Crotalus thalassoporus

{{Short description|Species of Mexican rattlesnake}}

{{Species box

| genus = Crotalus

| species = thalassoporus

| authority = Meik et al., 2018

}}

Crotalus thalassoporus, or the Louse Island speckled rattlesnake, is a species of rattlesnake from Piojo Island, Baja California, Mexico. The species is named after the Greek word for 'Seafaring' in reference to the assumed overseas dispersal from Piojo Island to Smith Island.{{Cite journal |last1=Meik |first1=Jesse M. |last2=Schaack |first2=Sarah |last3=Flores-Villela |first3=Oscar |last4=Streicher |first4=Jeffrey W. |title=Integrative taxonomy at the nexus of population divergence and speciation in insular speckled rattlesnakes |journal=Journal of Natural History |date=2018-03-30 |volume=52 |issue=13–16 |pages=989–1016 |url=https://www.researchgate.net/publication/323226967 |doi=10.1080/00222933.2018.1429689 |bibcode=2018JNatH..52..989M }} As with all rattlesnakes, it is venomous.{{Cite web |title=Crotalus thalassoporus |url=https://reptile-database.reptarium.cz/species?genus=Crotalus&species=thalassoporus |access-date=2025-01-07 |website=The Reptile Database}}

Only separated from mainland species by rising oceans within the past 10 thousand years, C. thalassoporus displays rapid dwarfism of its species from when it was split off.