Pantodonta was one of the first groups of eutherians to evolve at the beginning of Cenozoic era,including the largest herbivores at that time.Pantodonta shows considerable diversity during the Paleocene and Eocene,wit...Pantodonta was one of the first groups of eutherians to evolve at the beginning of Cenozoic era,including the largest herbivores at that time.Pantodonta shows considerable diversity during the Paleocene and Eocene,with most of the species having been discovered in Asia and North America.Here,we report on a new pantodont,represented by lower jaws with well-preserved dentition,discovered from the Middle Paleocene Nongshan Formation of the Nanxiong Basin,Guangdong Province,China.Its unique dental and mandibular characteristics distinguish it well from any known Asian pantodont,but are quite consistent with North American taxa,especially Pantolambda and Titanoides.The new specimen is identified as Nanxiongilambda yei gen.et sp.nov.,characterized by the combination of the following morphological features:thick and robust mandible with a conspicuous anteroexternal flange,high positioned condyloid process,posteriorly protruding angular process,robust but not elongated lower canines,double-rooted p1,small but distinct talonids on posterior lower premolars,talonids nearly as wide as trigonids on lower molars,and m3 with a well-developed hypoconulid and a distinct entoconid.The new discovery marks the first record of a pantolambdid pantodont outside of North America,suggesting a broader geographical distribution and intercontinental dispersal of this clade during the Paleocene.Considering the more primitive Pantolambda only found from Torrejonian to early Tiffanian NALMA(equivalent to middle-late Shanghuan to early Nongshanian ALMA),which is slightly earlier than Nanxiongilambda(early Nongshanian ALMA),pantolambdids have likely undergone a particular wave of migration from North America to Asia during the Early-Middle Paleocene.Previous researches have suggested that pantodonts had dispersed only from Asia to North America during the Early Paleocene,but our new specimen indicates the biotic dispersal may have occurred in the opposite direction.The new specimen also contributes to the renewal of the evolutionary history of pantodonts and provides further insights into the migration and dispersal of Paleocene mammals.展开更多
武汉地质学院王良忱于1983年8月,在湖南省桂阳县莲塘公社南约五公里处的晚泥盆世地层中,采得一块保存相当好的肺鱼脑颅化石。中国过去发现的肺鱼化石只用于分离的齿板(刘宪亭、叶祥奎1957,1960;王俊卿,1981)。新近在云南省发现的泥盆纪...武汉地质学院王良忱于1983年8月,在湖南省桂阳县莲塘公社南约五公里处的晚泥盆世地层中,采得一块保存相当好的肺鱼脑颅化石。中国过去发现的肺鱼化石只用于分离的齿板(刘宪亭、叶祥奎1957,1960;王俊卿,1981)。新近在云南省发现的泥盆纪早期的希望奇异鱼(Diabolichthys speratus Chang et Yu,1984)又和过去已知的肺鱼有较大差别。莲塘的肺鱼化石表现了典型的泥盆纪肺鱼特征,可归入双翼鱼科(Dipteridae)的掌双翼鱼属(Chirodipterus)。展开更多
文摘Pantodonta was one of the first groups of eutherians to evolve at the beginning of Cenozoic era,including the largest herbivores at that time.Pantodonta shows considerable diversity during the Paleocene and Eocene,with most of the species having been discovered in Asia and North America.Here,we report on a new pantodont,represented by lower jaws with well-preserved dentition,discovered from the Middle Paleocene Nongshan Formation of the Nanxiong Basin,Guangdong Province,China.Its unique dental and mandibular characteristics distinguish it well from any known Asian pantodont,but are quite consistent with North American taxa,especially Pantolambda and Titanoides.The new specimen is identified as Nanxiongilambda yei gen.et sp.nov.,characterized by the combination of the following morphological features:thick and robust mandible with a conspicuous anteroexternal flange,high positioned condyloid process,posteriorly protruding angular process,robust but not elongated lower canines,double-rooted p1,small but distinct talonids on posterior lower premolars,talonids nearly as wide as trigonids on lower molars,and m3 with a well-developed hypoconulid and a distinct entoconid.The new discovery marks the first record of a pantolambdid pantodont outside of North America,suggesting a broader geographical distribution and intercontinental dispersal of this clade during the Paleocene.Considering the more primitive Pantolambda only found from Torrejonian to early Tiffanian NALMA(equivalent to middle-late Shanghuan to early Nongshanian ALMA),which is slightly earlier than Nanxiongilambda(early Nongshanian ALMA),pantolambdids have likely undergone a particular wave of migration from North America to Asia during the Early-Middle Paleocene.Previous researches have suggested that pantodonts had dispersed only from Asia to North America during the Early Paleocene,but our new specimen indicates the biotic dispersal may have occurred in the opposite direction.The new specimen also contributes to the renewal of the evolutionary history of pantodonts and provides further insights into the migration and dispersal of Paleocene mammals.
基金supported by the National Basic Research Program of China (Grant No.2012CB821900)the Chinese Academy of Sciences (Grant No.XDB03020104)+1 种基金the National Natural Science Foundation of China (Grant Nos.41372001,41430102)the Special Research Program of Basic Science and Technology of the Ministry of Science and Technology (Grant No.2015FY310100-14)~~
基金supported by the National Basic Research Program of China(Grant No.2006CB806400)the Chinese Academy of Sciences(Grant No.KZCX2-EW-106)+3 种基金the Basic Work Program of MST of China(Grant No.2006FY120300-15)the National Natural Science Foundation of China(Grant No.40532010)Special Fund for Fossil Excavation and Preparation of Chinese Academy of SciencesUS National Science Foundation(Grant No.EAR-0120727,BCS-0309800,BCS-0820602)~~
文摘武汉地质学院王良忱于1983年8月,在湖南省桂阳县莲塘公社南约五公里处的晚泥盆世地层中,采得一块保存相当好的肺鱼脑颅化石。中国过去发现的肺鱼化石只用于分离的齿板(刘宪亭、叶祥奎1957,1960;王俊卿,1981)。新近在云南省发现的泥盆纪早期的希望奇异鱼(Diabolichthys speratus Chang et Yu,1984)又和过去已知的肺鱼有较大差别。莲塘的肺鱼化石表现了典型的泥盆纪肺鱼特征,可归入双翼鱼科(Dipteridae)的掌双翼鱼属(Chirodipterus)。
