{"product_id":"astrhelia-palmata-fossilized-white-stony-coral-specimen","title":"Astrhelia Palmata, Fossilized White Stony Coral Specimen (Individual Branch) - Choptank Formation, Calvert Co, Maryland, USA","description":"\u003cp\u003eThis listing is for one unique Astrhelia Palmata, Individual Branch Specimen of White Fossilized Stony Coral which is sold as seen.\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eDimensions:\u003c\/strong\u003e approx. 4.7cms x 2.5cms x 1.5cms\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003e\u003cstrong\u003eWeight:\u003c\/strong\u003e 9g\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eGeology \u0026amp; History: \u003c\/strong\u003eAstrhelia Palmata, this extinct species of stony coral is a classic index fossil from the Miocene epoch (approximately 5 to 23 million years ago). Its known geological distribution is completely confined to the Atlantic Coastal Plain of North America. It is an extinct species of stony \"star coral\", a branching colonial coral whose branches often fused together into a webbed, hand-like, or \"palmate\" structure, which gives the species its name (palmata). Whilst living polyps were colourful, the fossils however, are typically a chalky, natural off-white to beige colour.  Close examination of the surface reveals small, circular, star-like cups called chalices or corallites, measuring only 2 to 3 millimetres in diameter. Each cup features 12-20 fine, internal partitions (septa) radiating inward like the spokes of a wheel. The skeletal structure was originally built from calcium carbonate (aragonite) secreted by tiny marine polyps but over millions of years, it calcified into hard stone.\u003c\/p\u003e\n\u003cp\u003eDuring the Middle Miocene era, Astrhelia Palmata thrived in the shallow, cool-temperate sea covering what is now Maryland. The Choptank Formation, Calvert Co, is a geological rock layer made of the sandy and clay-rich sediment left behind by this ancient ocean. The massive fossil and shell beds found in this formation were created by intense prehistoric storms and ocean currents, which repeatedly churned up the seafloor, gathered the dead corals and shells together, and buried them rapidly in dense, packed layers before they could erode away. The extinction of this species was primarily caused by severe global cooling and changing ocean currents during the late Miocene and Pliocene epochs and was a gradual response to a radically shifting climate.\u003c\/p\u003e","brand":"All About The Box","offers":[{"title":"Default Title","offer_id":52567273537810,"sku":null,"price":5.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0081\/4442\/0975\/files\/PXL_20260807_114349958.jpg?v=1786626280","url":"https:\/\/www.allaboutthebox.co.uk\/products\/astrhelia-palmata-fossilized-white-stony-coral-specimen","provider":"All About The Box","version":"1.0","type":"link"}