Two species of animals that are a previously unknown genus have been found in a collection of specimens taken from the deep ocean off Victoria, Australian in 1986. Jean Just and colleagues from the University of Copenhagen in Denmark determined that the animals were a new species recently. The study of one of the world’s oddest and potentially oldest animals was reported in the Sept. 3, 2014, edition of the journal Public Library of Science.
Dendrogramma enigmatica and Dendrogramma discoides were both found at depths between 1,300 feet and 2,400 feet. The animals are irregularly shaped and look more like a mushroom than anything else that is known to exist. The new species has some characteristics of Ctenophora and Cnidaria, two groups of well know simple organism that lives in the ocean, but are too distinctively different to be classified as either.
Dendrogramma have a well-defined epidermis and gastrovascular system. The mouth of the animal is located at the end of the stalk that looks like the stalk of a mushroom. A gelatinous layer separates the epidermis from the internal organs. The samples were fixed in formaldehyde and stored in 80 percent ethanol for 28 years. The determination of molecular composition was made impossible by the storage but the researchers plan to obtain new samples.
Dendrogramma presents several distinct structures that are very similar to a small group of animals from the genus Trilobozoa that lived 600 million years ago. These Precambrian animals are considered to be one of nature’s first attempts at multicellular life and are all extinct. Dendrogramma may have an extremely ancient lineage.