>  > Many Pleistocene species are still living
>>  unchanged... in fact the
>>  majority of Pleistocene species are (the Pleistocene
>>  began 1.8my
>>  ago). Many Recent species evolved in the Pliocene
>>  (5-1.8my), some in
>>  the Miocene (24-5my)... and a few even in the middle
>>  Eocene (42-46my)!.
>
>Don't forget the Pleurotomariidae, which evolved in
>the Triassic (245-208 mya) and are still here today.
>Of course, the living species evolved in more recent
>times, but that's still some incredible longevity!
>
>James

Many families appeared a long time ago. Most living families were
well-established by the late Cretaceous.

The Epitoniidae and Aporrhaidae can be traced back to the Jurassic.
Pleurotomariidae goes back at least to the late Triassic, and though
the genera then are now extinct, they differed only in detail.
Perotrochus was crawling smartly in the early Jurassic! If you
include Eotomariidae as a subfamily, this extends it back into the
Permian. Apparent close relatives of Acteonidae were around in the
Devonian and possibly Carboniferous....
--
Andrew Grebneff
Dunedin, New Zealand
64 (3) 473-8863
<[log in to unmask]>
Fossil preparator
Seashell, Macintosh & VW/Toyota van nut
________________________________
I want your sinistral gastropods!
________________________________
Opinions in this e-mail are my own, not those of my institution
_______________________________________________
A: Because it reverses the logical flow of conversation.
Q: Why is top posting frowned upon?