| The head and thorax are fused into a cephalothorax and may be difficult to distinguish. |
| The cephalothorax of spiders is a sclerotized body part that does not change after the final molt. |
| Some species, however, such as certain members of the suborder Cyphophthalmi, lack eyes or have eyes positioned laterally on the cephalothorax. |
| Although remains of the cephalothorax, abdomen, and telson are preserved, none of the specimens is articulated. |
| The nervous system of spiders, unlike that of other arachnids, is completely concentrated in the cephalothorax. |
| They become adolescent when their cephalothorax is over approximately 40 mm. |
