Zygorhiza kochii is an extinct species of cetacean.
Zygorhiza was a smaller, less elongated, 6 m (20 foot) long relative of the famous Basilosaurus

Basilosaurus

Basilosaurus is a genus of cetacean that lived from in the Late Eocene. Its fossilized remains were first discovered in the southern United States . The American fossils were initially believed to be some sort of reptile, hence the suffix -"saurus", but later found to be a marine mammal...

. Its bodily proportions were similar to those of modern whales, although, unlike modern species, it had a distinct neck, and flippers which could be moved at the elbow. Its hind limbs were rudimentary. Zygorhiza's one-metre (3-foot) skull

Skull

The skull is a bony structure in the head of many animals that supports the structures of the face and forms a cavity for the brain.The skull is composed of two parts: the cranium and the mandible. A skull without a mandible is only a cranium. Animals that have skulls are called craniates...

 had fearsome jaws with deadly teeth. Unlike modern cetaceans, it had a neck with seven vertebrae.

Zygorhiza was also featured in the "Back To The Seas" episode of Paleoworld

Paleoworld

Paleoworld was a documentary television series that was produced for The Learning Channel, and has had a total of 50 episodes. Some consider it to be the largest and most comprehensive paleontology series ever made. The series began in late September 1994 and, after 4 seasons, ended in 1997...

 as well as on the "Whales" episode of "The Ultimate Guide" nature series.

State symbol

Zygorhiza kochii is the state fossil of Mississippi

Mississippi

Mississippi is a U.S. state located in the Southern United States. Jackson is the state capital and largest city. The name of the state derives from the Mississippi River, which flows along its western boundary, whose name comes from the Ojibwe word misi-ziibi...

. The mounted specimen in the Mississippi Museum of Natural Science in Jackson is commonly referred to as "Ziggy".