FIGURE 1. Geological map of the Prague Basin (Bohemia, Czech Republic), showing the approximate positions of the localities yielding Conularia fragilis (red arrow). A, location of the Prague Basin within the Czech Republic and the Bohemian Massif (shaded in grey). B, the Prague Basin. Figure modified from Zicha et al. (2020).
FIGURE 2. Stratigraphic chart of the Devonian of the Prague Basin, modified after Mergl and Kraft (2023). Koněprusy Limestones highlighted in yellow.
FIGURE 3. Selected localities yielding Conularia fragilis in the vicinity of Koněprusy village. 1, Zlatý Kůň; 2, the Čertovy Schody Quarry and the old Císař Quarry; 3, Plešivec; 4, Suchomasty.
FIGURE 4. Measurements on the 54 specimens of Conularia fragilis measuring ≥ 30 mm in length. A, Apical angle of the periderm (o); B, Percentage of the total preserved length of the periderm exhibiting bending (%); C, Maximum angle of bending of the periderm (o). For explanation of parameters see Supplementary Figure 1.
FIGURE 5. Micro-CT images of the peridermal cavity and inner surface of specimen NML 59518 (Conularia fragilis) from the Koněprusy locality. A-B, isosurface mode images showing both the back and front faces. C, visualization of the external surface and slice showing the interior of the periderm with two post-mortem fractures. Scale bar equals 5 mm.
FIGURE 6. Conularia fragilis Barrande, 1867 from the Koněprusy Limestone of the Prague Formation (Lower Devonian, Pragian). A, NML 59518, Koněprusy locality; B, NML 52655, Koněprusy locality; C, NML 63463, Suchomasty locality; D, NML 59516, Koněprusy locality; E, NML 52645, Koněprusy locality; F-G, NML 59514, Koněprusy locality; H, NML 63487, Suchomasty locality; I, NML 63473, Suchomasty locality. Scale bar equals 5 mm.
FIGURE 7. Schematic line drawings of peridermal bending in selected specimens of Conularia fragilis. Red lines indicate the facial midline, black lines the corners of the periderm, green lines the broken ends of the specimens. Scale bar equals 5 mm.
FIGURE 8. Schematic line drawings of peridermal bending in selected specimens of Conularia fragilis. Red lines indicate the facial midline, black lines the corners of the periderm, green lines the broken ends of the specimens. Scale bar equals 5 mm.
FIGURE 9. A-D, Other conulariids showing peridermal bending. A, Archaeoconularia sp., NML 65606 from the Vinice Formation (Sandbian, Upper Ordovician, Czech Republic), Knížkovice; B, Conulariid specimen NMS 6031 from the Sandbian (Upper Ordovician) of Morocco, N´Kob; C, Paraconularia planicostata (Dawson) NMS 4948 from the Upper Mississippian of western Newfoundland, Canada; D, Archaeoconularia consobrina (Barrande), NMS 6000 from the Upper Ordovician of Morocco, Erfoud; E, Rugose coral Chonophyllum, NML 66191 from the Koněprusy Limestone of the Prague Formation (Koněprusy locality). F-G, specimens of Conularia fragilis showing two peridermal bends. F, NML 63474, Suchomasty locality; G, NML 59518, Koněprusy locality; H, Rugose coral Pselophyllum, NML 67456 from the Koněprusy Limestone of the Prague Formation (Koněprusy locality); I, Rugose coral Chonophyllum, NML 67215 from the Koněprusy Limestone of the Prague Formation (Koněprusy locality); J, Rugose coral Chonophyllum, NML 67216 from the Koněprusy Limestone of the Prague Formation (Koněprusy locality). F-G F-G F-J Scale bar equals 5 mm.
FIGURE 10. Details of malformed transverse ribs in bent portions of the periderm of Conularia fragilis. A-D, NML 61406, Plešivec locality; E-H, NML 59518, Koněprusy locality. Scale bar equals 5 mm.
FIGURE 11. Backscattered electron (BSE) images of sectioned specimens of Conularia fragilis. A.-F, Specimen NML 59547, Koněprusy locality. A, Transverse section showing post-mortem fractures in the periderm filled with diagenetic Fe oxides; B, Transverse section showing pyrite crystals on the inner surface of the periderm; C, Transverse section showing the microlamellae; D, Transverse section showing light and dark microlamellae along with thickening of microlamellae within the transverse ribs; E. Transverse section showing microlamellae; F. Transverse section showing light and dark microlamellae along with thickening of microlamellae within the transverse ribs; G. Specimen NML 59514, Koněprusy locality. Transverse section showing light and dark microlamellae along with thickening of microlamellae within the transverse ribs.
FIGURE 12. Reconstruction of the Koněprusy fore-reef slope zone with Conularia fragilis and associated fauna. Drawing by Jiří Svoboda.
