The first every multicellular animals found in an oxygen-free environment. No multicellular animal capable of living without oxygen has been discovered in the 236 years since oxygen was identified (http://www.popsci.com/science/article/2010-04/first-ever-multicellular-animals-found-oxygen-free-environment). Researches have discovered thee new species that life there entire life in an oxygen free pit beneath the Mediterranean Sea. Prior to this discovery the only organisms capable of life in oxygen-free environments were viruses and bacteria. The newly discovered animal species have some sort organelle that resembles a hydrogenosome, a cellular component used by some microbes to produce energy with complex enzymatic reactions. If these strange creatures can live without oxygen there is potential for many other species to be out there.... makes you wonder!
