Last Thoughts on Pterorytis…

As alluded to in my previous posts on the genus Pterorytis, Vermeij and Vokes (1997) have synonymized several species listed in Petuch’s (1994) Atlas of Florida Fossil Shells with P. umbrifer and P. fluviana. However, everyone must make their own decision as to which scientific opinion they feel is correct, or whether the truth lies somewhere in between.

When trying to determine which of the 8 documented taxa of Florida Pterorytis (plus P. conradi from outside Florida) are in fact valid species, it certainly helps to have access to as many specimens from a single locality as possible, to better gauge “normal” variability. I am in fact lucky enough to have a fairly large sample of Pterorytis specimens from both the Florida Kissimmee River region, and from Lee Creek Mine in North Carolina. I have selected some representative specimens of the more common sculptural forms, and present them here for your review. (Since many of the readers of my blog live outside the US, it is probably safe to assume that they may have only 1 or 2, or perhaps a handful, of specimens of each Pterorytis morphotype — most likely not enough to perform their own comparison. Thus this post may be helpful to some fossil muricid collectors out there, even if they already have access to the extant literature.)

Kissimmee River Pterorytis ("smoother" forms; click to enlarge)

Kissimmee River Pterorytis ("intermediate" forms with subtle hints of intervarical fimbriation; click to enlarge)

Kissimmee River Pterorytis ("scabrous" forms; click to enlarge)

Kissimmee River Pterorytis ("intervarical nodes?"; click to enlarge)

Kissimmee River Pterorytis (recurved "P. lindae" form; click to enlarge)

Kissimmee River Pterorytis (worn "P. seminola" form; click to enlarge)

Lee Creek Mine Pterorytis ("P. conradi" form; click to enlarge)

Lee Creek Mine "P. conradi" form with 2 labral teeth (click to enlarge)

To close out both this post and this topic, I now summarize the Pterorytis species identifications provided in the two works of literature referenced above (and listed below). Once again, the reader is free to their own research and come to their own conclusions as to which scientific work they prefer to follow in labeling their own specimens.

• Atlas Plate 44, Fig. A (umbrifer) = same ID in Vermeij & Vokes
• Atlas Plate 44, Fig. B (fluviana) = same ID in Vermeij & Vokes
• Atlas Plate 44, Fig. C (marshalli) = umbrifer in Vermeij & Vokes
• Atlas Plate 44, Fig. D (squamulosa) = fluviana in Vermeij & Vokes
• Atlas Plate 44, Fig. E (squamulosa) = fluviana in Vermeij & Vokes
• Atlas Plate 44, Fig. F (wilsoni) = fluviana in Vermeij & Vokes
• Atlas Plate 44, Fig. G (seminola) = fluviana in Vermeij & Vokes
• Atlas Plate 44, Fig. H (roxaneae) = same ID in Vermeij & Vokes
• Atlas Plate 44, Fig. I (seminola) = umbrifer in Vermeij & Vokes
• Atlas Plate 44, Fig. J (lindae) = fluviana in Vermeij & Vokes
• Atlas Plate 44, Fig. K (lindae) = fluviana in Vermeij & Vokes

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References:

Petuch, E. J. (1994). Atlas of Florida Fossil Shells (Pliocene and Pleistocene Marine Gastropods), Chicago Spectrum Press, Evanston, IL.

Vermeij, G. J. and Vokes, E. H. (1997). “Cenozoic Muricidae of the Western Atlantic Region part XII — The Subfamily Ocenebrinae (In Part),” Tulane Studies in Geology and Paleontology, Vol. 29(3).