Acanthochaetetes reitneri nov. sp. (Porifera: Demospongiae) from the Lower Cretaceous (upper Aptian-lower Albian) Tuburan Limestone of Cebu Island (Philippines) and its stratigraphic and palaeobiogeographic implications

The chaetetid demosponge Acanthochaetetes reitneri nov. sp. is described from upper Ap-tian-lower Albian carbonates of Cebu Island, Central Philippines. Despite the absence of primary skeleton remains, this new species was described based on the combination of features within the genus, such as its long calicles (usually more than 2 mm), and the thin double walls, ranging from 0.05 to 0.125 mm. This combination of features is diagnostic at the species level within Acanthochaetetes. The present study reports the first record of the genus Acanthochaetetes from the Philippines, and extends its palaeobiogeographic distribution to the easternmost part of the Eastern Tethys Realm. Additionally, the discovery of Acanthochaetetes reitneri nov. sp. goes on to fill a stratigraphic gap for the Aptian and Albian in this region.