NEOPELTIDAE Sollas, 1888: 344

Kelly, Michelle, 2000, Description of a new lithistid sponge from northeastern New Zealand, and consideration of the phylogenetic affinities of families Corallistidae and Neopeltidae, Zoosystema 22 (2), pp. 265-283 : 281-282

Family NEOPELTIDAE Sollas, 1888: 344

DIAGNOSIS. — Stipitate, clavate, pedunculate, lamellate, or plate-like Astrophorida with monocrepid megarhizoclone desmas consisting of sinuous, smooth or tuberculate zygomes, four smooth clones emanating from a short epirhabd with a distinctive fine monaxonal crepis; other megascleres include large fusiform oxea with strongylar modifications and ectosomal pseudotriaenes with morphology and disposition reminiscent of dichotriaenes; ectosomal pseudotriaenes are modified desmas which can be digitate, bifurcate, phyllamentous, or discate, with crenulate or denticulate margins, which are pithed and laminated, occasionally with blunt conical projections. The pseudorhabdome is short, curved and irregularly thickened when it is present. These megascleres lack the triaenose inceptional canals of the triaene. In Macandrewia , three minute tetractine-like canals emanate from one end of the thread-like crepis in leading to foliate expansions at the proximal end of the rhabdome, these expansions are granular in Daedalopelta and Callipelta , and Homophymia lack all such canals. Microscleres are spined amphiasters in Homophymia , and Callipelta , with metaster-like modifications in Neopelta and Daedalopelta , these are absent in Macandrewia . Acanthose microxea are present in Neopelta and smooth spinulate microxea are found in Macandrewia .

REMARKS

The genus Plinthosella (family Plinthosellidae Schrammen ) was initially created for tetracladine fossil lithistids with superficial siliceous plaques in the ectosomal region of the sponge. Lévi (1991) considers that the tetracrepidial nature of the desmas of species described within the genus is not always easy to demonstrate, and that they could very well be more reminiscent of megarhizoclones of Neopelta and indeed, Macandrewia , Callipelta and Homophymia . Thus, as suggested by Lévi (1991), a thorough comparison of spicules in Mesozoic species will need to be made before family Plinthosellidae Schrammen, 1910 can be confirmed as a synonym of Neopeltidae in the suborder Dicranocladina .

The separation of the suborder Dicranocladina into two families containing predominantly Recent taxa, family Corallistidae and family Neopeltidae is upheld, but it is suggested that Callipelta , Homophymia , Daedalopelta and Macandrewia be transferred to family Neopeltidae , the group appearing to share a common origin with fossils such as Pachinion , but having lost the ancestral dicranoclone and dichotriaene skeletal components. Recent genera Corallistes and Herengeria , on the other hand, are retained in the family Corallistidae , having potential common ancestry with Procorallistes, Iouea , Gignouxia and Phrissospongia , and also sharing a possible common origin with Pachinion and Dicranoclonella -like ancestors that have reduced the megarhizoclone component of their skeletons. Ongoing molecular systematics research by the author and colleagues is focused upon verification of the above hypothesis.