Siskemia Smith, 1909

Discussion: The ichnogenus Siskemia was established by Smith (1909) for arthropod trackways with two medial imprints. At the time it was established, eight species were recognized. In her revision of Smith’s work, Walker (1985) reduced the number of included ichnospecies to three, including Siskemia elegans, Siskemia bipediculus, and Siskemia lata-via. Siskemia bipediculus has widely separated series of two to three tracks, whereas Siskemia lata-via has closely spaced series of three tracks. Siskemia elegans is smaller than the other two species and consists of two medial imprints between two rows of tracks arranged into discrete series of up to four tracks. The Massachusetts material is more similar to the Siskemia elegans in size and morphology, and is thus assigned to that species.