Bucania sp.
publication ID |
https://doi.org/10.4202/app.01208.2024 |
persistent identifier |
https://treatment.plazi.org/id/EC118355-FF97-AB21-FFC6-BE215E34BAEF |
treatment provided by |
Felipe |
scientific name |
Bucania sp. |
status |
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Fig. 2C View Fig .
2020 Bucania sp. ; Bertero 2020: 39, pl. 1: 5, 6.
Material.— CEGH-UNC 24733–24736 , four recrystallized teleoconchs; from the Sandbian, Upper Ordovician , La Pola Formation, Sierra de Villicum, San Juan Province, Argentina .
Description.—Shell relatively small, narrow with three or four rounded whorls. The height is 20 mm and the width 18 mm. The aperture has a thin lip and a broad V-shaped sinus. Slit not clearly visible. The selenizone is central, narrow and slightly elevated; the umbilicus is widely open forming an umbilical angle of 85° ( Fig. 2C View Fig 1 View Fig ). The shell is dorsally convex, ornamented by regularly spaced, crowded and transversal growth lines that are intercepted by more or less separated spiral threads.
Remarks.—Taking into consideration the characters such as a widely open umbilicus, the presence of a V-shaped sinus, a narrow selenizone and a shell surface ornamented by spiral threads, the material herein described certainly represents a member of Bucania . Bucania emmonsi Ulrich in Ulrich and Scofield, 1897 (in Wahlman 1992: 128, pl. 12: 1–4), from the Sandbian–Katian, Upper Ordovician of North America, is comparable to Bucania sp. , although the Laurentian form is much smaller, has stronger and more deeply incised spiral threads and a slightly concave selenizone. Bucania lindsleyi ( Safford, 1869) (in Wahlman 1992: 131, pl. 18: 1–9), from the Katian, Upper Ordovician of North America, differs from the Argentinean species in having more rapidly expanding whorls, a wide and broadly concave selenizone which is marked by strong lunulae. Bucania frankfortensis Ulrich in Ulrich & Scofield, 1897
in Wahlman 1992: 133, pl. 13: 22–44, pl. 16: 1–4), also from the Katian, Upper Ordovician of North America, has a distinctly triangular outline, narrower whorls, regularly spaced and wrinkled growth lines and very weak spiral threads. Bucania rugatina Ulrich in Ulrich and Scofield, 1897 (in Wahlman 1992: 136, pl. 16: 9–15; pl. 17: 1–12), from the Katian, Upper Ordovician of North America, differs from the Argentinean species in having a narrower and deeper umbilicus, a wider selenizone bordered by fine ridges, closely spaced growth lines and wrinkled and sublamellose spiral threads. Bucania gracillima Koken, 1896
in Ebbestad 1998: 27–28, figs. 2, 3), from the Sandbian– Katian, Upper Ordovician of Sweden, is much larger than Bucania sp. (length and height 88– 72 mm, respectively), has a more developed ornament pattern consisting on crenulated growth lines, and a clearly visible dorsal selenizone with lunulae. Bucania erratica Frisk & Ebbestad, 2007
89, fig. 4I– T; Ebbestad et al. 2013: fig. 20: 8O–W), from the Sandbian, Upper Ordovician of Sweden, differs from the Argentinean form in having four depressed lenticular whorls, and ornamentation consisting on dense, crenulated and non-lamellose growth lines. Bucania czekanowskii ( Schmidt, 1858) (in Isakar and Ebbestad 2000: 57, figs. 6a– h, 7a–i), from the Sandbian, Upper Ordovician of Estonia, differs from Bucania sp. in having an ornament pattern consisting of flaring growth lines on regular intervals that create a geometrical pattern resembling triangles in lateral view. Bucania cornu Koken, 1897 (in Isakar and Ebbestad 2000: 66, fig. 12a–g), from the Katian, Upper Ordovician of Estonia, has a slit reaching about 1/2 whorl back, but close to form a trema when the widely expanded aperture is developed in shells of maturity. Finally, Bucania radi ata ( d’Eichwald, 1856) (in Isakar and Ebbestad 2000: 61, fig. 11a–k), from the Katian, Upper Ordovician of Estonia, differs from the species here described in having a marked expansion of the whorl during ontogeny and an increased angulation of the dorsal surface at the median carina giving a distinctly acute median part of the whorl.
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Tavera, Department of Geology and Geophysics |
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Bucania sp.
Ferrari, Mariel, Bertero, Verónica & Carrera, Marcelo G. 2024 |
Bucania sp.
Bertero, V. 2020: 39 |