The 366 daily episodes in 2014 were chronological snapshots of earth history, beginning with the Precambrian in January and on to the Cenozoic in December. You can find them all in the index in the right sidebar. In 2015, the daily episodes for each month were assembled into monthly packages, and a few new episodes were posted. Now, the blog/podcast is on an occasional schedule with diverse topics, and the Facebook Page showcases photos on Mineral Monday and Fossil Friday. Thanks for your interest!

Saturday, February 8, 2014

February 8. The Chengjiang fauna





Chengjiang, in Yunnan, southwest China, is one of the most celebrated and important fossil localities in the world. When well-preserved soft-bodied animals were found there in the 1980s, they were immediately compared to the famous Burgess Shale fossils that we’ll talk about in a few days. And at about 525 million years old, they were found to be about 10 million years older than the Burgess fauna.

Maotianshania cylindrica, a nematode worm.
This was a big deal – because the Burgess shale animals were practically unique in the world. With the discovery of Chengjiang, the record of early Cambrian life forms expanded in time as well as space. Many of the fossils in China are the same types as those in the Burgess Shale, and these critters are critical to our understanding of the Cambrian Explosion.

The life that lived in the Cambrian of China included trilobites, as well as sponges, jellyfish, lots of kinds of worms, and importantly, the oldest probable chordates. Chordates have notochords, a linear arrangement of nerves that in vertebrates like us has evolved into our backbone and spinal chord. This means that the ancestors of modern birds, reptiles, fish, amphibians, and mammals – and us – are pretty ancient, at least 525 million years old.

I would encourage listeners to check the links below to sources for more information and photos of the Chengjiang fauna.

Photo by SNP under GFDL

Update (April 2014): New arthropod with cardiovascular system reported
http://en.wikipedia.org/wiki/Maotianshan_Shales
http://www.fossilmuseum.net/Fossil_Sites/Chengjiang.htm

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