![]() ![]() Ancient forms of the Rhizaria family likely date back 770 million years, much older than the sponge fossils. Algae instead of spongesĪ team around group leader Christian Hallmann and Nettersheim, both from the Max Planck Institute for Biogeochemistry, now surprisingly found the same molecules formerly attributed to sponges, in Rhizaria: a group of unicellular organisms that include many predatory algae. ![]() ‘That’s a huge gap, the molecules and spicules cannot both be right.’ summarizes Nettersheim who recently published this critique in a News article in the same journal. ‘But the first unambiguous sponge fossils ever found, shaped as needles or spicules, are 100 million years younger than these old sponge molecules’, says Benjamin Nettersheim, first author of a study. Sponges belong to the oldest and most simple animals that had evolved, and their discovery in such old rocks meant that they may have been the first animals. In 2009 researchers discovered fossil fat molecules, presumably originating from sea-sponges, in rocks 645 million years old. Finding out exactly when animals first arose is a central, yet unresolved question in evolutionary research. Prior to that, the world’s oceans were inhabited solely by microorganisms such as bacteria and algae. ![]() Animals, the most complex form of life on our planet, have only existed for the last few hundred million years, which accounts for less than one fifth of Earth history. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |