I guess that would refer to tadpole shrimps? They also show high diversification despite overall morphological conservation. I did not come across the shark thingy, though.

19 hours ago, Ten oz said:

Perhaps not this time though. Living fossil is a superficial title and we all agree. 

The OP is asks about DNA. We don't have testable DNA from a hundred million years ago. 

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Thanks, I learned this time though.

When I think of "living fossil" my first thought are cycads. Now the cycads alive today are obviously different from the cycads known from the fossil record, BUT there are more species known from fossil than are alive today. Predate flowering plants on earth.

Since reading Tim Low's latest ("Where Song Began - Australia's birds and how they changed the world"), I also think of the Australian lyre bird. Not really a living fossil, but certainly a direct descendant of possibly the first song bird.

In these discussions we need to reconsider the term "primative" - where it is thought to mean poor and rudimentary. In many ways these species have extraordinary strength in survival.

Edited April 7, 20196 yr by druS