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When out fossil hunting...

So I thought I would do a post about things to remember when out and about doing your own fossil hunts, hopefully you'll find it helpfu...

Thursday, 18 August 2016

The Difference Between...Anapsids, Synapsids, Diapsids and Euryapsids

Simplified skull diagrams of anapsid, synapsid, diapsid and euryapsid.
Image taken from Benton 2005
You will come across various references to amniote skull types such as synapsid and diapsid, these are the more commonly used ones. So for this post I will go through how to tell which is which by looking at the skull.

(a) Anapsid Skull: Skulls that lack openings, known as temporal fenestrae, are anapsids. These include turtles, modern and prehistoric, as well as extinct reptile species.

(b) Synapsid Skull: There is a single temporal fenestrae situated below the postorbital bone, in a similar position to the lower opening of a diapsid. Synapsid reptiles are now extinct but mammals are also synapsid and believed to be descendants of these reptiles.

Dimetrodon Skull, an example of a synapsid. Image credit:
mercyhurst.edu
(c) Diapsid Skull: Perhaps the most famous diapsids are the dinosaurs, but diapsid also covers snakes, crocodiles, lizards and birds. There are two temporal fenestrae behind the orbit. One is inferior (smaller) and one superior (bigger).

(d) Euryapsid Skull: This is probably the least known of the amniote skull. Although it appears to be similar to the synapsid skull it differs as it is positioned above the postorbital bone rather than beneath it. The Euryapsids include Ichthyosaurs and Plesiosaurs.

16 comments:

Anuj Shinde said...

Really Helpful, Thank you!

Unknown said...

Extremely thought provoking. Thank you.
John Foster
23.01 11June 2020

Anonymous said...

Was accurate and straight to point

Unknown said...

Helpful

Unknown said...

Extremely helpful

Anonymous said...

Awesome

Anonymous said...

Very helpful 👍

Anonymous said...

Nice content ever

Anonymous said...

Yes 😌

Anonymous said...

Really

Anonymous said...

Nice content..(harman)

Anonymous said...

Awasome content*Arjendu*

Anonymous said...

🙏🏻

Anonymous said...

Hi there,🙋🏻‍♂️🎄
Thanks for the short info on these skulls hoping to find out what they are for.🙋🏻‍♂️

Anonymous said...

The openings that is!!?

Anonymous said...

I’ve just found out from another post that they are for muscle attachment.
Thank-you, merry Xmas.