EARLIEST TETRAPOD RECORD

• Ichthyostega means 'fish plate' because the roof of the skull was shaped like a fish plate.
• This is considered the most primative of all tetrapods.
• Acanthostega means 'spine plate' because of prongs found at the back of the skull.
• This is a type of jawless fish that is under debate as to whether it can be considered the more primative tetrapod.