Anthracomartus

Anthracomartus is an extinct genus of Carboniferous-aged trigonotarbid arachnids. A fossil of the species Anthracomartus hindi (synonym: Cryptomartus hindi) was found to be 23 mm long and 14 mm wide.

3-D modeling
Scientists at Imperial College London created a detailed 3D computer model of A. hindi from fossils. 3D imaging revealed A. hindi has a flat body and large front limbs, indicating ambush hunting techniques similar to that of modern crab spiders due to the similarities in their anatomical features.