Trapdoor spiders exhibit a vast range of sizes, from the enormous and fearsome Euoplos dignitas to the petite brush-footed trapdoor spiders native to Australia.
Recently, a newly discovered sizable trapdoor spider fossil provides insights into a predecessor of the brush-footed variety, believed to be about four times the size of its contemporary counterparts.
This newly unearthed fossil reveals that the prehistoric trapdoor spider, christened Megamonodontium mccluskyi, possessed a body approximately 23.31 millimeters long – close to an inch. When considering its extended legs, scientists suggest it could snugly fit within a human hand.
To provide some perspective, this size is about quadruple the dimensions of present-day brush-footed trapdoor spiders in Australia.

This difference highlights the evolutionary journey of these arachnids, shrinking over multiple millennia. Intriguingly, the age of this colossal trapdoor spider fossil is approximately between 11 and 16 million years.
The relic was unearthed in the arid expanse of McGraths Flat in New South Wales, Australia. This find represents not only the inaugural specimen of this specific species but also a rare discovery, being only the fourth spider fossil ever located in Australia.
Its significance isn’t solely based on size, but the scarcity of ancient spider fossils in general.
This breakthrough offers a wealth of information, shedding light on the demise of ancient, enormous trapdoor spiders. It also bridges gaps in our historical comprehension of these creatures and their evolutionary adaptations.
While about 300 distinct species of brush-footed trapdoor spiders currently inhabit our planet, their fossil records are sparse. This makes the new find pivotal in piecing together their history.