Lappets

Here's a dimorphic pair - Phlycticeras and Oecoptychius, both 15 mm and preserved in pyrite. They are from the Callovian (Middle Jurassic) of Gruibingen, Germany. This Oecoptychius hasn't retained its lappets unfortunately (but what they look like can be seen in the French example posted earlier).
 

Attachments

  • conv_294608.jpg
    conv_294608.jpg
    76.6 KB · Views: 127
Neale Monks;141053 said:
I can't speak for regular ammonites, but at least some heteromorph ammonites show distinct apertural modifications depending on their gender. Among Lechites for example (if I remember correctly) the macroconchs have a curved aperture, so that the end effectively curls over by almost 90 degrees; by contrast the microconchs this is not the case, but the aperture is fluted, a bit like a complex spout. I think Sciponoceras shows a similar thing.

Cheers, Neale

A nice specimen of Sciponoceras gracile collected by Jim Jenks in the Tropic Shale of Southern Utah.


A close up of the aperture in possible life position


I don't know if this is a gender thing for these or not.
 

Attachments

  • conv_295727.jpg
    conv_295727.jpg
    107.4 KB · Views: 131
  • conv_295728.jpg
    conv_295728.jpg
    89.3 KB · Views: 132
A French Jurassic perisphinctid (cf Elatmites), 65 mm, with lappets. This one is often in the tank with Ramses the cuttlefish.
 

Attachments

  • conv_297709.jpg
    conv_297709.jpg
    298.4 KB · Views: 163
Turonian dimorphic pair



Macro and Microconchs of Yezoites pueneulus from the Turonian of Japan
Micro with lappet
 

Attachments

  • conv_297710.jpg
    conv_297710.jpg
    3.9 MB · Views: 137
  • conv_297711.jpg
    conv_297711.jpg
    3.9 MB · Views: 137

Shop Amazon

Shop Amazon
Shop Amazon; support TONMO!
Shop Amazon
We are a participant in the Amazon Services LLC Associates Program, an affiliate program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.
Back
Top