	Authors	Year	Title
	Manger & Saunders	1980	Lower Pennsylvanian (Morrowan) ammonoids from the North American midcontinent. Journal of Paleontology, 54, Suppl.(3): 1-56, fig.1-21, pl.1-6, tab.1-10; Tulsa, Okla.
	McCaleb	1964	Two New Genera of Lower Pennsylvanian Ammonoids from Northern Arkansas. Oklahoma Geological Notes, 24 (10): 233-237, pl.1; Norman.
	Quinn & Saunders	1968	The ammonoids Hudsonoceras and Baschkirites in the Morrowan series of Arkansas. Journal of Paleontology, 42; 397-402, fig.1-3, pl.57; Tulsa, Okla.
	Saunders	1971	The Somoholitidae: Mississippian to Permian ammonoids. Journal of Paleontology, 45 (1): 100-118, fig.1-6, pl.23-24; Tulsa, Okla.
	Saunders, Manger & Gordon	1977	Upper Mississippian and lower and middle Pennsylvanian ammonoid biostratigraphy of Northern Arkansas. Oklahoma Geolological Survey Guidebook 18: 117-137, fig.1-2, tab.1-2, pl.1-6.