Tyrannophontes is an extinct genus of mantis shrimp that lived during the late Carboniferous period in what is now the Mazon Creek fossil beds of Illinois.

The holotype of Tyrannophontes theridion (PE12098) was collected from the Mazon Creek fossil beds in Illinois, USA by Calvin George and donated to the Field Museum of Natural History.

Aside from the holotype, a few other specimens of T. theridion have also been collected from the Mazon Creek fossil beds, though Schram noted that the species was quite rare.

[2] Smith et al. (2023) conducted a phylogenetic analysis to determine the relations between fossil mantis shrimps, the results of which are displayed in the cladogram below:[7]

Archaeocaris vermiformis Archaeocaris graffhami †Bairdops elegans Perimecturus parki Perimecturus rapax †Bairdops beargulchensis †Daidal pattoni †Daidal schoellmanni †Daidal acanthocercus Gorgonophontes fraiponti Gorgonophontes peleron †Chabardella spinosa †Tyrannophontes theridion †Tyrannophontes gigantion †Triassosculda ahyongi †Tyrannosculda laurae †Pseudosculda laevis †Archaeosculda phoenicia †Sculda pennata †Sculda syriaca †Ursquilla yehoachi †Lysiosquilla nkporoensis †Nodosculda fisherorum Squilla mantis

However, while modern mantis shrimps are primarily benthic, Tyrannophontes has been theorized to be a benthopelagic animal, swimming above the seabed while it hunted, and perhaps grabbing prey from above using its raptorial appendages.

[9][10] Both species of Tyrannophontes originate from the Mazon Creek fossil beds of Illinois, which date back to the Moscovian age of the late Carboniferous period, around 309 million years ago.

These include over 25 species of fish and numerous types of invertebrates, with the Sea anemone Essexella being the most abundant animal from this location.