Table 3 Homology of the head sensory structures in the heterotardigrade species Echiniscus testudo and eutardigrade species Ramazzottius groenlandensis sp. nov. and Hypsibius exemplaris, based on Gross et al. [20]
Echiniscus testudo (heterotardigrade) | Ramazzottius groenlandensis sp. nov. (eutardigrade) | Hypsibius exemplaris (eutardigrade) |
|---|---|---|
Internal cirri + secondary clavae | Frontal lobe | Anterolateral sensory field (ASF) |
External cirri | Anteroventral lobe (AVL) | Ventrolateral sensory field (VSF) |
Lateral cirri + primary clavae | Elliptical organ (EO) | Posterolateral sensory field (PSF) |
Median sensory field (MED) (Median cirrus in marine heterotardigrades) | Centrodorsal organ (CO) | Median sensory field (MED) |