Through exceptional preservation, we establish a phylogenetic connection between Ediacaran and Cambrian metazoans. We describe the first three-dimensional, pyritized soft tissue in Namacalathus from the Ediacaran Nama Group, Namibia, which follows the underlying form of a stalked, cup-shaped, calcitic skeleton, with six radially arranged lobes projecting into an apical opening and lateral lumens. A thick body wall and probable J-shaped gut are present within the cup, and the middle layer of the often-spinose skeleton and skeletal pores are selectively pyritized, supporting an organic-rich composition and tripartite construction with possible sensory punctae. These features suggest a total group lophotrochozoan affinity. These morphological data support molecular phylogenies and demonstrates that the origin of modern lophotrochozoan phyla, and their ability to biomineralize, had deep roots in the Ediacaran.

https://advances.sciencemag.org/content/7/1/eabf2933

dv said:

Through exceptional preservation, we establish a phylogenetic connection between Ediacaran and Cambrian metazoans. We describe the first three-dimensional, pyritized soft tissue in Namacalathus from the Ediacaran Nama Group, Namibia, which follows the underlying form of a stalked, cup-shaped, calcitic skeleton, with six radially arranged lobes projecting into an apical opening and lateral lumens. A thick body wall and probable J-shaped gut are present within the cup, and the middle layer of the often-spinose skeleton and skeletal pores are selectively pyritized, supporting an organic-rich composition and tripartite construction with possible sensory punctae. These features suggest a total group lophotrochozoan affinity. These morphological data support molecular phylogenies and demonstrates that the origin of modern lophotrochozoan phyla, and their ability to biomineralize, had deep roots in the Ediacaran.

https://advances.sciencemag.org/content/7/1/eabf2933

Thanks. Very interesting.

Fig. 1 N. hermanastes, Nama Group, Namibia.

Museum No. F1547, Museum of the Geological Survey of Namibia. For numbered individuals, see fig. S2A. Scale bars, 2 mm.

(A to D) Upright Namacalathus cup showing the central opening (CO) with folds (white arrows). Ridges ® and domes (D) are present around the CO, with intervening pillow-like lobes (Lo), and iron (oxyhydr)oxide staining (FeOx) of sediment around fossil.

(B) Folds (arrowed) around the CO and associated D.

© Inset of (B), showing radiating D (black arrows) and folds (white arrows) around the CO.

(D) Upright view showing folds (white arrows) around the central CO and lumens (L) with opposing folds (black arrows).

(E) Cast preservation, with the CO and top of three L with calcite skeleton (black arrows). Sediments between lumens stained with FeOx (brown arrows).

(F) CO and L preserved in FeOx, with calcite skeleton beneath (black arrows).

(G) Toppled Namacalathus cup with R and D around L.

(H) Inset of (G), showing domes and ridges (black arrows) around L.

(I) Cast of toppled Namacalathus with L and CO.

(J) Toppled Namacalathus with spines (Sp).

Fig. 5 Reconstruction of N. hermanastes as a total group lophotrochozoan.

Michael V said:

dv said:

Through exceptional preservation, we establish a phylogenetic connection between Ediacaran and Cambrian metazoans. We describe the first three-dimensional, pyritized soft tissue in Namacalathus from the Ediacaran Nama Group, Namibia, which follows the underlying form of a stalked, cup-shaped, calcitic skeleton, with six radially arranged lobes projecting into an apical opening and lateral lumens. A thick body wall and probable J-shaped gut are present within the cup, and the middle layer of the often-spinose skeleton and skeletal pores are selectively pyritized, supporting an organic-rich composition and tripartite construction with possible sensory punctae. These features suggest a total group lophotrochozoan affinity. These morphological data support molecular phylogenies and demonstrates that the origin of modern lophotrochozoan phyla, and their ability to biomineralize, had deep roots in the Ediacaran.

https://advances.sciencemag.org/content/7/1/eabf2933

Thanks. Very interesting.

Fig. 1 N. hermanastes, Nama Group, Namibia.

Museum No. F1547, Museum of the Geological Survey of Namibia. For numbered individuals, see fig. S2A. Scale bars, 2 mm.

(A to D) Upright Namacalathus cup showing the central opening (CO) with folds (white arrows). Ridges ® and domes (D) are present around the CO, with intervening pillow-like lobes (Lo), and iron (oxyhydr)oxide staining (FeOx) of sediment around fossil.

(B) Folds (arrowed) around the CO and associated D.

© Inset of (B), showing radiating D (black arrows) and folds (white arrows) around the CO.

(D) Upright view showing folds (white arrows) around the central CO and lumens (L) with opposing folds (black arrows).

(E) Cast preservation, with the CO and top of three L with calcite skeleton (black arrows). Sediments between lumens stained with FeOx (brown arrows).

(F) CO and L preserved in FeOx, with calcite skeleton beneath (black arrows).

(G) Toppled Namacalathus cup with R and D around L.

(H) Inset of (G), showing domes and ridges (black arrows) around L.

(I) Cast of toppled Namacalathus with L and CO.

(J) Toppled Namacalathus with spines (Sp).

Fig. 5 Reconstruction of N. hermanastes as a total group lophotrochozoan.

Thanks to both of you. Yes. It is very interesting.