Assuming this to be the audacious purchase from Sonerscheins referred to earlier, we now have some information about Mr. Ryder's terra-cotta bull.
The Etruscan civilization had established itself in Central Italy by about the 7th Century BC, and had probably been in existence for several centuries prior to that time. It is likely that the decline of the civilization occurred towards the 3rd Century BC, although views on this issue appear to vary.
Much, though not all, of Etruscan Art was destroyed. What has survived tends to fall into the category of funerary art (artworks related to the burial of the dead).
As Mr. Ryder's terra-cotta bull was previously described as being from the 5th Century, we must assume, if it is Etruscan, that this refers to the fifth century BC.