Pristiograptus and other Monograptids

Kingdom: Animalia Phylum: Hemichordata Class: Pterobranchia Subclass: Graptolithina Order: Graptoloidea Family: Monograptidae Genus: Pristograptus (Jackal, 1889) Three samples, labeled a, b, and c, of shales with several rhabdosomes along the surface of the sediment. The second smallest sample has two large prominent rhabdosomes. The rhabdosomes are straight and sicula is unknown. 2TRD for Th2 is ~1.9 mm and width is ~1.5 mm. Mesially and distally the 2TRD increases to 2.1 mm and width to 1.9 mm. Thecal overlap is extensive and protheca-metatheca transition is straight. Thecae are simple tubes with a concave-convex prothecal ventral wall. The smallest sample appears to have Campograptus specimens and the largest sample has various long straight rhabdosomes of Pristograptus, Monograptus and other genera.