| Hyolithida Temporal range: | |
|---|---|
| | |
| Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Class: | † Hyolitha |
| Order: | † Hyolithida Sussoiev, 1957 |
| Families | |
See text | |
The Hyolithida are lophophorates, one of the two orders of hyolithid, the other being the Orthothecida. Most of our knowledge of the hyolithids comes from studies on the Hyolithida. [2] Both orders had an operculum that was not hinged to the conch. However, the Hyolithida are distinct from the Orthothecida in having additional paired, curved, tusk-like appendages. The Hyolithida were probably bottom feeders living in shallow water, and had tentacules. [2]