The Ascospongiae: a new (old) fifth class of sponges скачать в хорошем качестве

The Ascospongiae: a new (old) fifth class of sponges

Sponges have four living classes, and lots of weird fossils. One group of those weird fossils has long been called demosponges, under the name Protomonaxonida. They include iconic Burgess Shale genera like Choia, Leptomitus, Pirania and Halichondrites, and form a coherent group... but they don't fit anywhere among living forms. After years of deliberating, I eventually defined a new class, the Ascospongiae, to accommodate them. This is the story of how that process happened, the history of the group, and the work that led to puzzling out their origins, as far as we've been able to do so far... Previous videos: Introduction to sponges:    • Sponges: the essentials   The Hexactin Problem:    • Sponges: the hexactin problem and its impo...   The ancestry of Demosponges:    • The ancestry of demosponges   Chancelloriids:    • Chancelloriids: slugs or sponges?   Papers available open access: Ascospongiae proposal: https://www.google.com/url?sa=t&sourc... Protomonaxonid relationships: https://palaeo-electronica.org/conten... Lenica spicules: https://www.scup.com/doi/full/10.1111... Presented by Joe Botting, independent palaeontologist and Honorary Research Fellow at the National Museum Wales. ---------------------------------------------------------------------------------------------------------------------------------------------------- Channel Membership: to support the channel for £3.99 per month, please investigate the 'join' button underneath the video. You can expect 2-3 extra videos per month, showing current research, related mainly to the Ordovician Castle Bank Biota.