שמור ב:
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| פורמט: | Recurso digital |
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Zenodo
2025
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| נושאים: | |
| גישה מקוונת: | https://doi.org/10.5281/zenodo.14988537 |
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תוכן הענינים:
- <p><b><i>Cyrtorizoceras hariense</i> sp. nov.</b></p><p>urn:lsid:zoobank.org:act: 08D1598D-B9FB-4C73-B47A-C2C7371DE0A7</p><p>Fig. 32E–F</p><p><b>Diagnosis</b></p><p>Large <i>Cyrtorizoceras</i> with nearly circular conch cross section, reaching a mature size of more than 60 mm; phragmocone expands at an angle of 18°–20°; conch only weakly curved; conch surface nearly smooth.</p><p><b>Etymology</b></p><p>Refers to Hari Strait, which is the sea strait west of Saxby shore, the type locality.</p><p><b>Type material</b></p><p><b>Holotype</b></p><p>ESTONIA • Vormsi Island, Saxby shore (N); Kõrgessaare Formation, Vormsi Regional Stage; GIT 878- 71.</p><p><b>Description</b></p><p>The holotype is a curved fragment of a phragmocone and a nearly complete body chamber. The conch surface is nearly smooth, ornamented with relatively coarse growth lines near the aperture. At the base of the body chamber, the conch cross section is circular or nearly so with a height of 48 mm. At the peristome, the width is 62 mm. The body chamber is 55 mm long, with a slightly curved growth axis, and in lateral view its dorsal and ventral margins have a concave and a convex curvature, respectively. The diameter of the body chamber increases continuously from its base toward the peristome. The phragmocone is 45 mm long and increases in diameter from 34 mm to 48 mm (angle of expansion = 18°). The sutures are directly transverse and 6 mm apart where the conch height is 45 mm (RCL = 0.13). The siphuncle is marginal or nearly so and expands into the chambers with a diameter of ca 5 mm where the chamber length is ca 6 mm (SCR = 0.83).</p><p><b>Remarks</b></p><p>This species of <i>Cyrtorizoceras</i> is unique in having large mature size in combination with a nearly circular conch cross section.</p>