A new carcinosomatid eurypterid, Rhinocarcinosoma dosonensis sp. nov., and Hughmilleria sp., are
described from the Do Son Formation of the Do Son Peninsula, northern Vietnam. R. dosonensis is characterized by
podomere 7 of prosomal appendage VI produced into an anterodistal spine, a metastoma with a cordate posterior
margin, and an indented opisthosomal differentiation (i.e. preabdomen-postabdomen margin is concave). The Do Son
Formation was originally interpreted as Late Devonian (Givetian/Frasnian) in age but the unit containing the
eurypterid assemblage is now considered much older (Late Silurian). A deltaic palaeoenvironmental setting is
interpreted from biotic associations and sedimentological evidence.
Braddy, S. J., Selden, P. A. & Truong, D. N. 2002. A new carcinosomatid eurypterid from the Siluro-Devonian of northern Vietnam. Palaeontology 45, 897–915. http://dx.doi.org/10.1111/1475-4983.00267