This is the best I could do last weekend. Just the mud infill of the body chamber of a large endocerid, would have been about 4 to 5 feet long I guesstimate. A small peice of the endocones is visible in the first photo (upper right corner), with some mud filling the siphuncle at the end of the body chamber producing the nob. And an end view showing the shape of the shell and location of the siphuncle.