Jones1rocks Posted December 21, 2017 Share Posted December 21, 2017 I have a Palaeoxyris that is significantly larger than this specimen. Is this a Palaeoxyris, and why would there be such a discrepancy in size between specimens? 1 Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted December 21, 2017 Share Posted December 21, 2017 Palaeoxyris is the generic name for egg cases of hybodont sharks. So the two specimens could be from two entirely different species of differing sizes. 5 Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
Fossildude19 Posted December 21, 2017 Share Posted December 21, 2017 Yup. Definitely an egg case. 1 Tim - VETERAN SHALE SPLITTER VFOTM --- APRIL - 2015 __________________________________________________ "In every walk with nature one receives far more than he seeks." John Muir ~ ~ ~ ~ ><))))( *> About Me Link to comment Share on other sites More sharing options...
Jones1rocks Posted December 21, 2017 Author Share Posted December 21, 2017 Thanks guys! Link to comment Share on other sites More sharing options...
fossilized6s Posted December 21, 2017 Share Posted December 21, 2017 I agree with egg case. 1 ~Charlie~ "There are those that look at things the way they are, and ask why.....i dream of things that never were, and ask why not?" ~RFK ->Get your Mosasaur print ->How to spot a fake Trilobite ->How to identify a CONCRETION from a DINOSAUR EGG Link to comment Share on other sites More sharing options...
Archie Posted December 21, 2017 Share Posted December 21, 2017 A gorgeous one too! 1 Link to comment Share on other sites More sharing options...
oilshale Posted December 21, 2017 Share Posted December 21, 2017 Seems to be Palaeoxyris helicteroides Morris in Prestwich, 1840 Chondrichthyan egg capsule card.pdf 2 Be not ashamed of mistakes and thus make them crimes (Confucius, 551 BC - 479 BC). Link to comment Share on other sites More sharing options...
Jones1rocks Posted December 22, 2017 Author Share Posted December 22, 2017 1 hour ago, oilshale said: Seems to be Palaeoxyris helicteroides Morris in Prestwich, 1840 Chondrichthyan egg capsule card.pdf Very informative! Link to comment Share on other sites More sharing options...
fiddlehead Posted January 3, 2018 Share Posted January 3, 2018 The shark egg capsules seen here are called Palaeoxyris prendeli 1870. Lesquereux. They are by far the most prevalent Middle Pennsylvanian egg cases found in North American. But they are unknown in Europe. More on this latter. Egg capsules are identified by band count and suture patterns. E.g., P. helicteroides has a simple and very consistent pattern of large band/small band/large band. P. prendelli has a weak (often missing), complicated and highly variable pattern roughly going small/medium-broad/broad/broad/small. One thing to keep in mind is size of the egg case does not matter in identification. Larger sharks of a species lay larger eggs than younger and smaller sharks do. This character is seen today in modern egg laying sharks. Though it has not been published yet, there is an privately owned example of P. prendelli with a shark partially emerged which is surrounded by a stain that can be interpreted as embryonic fluid. Based on its features like a long and narrow snout, the shark is easily referable to a Bandringa rayi. It should be noted that B. rayi is unknown in Europe as should be expected since as mentioned earlier, P. prendelli is not found there. Hope this helps, Jack 8 Link to comment Share on other sites More sharing options...
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