Chengjiang Maotianshan Zoolites Site

Chengjiang Maotianshan Zoolites Site

On July 1st, 1984, Mr Hou Xianguang, a renowned 
paleontologist, discovered the paleontological
 fossil site in Maotianshan Mt of Chengjiang 
County. A massive, systematic collecting work 
was then launched.

According to the geological survey in 1984
 and 1985, Chengjiang zoolites had been
 found to widely distribute, and they can 
date back to the early Cambrian Period which
 is about 520 million years ago.

These fossils cover a complete range of marine
 life, and they are currently considered the
 best-preserved paleontological fossils in the
 world. Most importantly, these fossils shed
 light on the wonder and pristine features of
 marine life during the Cambrian Period; and 
they are pretty valuable proofs for study into 
the origin of life, organic evolution, and ecology
 in the early stage of the Earth.

The discovery of Chengjiang zoolites has shocked 
the science circle of the world, and it has been
 claimed “one of the most amazing discoveries
 in the 20th century”.

What are there at the fossil site?
The Chengjiang biota came into being during
 the Cambrian Explosion. Most representatives
 of the existent animals can be found here. (Picture on the left:
 Maotianshania)

Porifera (Spongia)
The Spongia animal fossils vary, including at least 20 genera and species
 which belong to Class Hexactinellida and Desmospongia.

Brachiopoda
Four genera and four species have been discovered so far.

Cnidaria (Coelenterate)
Two genera and two species have been discovered, belonging to Actinia 
and Ctenophora.

Nematomorpha
Worm (animals) fossils under this phylum are one of the most common
 at Chengjiang fossil site. Their bodies resemble to slim cylinders. So far,
 three genera and three species have been discovered. 

Priapulida
Four genera and four species

Kinorhyncha
At least four genera and four species

Lobopodia
At least six genera and six species

Mollusca
Four genera and four species

Arthropoda
It is the most enormous fossil category among the zoolites. At present,
 40 genera and 40 species have been described, and they belong to 
three super-classes. No uniramia animal fossils have been discovered.

Echinodermata
One genera and one species have been reported currently.

Uncategorised
Due to the insufficient research, there have been 12 genera and 12
 species uncategorised, such as jellyfish-like fossils, Yunnanozoon, and
 Facivermis yunnanicus Hou et Chen.

Algae
A huge number of algae fossils have been found existing on rock surfaces
 at Chengjiang fossil site. With most having no branches, these fossils
 turn out to be filaments of different diameters, and a few of them are in
 the shape of spiral.

(Yunnanzoon)

What is the significance?
Before the discovery of Chengjiang zoolites, the oldest fossil site had been
 the Burgess Shale Fossil Beds of Canada, which can date back to the middle
 Cambrian Period and is in fact 10 million years younger than Chengjiang 
zoolites.

Chengjiang fossil site practically unveils the original look of the oldest marine 
animals, making people realise: various animals have been living in the sea 
since the Cambrian Explosion.

Chengjiang zoolites have depicted a diagram of the complete and oldest 
marine biota-for which there had been little knowledge before. To date, the 
 zoolites have offered not only knowledge of what animals appeared as a
 result of the Cambrian Explosion of life, but also the first understanding of
 how different animals lived and their feeding habits.

Furthermore, these fossils are most likely to reveal the cause of the 
Cambrian Explosion and more information about the later organic evolution.

On July 1st, 2012, at the 36th World Heritage Conference held in St Petersburg,
 Russia, Chengjiang fossil site was inscribed into the World Natural Heritage List.