Sources

Show the evidence. Keep the gaps.

Every paper this site cites, what each one supports, and what it doesn’t. Links go to the published paper through its DOI.

Burgess, Muirhead & Bowring 2017. Initial pulse of Siberian Traps sills as the trigger of the end-Permian mass extinction. Nature Communications.
What it supports: The timing of Siberian Traps magma intruding into sediments, a proposed trigger for massive greenhouse-gas release at the start of the end-Permian extinction.
Cited in: The end-Permian extinction
Carlisle et al. 2023. A timescale for placental mammal diversification based on Bayesian modeling of the fossil record. Current Biology.
What it supports: A model placing the origin of placental mammals shortly before the asteroid impact, with most modern mammal orders appearing at or after it. Definitive Cretaceous placental fossils are still lacking.
Cited in: Beneath Giants
Daeschler, Shubin & Jenkins 2006. A Devonian tetrapod-like fish and the evolution of the tetrapod body plan. Nature.
What it supports: Tiktaalik’s mix of fish and tetrapod features, including a mobile neck and a functional wrist joint, and a setting of shallow, marginal waters. It does not show how far the animal travelled on land.
Cited in: The Water’s Edge
Evans et al. 2020. Discovery of the oldest bilaterian from the Ediacaran of South Australia. PNAS.
What it supports: Ikaria wariootia: a small, simple animal with a distinct front and back, matching the predicted maker of nearby burrow traces. It is not a proven direct ancestor.
Cited in: The Garden of Ediacara
Fernandez et al. 2013. Synchrotron reveals Early Triassic odd couple: injured amphibian and aestivating therapsid share burrow. PLOS ONE.
What it supports: A Thrinaxodon, a mammal-line animal, curled in a burrow from the harsh Early Triassic aftermath of the extinction. The dormancy is an interpretation.
Cited in: The end-Permian extinction
Henshilwood et al. 2011. A 100,000-year-old ochre-processing workshop at Blombos Cave, South Africa. Science.
What it supports: An ochre-rich mixture made and stored in abalone shells about 100,000 years ago. What it was used for is unknown.
Cited in: The Ember
Hollaar et al. 2026. Continental-scale fern savannah wildfires during end-Triassic greenhouse warming. Nature Geoscience.
What it supports: Records of widespread wildfire in fern-dominated landscapes during end-Triassic warming. It is regional evidence, not a single planet-wide fire.
Cited in: The end-Triassic extinction
Hublin et al. 2017. New fossils from Jebel Irhoud, Morocco and the pan-African origin of Homo sapiens. Nature.
What it supports: Fossils about 315,000 years old that document early stages of our species, with modern faces and older-looking braincases.
Cited in: The Ember
Janis et al. 2025. Down to earth: therian mammals became more terrestrial towards the end of the Cretaceous. Palaeontology.
What it supports: Fossil limb bones suggesting that mammals in western North America were becoming more ground-dwelling towards the end of the Cretaceous.
Cited in: Beneath Giants, The end-Cretaceous extinction
King et al. 2008. The genome of the choanoflagellate Monosiga brevicollis and the origin of metazoans. Nature.
What it supports: Choanoflagellates, the closest living relatives of animals, carry genes for cell adhesion and signalling that were once thought to be unique to animals. They are living cousins, not unchanged ancestors.
Cited in: Between the Grains, Becoming a body
Kunimatsu et al. 2007. A new Late Miocene great ape from Kenya and its implications for the origins of African great apes and humans. PNAS.
What it supports: Nakalipithecus, a great ape about 9.9 to 9.8 million years old known from jaw and teeth, possibly close to the common ancestor of African apes and humans.
Cited in: The Canopy
Long et al. 2025. Earliest amniote tracks recalibrate the timeline of tetrapod evolution. Nature.
What it supports: Clawed footprints from early Carboniferous rocks in Victoria, Australia, interpreted as made by an amniote. If correct, amniotes arose much earlier than their oldest body fossils suggest.
Cited in: Life away from water
Marean et al. 2007. Early human use of marine resources and pigment in South Africa during the Middle Pleistocene. Nature.
What it supports: Shellfish gathering, pigment use and bladelet tools at Pinnacle Point by about 164,000 years ago. It is not evidence for any particular family’s journey.
Cited in: The Ember
Moody et al. 2024. The nature of the last universal common ancestor and its impact on the early Earth system. Nature Ecology & Evolution.
What it supports: An estimate that LUCA lived about 4.2 billion years ago, and a reconstruction of it as a microbe living within an existing ecosystem. Both are model-based inferences.
Cited in: LUCA, the last universal common ancestor
Niedźwiedzki et al. 2010. Tetrapod trackways from the early Middle Devonian period of Poland. Nature.
What it supports: Trackways that suggest limbed animals existed millions of years before Tiktaalik. Their interpretation has been debated.
Cited in: The Water’s Edge
Peppe et al. 2023. Oldest evidence of abundant C4 grasses and habitat heterogeneity in eastern Africa. Science.
What it supports: Grass-rich habitats in eastern Africa by about 21 to 16 million years ago, within landscapes that ranged from forest to wooded grassland.
Cited in: The Canopy
Raichlen et al. 2010. Laetoli footprints preserve earliest direct evidence of human-like bipedal biomechanics. PLOS ONE.
What it supports: Experiments suggesting that the makers of the 3.6-million-year-old Laetoli footprints walked with extended, human-like legs. Why walking upright evolved is not settled.
Cited in: Walking upright
Sallan & Coates 2010. End-Devonian extinction and a bottleneck in the early evolution of modern jawed vertebrates. PNAS.
What it supports: Two Late Devonian extinction pulses (about 374 and 359 million years ago) and the heavy losses among vertebrates at the second, the Hangenberg event.
Cited in: The Late Devonian crises
Saupe et al. 2019. Extinction intensity during Ordovician and Cenozoic glaciations explained by cooling and palaeogeography. Nature Geoscience.
What it supports: Modelling that links the severity of the end-Ordovician marine extinction to global cooling combined with the arrangement of the continents. It does not describe any particular animal’s survival.
Cited in: The end-Ordovician extinction
Schulte et al. 2010. The Chicxulub asteroid impact and mass extinction at the Cretaceous-Paleogene boundary. Science.
What it supports: A synthesis concluding that the Chicxulub impact triggered the end-Cretaceous mass extinction, based on a worldwide ejecta layer that coincides with the extinctions.
Cited in: The end-Cretaceous extinction
Senel et al. 2023. Chicxulub impact winter sustained by fine silicate dust. Nature Geoscience.
What it supports: Modelling in which fine dust from the impact darkened and cooled the planet and cut plant growth. Exact durations depend on the model.
Cited in: The end-Cretaceous extinction
Shu et al. 2003. Head and backbone of the Early Cambrian vertebrate Haikouichthys. Nature.
What it supports: Haikouichthys anatomy: eyes, possible nasal sacs, and a notochord with separate vertebral elements. Behaviour and ecology are not preserved.
Cited in: Backbone
Wang et al. 2025. Photic-zone euxinia had a major role in the Devonian-Carboniferous boundary mass extinction. Communications Earth & Environment.
What it supports: Evidence that oxygen-free, sulfide-rich water reached the sunlit upper ocean during the Hangenberg crisis. It concerns marine settings, not every river or lake.
Cited in: The Late Devonian crises
Williams 2000. Geological constraints on the Precambrian history of Earth’s rotation and the Moon’s orbit. Reviews of Geophysics.
What it supports: Tidal layers in rock recording that, about 620 million years ago, a year held roughly 400 days, so each day was shorter than today.
Cited in: Between the Grains
Wilson Mantilla et al. 2021. Earliest Palaeocene purgatoriids and the initial radiation of stem primates. Royal Society Open Science.
What it supports: Teeth of Purgatorius, an early primate relative, from rocks laid down within a few hundred thousand years after the impact. The primate line probably began before the impact.
Cited in: The first primates
Xia et al. 2024. On the genetic basis of tail-loss evolution in humans and apes. Nature.
What it supports: A genetic change in the TBXT gene, shared by apes and humans, that may have contributed to the loss of the tail.
Cited in: The Canopy
Zhu et al. 2016. Decimetre-scale multicellular eukaryotes from the 1.56-billion-year-old Gaoyuzhuang Formation in North China. Nature Communications.
What it supports: Large, regularly shaped multicellular fossils about 1.56 billion years old. Their place in the tree of life is uncertain, and they are not animals.
Cited in: Between the Grains, Becoming a body