Kazakhstania colubrella
Goniatites are a group of ammonoid cephalopods with relatively simple suture
patterns. Sutures are the lines formed by the intersection of the outer
shell wall and the internal walls (septa) that separate chambers.
Nautiloid cephalopods (e.g., the modern pearly
nautilus) generally have curvilinear suture patterns. Ammonoid
cephalopods have goniatitic,
ceratitic, or ammonitic suture patterns. Goniatitic sutures are
characterized by having several broad lobes & saddles. Goniatitic
sutures are seen in the earliest ammonoids.
Here’s a scarce species of ammonoid cephalopod.
This is Kazakhstania colubrella (formerly Prolecanites
colubrellus) from the Byer Sandstone of Chatham, Ohio, USA. It has a
planispirally coiled shell (as do almost all ammonoids) and a distinctive
goniatitic suture pattern (see Manger, 1971, figure 6D). Adult shells
show four, narrow, external constrictions (not seen in this specimen) (see
Manger, 1971, plate 12, figures 8, 10-12).
Classification: Animalia, Mollusca, Cephalopoda, Ammonoidea,
Goniatitina, Imitoceratidae
Stratigraphy: float from the Byer Sandstone Member, lower Logan Formation, Waverly
Group, Osagean Stage, upper Lower Mississippian
Locality:
loose piece from rubble along petroleum well access road, southern side of St.
Joseph Road, due east of Chatham, northwestern Newton Township, northern Licking
County, central Ohio, USA (~40º 09’ 18.7” North, ~82º 26’ 29.2” West)
Kazakhstania colubrella (Morton, 1836) external mold (1.75 cm across) in
slightly micaceous quartzose sandstone (Byer Sandstone, Lower Mississippian;
Chatham, Ohio, USA). The yellowish-brown wavy lines are the sutures -
these are goniatitic sutures.
Specimen
collected & owned by Nicole Byrd.
Reference cited:
Manger, W.L. 1971. The Mississippian
ammonoids Karagandoceras and Kazakhstania from Ohio. Journal
of Paleontology 45: 33-39.