Joseph John Sepkoski Jr. was a University of Chicago paleontologist. Sepkoski studied the fossil record and the diversity of life on Earth. Sepkoski and David Raup contributed to the knowledge of extinction events. They suggested that the extinction of dinosaurs 66 mya was part of a cycle of mass extinctions that may have occurred every 26 million years.
Dwykia is an extinct genus of prehistoric bony fish.
Dialipina is an extinct genus of prehistoric bony fish.
Yuchoulepis is an extinct genus of prehistoric ray-finned fish.
Westollia is an extinct genus of prehistoric bony fish.
Willomorichthys is an extinct genus of prehistoric bony fish.
Syntegmodus is an extinct genus of prehistoric bony fish.
Sundayichthys is an extinct genus of prehistoric bony fish.
Seefeldia is an extinct genus of prehistoric ray-finned fish.
Rhadinichthys is an extinct genus of prehistoric bony fish.
Greenwoodella is an extinct genus of prehistoric bony fish.
Hengnania is an extinct genus of prehistoric ray-finned fish.
Tarasiiformes is an extinct order of prehistoric ray-finned fish.
Calycoceras is an extinct genus of cephalopods belonging to the subclass Ammonoidea and family Acanthoceratidae that lived during the Cenomanian stage of the Late Cretaceous, 100-94 Mya. Their shells had ornate ribs.
Strophomena is a genus of brachiopods belonging to the order Strophomenida family Strophomenidae, named by Rafinesque in 1824. They were stationary epifaunal suspension feeders.
Ampullina is an extinct taxonomic genus of deep-water sea snails, marine gastropod molluscs in the clade Caenogastropoda. These sea snails were epifaunal grazers. They lived from the Middle Triassic period to the Lower Pliocene age.
Lopha is a genus of marine bivalve molluscs in the family Ostreidae.
Neophylloceras is an extinct genus of cephalopod belonging to the Ammonite subclass.
Metoioceras is an extinct genus of cephalopod belonging to the Ammonite subclass which lived during the Cenomanian.
Pterotrigonia is an extinct genus of saltwater clams, marine bivalve molluscs in the family Megatrigoniidae. This genus is known in the fossil record from the Jurassic period Tithonian age to the Cretaceous period Maastrichtian age. Species in this genus were facultatively mobile infaunal suspension feeders. The type species of the genus is Pterotrigonia cristata.
