NOTES ON T HE FAUNA OF THE CHIPOLA FORMATION- XV

ON THE OCCURRENCE OF "RANELLA" POPPELACKI HORNES ,

A GASTROPOD OF UNCERTAIN AFFINITIES

EMILY H. VOKES TULANE UNIVERSITY

Although the affinities of the Chipola Leitha limestone (Leithakalk ), d eveloped Formation with the European Miocene beds around the Leitha Massif, which formed an of the Aquitaine Basin have been noted island surrounded by rocky depths, and previously (Vokes, 1965), the similarities of which is therefore an organic facies with the fauna to that of the Vienna Basin are less Lithothamnium, bryozoans, large ornate obvious. There is a certain degree of likeness, pelecypods (s pondyles, pectens) and reef as both have numerous tropical genera in echinoids." Obviously a marl much like that common, with species of Mitra, Cypraea, found in the Chipola, it is not surprising that Cassis, and such, that have an air of famili­ Typhis wenzelidesi, the only other Vienna arity about them. But the differences in the Basin species that has a very near Chipola fauna are more conspicuous and there are equivalent in Pterotyphis vokesae Gertman, numerous genera that arc totally lacking in also comes from Steinabrunn. the Chipola but present to a greater or lesser The generic assignment of "Ranella" pop­ degree in the Vienna Basin. One of these pelacki is a genuine puzzle. Although de­ would be Tibia, certainly a tropical genus, scribed as Ranella, it obviously does not that occurs in the Vienna fauna but not in belong in this group for the differences the Chipola. Even more noticeable are the between it and the members of the Bursidae Mediterranean elements such as Ocenebra, (Ranellidae of authors) are immediately ob­ Ocinebrina, Aporrhais, A rgobuccinum, etc., vious. The two characters that they do have that have no equivalent in the Chipola fauna. in common consist of the pronounced anal Therefore, it is of special interest to discover notch and a tendency toward two varices on a species, which occurs in both faunas, that opposite sides of the aperture. However, the is not only similar but probably identical. bursids, or "Frog Shells," as the name The specimen here illustrated (text fig. 1) implies are typified by a "warty" surface is the sole toxample known from the Chipola ornamentation; the varices are neatly aligned Formation (at TU 9 51 ) and, as a comparison up the spire, and the siphonal canal is much with the HOrnes illustration also given (text shorter. fig. 2) will demonstrate, there seems to be The species has also been referred to the no discernable difference between the Chipola shell and the one from the Vienna genus Eupleura by Glibert (1952, p. 309) in Basin. This small species (both are about 12 a discussion of a French species that bears a mm) was named Ranella poppelacki by slight similarity to our little enigma. The Homes (1853, p. 215) and was said by him French species, "Ranella" alata Millet, dif­ to be very rare at Steinabrunn. fers from "R." poppelacki in having a very The beds at Steinabrunn, which is about slight anal sinus and in having a strongly 50 miles north of Vienna, are almost cer­ cancell ate surface ornamentation. However, tainly Tortonian in age, and the similarity of neither is referable to Eupleura, a genus that the species in the Chipola and at Steina­ is apparently confined to the New World, brunn are best attributable to facies. Accord­ and is characterized by thickened rather ing to Homes (1856, map. p. 712) the than thin flange-like varices and a calcitic locality is in the "Lethyakalk" facies, of shell. No known species of Eupleura has an which Gignoux (1955, p. 569) says: The anal notch. "Ranella" awta Millet, from the middle Tortonian, well developed in the intra­ Miocene of the Aquitaine Basin, and another Alpine Basin, is represented by two principal French specie s, uA rgobuccinum" boutillieri facies ... The second is the facies of the Cossmann, from the Lutetian of the Paris

96 No.2 Notes on the Fauna of the Chipola Formation- XV 97

Basin, are much alike, both having a strongly The search for a genus, or even family, can~ellate. surface ornamentation, two op­ for this species led to the Australian species posite vances, and only the slightest of anal originally described as Daphnellopsis murex notches. These two species have proved to Hedley, 1922. * The type, a tiny 5 mm be a problem to French workers equal to our specimen, has a very marked resemblance to '~Ranella," in that the generic assignments "R." poppelacki, differing only in that the for the two over the years have included: Recent form has even fewer varices, just two Ranella, Triton, Colubraria, A rgobuccinum, on the body whorl, and one on the Eutritonium, and Eupleura. This is virtually penultimate whorl, none prior to that. But a catalogue of all genera with two varices. this is clearly a juvenile specimen with only They obviously fit in none of these but just three post-nuclear whorls. At the same stage where they do fit has been a mystery. of development "R." poppelacki would have The general tendency has been to place an almost identical appearance. these two-varixed species into either the The Australian species Daphnellopsis Bursidae or the Cymatiidae. The writer, for a murex is unquestionably congeneric with time, also considered the possibility of the our Chipola shell. The only differences seen Muricidae. Although the vast majority of the between the two forms are the stronger Muricidae do have at least three varices, intervarical nodes of the older species, and a there is one genus of Typhinae more rounded aperture. However, whether (Distichotyphis Keen and Campbell, 1964) the two are referable to the genus that has but two varices. The nature of the Daphnellopsis seems very doubtful. aperture in these "Ranella" species is much Daphnellopsis was described in the Siboga like that of the Muricinae, with a thick, Reports (Schepman, 1913) on the basis of five wing-like varix and a completely separate lip small specimens (all dead) of a new species formed in advance. Indeed, except for the taken at 24 7 meters in the Suva Sea, off the irregularly placed varices there is a strong Lesser Sunda Islands, Indonesia. The type resemblance between "'R." poppelacki and species, Daphnellopsis lamellosa, has strong the species assigned to the subgenus cancellate ornamentation and possesses but a Pterynotus (Pterochelus). However, there is single terminal varix unlike the other species one very critical difference between this under discussion. The two specimens enigmatical form and all of the members of originally ftgured by Schepman (1913, pl. 30, Pterynotus ~nd this is the nature of the early ftg. lOa, b, c) are about the same size, 9 mm whorls. As the writer has noted previously (one lacks the protoconch and issmaller ), and (e.g., Vokes, 1968, p. 86 ), the members of have four post-nuclear whorls, so it cannot be the genera Pterynotus and Poirieria, two of certain whether this is the adult stage or not. the most ancient muricine lines, are marked Ire dale (1918, p. 33) has rejected by having on the ftrst post-nuclear whorl six Daphnellopsis as a turrid, stating that "from small flange-like varices. In Poirieria these the figure, Schepman 's Daphnellopsis is a simply continue to the adult stage, but in close relation to the groups Dall separates as Pterynotus on about the second post-nuclear I'vlacutotriton, etc., the canal in this case whorl every other varix is lost, or greatly being the one seen in the Bursa family, and weakened, and a shell with three varices and not of turrid significance." But to this three intervarical nodes per whorl develops. writer the illustration certainly shows an In "'R." poppelacki on the first post-nuclear in bending of the axial ornamentation that is whorl there are a dozen raised, cord-like ribs, consistent with the Turridae, and the nature equal in strength from suture to suture. of the elongate aperture seems closer to the They bear absolutely no resemblance to the turrids than to either the Australian or the Chipola species. The appearance of only a early varices of Pterynotus. On the second post-nuclear whorl certain of the ribs form terminal varix on D. lamellosa, as opposed to small open varices, but these are random in arrangement with from two to five *The writer recently referred this species to Pterochelus (Vokes, 1971, Bulls. A mer. P