[no subject]

[Tommy Tyrberg <tommy.tyrberg@norrkoping.mail.telia.com>]

David Marjanovic Wrote:

>Interesting. What I've read (forgot where) is that ammonites had planktonic
>larvae (do we know that, actually?), while nautiloids don't, and the
>plankton was decimated while deeper-sea K-strategists like nautiloids
>weren't.

Yes we know, because the smallest (presumably newly-hatched) ammonites are
_really_ small (about 1 mm), while a _Nautilus_ hatchling is about an inch
across. Another important difference: Nautilus eggs take about a year to
hatch while ammonites probably hatched quickly. Quite possibly every adult
Nautiloid and Ammonite were killed at the K/T boundary, but by the time the
last nautiloid eggs hatched things had settled down enough for a few to
survive. 

Tommy Tyrberg