Pachastrellidae Carter, 1875

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 : 876

Family Pachastrellidae Carter, 1875 Pachastrellidae indet.

Figs. 3D, G–K, O–T , 7Y , 8L .

Material.—Lower Eocene, middle Eocene, upper Eocene, lower Oligocene, south-central Ukraine.

Remarks.—Pachastrellid affinity is apparent for numerous calthrops ( Fig. 3T ), mesotriaenes ( Figs. 3D, I, K, O, P , 8L ), mesodichotriaenes ( Fig. 3J ), and triods ( Fig. 3Q, R ) (compare Maldonado 2002; Łukowiak and Pisera 2016). A big plesiaster illustrated on the Fig. 3S may also be attributed to pachastrellids. It displays a great similarity to Characella pachastrelloides ( Carter, 1876) (compare Lévi and Lévi 1989: fig. 33). The same is true for long club-shaped spicule

Fig. 7Y ) whose morphology resembles that of the modern pachastrellid Ancorella paulini Lendenfeld, 1907 (compare with Lendenfeld 1907: pl. 12: 9). The pachastrellid affinity of some other spicules cannot be ruled out (e.g., Figs. 3A–C, F–H ). However, these spicules might also belong to geodiids, calthropellids, ancorinids, or even tetillids.

Figures

Fig. 3. Spicule morphotypes from south-central Ukraine; Černoleska, upper Eocene (A), Pesčanoe, upper Eocene (B), Russkie Tiŝki, middle Eocene (C, I, Q), Verhnee, lower Eocene (D, F, H, J, K, O, P), Nikol’skoe, upper Eocene (E, L), Staroverovka, middle Eocene (G), Markovka, upper Eocene (M), Kiselevka, lower Eocene (N), Grigorevka, middle Eocene (R), Kiselevka, middle Eocene (S), Markovka, middle Eocene (T), and Pesčanoe, upper Eocene (U). A, C. Anatriaenes. B. Orthodichotriaene. D, I–K, O, P. Mesotriaenes. E. Prodichotriaene. F, T. Calthrops. G, H. Dichotriaenes. L. Tylostyle. M, N. Mesodichotriaenes. Q, R. Triods. S.?Plesiaster. U. Oxyaster. After Ivanik (2003); modified.

Fig. 7. Spicule morphotypes from south-central Ukraine; Markovka, upper Eocene (A, E, K), Kiselevka, middle Eocene (B, U), Lipcy, middle Eocene (C), Russkie Tiŝki, middle Eocene (D, J, P, R, V, W, X, AB), Nikol’skoe, upper Eocene (F, H, Y), Kantemirovka, upper Eocene (G, L, AA), Kiselevka, upper Eocene (I, O, Z), Pogonovka, upper Eocene (M, N), Melovoe, upper Eocene (Q, T), Černoleska, upper Eocene (S), and Staroverovka, middle Eocene (AC). A–E. Oxeas. F, H. Acanthoxeas. G. Acanthorhabd. I, J. Acanthostrongyles. K, M, N. Acanthostyles. L, O–Q. Styles. R. Reduced triaene. S. Anatriaene. T, U. Unknowns spicule. V. Orthotriaene. W, X. Tylostyles. Y. Spicule fragment. Z. Exotyle. AA.?Fragment of a triaene. AB. Amphiaster.AC. Spheraster. After Ivanik (2003); modified.

Fig. 8. Spicule morphotypes from south-central Ukraine; Verhnee, lower Eocene (A, K, L, P), Russkie Tiŝki, middle Eocene (B, D, N, Q), Nikol’skoe, upper Eocene (C, E, G, J), Markovka, upper Eocene (F, O), Lipcy, middle Eocene (H), Melovoe, upper Eocene (I), and Kantemirovka, upper Eocene (M). A.?Fragment of dictional skeleton. B. Pentactine. C. Hexactine. D, E.?Oxeas. F, G, O. Amphiclads. H. Broken lophodiactine. I, J. Lophocalthrops. K.?Lophocalthrop. L. Spicule fragment. M.?Spicule fragment. N. Dichotriaene. P. Calthrop. Q. Fragment of a diatom. After Ivanik (2003); modified.