I forgot to say that the genus Crotalus comes from the Greek krotalon or krotos for rattle or rattling. (A couple favorite native plants are called rattle-box and the genus Crotalaria) The specific epithet of the mojave rattlesnake is scutulatus and refers to the 2 or 3 are large scales between the supraoculars (above the eyes). The species name of the western diamond back is atrox from Latin for harsh or horrible. It’s the root of the word atrocious!
The photos are mine and if you’re still feeling herpetological, here are some sources:
Advocates for Snake Preservation (ASP), The Tucson Herpetological Society and these 2 field guides:
Amphibians and Reptiles of Arizona
Thomas C. Brennan and Andrew T. Holycross
The first edition looks pretty good on my truck seat, but a 2nd edition is due out Spring of 2022.
Arizona’s Amphibians and Reptiles: A Natural History and Field Guide
John Murphy
A nice hefty field guide with a lot of information.