A fair size mainland specimen! The grandpappy of Cook's turbans, and in amazingly good condition for it's size, often they are beaten about to pure nacre and very glamorous thus.
Powell listed them as maxing out at 90 X 80. Te Papa says 119 X 90.
Was interested to note three separate layers in the shell formation, something I don't recall absorbing before.
Seems to be out of usual habitat [rocky coast],
however the mouth of the Pakawau inlet is quite bouldery and I have in the past observed many specimens on this beach, perhaps such spots are the secret to longevity.