Bulbaspis ("bulb shield") is a late Ordovician genus of asaphid trilobites of the family Raphiophoridae found primarily in upper Ordovician-aged deepwater marine strata of Kazakhstan, China, and possibly Tasmania. Species of Bulbaspis are similar to other raphiophorids such as Ampyx and Raphiophorus, save that the long spine that emanates from the glabella of the latter two genera has been modified into a knob-like or bulb-like structure in Bulbaspis that developed incrementally in the animal's growth.Zhiqiang, Zhou, and Zhou Zhiyi. "Late Ordovician trilobites from the Zhusilenghaierhan area, Ejin Banner, western Inner Mongolia, China."MEMOIR-ASSOCIATION OF AUSTRALASIAN PALAEONTOLOGISTS 32 (2006): 383. The function of the bulb is currently unknown: one hypothesis suggests sexual selection may have had a role in its evolution in the genus.Knell, Robert J., and Richard A. Fortey. "Trilobite spines and beetle horns: sexual selection in the Palaeozoic?." Biology letters 1.2 (2005): 196-199.

Species ovulum group B. lageniformis Zhou et al. 1982 B. ovulum Weber 1948 B. ordosensis Lu et al. 1976 bulbifer group B. brevis Zhou & Zhou, 2006 B. bulbifer (Weber, 1932) B. korlaensis Zhang, 1981 B. mirabilis Chugaeva, 1958 B. sphaerornatus Chugaeva, 1958

See also List of trilobites

References