Final answer:
The pedicle of brachiopods is a fleshy stalk-like feature used for attachment, likely composed of proteins and possibly some mineral content. The brachiopod shells, made of calcium carbonate, are more likely to be preserved in the fossil record, often showing an opening for the pedicle.
Step-by-step explanation:
The substance that covers the stalk, or pedicle, of brachiopods is typically not preserved in fossil records. However, it is known that the pedicle of a brachiopod is a fleshy, stalk-like feature which some groups use to attach themselves to a hard rocky seafloor. While the exact composition of the stalk-like feature isn’t detailed in the information provided, we can infer that it would likely have been composed of organic materials similar to other marine organisms, primarily consisting of proteins and possibly some mineral content for the attachment mechanism.
Brachiopods are known for their two distinct valves, the brachial valve and the pedicle valve, with the latter usually having a hole for the pedicle. This fleshy stalk allows them to anchor to substrates in the marine environment. The shell of the brachiopod, which is composed of calcium carbonate, would preserve more readily and often includes an opening where the pedicle would have been.