These ancient objects appear alone and strung together by each of their protruding fins, large to smallest. Most point in the same direction. They are enormous. One would require over 20 acres of space. When strung together, the length would be in miles. The holes are from 100-400 feet diameter and the thickness of each pod would be over 50 feet of "shell" material. Calcium? They are in grouping which could be colonys, or a single organism covering miles. It would be impossible for these things to be made geologically over vast distances on the planet. Probably "lived?" during the age when Mars had oceans of water, like Earth.