Nyctosauridae is a family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 of specialized soaring 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...

s of the Cretaceous Period of North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 and, possibly, Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

. It was named in 1889 by Henry Alleyne Nicholson

Henry Alleyne Nicholson

Henry Alleyne Nicholson was a British palaeontologist and zoologist.The son of Dr. John Nicholson, a biblical scholar, was born at Penrith, Cumbria on 11 September 1844. He was educated at Appleby Grammar School and at the universities of Göttingen and Edinburgh...

 and Richard Lydekker

Richard Lydekker

Richard Lydekker was an English naturalist, geologist and writer of numerous books on natural history.-Biography:...

.

Nyctosaurids are characterized by their lack of all but the wing finger. In most pterosaurs, the hand has four fingers, with the fourth elongated to support the wing, and the remaining three are usually small, clawed, and used in walking or climbing. The lack of functional fingers in nyctosaurids may suggest that they spent almost all of their time in the air, rarely walking on the ground. Nyctosaurids also possessed a distinctively enlarged crest for muscle attachment on their upper arm bone, or humerus, the deltopectoral crest.

Nyctosaurids have occasionally been included in the similar family Pteranodontidae

Pteranodontidae

The Pteranodontidae are a family of large pterosaurs of the Cretaceous Period of North America.The family was named in 1876 by Othniel Charles Marsh....

, though researchers including Christopher Bennett and Alexander Kellner have both concluded that they belonged to a separate lineage. Analyses by David Unwin did indicate a close relationship between Pteranodon

Pteranodon

Pteranodon , from the Late Cretaceous geological period of North America in present day Kansas, Alabama, Nebraska, Wyoming, and South Dakota, was one of the largest pterosaur genera and had a maximum wingspan of over...

and Nyctosaurus

Nyctosaurus

Nyctosaurus is a genus of pterodactyloid pterosaur, the remains of which have been found in the Niobrara Formation of the mid-western United States, which, during the late Cretaceous Period, was covered in an extensive shallow sea. The genus Nyctosaurus has had numerous species referred to it,...

, though he used the name Pteranodontia for the clade containing both genera. Both opinions were published before the discovery of the second definitively known nyctosaurid, Muzquizopteryx

Muzquizopteryx

Muzquizopteryx was a genus of pterosaur from the Late Cretaceous of what is now Coahuila, Mexico. It is based on a nearly complete, articulated skeleton that includes soft tissue remains from the arms, from Coniacian-aged rocks...

, in 2006.

Most nyctosaurid fossils have been found in formations dating to the late Cretaceous period of the western United States

United States

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

 and Mexico

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

. Nyctosaurus dates from 85-84.5 million years ago, in the Niobrara Formation

Niobrara Formation

The Niobrara Formation, also called the Niobrara Chalk , is a geologic formation in North America that was laid down between 87 and 82 million years ago during the Coniacian, Santonian, and Campanian ages of the Late Cretaceous. It is composed of two structural units, the Smoky Hill Chalk Member...

 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...

. Muzquizopteryx is the oldest nyctosaurid known from definitive remains, dating to the Turonian

Turonian

The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous epoch, or a stage in the Upper Cretaceous series. It spans the time between 93.5 ± 0.8 Ma and 89.3 ± 1 Ma...

-Coniacian

Coniacian

The Coniacian is an age or stage in the geologic timescale. It is a subdivision of the Late Cretaceous epoch or Upper Cretaceous series and spans the time between 89.3 ± 1 Ma and 85.8 ± 0.7 Ma...

 boundary, 85.8 million years ago, in Coahuila

Coahuila

Coahuila, formally Coahuila de Zaragoza , officially Estado Libre y Soberano de Coahuila de Zaragoza is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico...

. However, a partial humerus with the distinctive nyctosaurid deltopectoral crest was found in Cornet

Cornet

The cornet is a brass instrument very similar to the trumpet, distinguished by its conical bore, compact shape, and mellower tone quality. The most common cornet is a transposing instrument in B. It is not related to the renaissance and early baroque cornett or cornetto.-History:The cornet was...

, Romania

Romania

Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...

, and identified as a possible European, early Cretaceous (late Berriasian

Berriasian

In the geological timescale, the Berriasian is an age or stage of the Early or Lower Creteceous. It is the oldest or lowest subdivision in the entire Cretaceous. It spanned between 145.5 ± 4.0 Ma and 140.2 ± 3.0 Ma...

age, about 140Ma ago) nyctosaurid by Gareth Dyke and colleagues in 2010.