The City of Las Cruces operates two museums that are co-located on Main Street: a natural history museum and an art museum. Nancy and I visited both in late November after strolling through the Farmers and Crafts Market. The Museum of Nature & Science has several very interesting and well-designed permanent exhibits. I think we appreciated the reptilian and amphibian wonders of the Desert Life exhibit the most, and Nancy made friends with a common snapping turtle named Zilla.
One of the first exhibits is this fine cast of a dimetrodon, which is not a dinosaur but a species of animal (it’s more closely related to mammals than reptiles, but it is not an ancestor of modern mammals) that went extinct 40 million years before dinosaurs came on the scene. Fossils of dimetrodon have been found in what is now the Robledo Mountains area northwest of Las Cruces. Theories differ on the purpose of the spined sail along the back, ranging from use as an actual sail while swimming, to assisting with controlling the temperature of the animal, to helping support the back of the animal while it walked in a side-to-side motion.
Most fossils of Dimetrodon species have been found in the southwestern United States, but one species has been unearthed in Germany and another in Canada. They lived about 300 million years ago, and were 6 to 15 feet long. I didn’t know that animals that are more closely related to present-day mammals than to dinosaurs even existed before dinosaurs ruled the Earth, so I learned something just minutes after stepping into the museum.
Here’s a mounted skeleton of a western diamondback rattlesnake. These reptiles can have up to 300 vertebrae, and their rattles are modified scales. They get a new rattle each time they shed their skin, which is three or four times each year. Adult diamondbacks commonly grow to 4 feet in length. This species is responsible for the greatest number of snakebites in the United States, and is found in the southwestern region of the country as well as the northern half of Mexico.
Tyrannosaurus roamed much of the present-day western United States, including the area that’s now New Mexico, up until the day the dinosaurs went extinct about 65 million years ago. The largest specimens are estimated to have been more than 40 feet long and weigh more almost 8 tons. Sharp-eyed tyrannosaurus enthusiasts will recognize this cast as coming from the skull of Stan, one of the more famous fossils for which there is a nearly complete skeleton. Stan was found in 1992 in South Dakota’s celebrated Hell Creek formation; he has a hole in the back of his skull that’s about the size of a Tyrannosaurus tooth, so make of that what you will.Some of the museum’s exhibits featured animals not yet fossilized or skeletonized. Here’s an intense-looking Trans-Pecos rat snake; they are very gentle and non-venomous snakes, and usually don’t attempt to bite. They are natives of the Chihuahuan Desert, and the largest grow to about 5 1/2 feet long.These are Woodhouse’s toads. Kinda grumpy-looking toads, don’t you think? They live in the west-central United States from Texas up north into the Dakotas. They can grow up to about five inches long. One must resist the urge to lick a Woodhouse toad, as they have toxins on their skin to make them taste bad to potential predators. And, I don’t think licking this toad would make it any less grumpy anyway.Finally we come to Zilla, the museum’s common snapping turtle. This species is native only to the Cimarron and Pecos rivers region of northeastern New Mexico, but populations are now being found in the Rio Grande River in the central third of the state. Common snapping turtles are found in the United States north and east of New Mexico to Canada and the Atlantic Coast. Nancy was really taken with Zilla.And who wouldn’t be? Contrary to common belief, common snapping turtles probably aren’t capable of biting off a human finger: humans have more force in their jaws than do common snapping turtles. A non-closely related species, the alligator snapping turtle, is definitely capable of biting off fingers, so you’re probably safe sticking your fingers in front of a common snapping turtle but don’t do it in front of an alligator snapping turtle.According to a staff person at the museum, Zilla is about 25 years old. It’s thought that common snapping turtles can live more than one hundred years in the wild, so who knows how long Zilla will keep going. They keep growing with age and the heaviest one found in the wild weighed about 75 pounds, so they get pretty big.Here’s a study of Zilla’s front left claws. Snapping turtles’ impressive claws are used for digging for food in the rocks and mud and not, as one might think, in swift slashing offensive attacks. They’re turtles.
We enjoyed the visit to the Museum of Nature & Science. We both learned a lot about animals that live in New Mexico (now and tens of millions of years ago), and Nancy left with her heart warmed by meeting Zilla.
Tales of The Goddard 
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