Fig. 9

Patterns of histaminergic neurons in the ventral ganglia for the major euarthropod taxa. Blue, green, and red neurons are interpreted as homologous neurons within the respective taxa. Gray neurons in the crustacean taxa might be homologous, but this has to be proven in future studies. Black neurons do not have corresponding cells in other taxa. Numbers near cell groups depict the variability in cell number of the respective group. Open circles in the zygentoman pattern show neurons that are only found in the thoracic ganglia. Patterns are based on the original descriptions from 1: [42]; 2: [43]; 3: this study; 4: [45]; 5: [41]; 6: [47]; 7: [48]; 8: [49]; 9: [51]; 10: [52]; 11: [53]; 12: [55]