Answer:
n stage 13, all four limb buds are present. In stage 13, the upper limb buds resemble flippers. In stage 23, the upper limb shows well-formed arm, elbow, wrist, and fingers. In stage 23, the lower limb shows well-formed toes, feet, and knees.
Explanation:
I think that since it lives on the ocean floor, at the deepest of the ocean. So anyway, the fin on the Eurypterids is still necessary but not that much, since they live on the ocean floor. Their movements mostly on the ocean floor. So fin would not help them "stick" to the floor. Also there are still gravity acts on the Eurypterids and the feet would help them move faster. Hope this helps.
Eukaryotic cells have a nucleus
Proteins help with transport, building channels in cell membranes, and structure.
