Megarhiza dubia
Schrammen 1901
Megarhiza dubia is a moderately rare and peculiar sponge. It has a pronounced stratified body, with sponge layers intercalating with sediment.
Although all specimens known to the author are circular in outline, this shape may not reflect the original situation. It is possible that Megarhiza dubia is an encrusting species, and that the specimens found are rounded (rolled) fragments.
The scleres of Megarhiza dubia are also unusual, which makes it difficult to classify this species. They are similar to large rhizoclones, but also bear similarities to megaclones. On the sponge laminae, one can also find flat, phyllotriaene-like scleres. Schrammen (1924) has created an extra suborder "Megarhizomorina" for these reasons.
Megarhizoclones of Megarhiza dubia
(after Schrammen, 1910)