矛头虫(学名:Lonchodomas),是一属已灭绝的三叶虫，生存于奥陶纪。

• Dinosaurs to Dodos: An Encyclopedia of Extinct Animals By Don Lessem and Jan Sovak

Lonchodomas is a genus of trilobites, that lived during the Ordovician. It was eyeless, like all raphiophorids, and had a long straight sword-like frontal spine, that gradually transforms into the relatively long glabella. Both the glabellar spine and the backward directed genal spines are subquadrate in section. Lonchodomas has five thorax segments and the pleural area of the pygidium has two narrow furrows. Lonchodomas occurred in what are today Argentina, Canada (Newfoundland), Estonia, Latvia, Norway, the Russian Federation (St. Petersburg region) and the United States (Oklahoma, Virginia).