Echinoid Spines

[Julian Griffiths]

      I am trying to identify the species of a number of incomplete but highly detailed Echinoid ' club' spines ( tubercles ) I have found in one , very small fossil ground in Ibiza ( Balearic Islands ). I have been in contact with Andreas Kroh, Editor-in-Chief of the Geological-Paleontological department of the Natural History Museum of Vienna , but all he can tell me on the matter is that he doesn't think they are genus Pseudocidaris , but thinks he may have seen such spines in a paper ......but can't remember when .

 

   Any help from Echiboid specialists out there to identify these spines would be great ! 

       

[Pemphix]

Ibiza is big and it's geology is partially complex.

You should give a little bit more info about location, strata etc.

 According to: https://eprints.ucm.es/3085/1/T17117.pdf

i would say it is Balanocidaris sp. cf. gibberula or Pseudocidaris sp. cf. clunifera.

 

 

[Julian Griffiths]

Thank you Pemphix for your feedback ! I believe the shale strata to be late Cretatious although it seems to be very difficult to gain any information from Balearic Paleontologists on the Balearic Islands . The small science museum in Mallorca said they would pass my photos of the spines to their associate Paleontologists ( they say they have three ) , but I haven't heard back from them , so gaining information from local sources seems a dead end . The sciences are of little mainstream interest in Spain which is why I'm delighted this forum exists , otherwise I'd just be on my own . 

    I will peruse your Balanocidaris speculation , as Andreas Kroh has basically already ruled out any Pseudocidaris .

 

Any more help from anybody on this identification much appreciated .

[Julian Griffiths]

Well... Neither of those two species spines resemble my find ! Although I have only fragments , mostly the tips , what is notable is that the ridges are smoothe and unbroken and all the tips , both large and small come to a point like rugby balls . Non of them are rounded !

                                                                       INFO ON THE SITE 

These spine fragments are exclusive in Ibiza, to one small costal erosion site , perhaps 200 m2 ( to the best of my knowledge )

at the mouth of the bay of Puerto San Miguel . They are lose among shale which forms a steep bank below the sea cliff of which the shale and limestone strata have been pressed up at an angle of 45 degrees . This is typical of the Balearic geology, as the islands were driven up under the compressions of the African plate colliding with the Iberian micro- plate , so all fossil bearing strata have been through the gristmill . It would appear that the fossils to be found on this bank have weathered free along with the softer shale and fallen from the cliff above , but the cliff is too steep and unstable to climb and investigate .

 

   All other fossils that I have found on the island point to lower Cretatious. I am curious as to if any geologists have found the K-T boundary in Ibiza , but , like I said, Spain is a little poor on mainstream scientific information as there is seemingly little popular interest in the sciences .