Petrosiidae

Łukowiak, Magdalena, 2015, Late Eocene siliceous sponge fauna of southern Australia: reconstruction based on loose spicules record, Zootaxa 3917 (1), pp. 1-65 : 30-31

Family Petrosiidae van Soest, 1980

The stout strongyles are common in the studied samples ( Figs. 16 A–F). These elongated bean-shaped spicules of size ranging from 100 to about 400 µm are characteristic to haplosclerid Petrosia sp. ( Vosmaer, 1885). Also, another haplosclerid genus, Haliclona (Reniera) Schmidt, 1862 has spicules similar in morphology but the spicules studied here resemble those of Petrosia the most. Today, petrosiids are widely distributed in shallow and deeper warm-temperate to cold waters in many parts of the world ( Desqueyroux-Faúndez & Valentine 2002). There are four species of Petrosia recorded from the Australian coasts: P. (Petrosia) pigmentosa Fromont, 1991 , P. hebes Lendenfeld, 1888 , P. (Petrosia) nigricans Lindgren, 1897 , and P. (Strongylophora) strongylata Thiele, 1903 (Atlas of Living Australia). Unfortunately, the assignment of studied spicules to one of these species is not possible because of their very simple morphology.

The spicules of such shape are common in the fossil record and were described among others from the Devonian of Poland by Hurcewicz (1985, pl. 2, fig. 2; described as Reniera , but this paper is highly unreliable—see Rigby et al. 2001, and Pisera personal comm.). Such strongyles were also described from the Cretaceous (Maastrichtian & Campanian) sediments of NW Germany by Schrammen (1924, pl. 4, figs. 42–45), Early Cretaceous of N Germany by Rüst (1885), and by Hinde (1888) from the Early Carboniferous of England (described as Reniera clavata Levinsen, 1887 ; pl. 9, fig. 5).

Figures

FIGURE 16. Spicules of sponges of the order Haplosclerida; A – F—Different types of strongyles of Petrosia sp., family Petrosiidae.