Holoplicatella, Clausen & Álvaro, 2006

Clausen, Sébastien & Álvaro, J. Javier, 2006, Skeletonized microfossils from the Lower-Middle Cambrian transition of the Cantabrian Mountains, northern Spain, Acta Palaeontologica Polonica 51 (2), pp. 223-238 : 233

Holoplicatella ? sp.

Fig. 5H.

Material.—One isolated specimen from the “Beleño” facies, section Cr 4.

Description.—Bilaterally symmetric, concavoconvex sclerite, ca. 750 µm in diameter. The convex face of the sclerite is subcircular in outline, bearing two pairs of distinct symmetric folds on the anterolateral half of the face. The anterior margin of the concave side bears two lateral symmetric, sharp−pointed domes, which correspond to the prolongation of the above−described folds, connected by an offset marginal platform, U−shaped, and bounded by steep slopes. In lateral view, both domes and the platform are prolonged into a subtriangular face bearing a central pit, circular in outline and 120 µm in diameter. The posterior margin of the concave face is depressed, connected with the center of the concavity and with the steep slopes that bound the U−shaped offset marginal platform. The posterior margin is rounded and has no notch.

Remarks.—Although the specimen is morphologically close to Holoplicatella margarita gen. et sp. nov, open nomenclature is preferred: Holoplicatella ? sp. differs from P. margarita in the absence of a prominent notch on the posterior margin, and the presence of two pointed domes on the anterior margin and of a distinct pit on the anterior margin of the sclerite. These characters do not seem preservational artifacts and are maintained here as morphologically distinctive.