Sample Detail of
Sample: Sample No. 77AHeA -- USGS No. 27243-PC
Locality: Field No. 77AHeA
Description: Misheguk Mts. quad., Alaska. NPRA Land Use Project. Lat. 68o 21.7 min. N.; long. 161o 33 min. W. Silicified cephalopod found as float on a stained area of slope near Kagvik Creek in black recrystalline chert. From sequence of black shale and chert correlated with Lisburne Group rocks.
Location: Alaska Quadrangle: Misheguk Mtn B-5
Lat.: 68o21.7 ' Long.: 161o33' "
Reference
Title: Report on Referred Fossils ,  1978 (06/30)
This report is based on a single incomplete silicified specimen of orthoconic nautiloid from northwestern Alaska in the area north of the Noatak River. I recognized the specimen as an actinoceroid and gave it to Keith Moore to section along the endosiphuncle, which could be seen at one end. The sectioned specimen preserves the connecting rings, septa, and recurved septal necks. Areas which could represent episeptal and hyposeptal camerae deposits are obscured by the silicification which has taken place, but adjacent areas of infilling of the camerae look as if they replace secondary calcite.

The siphuncular segments are slightly longer than wide (11 mm x 10.6 mm) and the length of the camerae are about 3.6 times the width. The only species of RAYONNOCERAS known in which the siphuncular segments are longer than wide is RAYONNOCERAS RANGIFER Gordon of which the holotype came from approximately 18 miles northeast of this locality. However, the holotype has camerae the width of which is 2.7 times their length. As the range of variation in R. RANGIFER is not known, the identification is shown as questioned because of the discrepancy cited above.
Report by: Mackenzie Gordon , Jr.
Referred by: Michael Churkin , Jr.
Age: Late Mississippian
Comment:RAYONNOCERAS is restricted to rocks of Late Mississippian age.
Occurrence(s)
No. Group Name Qty Notes
1 Cephalopods Rayonnoceras rangifer Gordon ?