Zyzzya sp.

Łukowiak, Magdalena, Pisera, Andrzej & Stefanska, Tetiana, 2019, Uncovering the hidden diversity of Paleogene sponge fauna of the East European Platform through reassessment of the record of isolated spicules, Acta Palaeontologica Polonica 64 (4), pp. 871-895 : 886

Zyzzya sp.

Fig. 6P–R .

Material.—Upper Eocene, south-central Ukraine.

Remarks. —The verticillate acanthostrogyles ( Fig. 6Q, R ) and acanthostrongyle ( Fig. 6P ) can be assigned to one of the species of Zyzzya . Five species are currently distinguished within this genus ( van Soest et al. 2018). Amongst them, Z. fuliginosa ( Carter, 1879) is characterized by presence of both these spicule types (compare van Soest et al. 1994: figs. 19, 20). The length of the acanthostrongyles found in modern Z. fuliginosa is up to 250 μm (see van Soest et al. 1994: table 2), while the fossil spicule is 165 μm long, thus falling within the range observable in that taxon. There are also some other spicules of similar morphology ( Fig. 5U). However, contrary to the verticillate acanthostrongyles of Zyzzya , these spicules are strongly sculptured also at the tips. Such morphology makes their attribution to Acarnidae less likely.

Figures

Fig. 6. Spicule morphotypes from south-central Ukraine; Russkie Tiŝki, Middle Eocene (A, H, O, Y, Z), Kiselevka, upper Eocene (B, C), Markovka, middle Eocene (D), Russkie Tiŝki, upper Eocene (E), Kiselevka, upper Eocene (F, G, M), Pogonovka borehole, upper Eocene (I), Markovka, upper Eocene (J, K, N), Nikol’skoe, upper Eocene (L, P), Grigorevka borehole, upper Eocene (Q, R, S, T), Melovoe, upper Eocene (U, V), and Kiselevka, middle Eocene (W, X). A. Spherostyle. B–D. Tylostyles. E, F, I–K, M. Acanthostyles. G, H. Exotyles. L. Clavidisc. N, O. Acanthoxeas. P–R. Acanthostrongyles. S, T. Sigmas. U, V. Anisochelae. W. Isochela. X. Spheraster. Y, Z. Tylotes. After Ivanik (2003); modified.