Abstract: In early 1991, when I was at the Canadian National Museum, Dr. D. A. Russell kindly provided me some hesperornithid fossils for study. The specimens were collected from Bylot Island, Canada. Hesperornis is largely restricted to North America, especially in the Niobrara Formation of the United States (Feduccia, 1996) The youngest individual of the genus, represented by a left tarsometatarsus, was recovered from Western Alberta in Canada (Fox, 1974). The hesperornithid fossils from the Bylot Island represent the latest record of the Hesperornithidae, and the northernmost occurrance so far. The large size and morphologic specializaion are the main cause for its extinction.

摘要： 加拿大北极地区Bylot岛晚白垩世陆相沉积中发现一黄昏鸟化石。这是首次在极地地区发现这类不会飞行的已绝灭的潜水鸟类，该地点也是白垩纪最晚期的黄昏鸟产地。新材料的形态构造与Hesperornis regalis比较接近，但它个体大，颈椎椎体后部特别向两侧扩展，椎体侧凹亦特别大而深等，具特化的性状，因而建一新属新种:Canadaga arctica gen. et. sp. nov.。