Amphibian
Acanthostega gunnari
Acanthostega gunnariAcanthostega was among the earliest vertebrates with fully formed digits, paddling through shallow Devonian freshwater ecosystems using paddle-like, eight-toed limbs. Retained internal gills, a finned tail, and delicate wrists indicate an entirely aquatic existence rather than terrestrial locomotion. Its flattened skull and sharp dentition allowed it to snap up small prey amidst dense submerged vegetation.
FossilAquaticCarnivorous
—observations
—countries
—peak records
ExtinctConservation statusIUCN Red List categoriesLCNTVUENCREWEXExtinctRed List categories, explained →
Diet & preyEarly actinopterygian fish, Aquatic arthropods, Small sarcopterygians
Predators
- Tristichopterid fishes
- Placoderms
ThreatsLate Devonian extinction pulses and large predatory fish
HabitatsDevonian freshwater rivers, oxbow lakes, and coastal swamps
Life spanEstimated 10–20 years
Classification
- FamilyAcanthostegidae
- GenusAcanthostega
- SpeciesAcanthostega gunnari
Range data is not available yet.
Interaction riskLow
- Low
- Moderate
- High
- Very high
- Why interaction risk is low
- Extinct species known strictly from Devonian fossil deposits.
Responsible observation
- Museum Exhibits: Look for mounted fossil casts to observe the eight delicate digits on each limb.
- Skeletal Anatomy: Note the retention of bony gill supports alongside fully formed toes.
Stem Ancestor Eduard Solà / CC BY-SA 3.0 · cc-by-sa
Lobe-finned Kin Nobu Tamura (http://spinops.blogspot.com) / CC BY 2.5 · cc-by
Image unavailableClose Relative 
Close Relative Nobu Tamura (http://spinops.blogspot.com) / CC BY 3.0 · cc-by
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