Fig 1.
Geological map of Skåne (southern Sweden), showing the location of the studied drill core Kävlinge BH-928, modified after [33].
Fig 2.
Holotype, NRM X12700; Kävlinge BH-928 core depth 40.40–39.60 m. (a) Scanning electron micrograph of whole specimen at low magnification. (b) Enlargement (SEM image), showing surface ornamentation in central part.
Fig 3.
Enlargement of the holotype (NRM X12700) of Kuqaia scanicus sp. nov.
Kävlinge BH-928 core depth 40.40–39.60 m. Scale bars = 100 μm, unless otherwise stated. (a) Well-developed radial ridges at the anterior (SEM image). (b) Weakly defined ridges at the posterior (SEM image). (c) Weak, parallel and transverse ridges on peduncles (SEM image). (d) Complex surface ornament revealed in UV-fluorescence microscopy. (e) Weakly defined ridges on peduncles evident in fluorescence microscopy.
Fig 4.
Line drawings showing the morphological characteristics of Kuqaia species.
Note that transitional types were indicated for Kuqaia concentrica and K. radiata.
Fig 5.
Scanning electron micrographs of Kuqaia species from the Pliensbachian of Skåne.
(a)–(e) Kuqaia concentrica Li, 1993; (a) whole specimen (NRM X12701), and (b) enlargement of concentric ridges; Kävlinge BH-928 core depth 57.00–56.50 m; (c) whole specimen (NRM X12702); (d) and (e) enlargement of concentric ridges; Kävlinge BH-928 core depth 46.97–46.01 m. (f) and (g) Kuqaia quadrata Li, 1993; (f) whole specimen in oblique compression (NRM X12703), and (g) enlargement of intersecting concentric and radial ornament; Kävlinge BH-928 core depth 46.97–46.01 m. Scale bars = 100 μm, unless otherwise stated.
Fig 6.
Scanning electron micrographs of Kuqaia species from the Pliensbachian of Skåne.
Kuqaia quadrata Li, 1993; (a) one broken specimen (NRM X12704) showing intersecting concentric and more prominent radial ridges, (b) Collar-shaped postventral margin, and (c) enlargement of chequered ornament on the dorsal part; (d) lateral view of specimen (NRM X12705) showing typical intersecting concentric and radial ornament of equal prominence. All from Kävlinge BH-928 core depth 42.25–41.15 m. Scale bars = 100 μm, unless otherwise stated.
Fig 7.
Scanning electron micrographs of Kuqaia species from the Pliensbachian of Skåne.
(a)–(e) Kuqaia radiata Li, 1993; (a) whole specimen (NRM X12707), and (b) enlargement of radial ridges in lateral view, showing the prominence of radial ridges; (c) whole specimen (NRM X12708), (d) and (e) enlargements of radial ridges. (f) and (g) Kuqaia quadrata Li, 1993; (f) specimen (NRM X12706) in dorsal view showing the prominent intersecting ridged ornamentation and (g) enlargement of chequered ornament. All from Kävlinge BH-928 core depth 46.97–46.01 m. Scale bars = 100 μm, unless otherwise indicated.
Fig 8.
Geological ranges, palaeogeographic distributions, and apparent abundance pattern of Kuqaia.
The base and top of Kuqaia stratigraphic ranges from each starred locality were tentatively calibrated based on material from offshore mid-Norway and the northern North Sea. The palaeogeographic map was modified after [38] under the Creative Commons Attribution 4.0 International License.
Fig 9.
Kuqaia scanicus sp. nov. and morphologically similar fossils of Daphnia ephippia.
The geological ages, the estimated dates of differentiation of the Daphnia lineage, and the age of the oldest fossil record of Daphnia, are plotted. Scale bars = 100 μm. SEM image of Daphnia similis used with permission from [48]; line drawings of Daphnia pulicaria and ‘undefined Chyoridae’ compiled by the authors and interpreted from images in [34].