Late Eocene siliceous sponge fauna of southern Australia: reconstruction based on loose spicules record Author Łukowiak, Magdalena text Zootaxa 2015 3917 1 1 65 journal article 10.11646/zootaxa.3917.1.1 39ff92ed-ddb8-4ec4-af8a-19e3288fdbd1 1175-5326 287785 D8CB263D-645B-46CE-B797-461B6A86A98A Family Myxillidae Dendy, 1922 Rare acanthostyles with echinated surfaces along the spicule ( Figs. 19 Q–S) or only with a echinated pointed end ( Fig. 19 T) occur in the studied samples. Such mucronate spicules characterize sponges of the family Myxillidae [e.g., Hymenancora orientalis Koltun, 1959 ; Myxilla (Styloptilon) ancorata ( Cabioch, 1968 ) ]. One can find, however, similar spicules in the family Crellidae [e.g., Crellomima incrustans Hentschel (1929) ], Raspailiidae , Microcionidae , and Hymedesmiidae but still, those discussed here resemble most the myxillid spicules. The lack of other spicules, like chelae or sigma microscleres that would allow for more precise placement within the family Myxillidae , permits their determination only to a family level. Moreover, myxyllids are noted today from all over Australia (Atlas of Living Australia ). The spicules of similar morphology are also known from the fossil record. For example, they were described by Schrammen (1924, pl. 4, figs. 54, 55) from the Cretaceous of Germany and Mostler (1990 , pl. 1, figs. 5–7) from the Jurassic of Austrian Alps.