Guitarridae Dendy, 1924

Łukowiak, Magdalena, 2015, Late Eocene siliceous sponge fauna of southern Australia: reconstruction based on loose spicules record, Zootaxa 3917 (1), pp. 1-65 : 35

Family Guitarridae Dendy, 1924

The very peculiar microsclere spicules called dischelae (in two size categories, about 50 and 80 µm in diameter) have been found but they are relatively rare ( Figs. 19 M, N). Such microscleres clearly belong to the guitarrid genus Coelodischela Vacelet, Vasseur & Lévi, 1976 . Two species of Coelodischela are known so far: C. massa Lévi & Lévi, 1983 described from New Caledonia and Cape Verde (van Soest 1988) and C. diatomorpha Vacelet, Vasseur & Lévi, 1976 that inhabits coasts of Madagascar (van Soest et al. 2013). The studied dischelae are similar to both C. diatomorpha and C. massa (compare Fig. 20 F, G with Hajdu & Lerner 2002, figs. 1L–N, respectively) but we can assume that they are more closely related to the former species because it occurs near Australia, around New Caledonia. Also the size of the studied spicules (50 and 80 Μm) suggests its affinity to C. massa which has clearly bigger dischelae (25 and 50 µm respectively) than C. diatomorpha (15 and about 30 µm; Lévi & Lévi 1984). The dischelae studied here belong most probably to ancestor of Recent C. massa .

Dischelae of this type have already been described as fossils form the Late Oligocene of Tasmania and Australia from the cores of the Deep Sea Project (after Kennet et al. 1975). There are also unsure findings of dischelae (with unusual tuberculated pattern and without two contiguous holes) in the Cretaceous of N Germany ( Zittel 1876).

Figures

FIGURE 19. Spicules of sponges of the order Poecilosclerida; A – E—Anisodiscorhabds of Sigmosceptrella quadrilobata, family Podospongiidae; F – H—Exotyles of Mycale (Rhaphidotheca) cf. loricata, family Mycalidae; I – L—Exotyles of Mycale (Rhaphidotheca) sp., family Mycalidae; M, N—Dischelae of Coelodischela cf. massa, family Guitarridae; O—Pseudoastrose acanthotylote of Discorhabdella cf. incrustans, family Crambeidae; P—Discorhabd of Sigmosceptrella quadrilobata, family Podospongiidae; Q – T—Acanthostyles of the family Myxyllidae, order Poecilosclerida.

FIGURE 20. Spicules of recent sponges of the order Poecilosclerida; A—Anisodiscorhabds of Sigmosceptrella carlinae (redrawn from Boury-Esnault & van Beveren 1982); B—Anisodiscorhabds of Sigmosceptrella quadrilobata (redrawn from Kelly & Samaai 2002); C—Pseudoastrose acanthotylote of Discorhabdella incrustans (redrawn from van Soest 2002 c); D, E—Exotyles of Mycale (Rhaphidotheca) loricata (redrawn from van Soest & Hajdu 2002, after Topsent 1896); F, G—Dischelae of Coelodischela diatomorpha (redrawn from Hajdu & Lerner 2002, after Vacelet et al. 1976).