Ancorinidae Schmidt, 1870

Łukowiak, Magdalena, 2015, Late Eocene siliceous sponge fauna of southern Australia: reconstruction based on loose spicules record, Zootaxa 3917 (1), pp. 1-65 : 20-21

Family Ancorinidae Schmidt, 1870

Among the diversified and very frequent triaenes in the studied samples, there are some that may be assigned to the ancorinid genus Stelletta Schmidt, 1862 ( Figs. 7 F–I). At least two different morphotypes of such triaenes clearly belong to this cosmopolitan genus. These are big (1000–3700 µm long), massive protriaenes with thick, squat rhabds ( Figs. 7 H, I), as well as others with short clads at right angles to the rhabd ( Figs. 7 F, G).

There are several species of the genus Stelletta recorded today from Australia: S. aeruginosa Carter, 1886 , S. brevis Hentschel, 1909 , S. centrotyla Lendenfeld, 1907 , S. clavosa Ridley, 1884 , S. communis ( Sollas, 1886) , S. conulosa Bergquist, 1968 , S. debilis Thiele, 1900 , S. mamilliformis Carter, 1886 , S. maori Dendy, 1924 , S. moseleyi ( Sollas, 1886) , S. pulchra ( Sollas, 1886) , S. purpurea Ridley, 1884 , S. pyriformis ( Sollas, 1886) , S. ridleyi ( Sollas, 1886) , S. sigmatriaena Lendenfeld, 1907 , S. splendens ( Tanita, 1965) , and S. tuberculata ( Carter, 1886) (Atlas of Living Australia). Unfortunately, having only loose spicules the problem of specific assignment exists, and thus they are determined here only as Stelletta sp. Also some other triaenes from my material (e.g., Figs. 9 A, K, L, N) may belong to Stelletta but in this case, the assignment is highly intuitive. The triaenes that may belong to Stelletta are common in the fossil record. They have been described e.g., by Reif from the Jurassic of the Germany (1967, pl. 13, figs. 17–19).

Apart from the previously discussed Stelletta sp. spicules, other moderately frequent spicules representing family Ancorinidae occur in my samples. These are characteristic calthrops and dichotriaenes ( Figs. 5 N, O) that resemble spicules of Dercitus Gray, 1867a (now Stoeba ). Some of these spicule types may also occur, however, in other Astrophorid families. For example, spicules illustrated in the Figure 4 R (as well as Fig. 5 N) may belong to a wide range of pachastrellid genera (e.g., Poecillastra , Pachastrella , Characella ), or to Vulcanella (family Vulcanellidae ), or even to Stelletta (family Ancorinidae ). Some sanidaster-ataxasters belong probably to Dercitus (now Stoeba ) ( Fig. 7 O). The illustrated here anatriaenes ( Figs. 7 A–E) may belong to the family Ancorinidae ; however, they also may belong to other taxa (e.g., family Geodiidae or Pachastrellidae ). Based on their shape, they have been assigned here to ancorinids. Both, the triaenes and the sanidaster-ataxasters, in my opinion, belong to Dercitus (Stoeba) -like sponge.

Figures

FIGURE 4. Spicules of sponges of the order Astrophorida; A – E—Sterraster microscleres of Geodia sp. 1, family Geodiidae; F – I—Sterraster microscleres of Geodia sp. 2, family Geodiidae; J – P—Different types of pynakids of the hypothetical species Dactylocalycites callodiscus, family? Geodiidae; Q – T—Spicules of the family Geodiidae; U – W—Triaenes of Penares cf. sclerobesa, family Geodiidae (subfamily Erylinae); X—Triaenes of Penares sp., family Geodiidae.

FIGURE 5. Spicules of sponges of the order Astrophorida; A—Mesodichotriaene, family Pachastrellidae; B—Dichotriaene, family Pachastrellidae; C – G—Mesotriaenes of Pachastrella - like sponge, family Pachastrellidae; H – J—Calthrops of Calthropella sp., family Calthropellidae; K—Spicule of the order Astrophorida; L—Triaene of Brachiaster cf. claudlevii, family Pachastrellidae; M—Triaene of Triptolemma cladosum, family Pachastrellidae; N – O—Calthrop and dichotriaene of Dercitus (Stoeba) - like sponge, family Ancorinidae.

FIGURE 7. Spicules of sponges of the order Astrophorida; A – E—Anatriaenes of Dercitus (Stoeba) - like sponge, family Ancorinidae; F – I—Different types of triaenes of Stelletta sp., family Ancorinidae; J – N—Different types of acanthoxeas of Alectona millari, family Thoosidae; O—Sanidaster-ataxaster of Dercitus (Stoeba) - like sponge, family Ancorinidae.

FIGURE 9. Undetermined astrophorid triaenes; A – D, L, M—Protriaenes of order the Astrophorida; E, F, J, K, N—Orthotriaenes of the order Astrophorida; G – I—Prodichotriaenes of the order Astrophorida.