to recover, which has happened in Earth’s past.

Professor Benjamin J. W. Mills, co-corresponding author
School of Earth and Environment
Leeds University, Leeds, UK.

Reflecting on the study’s broader mission, Professor Hongfu Yin and Professor Jianxin Yu of the China University of Geosciences, underscored the urgency of blending tradition with innovation:

Paleontology needs to embrace new techniques—from numerical modelling to interdisciplinary collaboration—to decode the past and safeguard the future. Let’s make sure our work transcends academia: it is a responsibility to all life on Earth, today and beyond. Earth’s story is still being written, and we all have a role in shaping its next chapter.

Professor Hongfu Yin, co-corresponding author.
State Key Laboratory of Geomicrobiology and Environmental Changes
School of Earth Sciences
China University of Geosciences, Wuhan, P.R. China.

Publication:
Xu, Z., Yu, J., Yin, H. et al.
Early Triassic super-greenhouse climate driven by vegetation collapse.
Nat Commun 16, 5400 (2025). https://doi.org/10.1038/s41467-025-60396-y

Abstract
The Permian–Triassic Mass Extinction (PTME), the most severe crisis of the Phanerozoic, has been attributed to intense global warming triggered by Siberian Traps volcanism. However, it remains unclear why super-greenhouse conditions persisted for around five million years after the volcanic episode, with one possibility being that the slow recovery of plants limited carbon sequestration. Here we use fossil occurrences and lithological indicators of climate to reconstruct spatio-temporal maps of plant productivity changes through the PTME and employ climate-biogeochemical modelling to investigate the Early Triassic super-greenhouse. Our reconstructions show that terrestrial vegetation loss during the PTME, especially in tropical regions, resulted in an Earth system with low levels of organic carbon sequestration and restricted chemical weathering, resulting in prolonged high CO² levels. These results support the idea that thresholds exist in the climate-carbon system whereby warming can be amplified by vegetation collapse.

Introduction
The latest Permian to Early Triassic (~252–247 million years ago; Ma) was a period of intense environmental and biotic stress^1,2. During the Permian–Triassic Mass Extinction (PTME) at ~252 Ma, around 81–94% of marine invertebrate species and 89% of terrestrial tetrapod genera became extinct². It is generally agreed that the PTME was driven by volcanogenic carbon emissions from Siberian Traps volcanism, potentially coupled with additional thermogenic releases, resulting in intense greenhouse warming^{3,4,5,6,7,8,9,10}. A major negative excursion in carbonate δ¹³C ratios, over a time interval of about 50–500 thousand years (kyrs), supports the notion of a major carbon cycle perturbation^4,5,6. However, it is not well understood why the extreme hothouse climate persisted throughout the 5 million years (Myrs) of the Early Triassic. The precise time interval of Siberian Traps degassing is uncertain, although the main phase of volcanism occurred around the Permian-Triassic Boundary (PTB), possibly with a further pulse about two million years later, during the Smithian Substage of the Early Triassic⁸. Nevertheless, it would normally be expected that atmospheric CO² and global surface temperature should have declined to pre-volcanism levels within ~100 kyr of the volcanic pulses, due to amplified global silicate weathering and/or increased burial of organic carbon².

The unusual multimillion-year persistence of super-greenhouse conditions has sparked considerable debate, and it has been suggested that it may be linked to a change in the silicate weathering feedback, such that CO² could not be efficiently removed from the surface system¹¹. This could potentially have been due to reduced availability of weatherable material from erosion¹¹, which would limit global silicate weathering rates^12,13. Alternatively, continental weathering may have been rapid and accompanied by high rates of reverse weathering in a silica-rich ocean, removing silicate mineral-derived cations into clays instead of forming carbonate minerals, and thus limiting overall CO² drawdown^14,15. These are intriguing hypotheses, but it remains unclear why a severe reduction in global erosion, and/or an episode of high ocean silica levels, would necessarily persist for ~5 Myrs and then recover during the Middle Triassic. Although uncertain, existing compilations of sedimentation rates^16,17 and the maintenance of sporadic siliceous rock records across and after the PTME¹⁸ (see Supplementary Fig. S1) are not clearly supportive of these timings, and suggest that while these processes likely contributed to climate regulation, our understanding of the timeframe of super-greenhouse conditions remains incomplete.

Here, we explore a further mechanism for elevated Early Triassic temperatures that is closely tied to the timeframe of extreme warmth. This approach is based on the concept of an ‘upper temperature steady state’, in which a change in the Earth system caused the climate-carbon cycle to stabilize at a much higher global temperature for millions of years19. Specifically, we investigate the hypothesis that the key driver of the transition to a super greenhouse Earth was the dramatic and prolonged reduction of low-latitude terrestrial biomass caused by the PTME^20,21 and its delayed recovery²². Tropical peat-forming ecosystems are responsible for substantial drawdown of CO², but these extensive biomes were lost at the end of the Permian^20,23,24,25. Indeed, plant species richness and abundance dropped significantly during the Permian–Triassic transition, which is the only genuine mass extinction level event of land plants through the whole Phanzerzoic²⁶, leaving a multimillion year “coal gap” in the Early to Middle Triassic where terrestrial plant materials did not build up as peat^20,23,25. To test this hypothesis, we quantify the distribution of terrestrial plant productivity across the PTME and Early-to-Middle Triassic from the plant fossil record and use this information to guide a linked climate-biogeochemical model of the Early Triassic hothouse, testing whether these biotic changes may have resulted in a higher temperature steady state.

Xu, Z., Yu, J., Yin, H. et al.
Early Triassic super-greenhouse climate driven by vegetation collapse.
Nat Commun 16, 5400 (2025). https://doi.org/10.1038/s41467-025-60396-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)

The reality of the Great Dying presents a profound challenge to creationist beliefs and the narrative found in the Book of Genesis. According to young-Earth creationism, the Earth and all life forms were created just a few thousand years ago in a deliberate and perfect act of divine will. Life is often portrayed as harmonious and unchanging until the corruption brought by human sin, usually associated with the story of Adam and Eve and the subsequent global flood. This framework allows no room for mass extinction events, deep time, or evolutionary processes.

In stark contrast, the fossil and geological records tell a vastly different story. The Great Dying, which occurred around 252 million years ago, is one of several mass extinctions in Earth's history, and it demonstrates just how precarious and contingent life has been. Rather than being created in a single moment and preserved ever since on a planet perfectly tuned for it, life has undergone repeated episodes of catastrophic loss, followed by long and gradual recoveries involving the emergence of entirely new forms of life. This fits with the evolutionary model of descent with modification over vast timescales but is wholly incompatible with the static, short chronology of the biblical account.

Moreover, the cause of the Great Dying — a period of extreme global warming triggered by massive volcanic eruptions — points to a natural, unplanned history governed by physical laws and environmental feedbacks, not divine orchestration. It is difficult to reconcile a "very good" creation, as described in Genesis, with a planet whose history includes such devastating and indiscriminate destruction. The idea that millions of species, many long extinct, were created fully formed only to perish in mass extinctions before humans ever appeared runs counter to the central claim of the Genesis narrative: that humans were the focal point and purpose of creation.

In short, the Great Dying and similar events expose the theological and empirical shortcomings of creationist claims. They reveal a world shaped by deep time, natural processes, and evolutionary contingency — not by recent, miraculous creation or by myths preserved from the worldview of ancient pastoralists.

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