Syndianella is an extinct genus of trilobite, a class of fossil marine arthropods, known from the Early Cambrian period. It was formally described by Lu Yen-hao in 1961, with the original description published in Acta Palaeontologica Sinica.
Taxonomy and Classification
Syndianella belongs to the phylum Arthropoda, class Trilobita, order Redlichiida, superfamily Redlichioidea, and family Redlichiidae. The type species is Syndianella yunnanensis Lu, 1961, identified from holotype cranidium specimens collected in eastern Yunnan, China. An additional species, Syndianella guizhouensis, is known from Guizhou Province.
Morphology
Syndianella is known primarily from cranidial (head shield) material. Characteristic features include oblique and horizontal glabellar furrows, an oblique and discontinuous occipital furrow, a less arcuate eye lobe with its posterior tip distant from the glabella, and a longer preglabellar field. The thorax and pygidium (tail) of Syndianella are unknown, as no specimens preserving these regions have been described.
Stratigraphic Range and Distribution
Syndianella lived during the later part of the Botomian stage (Cambrian Stage 3), approximately 524 to 514 million years ago. Fossils are known exclusively from South China, particularly on the Yangtze Platform paleocontinent, in the provinces of Yunnan and Guizhou. The genus is associated with the Drepanuroides Zone of the Lower Cambrian.
Paleoecology
Syndianella is inferred to have occupied shallow marine environments on the Yangtze Platform, interpreted as nearshore settings within the early Cambrian Yangtze Sea. It likely exhibited an epibenthic (seafloor-dwelling) lifestyle, consistent with other members of the Redlichiidae family.
