Cristozoa Explained

Cristozoa (also known as crest animals) is a grouping of animals possessing a neural crest and derivatives.^[1]

It includes all the Craniata, as well as their immediate precraniate precursors. The precraniate crest animals, such Haikouella and Yunnanozoon, are all extinct and found only in Early Cambrian strata of Yunnan (southwestern China).^{[1] [2]}

Notes and References

1. Chen . J. ‐Y.. Early crest animals and the insight they provide into the evolutionary origin of craniates. Genesis. 46. 11. 623–639. 2008. 19003927. 10.1002/dvg.20445.
2. 2009. 19557680. 10.1387/ijdb.072513cj. 733–751. 5–6. The sudden appearance of diverse animal body plansduring the Cambrian explosion. The International Journal of Developmental Biology. 53. Chen. free.