Spongillidae, Gray, 1867

Pronzato, Roberto, Pisera, Andrzej & Manconi, Renata, 2017, Fossil freshwater sponges: Taxonomy, geographic distribution, and critical review, Acta Palaeontologica Polonica 62 (3), pp. 467-495 : 488-489

Spongillidae spp. sensu Williams 1985

Fig. 22 .

Horizon: Miocene.

Locality: Lacustrine deposit at Oviatt Creek, northern Idaho, USA. References: Williams 1985.

Description (emended from Williams 1985).—Spicular remains. Megascleres abundant, as smooth and spiny oxeas and strongyles (185–263 μm in length). Thickness not reported. Microscleres pseudobirotules (18–26 μm in length). Thickness of the shaft and pseudorotules diameter not reported. Gemmuloscleres of various types. Gemmuloscleres strongyles (40–105 μm in length) variably spiny. Thickness not reported. Gemmuloscleres birotules (24–34 μm in length). Thickness of the shaft and rotules diameter not reported.

P Q R S T U V

W X Y Z AA AB

Remarks.—A total of 28 spicules are described, illustrated and ascribed by Williams (1985) to the following genera: Anheteromeyenia , Corvospongilla , Eunapius , Radiospongilla , and Spongilla . In some cases an identification at species level is proposed ( A. ryderi , E. fragilis , R. crateriformis , S. lacustris , and T. pennsylvanica ) referring to Penney and Racek (1968) and to the help of A.A. Racek personally. The megascleres are not very useful for the identification of Spongillida ; the majority (both living and fossil) bears monaxial megascleres, as smooth and/or spiny oxeas to strongyles. Also the spicule morphometries indicated by Williams (1985) are not diagnostic. Spicules identified as microscleres pseudobirotules are exclusive of the genera Corvoheteromeyenia , Corvomeyenia , and Corvospongilla . Monaxial gemmuloscleres are in agreement with the genera Eunapius , Radiospongilla , and Spongilla . Birotules could match the gemmuloscleres of the genus Anheteromeyenia , but some resemblance to the genera Ephydatia and Heteromeyenia also exists. The identification at the species level, and their identity with present taxa, seem hazardous considering rather poor material, but there is no doubt that several species/ genera are present in this palaeofauna. The set of data from the Oviatt Creek, once again, evidences the high conservativeness of spicular morphotraits of freshwater sponges.

Figures

Fig. 22. Spicular remains of Spongillidae. Miocene, Lacustrine deposit at Oviatt Creek, northern Idaho, USA. Megascleres (A–F, S, W–AB), microscleres (L–N), and gemmuloscleres (G–K, P–V), ascribed originally to several genera: Anheteromeyenia, Corvospongilla, Eunapius, Radiospongilla, Spongilla, Trochospongilla; X, originally enlarged × 1200, AB, originally enlarged × 700. O. Axial canal of a broken spicule, originally enlarged × 5300. G, O, P, SEM images. Modified from Williams (1985).