Biologists from the University of Arkansas recently identified six new species of western U.S. rattlesnake. This discovery adds to a growing number of creepy crawlies that have recently revealed themselves to science.
Previously, the six newly named rattlers were regarded as subspecies of the western rattlesnake. Based on a reexamination of head shape and genetic analyses, however, researchers found the reptiles in question were in fact unique and deserved to be elevated to full species status.
"These snakes have long been recognized by herpetologists as being demonstrably different, and in fact were designated as western rattlesnake subspecies in the first half of the 20th century," explained co-author Michael Douglas, a professor of biological sciences at the University of Arkansas.
Rattlesnakes, characterized by relatively heavy bodies and diamond-shaped heads, are venomous. They have a natural range across North and South America but are most concentrated in the southwestern U.S.
In addition to DNA testing, head shape serves as a good standard for telling rattlesnakes apart because it can vary drastically between different species and potentially reflect what kind of prey the snake prefers.
The six new snakes have subsequently been named: the prairie rattlesnake, Crotalus viridis; the northern Pacific rattlesnake, Crotalus oreganus; the Arizona black rattlesnake, Crotalus cerberus; the southern Pacific rattlesnake, Crotalus helleri; the midget faded rattlesnake, Crotalus concolor; and the great basin rattlesnake, Crotalus lutosus.
"Crotalus" comes from the Greek word krotalon meaning "rattle" or "castanet." All such snakes are venomous pit vipers. Both the scientific and standard English names will be submitted to the International Committee on Zoological Nomenclature for approval.
"None are currently considered rare, but species designation allows them to gain certain legal protection, particularly within individual states," Douglas, Twenty-First Century Chair in Global Change Biology, added in a news release.
He and co-author Marlis Douglas worked alongside colleagues Mark Davis, a research scientist at the Illinois Natural History Survey, and with Michael Collyer of Western Kentucky University. As part of his doctoral research, Davis had previously collected data from nearly 3,000 western rattlesnakes available in natural history museums across the western U.S.
The recent study, published in the journal PLOS one, has important implications for ecological conservation efforts across the U.S. An upgraded species listing not only gives the snakes greater legal protections should they become threatened or endangered but also helps researchers better estimate their natural range and threats.
The identification of these six new species follows the discovery of 14 new hairy, large-bodied tarantula species in the southwestern U.S., including one that was named after the late famous singer-songwriter Johnny Cash.
This find, made by researchers from the Auburn University Museum of Natural History, nearly doubled the number of known tarantula species from the region, which is now home to a total of 29.
The 14 spiders reportedly belong to the Aphonopelma genus, which includes some of the most unique spiders in the U.S. due to the extreme size differences between species. For instance, some have a leg span about as long as the face on an American quarter, while others reach six inches in leg span.
Finds such as these highlights how much remains unknown about our planet's biodiversity.
