Buckland also concluded that the spiral markings on the fossils indicated that ichthyosaurs had spiral ridges in their intestines similar to those of modern sharks, and that some of these coprolites were black because the ichthyosaur had ingested ink sacs from belemnites.
22.
To load the pen with ink, one would remove the outer casing of the pen body, lower the nib into a bottle of ink, and squeeze-and-release the ink sac, drawing ink into the pen as the springy rubber sac returned to its rest shape.
23.
Several different melanins include melanoprotein ( dark brown melanin that is stored in high concentrations in the ink sac of the cuttlefish Sepia Officianalis ), echinoidea ( found in sand dollars, and the hearts of sea urchins ), holothuroidea ( found in sea cucumbers ), and ophiuroidea ( found in brittle and snake stars ).
24.
Of these, the holotype is the largest, at 33.8 mm mantle length ( ML ) . " C . tongaensis " is characterised by several distinct morphological features : the mantle is free from the head in the nuchal region, a large, circular visceral photophore and ventral shield are present on the ventral surface of the ink sac, and the broad keel extends the full length of the club.
