Examination of a historic collection of isolated cranial and appendicular hadrosaurid material from the lower Kirtland Formation of the San Juan Basin, New Mexico

The Field Museum of Natural History collection contains several isolated hadrosaurid specimens collected by Charles H. Sternberg from the lower Kirtland Formation of the San Juan Basin, New Mexico, that have been previously overlooked. Cranial elements described herein consist of a dentary and three jugals while appendicular material is limited to two humeri and two pubes. Many of the specimens preserve taxonomically informative characters that show strong affinities with Kritosaurini but are distinct from Kritosaurus navajovius (Brown, 1910) suggesting that the saurolophine-dominated San Juan Basin diversity is greater than currently recognized. Future examination of currently unprepared material will add to our developing understanding of the ambiguous hadrosaurid diversity of the San Juan Basin.

菲尔德自然历史博物馆（Field Museum of Natural History）馆藏包含若干此前被忽视的孤立鸭嘴龙类（hadrosaurid）标本，这些标本由Charles H. Sternberg采自美国新墨西哥州圣胡安盆地的下柯特兰组（lower Kirtland Formation）。本文记述的颅骨标本包括1块齿骨（dentary）与3块轭骨（jugal），附肢骨骼标本仅存2块肱骨（humeri）与2块耻骨（pubes）。多数标本保留了具有分类学意义的特征，这些特征显示其与克里特龙族（Kritosaurini）亲缘关系密切，但又区别于纳瓦霍克里特龙（Kritosaurus navajovius, Brown, 1910），这表明以赖氏龙亚科（saurolophine）类群为主的圣胡安盆地鸭嘴龙类多样性，较当前学界认知的更为丰富。未来对当前尚未制备的标本开展研究，将有助于深化我们对圣胡安盆地尚未明确的鸭嘴龙类多样性的认知。