BLASTOID FOSSIL PLATE Sea Life Matrix Mineral Specimen Echinoderm ILLINOIS RARE

Description: This blastoid fossil plate weighs 197 grams. The entire plate measures 72 mm x 72 mm x 35 mm. The individual blastoids measure 10 mm, 19 mm, and 19 mm respectively. I offer a shipping discount for customers who combine their payments for multiple purchases into one payment! The discount is regular shipping price for the first item and just 50 cents for each additional item! To be sure you get your shipping discount just make sure all the items you want to purchase are in your cart. Auctions you win are added to your cart automatically. For any "buy it now" items or second chance offers, be sure to click the "add to cart" button, NOT the "buy it now" button. Once all of your items are in your cart just pay for them from your cart and the combined shipping discount should be applied automatically. I offer a money back guarantee on every item I sell. If you are not 100% happy with your purchase just send me a message to let me know and I will buy back the item for your full purchase price. Hi there. I am selling this really amazing Pentremites godoni blastoid fossil plate. In addition to the three blastoid specimens there are fragments of fossilized sea fans. I bought it at a gem show in Arizona and it was found in the Ridenhower Formation, St. Clair, Illinois, USA. The blastoids on this plate date to the Upper Mississippian period about 340 million years ago. It was one of the nicest and most detailed pieces that I have ever seen. THE DETAIL OF THESE SPECIMENS IS AMAZING!!! It's really interesting and I hope it finds a good home out there. BlastoidFrom Wikipedia, the free encyclopediaJump to navigationJump to searchBlastoidsTemporal range: Ordovician - Permian PreЄЄOSDCPTJKPgNPentremites Glen Dean Fm KY.jpgPentremites godoni, a blastoid from the Lower Carboniferous of Illinois.Scientific classificationKingdom:AnimaliaPhylum:EchinodermataSubphylum:BlastozoaClass:BlastoideaSay, 1825OrdersFissiculataSpiraculata Incertae sedis:†Macurdablastus "Blastoidea", from Ernst Haeckel's Art Forms of Nature, 1904Blastoids (class Blastoidea) are an extinct type of stemmed echinoderm, often referred to as sea buds.[1] They first appear, along with many other echinoderm classes, in the Ordovician period, and reached their greatest diversity in the Mississippian subperiod of the Carboniferous period. However, blastoids may have originated in the Cambrian. Blastoids persisted until their extinction at the end of Permian, about 250 million years ago. Although never as diverse as their contemporary relatives, the crinoids, blastoids are common fossils, especially in many Mississippian-age rocks. Contents1Description2Taxonomy3References4External linksDescriptionLike most echinoderms, blastoids were protected by a set of interlocking plates of calcium carbonate, which formed the main body, or theca. In life, the theca of a typical blastoid was attached to a stalk or column made up of stacked disc-shaped plates. The other end of the column was attached to the ocean floor by a holdfast, very much like stalked crinoids. The stalk was usually relatively short, and in some species, was absent, with the holdfast being attached directly to the base of the theca. The mouth was located at the summit of the theca. Radiating like flower petals from the center were five food grooves, or ambulacra. Each ambulacrum had many long, thin, fine structures called brachioles, which were used to trap food particles and bring them to the mouth. Brachioles were delicate structures, and in fossils are not usually preserved in place. A series of five spiracle plates surrounded the star-shaped mouth, which included the anus, mouth and entrances to a set of five complex, folded respiratory organs known as hydrospires. These spiracles prevented mixing of the various fluids. Waste elimination was through the anispiracle, an opening formed by the fusing of anus and adjacent spiracles. Pentremites godoni, a blastoid from the Lower Carboniferous of Illinois; basal view of theca.Like crinoids, blastoids were high-level, stalked suspension feeders (feeding mainly on planktonic organisms) that inhabited clear-to-silty, moderately agitated ocean waters from shelf to basin. The food gathering system of blastoids consisted of several types of ambulacra. Food entered the brachiolar ambulacra, was transferred to the side ambulacra through the brachiolar pit, then transferred to the main (median) ambulacra, and finally entered the mouth. Each of these ambulacra was roofed by cover plates. The cover plates of the brachiolar groove were movable and could open, allowing food to enter, or close as needed. Other cover plates may also have been movable. TaxonomySee also: List of echinodermata ordersBlastoids are assumed to have evolved from the Cystoids. Blastoids are subdivided into two orders: Fissiculata, which are characterized by direct entrance to the individual hydrospires by way of slits; and Spiraculata, which are characterized by indirect entrance to the hydrospires through canals by way of pores. The earliest blastoid yet found, Macurdablastus from the Middle Ordovician of Tennessee, cannot be classified as either order.

Price: 219.99 USD

Location: Tucson, Arizona

End Time: 2024-11-13T08:05:32.000Z

Shipping Cost: 10.95 USD