Apatomerus is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of extinct reptile

Reptile

Reptiles are members of a class of air-breathing, ectothermic vertebrates which are characterized by laying shelled eggs , and having skin covered in scales and/or scutes. They are tetrapods, either having four limbs or being descended from four-limbed ancestors...

 known from a single fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

 (KUVP

University of Kansas Natural History Museum

The University of Kansas Natural History Museum is part of the University of Kansas Natural History Museum and Biodiversity Research Center, which is itself part of the KU Biodiversity Institute....

 1199) from the Albian

Albian

The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous epoch/series. Its approximate time range is 112.0 ± 1.0 Ma to 99.6 ± 0.9 Ma...

-age (Lower Cretaceous) Kiowa Shale

Kiowa Shale

The Kiowa Shale is a Mesozoic geologic formation. Plesiosaur remains are among the fossils that have been recovered from its strata....

 of Kansas

Kansas

Kansas is a US state located in the Midwestern United States. It is named after the Kansas River which flows through it, which in turn was named after the Kansa Native American tribe, which inhabited the area. The tribe's name is often said to mean "people of the wind" or "people of the south...

, USA

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. This bone, collected in 1893, was first identified as the thighbone

Femur

The femur , or thigh bone, is the most proximal bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in...

 of a crocodilian, but was described in 1903 by Samuel Wendell Williston

Samuel Wendell Williston

Samuel Wendell Williston was an American educator and paleontologist who was the first to propose that birds developed flight cursorially , rather than arboreally . He was also an entomologist, specialising in Diptera.-Early life:Williston was born in Boston, Massachusetts to Samuel Williston and...

 as belonging to a pterosaur

Pterosaur

Pterosaurs were flying reptiles of the clade or order Pterosauria. They existed from the late Triassic to the end of the Cretaceous Period . Pterosaurs are the earliest vertebrates known to have evolved powered flight...

. This identification held through the 1970s, but has been abandoned. Recent summaries of pterosaur genera, such as Wellnhofer

Peter Wellnhofer

Peter Wellnhofer is a German paleontologist at the "Bayerische Staatssammlung fur Paläontologie" in Munich. He is best known for his work on the various fossil specimens of Archaeopteryx or "Urvogel", the first known bird...

, 1991 and Glut

Donald F. Glut

Donald F. Glut is an American writer, motion picture director, screenwriter, amateur paleontologist, musician and actor....

, 2004 did not include it, and Mike Everhart, an authority on the rocks of the Western Interior Seaway

Western Interior Seaway

The Western Interior Seaway, also called the Cretaceous Seaway, the Niobraran Sea, and the North American Inland Sea, was a huge inland sea that split the continent of North America into two halves, Laramidia and Appalachia, during most of the mid- and late-Cretaceous Period...

 (including the Kiowa Shale) identifies the bone as more likely the upper part of a plesiosauria

Plesiosauria

Plesiosauria is an order of Mesozoic marine reptiles. Plesiosaurs first appeared in the Early Jurassic Period and became especially common during the Jurassic Period, thriving until the K-T extinction at the end of the Cretaceous Period.The name "plesiosaur" is used to refer to the order...

n propodial (a limb bone).