| | THE KIRTLANDIAN LAND-VERTEBRATE “AGE”—LATE CRETACEOUS OF WESTERN NORTH AMERICA |
 | | We recently “filled-in” the youngest of these gaps (between the Judithian and Edmontonian) by naming the Kirtlandian LVA based on the vertebrate faunas (Hunter Wash and Willow Wash local faunas) from the Upper Cretaceous Fruitland and Kirtland formations, San Juan Basin, New Mexico. |
 | | Radioisotopic dates confirm that the Kirtlandian spans ~ 2.9 my, and is equivalent to “Bear Paw time.” The Kirtlandian LVA is defined as the time between the first appearance of Pentaceratops sternbergii, (which is also designated as the index taxon for the Kirtlandian) and the first appearance of Pachyrhinosaurus canadensis. |
 | | However, a few dinosaur taxa, notably Pentaceratops sternbergii, Parasaurolophus cyrtocristatus and Kritosaurus navajovius, are now known to occur in other North American vertebrate faunas, thus allowing for biostratigraphic correlation of the Kirtlandian outside of the San Juan Basin, NM. |
| gsa.confex.com /gsa/2004RM/finalprogram/abstract_71917.htm (492 words) |