Eoborus sanctijosephi ( Maury, 1935 )

Salvador, Rodrigo Brincalepe & Simone, Luiz Ricardo Lopes De, 2013, Taxonomic Revision Of The Fossil Pulmonate Mollusks Of Itaboraí Basin (Paleocene), Brazil, Papéis Avulsos de Zoologia 53 (2), pp. 5-46 : 5-46

Eoborus sanctijosephi ( Maury, 1935)

( Figs. 75-83 )

Strophocheilus sancti-josephi Maury, 1935: 7 (figs. 8, 9); Oliveira, 1936: 4; Mezzalira, 1946: 18; Trindade, 1956: 11 (pl. 2, figs. 1a, 2a); Magalhães & Mezzalira, 1953: 220 (pl. 64, fig. 259); Brito, 1967: 15 (pl. 2, fig. 2).

Strophocheilus (Microborus) sancti-josephi : Bequaert, 1948: 175.

Megalobulimus sancti-josephi : Paula Couto, 1949: 11.

Strophocheilus (Strophocheilus) charruanus (in part): Klappenbach & Olazarri, 1966: 233.

Strophocheilus sanctijosephi [ sancti-josephi ]: Parodiz, 1969: 171 (pl. 19, figs. 1, 2).

Eoborus sanctijosephi : Klappenbach & Olazarri, 1970: 180; Palma & Brito, 1974: 391 (pl. 1, fig. 7); Simone & Mezzalira, 1994: 50 (pl. 15, fig. 416); Salvador & Simone, 2012: 6 (figs. 16-17).

Eoborus sancti-josephi : Bergqvist et al., 2006: 60 (fig. 77).

Carinifex fluminensis Brito, 1967: 13 (pl. 3, figs. 1, 2).

Vorticifex fluminensis : Palma & Brito, 1974: 391 (pl. 1, fig. 4, 5); Simone & Mezzalira, 1994: 49 (pl. 14, fig. 411); Bergqvist et al., 2006: 59 (fig. 73).

Holotype: AMNH 24241 (examined; Fig. 80 ).

Type Locality: Limestones of Parque Paleontológico de São José de Itaboraí, Rio de Janeiro, Brazil. Park’s center coordinates: 22°50’20”S, 42°52’30”W .

Geographic and stratigraphic occurrence: Known only from the type locality: Sequences S1 and S2 ( Medeiros & Bergqvist, 1999; Bergqvist et al., 2006).

Age : Tertiary, Middle Paleocene.

Etymology: Reference to place of discovery, the then called Fazenda São José, of which Itaboraí Basin was a part.

Diagnosis: Shell large for genus (albeit small to medium-sized for family), slightly conoidal. Aperture elliptical, with upper palatal region of outer lip meeting continuously with preceding whorl, accompanying the whorl outline.

Re-Description: Shell large, slightly conic, approximately twice as tall as broad; shell small to medium-sized for family (larger specimens with ~ 45 mm of length), but large for genus. Spire angle ~65°. Greatest width on body whorl. Usually 6 whorls (more rarely 5). First 2 to 2½ whorls (protoconch) smooth; teleoconch with fine growth lines, well-marked, oblique. Protoconch conspicuous; transition to teleoconch clear. Profile of whorls slightly convex. Suture well-marked. Aperture elliptical, orthocline, without teeth or lamellae; ~½ shell length and ~⅔ width; aperture height ~1.5 times the width. Parietal suture of aperture well-marked. Peristome smooth and reflected. Upper palatal region of outer lip meeting continuously with preceding whorl, accompanying whorl outline. Body whorl ~⅔ shell length. Umbilicus wide.

Measures (in mm): Holotype: 5 or 6 whorls (shell apex and aperture broken); H = 44.0; D = 26.9. Mean (n = 24): 5 or 6 whorls (usually 6); H = 38.2 ± 3.8 (max 44.6; min 29.8); D = 20.8 ± 2.3 (max 22.9; min 18.3); S = 18.6 ± 2.6; h = 17.8 ± 1.7 (max 21.4; min 15.3); d = 12.7 ± 2.0 (max 15.0; min 11.1); H/D = 1.84; h/d = 1.40.

Examined material: Holotype. DGM 3736 -I (1 specimen), 4220-I (1 specimen), 4992-I (9 specimens), unnumbered (4 specimens); MNRJ 4337 -I (6 specimens), 4349-I (2 specimens), 4536-I (1 specimen); MZSP 86327 (9 specimens), 98179 (3 specimens). Type material of Vorticifex fluminensis : DGM 5003 -I (holotype).

Discussion: In the original description of E. sanctijosephi , the specific epithet had a hyphen, which has reappeared in some recent works, but must be omitted obeying the ICZN (1999) rules (Articles 11.2 and 32.5.2.4.1). E. sanctijosephi is certainly the largest pulmonate in Itaboraí Basin and the second species with the most numerous record (the first is Brasilennea arethusae ). E. sanctijosephi differs from E. rotundus Salvador & Simone, 2012 by its larger size, conic shell, oval aperture, less reflected peristome and the way in which the upper palatal region of outer lip meets with the preceding whorl accompanying its outline. Also, it differs from E. fusiforme sp. nov. by its much larger size, conic shell, less acuminated spire, slightly convex whorls and orthocline aperture.

Brito (1967) described Carinifex fuminensis ( Figs. 81-83 ) from Itaboraí. This species was subsequently transferred by Palma & Brito (1974) to the genus Vorticifex Meek in Dall, 1870, which has been previously a subgenus of Carinifex . Both genera are North-American: Vorticifex contains only fossil species dating as back as the Eocene, while Carinifex endured from the Pliocene to the Recent ( Baker, 1945). The change in the generic allocation of the Itaborahian species was due to the “body relatively high for the group” and the lack of the “typical carina of Carinifex ” ( Palma & Brito, 1974: 391).

However, V. fluminensis does not really share any feature with these genera or other planorbids. It can be clearly seen that the specimen is worn-out and had greater dimensions: the last whorl is almost completely broken, but in any case there is no indication that this missing whorl would be the body whorl of an adult specimen. This can be easily seen by the scar that the broken whorl has left on the medianlower portion of the specimen’s actual last whorl and also in the columellar region. Therefore, here we advance that the single V. fluminensis specimen known is actually the spire apex of an Eoborus sanctijosephi : the protoconch and spire apex of an E. sanctijosephi ( Figs. 75-78 ) show a pattern very close to that of V. fluminensis , including the supposed keel. By its size, it is most likely that V. fluminensis would be the protoconch of Eoborus sanctijosephi , the largest species in the genus.

Figures

FIGURES 70-77: 70-74. Eoborus rotundus (MCT 6941-I; holotype); shell length 23.5 mm. 70-72. Overview. 73. Umbilicus. 74. Smooth protoconch. 75-77. Eoborus sanctijosephi (DGM 4992); shell length 44.5 mm.

FIGURES 78-85: 78-79. Eoborus sanctijosephi (DGM 4992). 78. Smooth protoconch.79. Umbilicus. 80. E. sanctijosephi (AMNH 24241; holotype); shell length 44 mm. 81-83. E. sanctijosephi; specimen previously classified as Vorticifex fluminensis (DGM 5003-I; holotype); greater width 8.5 mm. 84-85. Eoborus fusiforme sp. nov. (MNRJ 5188-I; holotype); shell length 18.5 mm.