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XIPHACTINUS FOSSILS FOR SALE
What Is Xiphactinus?
Xiphactinus was one of the largest bony fish ever to have lived. During the late Cretaceous, about eighty million years ago, it prowled shallow seas worldwide. Though cosmopolitan in distribution, it is best known from the central regions of North America, especially Kansas and the American midwest. Eighty million years ago, the center of the continent was covered by a shallow sea called the Western Interior Seaway. This shallow sea was the perfect home for Xiphactinus and the perfect place to preserve its remains.
Xiphactinus audax in Cosmocaixa, Barcelona. Creative Commons License
What Did Xiphactinus Look Like?
An artist's rendering of Xiphactinus. Creative Commons License. By Julian Johnson
Xiphactinus was a large bony fish: its skeleton was made of bone instead of cartilage, like sharks or rays. It likely ranged in size from 15-20 feet (4.5-6 meters) and had a body much like a flattened tube. It was long and thin with little arc to the dorsal or ventral sides. It had large scales, a symmetrical sickle-shaped tail and three-inch teeth. It weighed five hundred to a thousand pounds. It likely looked like a toothy, oversized modern tarpon. Despite its size, however, it was not the apex predator of the day. Xiphactinus has been found in fossilized remains of the sharks Squalicorax and Cretoxyrhina. It also would likely have fed a variety of marine reptiles like plesiosaurs and mosasaurs.
When Did Xiphactinus Live?
Xiphactinus is thought to have evolved about one hundred twelve million years ago during the Middle Cretaceous. It disappears from the fossil record around the time of the Cretaceous-Palaeogene Extinction.
What Did Xiphactinus Eat?
Xiphactinus is often described as a voracious predator. It would have fed on whatever it could get its teeth on, including smaller fish, turtles, pterosaurs, and likely even juvenile reptiles such as mosasaurs. It also may have scavenged if the opportunity presented. A number of Xiphactinus skeletons have been found with undigested prey in their stomachs. The most famous of these is at the Sternberg Museum of Natural History in Hays, Kansas. A thirteen-foot long Xiphactinus has a completely preserved, six-foot Gillicus arctuatis in its stomach! It is likely that Xiphactinous died shortly after ingesting such large prey.
Where Are Xiphactinus Fossils Found?
Xiphactinus fossils have been found in Venezuela, Europe, Australia, Canada and the United States. The first specimens were found in the Niobrara Chalk Formation of Kansas. They have also been found in parts of the eastern United States, namely Georgia, Alabama, North Carolina, and New Jersey. The most common fossils found are vertebrae, but more complete specimens can be found.
What Was The World That Xiphactinus Lived In Like?
Xiphactinus lived in shallow seas like the Western Interior Seaway of North America. This was a body of water that divided what we now think of as North America into three distinct land masses. Aside from the unfamiliar species, it would have looked for the most part like any saltwater shoreline we would see today. The marine environment included all levels of life, from plankton to apex predators. There were even mollusks including ammonites and belemnites. Fish from the diminutive Chirocentrites to larger Enchodus, Pachyrhizodus and Ichthyodectes swam in the waters. Giant marine reptiles like mosasaurs, elasmosaurs and ichthyosaurs would have occupied the top of the food chain. Just below them would come the sharks Squalicorax and Cretoxyrhina. In addition to the marine animals, early birds and pterosaurs would have flown above the sea.
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