ammonites
Semibrachythyrina rhombiformis Shen and He 1994 (lamp shell)

Rhynchonellata - Spiriferida - Choristitidae

Full reference: S. Z. Shen and X. L. He. 1994. Changhsingian brachiopod faunas from Guiding, Guizhou. Acta Palaeontologica Sinica 33:440-454

Belongs to Semibrachythyrina according to S. Z. Shen and X. L. He 1994

Sister taxa: Alphaneospirifer anshunensis, Alphaneospirifer fasciculata, Alphaneospirifer mucronata, Alphaneospirifer ziyunensis, Semibrachythyrina nanlingensis, Semibrachythyrina mahaensis, Semibrachythyrina subpentagona

Type specimen: Its type locality is Wenjiangsi Section, Bed 45, Guiding County, which is in a Changhsingian carbonate limestone/mudstone in the Changxing Formation of China

Ecology: stationary epifaunal suspension feeder

Average measurements (in mm): valve 19.2 x 18.2