Episode 6.2 · 30 min

our synapsid ancestors and the end-Permian mass extinction

What did the synapsids that were not yet mammals reveal about the path toward our lineage—and how did that path survive the Great Dying? From the Karoo floodplains, this episode follows branching changes in teeth, jaws, palates and posture before reconstructing how Siberian Traps volcanism transformed land and sea through heat, oxygen loss and acidification. It also asks what Lystrosaurus and the disputed Karoo record reveal about survival.

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Visual credits

35 sources

Sources and credits for imagery used in this film, including material incorporated into explanatory animations.

Iziko Diictodon Corkscrew
Nkansahrexford
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Only the complete lateral crocodile skull with both open jaws and all visible teeth; exclude the human skull on the left. Preserve the full crocodile snout and jaw hinge. Materialize a tight standalone crop of this exact region, excluding neighboring panels and caption. (cropped figure, PDF page 1)
קובץ על יד
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Iziko Sabre-toothed reptiles
Nkansahrexford
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Madumabisa NHMUK PV R 37363 ventral
The Trustees of the Natural History Museum, London
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Procynosuchus delaharpeae jaw
Ghedoghedo
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Scientific figure · source page 1
Ghedoghedo
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Gorynychus masyutinae
Christian F. Kammerer
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Only the complete colored ventral Procynosuchus skull drawing at the top center, showing a long midline gap. Remove every neighboring fragment, letter, phylogenetic branch and caption. Keep the skull itself complete. IMPORTANT OUTPUT GEOMETRY: the crop tool expands your returned box by 0.015 of the WHOLE input page on each side. Locate the exact outer target region, then inset the returned box by 0.015 on each side (x0+0.015,y0+0.015,x1-0.015,y1-0.015), so tool expansion lands on the desired boundary. This is a one-page input: return page 1. (cropped figure, PDF page 1)
Gigliotti et al. 2026
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Brocklehurst et al. 2025 Figure 1 showing synapsid humerus form and 3D anatomy used to compare forelimb function (cropped figure, PDF page 4)
Brocklehurst et al. 2025
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Only the upper-left cat thermogram and its complete temperature scale. Remove the thin purple strip of the next panel at the bottom. Preserve the top and bottom scale numbers. IMPORTANT OUTPUT GEOMETRY: the crop tool expands your returned box by 0.015 of the WHOLE input page on each side. Locate the exact outer target region, then inset the returned box by 0.015 on each side (x0+0.015,y0+0.015,x1-0.015,y1-0.015), so tool expansion lands on the desired boundary. This is a one-page input: return page 1. (cropped figure, PDF page 1)
yellowcloud from Germany
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Procynosuchus skull
Ghedoghedo
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Permian Moschorhinus humerus cortex, Figure 5B
Adam K. Huttenlocker and Jennifer Botha-Brink (2014)
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Glossopteris sp. (fossil leaf) (Permian; Antarctica) 2 (49062918518)
James St. John
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Inostrancevia alexandrii skeleton 23
Ghedoghedo
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Only the complete rectangular photograph labelled B, including the B and 10 cm scale. Remove the left strip of another panel, all white outer margins, and the bottom strip labelled D. IMPORTANT OUTPUT GEOMETRY: the crop tool expands your returned box by 0.015 of the WHOLE input page on each side. Locate the exact outer target region, then inset the returned box by 0.015 on each side (x0+0.015,y0+0.015,x1-0.015,y1-0.015), so tool expansion lands on the desired boundary. This is a one-page input: return page 1. (cropped figure, PDF page 1)
Chen, Wu, Xie, Gao, Xiao and Tang (2024)
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Grand Canyon National Park- Brachiopod Fossils in Kaibab Limestone 0378 (7706182918)
Grand Canyon National Park
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Yabeina globosa fusulinid foraminifera (Akasaka Limestone, Upper Permian; Kinshozan, Gifu, Honshu, Japan) 1 (46845445741)
James St. John
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Native iron in basalt (Siberian Traps Flood Basalt, Permian-Triassic boundary times, 251 Ma; Putoran Plateau, Siberia, Russia) 2 (17338266745)
James St. John
View original source ↗Source licence: CC BY 2.0
Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Burgess, Muirhead and Bowring 2017 Figure 2 timeline of Siberian Traps magmatic stages relative to the end-Permian extinction interval (cropped figure, PDF page 3)
Burgess, Muirhead and Bowring 2017
View original source ↗Source licence: CC BY 4.0
Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Glossopteris fossil seed fern leaves in claystone (Illawarra Coal Measures, Upper Permian; Dunedoo area, New South Wales, Australia) (15448560516)
James St. John
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Hill at Karoo National Park
flowcomm
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Geology of Karoo Supergroup
Oggmus
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Only the left-hand outcrop photograph panels a b and d, including their panel letters and original scale. Completely exclude the measured column and all plots to the right. The right border of the selected area is the vertical edge between the photo panels and white column area. Materialize a tight standalone crop of this exact region, excluding neighboring panels and caption. (cropped figure, PDF page 1)
Gastaldo et al. (2020)
View original source ↗Source licence: CC BY 4.0 (article; subject to component credit lines)
Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Show only the UPPER measured stratigraphic-column portion: 70, 60 and 50 metre ticks, Katberg Formation label, the adjacent tan palynology strip, and the two complete upper lithology stacks. This is deliberately the upper section only, not the whole section. Desired final rectangle approximately [0.502,0.040,0.885,0.389]. Preserve this rectangle exactly after compensating tool padding. Completely exclude outcrop photos, all Hg plots, lower section, age labels and the lower stack beginning around y=0.394. IMPORTANT OUTPUT GEOMETRY: the crop tool expands your returned box by 0.015 of the WHOLE input page on each side. Locate the exact outer target region, then inset the returned box by 0.015 on each side (x0+0.015,y0+0.015,x1-0.015,y1-0.015), so tool expansion lands on the desired boundary. This is a one-page input: return page 1. (cropped figure, PDF page 1)
Gastaldo et al. (2020)
View original source ↗Source licence: CC BY 4.0 (article; subject to component credit lines)
Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Lystrosaurus georgi skeleton
Ghedoghedo
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Iziko Thrinaxodon fossil
Nkansahrexford
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Lystrosaurus skull
Ghedoghedo
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Proterosuchus fergusi skull, Iziko, SAM-PK-11208
Nkansahrexford
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Lystrosaurus declivis femur cortex, Figure 10A
Jennifer Botha (2020)
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Iziko Diictodon Hibernating Pair
Nkansahrexford
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Lystrosaurus embryo Figure 1a: The actual NMQR 3636 fossil photograph. No preserved shell is implied.
Benoit, Fernandez and Botha 2026
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Lystrosaurus embryo Figure 1b: Segmented digital skeleton, not a photograph. Original 10 mm scale retained.
Benoit, Fernandez and Botha 2026
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Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Lystrosaurus embryo Figure 2d: NMQR 3636 only: anterior jaw model, black arrow and original 5 mm scale. Pair with the selected CT view in the same authored comparison.
Benoit, Fernandez and Botha 2026
View original source ↗Source licence: CC BY 4.0
Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Lystrosaurus embryo Figure 2e: NMQR 3636 left CT section: open symphysis, dorsal direction and source annotations. No independent CT scale is invented; the 5 mm bar on the separate model applies to that model.
Benoit, Fernandez and Botha 2026
View original source ↗Source licence: CC BY 4.0
Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.
Lystrosaurus embryo Figure 1c: Sophie Vrard artistic reconstruction; signature retained. Reconstructed skin and egg, not preserved evidence.
Benoit, Fernandez and Botha (2026); artwork Sophie Vrard
View original source ↗Source licence: CC BY 4.0
Incorporated into an explanatory animation; presentation may include cropping, labels and overlays.

Animation design references 1 sources

These works informed the design of explanatory animations. A reference listed here is not necessarily reproduced on screen.

Iziko Odontocyclops
Nkansahrexford
View original source ↗Source licence: CC BY 3.0

Research references

Selected sources from the episode’s research and scientific figures.

Music

Meditation From The Star Orion
OctahedronMusic · Envato Elements

Footage and image usage

Credits and usage times retained from the published edition or its production credit record. Where present, times identify visual appearances, not documentary chapters. Source and licence corrections are listed in the visual credits above.

Original animations and figures created by this channel.

How this film was made

Created and editorially directed by Anders Lunde using a custom production system developed over six months. AI assists research, drafting, programming, and visual production; I review and edit the material and make the final editorial decisions. Narration uses text-to-speech. Visuals combine custom-built scientific animations, AI-generated reconstructions, and credited scientific imagery.

Generated reconstructions illustrate scientific interpretations. They are distinct from photographs, specimens, and measured data.

More about the creator and production →

Visual credits

Iziko Diictodon Corkscrew

Only the complete lateral crocodile skull with both open jaws and all visible teeth; exclude the human skull on the left. Preserve the full crocodile snout and jaw hinge. Materialize a tight standalone crop of this exact region, excluding neighboring panels and caption. (cropped figure, PDF page 1)

Iziko Sabre-toothed reptiles

Madumabisa NHMUK PV R 37363 ventral

Procynosuchus delaharpeae jaw

Scientific figure · source page 1

Gorynychus masyutinae

Brocklehurst et al. 2025 Figure 1 showing synapsid humerus form and 3D anatomy used to compare forelimb function (cropped figure, PDF page 4)

Procynosuchus skull

Permian Moschorhinus humerus cortex, Figure 5B

Glossopteris sp. (fossil leaf) (Permian; Antarctica) 2 (49062918518)

Inostrancevia alexandrii skeleton 23

Grand Canyon National Park- Brachiopod Fossils in Kaibab Limestone 0378 (7706182918)

Yabeina globosa fusulinid foraminifera (Akasaka Limestone, Upper Permian; Kinshozan, Gifu, Honshu, Japan) 1 (46845445741)

Native iron in basalt (Siberian Traps Flood Basalt, Permian-Triassic boundary times, 251 Ma; Putoran Plateau, Siberia, Russia) 2 (17338266745)

Burgess, Muirhead and Bowring 2017 Figure 2 timeline of Siberian Traps magmatic stages relative to the end-Permian extinction interval (cropped figure, PDF page 3)

Glossopteris fossil seed fern leaves in claystone (Illawarra Coal Measures, Upper Permian; Dunedoo area, New South Wales, Australia) (15448560516)

Hill at Karoo National Park

Geology of Karoo Supergroup

Lystrosaurus georgi skeleton

Iziko Thrinaxodon fossil

Lystrosaurus skull

Proterosuchus fergusi skull, Iziko, SAM-PK-11208

Lystrosaurus declivis femur cortex, Figure 10A

Iziko Diictodon Hibernating Pair

Lystrosaurus embryo Figure 1a: The actual NMQR 3636 fossil photograph. No preserved shell is implied.

Lystrosaurus embryo Figure 1b: Segmented digital skeleton, not a photograph. Original 10 mm scale retained.

Lystrosaurus embryo Figure 2d: NMQR 3636 only: anterior jaw model, black arrow and original 5 mm scale. Pair with the selected CT view in the same authored comparison.

Lystrosaurus embryo Figure 2e: NMQR 3636 left CT section: open symphysis, dorsal direction and source annotations. No independent CT scale is invented; the 5 mm bar on the separate model applies to that model.

Lystrosaurus embryo Figure 1c: Sophie Vrard artistic reconstruction; signature retained. Reconstructed skin and egg, not preserved evidence.

Iziko Odontocyclops

Research references

Music

How this film was made