Thalassematinae
| Thalassematinae | |
|---|---|
 | |
| Echiura at a market in South Korea | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Annelida |
| Clade: | Pleistoannelida |
| Clade: | Sedentaria |
| Order: | Capitellida |
| Family: | Thalassematidae |
| Subfamily: | Thalassematinae Bock, 1942 |
| Type genus | |
| Thalassema Pallas, 1774 | |
| Tribes | |
Thalassematinae is a subfamily of spoon worms, in which are contained two tribes. Unlike the Bonelliinae, they do not present any marked sexual dimorphism, making them sexually monomorphic.
Description
The Thalassematinae are described as being sexually monomorphic Thalassematidae, meaning they do not show any marked sexual dimorphism. Morphologically, they have a single pair of chaetae underside side at the front, whilst their gonoducts are paired and gonostomes are basally positioned. Meanwhile, the anal vesicles are unbranched, whilst the proboscis is not split into two. It has been noted that in the tribe Thalassematini, anal chaetae are present, whilst this is not the case for members of the tribe Echiurini.
Tribes
The following tribes are classified within the suborder:
- Thalassematini Forbes & Goodsir, 1841
- Echiurini Quatrefages, 1847
References
- ↑ Goto, Ryutaro; Monnington, James; Sciberras, Marija; Hirabayashi, Isao; Rouse, Greg W. (2020-02-10). "Phylogeny of Echiura updated, with a revised taxonomy to reflect their placement in Annelida as sister group to Capitellidae". Invertebrate Systematics. 34 (1): 101–111. doi:10.1071/IS19020. ISSN 1445-5226. Retrieved 2026-10-10.
- 1 2 Goto, Ryutaro; Monnington, James; Sciberras, Marija; Hirabayashi, Isao; Rouse, Greg W. (2020-02-10). "Phylogeny of Echiura updated, with a revised taxonomy to reflect their placement in Annelida as sister group to Capitellidae". Invertebrate Systematics. 34 (1): 101–111. doi:10.1071/IS19020. ISSN 1445-5226. Retrieved 2026-10-10.