Demopolis Chalk

Mosasaurus (; "lizard of the Meuse River") is the type genus (defining example) of the Mosasauridae, an extinct group of aquatic squamate reptiles. It lived from about 82 to 66 million years ago during the Campanian and Maastrichtian stages of the Late Cretaceous. The genus was one of the first Mesozoic marine reptiles known to science—the first fossils of Mosasaurus were found as skulls in a chalk quarry near the Dutch city of Maastricht in the late 18th century, and were initially thought to be crocodiles or whales. One skull discovered around 1780 was famously nicknamed the "great animal of

Xiphactinus (from Latin and Greek for "sword-ray") is an extinct genus of large predatory marine ray-finned fish that lived during the late Albian to the late Maastrichtian. The genus grew up to in length, and superficially resembled a gargantuan, fanged tarpon. It is a member of the extinct order Ichthyodectiformes, which represent close relatives of modern teleosts.

Prognathodon is an extinct genus of marine lizard belonging to the mosasaur family. It is classified as part of the Mosasaurinae subfamily, alongside genera like Mosasaurus and Clidastes. Prognathodon has been recovered from deposits ranging in age from the Campanian to the Maastrichtian in the Middle East, Europe, New Zealand, Africa and North America.

Appalachiosaurus ( ; "Appalachian lizard") is a genus of tyrannosauroid theropod dinosaur from the Late Cretaceous period of what is now eastern North America. It was a basal member of the clade Eutyrannosauria, meaning it was rather close in relation to the true tyrannosaurids such as Tyrannosaurus. Like most theropods, it was a bipedal predator. Only a juvenile skeleton has been found, representing an animal approximately long and weighing , which indicates an adult would have been significantly larger.

Squalicorax, commonly known as the crow shark, is a genus of extinct lamniform shark known to have lived during the Cretaceous period. The genus had a global distribution in the Late Cretaceous epoch. Multiple species within this genus are considered to be wastebasket taxa due to morphological similarities in the teeth.

Plioplatecarpus is a genus of mosasaur lizard. Like all mosasaurs, it lived in the late Cretaceous period, about 82-68 million years ago.

Protosphyraena is a fossil genus of swordfish-like marine fish, that thrived worldwide during the Cretaceous period (Albian-Maastrichtian). Fossil remains of this taxon are mainly discovered in North America and Europe, and potential specimens are also known from Asia, Africa and Australia. Its fossils are best known from the Smoky Hill Member of the Niobrara Formation of Kansas (Late Coniacian-Early Campanian).

Enchodus (from , 'spear' and 'tooth') is an extinct genus of aulopiform ray-finned fish related to lancetfish and lizardfish. Species of Enchodus flourished during the Late Cretaceous, where they were a widespread component of marine ecosystems worldwide, and there is some evidence that they may have survived to the Paleocene or Eocene; however, this may just represent reworked Cretaceous material.

Cretalamna is a genus of extinct otodontid shark that lived from the latest Early Cretaceous to Eocene epoch (about 103 to 46 million years ago). It is considered by many to be the ancestor of the largest sharks to have ever lived, such as Otodus angustidens, Otodus chubutensis, and Otodus megalodon.