Tyrannophontes theridion

Class Malacostraca, Subclass Hoplocarida, Order Stomatopoda, Order Lophogastrida, Suborder Archaestomatopodea, Family Tyrannophontidae

Geological Time: Mississippian (~320 m.y.a.)

Size (25.4mm=1 inch): Fossil is 60 mm (curve measure) Matrix: 70 mm by 83 mm

Fossil Site: Heath Shale Formation, Bear Gulch Limestone, Fergus County, Montana

Fossil Code: BGF398

Price: $175.00 - sold

The Bear Gulch Limestone is a deposit of some 70 square km in extent and 30 m in depth that has been a source of one of the most diverse assemblages of fossil fish with some 110 species having been described over the past 30 years. Most were new to science, and provided a unique view of the marine environment of Mississippian times. Fine preservation of both fish and invertebrates is a hallmark of these deposits, presumably due to an anoxic depositional environment. This specimen is a protomantis known as Tyrannophontes theridion. It is also known from the younger Mazon Creek deposits of Illinois. The modern Mantis Shrimps are rapacious carnivores that employ a slash and grab lifestyle. Presumably this taxon shared that same modus operandi. This one is well displayed cameo-style on an oval matrix.