Short communicationSEM morphological study of the type species of Ordosestheria Wang, 1984 (Spinicaudata) from Ordos Basin of mid-west China

- SEM morphological study reveals taxonomic features on carapace of ordosestheriids.
- Biostratigraphic data support an early Aptian age for the Jingchuan Formation.
- Ordosestheriids originated in North Africa and dispersed to eastern Asia in the Aptian.

SEM morphological study of the type specimens of Ordosestheria wujiamiaoensis Wang, 1984 from the non-marine lower Aptian Jingchuan Formation in Inner Mongolia of the Ordos Basin in mid-west China has revealed taxonomic features not previously seen: 1) a row of small pits along the lower margin of each growth band in the lower part of the carapace; 2) growth lines are serrated in their lower margins; 3) a row of small pores on each growth line may indicate that through which a row of setae has developed. In consideration of the first occurrence of Ordosestheria from the lower Barremian of southern Tunisia, ordosestheriids may most likely have originated in North Africa and then dispersed to eastern Asia in early Aptian, and became a member of the well-known Jehol Biota.