Tuesday, 28 November 2017

Bryozoans, Tiny Living Fossils from the Cambrian, Are Still Very Much Alive

Bryozoans come in many shapes and sizes. Image courtesy of Rob Kool, CC BY-SA 1.0.

Joel Kontinen

According to the evolutionary story, the world has changed dramatically in "500 million years."

But scientists now know that some Cambrian animals have resisted change for aeons:

Recently, a tiny bryozoan was named after David Jablonski and Susan Kidwell, who both are University of Chicago researchers.

This creature, called Jablonskipora kidwellae, is assumed to be “105 million years” old.

A University of Chicago news release attempts to highlight the significance of the find:

Lurking in oceans, rivers and lakes around the world are tiny, ancient animals known to few people. Bryozoans, tiny marine creatures that live in colonies, are “living fossils”—their lineage goes back to the time when multi-celled life was a newfangled concept. But until now, scientists were missing evidence of one important breakthrough that helped the bryozoans survive 500 million years as the world changed around them.”

This is obviously a problem for evolution, so they have to explain it away:

Bryozoans never figured out a symbiotic partnership with photosynthetic bacteria, as coral did, so their evolution took a different turn. Each one in a colony is genetically identical, but they have specialized roles, like ants or bees. Their shelly apartment complexes house thousands of the creatures, which have soft bodies with tiny tentacles to catch nutrients.”

The Cambrian Era is still an enormous enigma for evolution. For some, it might be a real headache, as the creatures assigned to this period are far too complex and some Cambrian fossils are too well preserved to be that old, calling their assumed age into question.


Lerner, Louise. 2017. Fossil that fills missing evolutionary link named after UChicago professors UChicago News (16 November).