Biserial Graptolites

Kingdom: Animalia Phylum: Hemichordata Class: Pterobranchia Subclass: Graptolithina Order: Graptoloidea Suborder: Axonophora Two samples of shales with various biserial graptolites on the surface of the shales. Appears to be two different type of graptolites species. Smaller sample has one clear rhabdosome. The rhabdosome is straight and sicula is unknown. Proximal 2TRD is ~ 3.2 mm and rhabdosome width is 2.5 mm. Mesially the 2TRD decreases to ~ 2.1 mm and width is 2.1 mm. Distally 2TRD is ~2.0 mm and width decrease to 1.5 mm. Angle of thecae is ~ 45 degrees proximally that increases to 105~ degrees distally. Proximal thecae have dorsal hoods that disappear mesially.