27MM Squalicorax Shark Vertebrae Fossil Bone Ozan Formation, North Sulfur River Texas

Location: Ozan Formation, North Sulfur River, Texas

Weight: 0.5 Ounces

Dimensions: 27MM

The item pictured is the one you will receive.   

Cretaceous Age, 75- 90 million years old. 

The Ozan Formation is an important geological unit in the Upper Cretaceous period, mainly located in Texas, Arkansas, and Oklahoma. It is well known for its abundant fossil record, especially marine fossils, including various shark species. The formation dates to the Late Cretaceous, about 75 to 90 million years old, and is recognized for its marine deposits and diverse fossils, such as shark teeth and vertebrae. It is part of the Gulf Series and mainly consists of clay, marl, and sand, with varying amounts of calcareous material, glauconite, and phosphatic nodules. Its lithology ranges from sandy, micaceous marl to massive, dark, sandy, micaceous marl, sometimes containing thin beds of hard limestone. In Texas, the Ozan Formation appears across numerous counties, including Bell, Falls, Hill, McLennan, Navarro, Collin, Dallas, Ellis, Kaufman, and Rockwall. It lies unconformably over the Austin Chalk and is typically overlain by the Wolfe City Formation or, in some areas, the Annona Chalk. The environment of deposition was mainly deep marine with low energy. Fossils from the Ozan Formation give valuable insights into the ancient marine ecosystems of the Late Cretaceous. Shark remains are common, with finds including teeth and vertebrae. Identified shark genera from the formation include Carcharias sp. and Squalicorax (often called "Crow Sharks"). These fossils suggest a diverse shark population in the Western Interior Seaway, which covered much of North America during the Cretaceous. Besides sharks, the formation also produces other marine fossils such as ammonites, bivalves, and microfossils. Trace fossils like burrows of Ophiomorpha, Thalassinoides, and Planolittes also reveal marine activity. The presence of phosphatic nodules and highly polished pebbles in the basal layers hints at periods of condensed sedimentation or sediment reworking. Paleomagnetic studies of the Ozan Formation in the Arkla basin have shown a normal magnetic polarity, believed to date to the Gubbio normal polarity zone.