{"product_id":"2-4-neuropteris-fossil-leaves-mazon-creek-nodule-pennsylvanian-age-split-pair","title":"4.1\" Neuropteris Fossil Leaves Mazon Creek Nodule Pennsylvanian Age Split-Pair","description":"\u003cp\u003eLocation: Francis Creek Shale Formation, \u003cspan\u003eIllinois\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eWeight: 1 Pound 13.3 Ounces\u003c\/p\u003e\n\u003cp\u003eDimensions: 4.8 Inches Long, 3.8 Inches Wide, 2 Inches Thick (\u003cstrong\u003e\u003cspan style=\"color: rgb(129, 63, 8);\"\u003eNodule\u003c\/span\u003e\u003c\/strong\u003e)\u003c\/p\u003e\n\u003cp\u003eLeaf Dimensions: 4.1 Inches Long, 1.6 Inches Wide\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"color: #6aa84f;\"\u003e\u003cstrong\u003eThe item pictured is the one you will receive.\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cdiv\u003ePensylvanian Age, 370 million years ago\u003c\/div\u003e\n\u003chr\u003e\n\u003cdiv\u003e\n\u003cp\u003e\u003cspan style=\"color: rgb(135, 69, 8);\"\u003e\u003cstrong\u003eNeuropteris Fossil Leaves\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eThe Mazon Creek fossils date back to the\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003ePennsylvanian sub-period (roughly 307 million years ago)\u003c\/strong\u003e. During this time, the area was a tropical delta environment. When leaves fell into the water, they were rapidly buried in silt and clay.\u003c\/p\u003e\n\u003cp\u003eThe unique chemistry of the sediment—specifically the formation of\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003esiderite (iron carbonate) nodules\u003c\/strong\u003e—created a \"time capsule\" around the plant material. As the plant decayed, it left behind a perfect impression (or a carbon film) inside the stone.\u003c\/p\u003e\n\u003cp\u003eYou will rarely find a whole tree; instead, you will find fragments of the lush swamp forests that once covered Illinois. Common finds include:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePecopteris:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eThe most common fern-like leaf. It has small, rounded leaflets attached to a central stem.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNeuropteris:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eA \"seed fern\" (Pteridosperm). These leaves are often larger and have a distinct, smooth, tongue-shaped leaflet.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAlethopteris:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eAnother seed fern, characterized by leaflets that are fused to the stem at the base.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAnnularia \/ Calamites:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eThese aren't leaves in the traditional sense, but whorls of needle-like leaves that grew around the stems of giant horsetail trees.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLepidodendron (Scale Trees):\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eWhile these are technically bark impressions, they are often mistaken for leaves. They look like a diamond-shaped grid pattern.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eMazon Creek fossils are almost exclusively found inside\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eironstone nodules\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe \"Split\":\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eWhen you find a nodule, you have to split it open. If you are lucky, the nodule will crack perfectly along the plane where the leaf was trapped, revealing the fossil on one side and the \"mold\" on the other.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFreeze-Thaw Method:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eCollectors often take unopened nodules home and put them through several cycles of freezing and thawing. This causes the internal stress of the rock to crack it open along the weakest point—usually the fossil line.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\u003chr\u003e\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cstrong\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/1250\/0441\/files\/IMG_4922.jpg?v=1777988148\"\u003e \u003cmeta charset=\"utf-8\"\u003e \u003c\/strong\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003cstrong\u003e\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\u003chr\u003e\u003c\/div\u003e","brand":"Mazon26","offers":[{"title":"Default Title","offer_id":52029252305176,"sku":"06MQQ18","price":95.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1250\/0441\/files\/5U8A8487_869abbb1-85ff-4c68-84b4-42a4d8b3e2a7.jpg?v=1778012777","url":"https:\/\/www.fossilageminerals.com\/products\/2-4-neuropteris-fossil-leaves-mazon-creek-nodule-pennsylvanian-age-split-pair","provider":"Fossil Age Minerals","version":"1.0","type":"link"}