XAML - Accessing static fields

How does one go about referencing a class's static properties in xaml? In other words, I want to do something like this:

C#

Class BaseThingy {
  public static readonly Style BaseStyle;
  ...
}

XAML

<ResoureDictionary ...>
  <Style BasedOn="BaseThingy.Style" TargetType="BaseThingy" />
</ResourceDictionary>

What is the syntax to do this in the BasedOn? I assumed it would involve using StaticResource to some degree, but I haven't gotten it to work for me.

From stackoverflow MojoFilter

• Use x:Static markup extension

  <ResoureDictionary ...
    xmlns:local="clr-namespace:Namespace.Where.Your.BaseThingy.Class.Is.Defined"
  >
    <Style BasedOn="{x:Static local:BaseThingy.BaseStyle}" TargetType="BaseThingy" />
  </ResourceDictionary>
  

  From aku