The Canadian Entomologist

Articles

Description of Caenoephemera shangyuanensis, gen.nov., sp.nov. (Ephemeroptera), from the Yixian Formation

Qi-Bin Lina1 c1 and Di-Ying Huanga1

a1 Nanjing Institute of Geology and Paleontology, Academia Sinica, 210008, Nanjing, People's Republic of China

Abstract

A fossil mayfly nymph Caenoephemera shangyuanensis, gen.nov., sp.nov., discovered in the lower part of the Upper Jurassic – Lower Cretaceous Yixian Formation of Jianshangou, Beipiao district, West Liaoning, China, is described. It has several archaic features typical of Paleozoic mayfly nymphs, such as 5 tarsal segments and hind wing pads not covered by fore wing pads, but also exhibits specialized modern features, such as a short metathorax, abdominal tracheal gills, and cerci. It appears to be intermediate in structure between Paleozoic and extant mayfly nymphs.

Résumé

On trouvera ici la description de Caenoephemera shangyuanensis, gen.nov., sp.nov., à partir d’une larve d’éphémère fossile découverte à la base de la formation Yixian (Jurassique supérieur – Crétacé inférieur, Jianshangou, district de Beipiao, Ouest Liaoning, Chine). Ce fossile présente non seulement plusieurs caractères archaïques typiques des éphémères paléozoïques comme des tarses à 5 articles et des fourreaux d’ailes postérieures non couverts par ceux des ailes antérieures, mais également des structures nettement "modernes" comme un métathorax court, des branchies abdominales et des cerques. Ce fossile semble être "intermédiaire" entre les éphémères paléozoïques et modernes.

(Received January 26 2001)

(Accepted August 06 2001)

Correspondence

c1 Author to whom all corresponding should be addressed (E-mail: linqibin1935@sina.com).