DataType is already a thing

[oxinabox]

typeof(Int) == DataType
As does basically all other types of types, with the exclusion of unions and unionalls.

While we can have multiple things using same name because of shadowing,
I would find a confusing to say this name used for anything other than the original definition

[ericphanson]

just to say I was confused by this recently. I think RecordType would be a better name, like a record in a database, since it has fields which carry data.