The Hare Fiord form of P. Arkansiensis described by Nassichuk appears to be more advanced than the Otuk Creek specimen. Nassichuk (1975, p.60) reports that at a diameter of 60 mm. his shell has 6 pairs of “lateral” lobes, 2 pair of umbilical lobes, and 4 pairs of internal lateral lobes. Including the ventral and dorsal lobes, this adds up to a total of 26 lobes in the suture. The Killik River shell at a diameter of 109 mm has 5 pairs of “lateral” lobes, 2 pairs of umbilical lobes, 3 pairs of internal lateral lobes and a total of 22 lobes. As addition of lobes within any continuum of a species group normally indicates a more advanced form and usually a younger from stratigraphically, a strong likelihood exists that the Otuk Creek shell is older than Nassichuk’s Ellesmere Island examples.

The species of Pseudopronorites are not well understood. Only one, P. arkansiensis Smith has been well documented by a number of authors. It occurs typically in Morrowan and Atokan rocks in Arkansas and Oklahoma. Nassichuk has interpreted it rather loosely to include specimens varying somewhat in width, with or without ventral ribbing, and having 22 to 26 lobes in the suture. He, moreover, suggests that all the American species described so far might belong in a single species. Two other species are known from Morrowan and Atokan rocks, P. quinni (Gordon) and P. llanoensis (Plummer and Scott).

Only one species is known from rocks younger than Atokan and this is P. kansasensis (Newell) from the Argentine Limestone of Missourian age, based on a single fragmentary specimen that showed only the ventral and five lateral lobes of the suture. Until more complete material is found, we have no way of evaluating this record.

Based on the evidence stated above, I would suggest identifying this form as Pseudopronorites cf. P. arkansiensis (Smith). I would also suggest a probable Morrowan age for this Otuk Creek specimen. Pseudopronorites has never been found in Mississippian rocks and pronoritids in our collections from the Calico Bluff Formation are obviously different, having flat ribbed venters; these probably belong in the genus Megapronorites Ruzhencev.

Now, as to the supposed belemnite, I can find no evidence of organic structure in the specimen and suggest that it is inorganic – some sort of concretion. This specimen is being returned but the pronoritid, which is of considerable significance, will be retained in the U. S. National Museum collection.

SUPPLEMENT [the supplement is from a later report dated 8/30/77 by Gordon – note by NZ]

In a recent report dated 7/15/77 on an ammonoid from Otuk Creek, I pointed out that all but one known specimen of Pseudopronorites came from Morrowan and Atokan rocks and therefore argued for a fairly early Pennsylvanian age for the Alaskan strata in which your specimen was found. The only upper Pennsylvalnian occurrence of Pseudopronorites, from rocks of Missourian age in Kansas, I said, was in need of verification.

A few days ago I was going over a collection of ammonoids from the Uddenites Zone in West Texas, which had been identified for the National Museum by workers at a prominent Midwestern university. In it, unrecognized as pronoritids, I found a number of specimens of an underscribed species of Pseudopronorites. It is proportionally wider than P. arkansiensis (Smith) and is obviously a different species. The point is that this extends the range of Pseudopronorites almost to the top of the Pennsylvanian. I can no longer argue that your specimen must have come from low in the Pennsylvanian, as the range of Pseudopronorites must now be considered to be thoughout the Pennsylvanian.