Yes, METASEQUOIA is a Scrabble word!

Letter values in Scrabble US: M 3, E 1, T 1, A 1, S 1, E 1, Q 10, U 1, O 1, I 1, A 1.

Is it a valid word?

METASEQUOIA is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

large fast-growing Chinese monoecious tree having flat bright-green deciduous leaves and small globular cones; commonly cultivated in United States as an ornamental; known as a fossil before being discovered in China

Also: dawn redwood, metasequoia glyptostrodoides.