Overview

• Researchers at the University of Turku officially defined the genus Satyrex in the journal ZooKeys, describing four new tarantula species and reclassifying Monocentropus longimanus.
• Male Satyrex spiders possess palps 2.23–3.85 times the length of their carapace, representing the longest known sperm-delivery organs among tarantulas.
• Satyrex ferox, the largest species, has a legspan of about 14 cm and palps nearly four times its carapace length, and exhibits threat posturing and hissing defenses.
• All Satyrex species are fossorial, inhabiting underground burrows at the base of shrubs or between rocks in arid habitats across the Arabian Peninsula and Horn of Africa.
• Researchers propose that the exaggerated palp length evolved as a mating adaptation to maintain a safer distance from aggressive females and reduce cannibalism risk.