Answer
A. Corals.
Step-by-step explanation:
The New York state index fossil valcouroceras is classified as a coral. It is the type genus for the Valcouroceratidae, a family in the nautiloid named by Rousseau Flower order Oncocerida. The shell of Valcouroceras is well rounded, with the ventral side on the outside curve. The body, or living, the chamber is gibbous, is less wide at the ends and more wide at the center comparatively.