Niquivilispongia, Carrera & Botting & Cañas, 2025

NIQUIVILISPONGIA gen. nov.

zoobank.org/ 0BB8C6D5-E886-4BDA-A27D-457D4E479096

Diagnosis. As for the species, by monotypy.

Etymology. After the Niquivil locality, San Juan Province, Argentina.

Remarks. The closest similarity of the new genus is to Ensiferites Reimann, 1945 . Niquivilispongia gen. nov. has comparable body morphology and both genera have fine monaxon-like spicules in addition to octactins. However, the new genus is differentiated by the absence of hypertrophied gastral rays in dermal-layer spicules and the presence of a conspicuous array of long, irregular, hypertrophied heteractinid rays and undulating monaxons, which may constitute a root tuft.

The unusual feature of an apparent root tuft may have helped in anchoring the sponge to the substrate. Such a feature is rare among heteractinids, with only Eiffelospongia Rigby and Collins, 2004 , possessing a root tuft of sub-vertically aligned monaxons. However, Eiffelospongia requires a careful revision, for it shows so many cross-laid spicules that these could be in fact diagonal stauractins overlaid by longitudinal monaxons, as in Diagoniella (JB personal observation of the type material).