It was eaten, just not by other lifeforms, this assumes that Basilisks use a Cytotoxic venom that they have limited immunity to, said immunity being based on a stomach lining like mucus membrane that must be continuously replaced and which separates the toxin from the rest of the Basilisk. As such once the creature is dead it's own venom rapidly leaks out of its venom sacs and spreads through its soft tissue and dissolves it from the inside out. It could decay to a skeletal state in just days.

It was eaten, just not by other lifeforms, this assumes that Basilisks use a Cytotoxic venom that they have limited immunity to, said immunity being based on a stomach lining like mucus membrane that must be continuously replaced and which separates the toxin from the rest of the Basilisk. As such once the creature is dead its own venom rapidly leaks out of its venom sacs and spreads through its soft tissue and dissolves it from the inside out. It could decay to a skeletal state in just days.

It was eaten, just not by other lifeforms, this assumes that Basilisks use a Cytotoxic venom that they have limited immunity to, said immunity being based on a stomach lining like mucus membrane that must be continuously replaced and which separates the toxin from the rest of the Basilisk. As such once the creature is dead it's own venom rapidly leaks out of it's venom sacs and spreads through its soft tissue and dissolves it from the inside out. It could decay to a skeletal state in just days.

It was eaten, just not by other lifeforms, this assumes that Basilisks use a Cytotoxic venom that they have limited immunity to, said immunity being based on a stomach lining like mucus membrane that must be continuously replaced and which separates the toxin from the rest of the Basilisk. As such once the creature is dead it's own venom rapidly leaks out of its venom sacs and spreads through its soft tissue and dissolves it from the inside out. It could decay to a skeletal state in just days.