520-Million-Year-Old Fossils in China Have Nerve and Verve

       The fossilized remains of Chengjiangocaris kunmingensis, a crustacean-like animal that lived 520 million years ago in what is now Xiaoshiba, China, were detailed in a paper published yesterday by researchers at the University of Cambridge.

      The species’s hard exoskeleton is well-preserved and its nervous system is outlined with such intricacy that individual nerves are distinguishable.

     

     Note that the animal’s ventral cord, the purplish line running down its center, above, is clearly visible. In addition, the tiny fibers that comprise the animal’s bundled ganglia are also detectable with precision instruments.

     This level of soft tissue preservation is rare, especially from the Cambrian period, when life on Earth first blossomed into the rich biodiversity we know today. But the Xiaoshiba fossil deposit, located in China’s Yunnan Province, is "chucky-jam full" of these Cambrian period fossils.

     Readers of PEOTS may remember our forays into the Kunming Karst topography of the Yunnan Province, including the limestone pillars from Kunming installed in a Denver, CO, USA, park.

      “Under normal circumstances it is extremely difficult to obtain preservation of soft tissues, as these decay rapidly and lose most of the morphological information,” according to study co-author Javier Ortega-Hernández, a research fellow at the University of Cambridge.

     “However, there are cases in which the environmental conditions are more prone to produce exceptional preservation,” he said. “These include when the animals are entombed rapidly by a large amount of fine sediment, and all of this occurs in an oxygen-depleted environment. This process helps to limit the extent of decay on the carcasses and may result in the superb preservation of delicate features such as the ventral nerve cord and other parts of the internal anatomy.”

     Studying this extinct animal’s nervous system demonstrated that some of the species’s modern relatives, like velvet worms, maintain a similar internal structure.

          "Others, like the nearly indestructible tardigrades (or water bears), have done away with the complex rubric of nerve fibers found in their Cambrian forebears, in favor of more minimalistic systems. These insights capture a broader evolutionary picture through the aperture of C. kunmingensis’s fossilized nerves."

How's your nerve and verve today?
Steph