Polydactyly in the earliest known tetrapod limbs

Upper Devonian East Greenland limb material documents eight digits in the Acanthostega forelimb, showing that five digits were not the fixed primitive condition and that digit-bearing limbs need not imply terrestrial walking.

Acanthostega is bounded here by described limb material from Famennian Upper Devonian deposits of East Greenland; this bounded sample context is not a global distribution or exact complete range.

The Acanthostega limb study treats the material as an early tetrapod and compares its digit number with Ichthyostega and Tulerpeton; this package does not convert that comparison into a universal phylogenetic tree.

The Acanthostega limb material cited here comes from East Greenland Upper Devonian deposits; the locality is a documented sample, not a global distribution estimate.

Described Acanthostega forelimb material preserves eight digits, demonstrating a non-pentadactyl Devonian limb condition; digit count alone does not demonstrate habitual terrestrial walking.

The cited Acanthostega limb study does not directly establish diet, habitat preference or observed locomotor behaviour; ecological fields therefore remain unresolved apart from the bounded depositional context.