I was looking for an up-to-date list of which element each dragon species originated from and I couldn't find one, so I made one. Here it is:
Dragon- Element
Aether- Arcane
Abberation- Plague
Auraboa- Nature
Banescale- Fire
Bogsneak- N/A
Dusthide- Earth
Coatl- Fire
Fathom- Water
Fae- Arcane
Gaoler- Ice
Guardian- Water
Imperial- Light
Mirror- Plague
Nocturne- Shadow
Obelisk- Earth
Pearlcatcher- Light
Ridgeback- Lightning
Sandsurge- Lightning
Skydancer- Wind
Snapper- Earth
Spiral- Wind
Tundra- Ice
Undertide- Water
Veilspun- Shadow
Wildclaw- Nature
Element- Dragons
Arcane- Fae and Aether
Earth- Snapper, Obelisk, and Dusthide
Fire- Banescale and Coatl
Ice- Gaoler and Tundra
Light- Imperial and Pearlcatcher
Lightning- Ridgeback and Sandsurge
Nature- Wildclaw and Auraboa
Plague- Mirror and Abberation
Shadow- Nocturne and Veilspun
Water- Guardian, Undertide, and Fathom
Wind- Skydancer and Spiral
Dragon- Element
Aether- Arcane
Abberation- Plague
Auraboa- Nature
Banescale- Fire
Bogsneak- N/A
Dusthide- Earth
Coatl- Fire
Fathom- Water
Fae- Arcane
Gaoler- Ice
Guardian- Water
Imperial- Light
Mirror- Plague
Nocturne- Shadow
Obelisk- Earth
Pearlcatcher- Light
Ridgeback- Lightning
Sandsurge- Lightning
Skydancer- Wind
Snapper- Earth
Spiral- Wind
Tundra- Ice
Undertide- Water
Veilspun- Shadow
Wildclaw- Nature
Element- Dragons
Arcane- Fae and Aether
Earth- Snapper, Obelisk, and Dusthide
Fire- Banescale and Coatl
Ice- Gaoler and Tundra
Light- Imperial and Pearlcatcher
Lightning- Ridgeback and Sandsurge
Nature- Wildclaw and Auraboa
Plague- Mirror and Abberation
Shadow- Nocturne and Veilspun
Water- Guardian, Undertide, and Fathom
Wind- Skydancer and Spiral