a little they reveal arms covered in fine hairs called cilia and when water streams into the shell they serve as a filter separating particles of food from the water. there are a range of similar finds across the line stone alps their sheer numbers can't be a coincidence so what explains their prevalence steffen killed believes that the brachiopods were dependent on one particular source of nutrition in the depths of the testis ocean methane in. oregon in the us state of oregon we found mass occurrences of the same brachiopods in deep water sediment from the same area called we were able to confirm that this was connected to a former methane deposit as the methane emerged from underground it would be ingested by bacteria which grew in numbers and the brachiopods in turn ate the bacteria we suspect this also happened here in the l i didn't. primeval times