Scientists believe that they found the oldest living land creature in Scotland - a fossilized relative of the modern millipede who existed about 425 million years ago.
The Primordial Soup Theory suggests that life began in water, in a pond, or an ocean, as a result of energy mixing with chemicals from the atmosphere to make amino acids. These building blocks of proteins eventually evolved into all species, beginning with stew, or arthropods. Myriapods, containing millipedes and centipedes, permanently settled on the land.
The ancient millipede, Kampecaris obanesis, was first discovered on the Scottish isle of Kerrera of 1899. It is only in a recent study that it was radiometrically dated to be some 425 million years old. There is also evidence of a myriad of bug deposits just 20 million years after Kampecaris moved to land. Another 20 million years later emerged spiders, insects, and tall trees forming ancient forest communities.
Michael Brookfield, a geoscientist from the University of Texas and the University of Massachusetts said that 'it's a big jump from these tiny guys to very complex forest communities, and in the scheme of things, it didn't take that long. There seems to be rapid radiation of evolution from these mountain valleys, down to the lowlands, and then worldwide after that.'
Who's Right?
The team believes that there had been earlier life forms than Kampecaris, but no evidence from land fossils tell otherwise. Thus, the ancient myriapod represents the vital turning point at which life moved from the sea into the land.Previous estimates of scientists using molecular clock dating, based on DNA mutation rates, say that the Kampecaris is 75 million years younger than a more ancient species.
Also, stemmed plant fossils have been measured to be about 75 million years younger than originally estimated. Determining if the ancient myriapod was the first creature to walk the earth, then scientists have overall underestimated how rapidly plants and bugs evolved to live on land. Co-author Elizabeth Catlos said, 'Who's right, us or them...we're setting up testable hypotheses - and this is where we are at in the research right now.'
Fossil Age
The study is also the first of it's kind to address the fossil's age. One reason this has been challenging for scientists is due to zircons, a microscopic mineral that helps determine fossil dates accurately. Extracting zircons from rock sediments that have preserved fossils requires perfect vision and flawless, steady hands because the micro-substance can easily be flushed away.
Stephanie Suarez, a geoscientist and co-author of the study, has mastered the technique of separating sediment from zircons for years since her undergraduate study. 'That kind of [delicate] work trained me for the work that I do here in Houston,' Suarez said.
With the precise technique, she previously dated a different millipede as the oldest bug specimen. Now, with the same type of work, she helped determine that the Kampecaris is 14 million years older than the previous kind, becoming the oldest critter to walk to Earth.
