Laopteryx Laopteryx Laopteryx is the name assigned to a pterosaur (flying reptile) from the Upper Jurassic Morrison Formation of Wyoming, United States; it was originally thought to be a bird. The genus was named in 1881 by Othniel Charles Marsh. The generic name is derived from Greek "laas", "stone", and "pteryx", "wing". The full species name given by Marsh was "Laopteryx priscum"; the specific name meaning "of venerable age" in Latin. However, Marsh incorrectly used the neuter form, while "pteryx" is feminine in Greek. (See grammatical gender.) This was in the 19th century emended to an, also incorrect, masculine "priscus" and
Cretaceous A 140 Ma age for the Jurassic-Cretaceous boundary instead of the usually accepted 145 Ma was proposed in 2014 based on a stratigraphic study of Vaca Muerta Formation in Neuquén Basin, Argentina. Víctor Ramos, one of the authors of the study proposing the 140 Ma boundary age sees the study as a "first step" toward formally changing the age in the International Union of Geological Sciences. From youngest to oldest, the subdivisions of the Cretaceous period are: Late Cretaceous Maastrichtian – (66-72.1 MYA) Campanian – (72.1-83.6 MYA) Santonian – (83.6-86.3 MYA) Coniacian – (86.3-89.8 MYA) Turonian – (89.8-93.9 MYA) Cenomanian