Egg Case Or Not Egg Case: That's The Question

[John]

Perhaps a CT scan would reveal something imperceptible to the naked eye or microscope.

I'd have to ask him about that but if a shark egg case could survive in some way perhaps at least the teeth of an embryo would be preserved especially if the egg was about to hatch when it was buried. Also, if something as soft-bodied as a worm could be preserved, why not a shark embryo? Complete sharks are known from Mazon Creek and a few appear to be at least young as juveniles.

The bottom line with all fossil eggs and the like is that unless identifiable embryonic remains are found inside, the identification as an egg is always uncertain. It sounds obvious, but you would be amazed at how many "eggs" and "egg cases" turn out to be other things. In the Mazon Creek instance, the evidence is very good that most of these fossils are indeed egg cases, but unless or until embryonic remains are found inside one, it is impossible to completely rule out the possibility that they are something else.

For now, yeah, they are probably shark egg cases.

[Terry Dactyll]

''Perhaps a CT scan would reveal something imperceptible to the naked eye or microscope.''

More often than not they are crushed completely flat.... but perhaps those that are not could be looked at using new technology but every indicator is pointing to they are shark eggcases and that is what they are widely considered to be.... I would imagine the ID's of many types of fossil eggs found is uncertain but that is palaeontology.... putting what pieces of the jigsaw we have together to get a better understanding until another piece to the puzzle is found to make us think different.... accepting one provisional identification and not another is a personal choice we make...was T Rex blind until we find an eyeball... I know you could say there are eye sockets in the skull etc.... but you get my drift...

Edited December 4, 2010 by Terry Dactyll

[Terry Dactyll]

Heres a gift from a friend.... The eggs were completely buried in the nodule besides the tips at one end and it got a little sticky towards the other end but I'm very happy with the results.... it is another example in the collection from the upper carboniferous of the UK... a 'double' Palaeoxyris..(Shark Eggcase)

I tell you whats favourable evidence from a collectors perspective in the argument for the shark eggcase theory (besides the scientific papers already written)... They are found with other Aquatic material like fishscales or cyclus and horsehoe crabs...No plant or seeds... strange eh

[Coco]

Coco

[Terry Dactyll]

Another recent Palaeoxyris....

[Nandomas]

Another recent Palaeoxyris....

Again? :o

You make me jaelous

[Terry Dactyll]

Again? :o

You make me jaelous

This ones a nice one from today... It popped great and is pretty d detailed

[oilshale]

A new article by Ronald Böttcher: "Description of the shark egg capsule Palaeoxyris friessi n. sp. from the Ladinian of Germany and discussion of all known egg capsules from the Triassic of the Germanic basin"

http://www.palaeodiversity.org/pdf/03/Palaeodiversity_Bd3_Boettcher.pdf

Thomas

[Bill]

Very interesting with stunning specimens. Cheers.

[Nandomas]

A new article by Ronald Böttcher: "Description of the shark egg capsule Palaeoxyris friessi n. sp. from the Ladinian of Germany and discussion of all known egg capsules from the Triassic of the Germanic basin"

http://www.palaeodiversity.org/pdf/03/Palaeodiversity_Bd3_Boettcher.pdf

Thomas

Thomas, thanks for posting this paper.

I was so lucky to meet that guy in person.

It's so perfect, big and sweet to let me thinking it's one of the best fossil ever found to date. For size comparison there is the A4 scientific paper on the left.

I am sorry the picture is not sharp how I should like

Edited February 15, 2012 by Nandomas

[Bill]

Very nice Nando.

[Coco]

Thanks for this nice publication, and for your marvelous fossil Nando. It is so weel preserved !

Coco

[RCFossils]

Incredible specimen

Thanks for posting the description!