From Sand Monsters to Rock Stars

Most posts on The Whirlpool of Life deal with weighty issues like mass extinction, sustainability, and shifting worldviews. Today’s offering stands in stark contrast, yet it addresses a question that I am asked frequently. How do paleontologists go about naming dinosaurs and other extinct creatures?

The trigger for this discussion is yesterday’s announcement of a new dinosaur, Seitaad reussi, from the high desert of southern Utah. Seitaad’s world debut was made in conjunction with publication of a paper in the online, open-access journal PLoS ONE describing this new Jurassic-aged beast (1). The exquisitely preserved partial skeleton was collected several years ago near Bluff, Utah, by the paleontology team from the Utah Museum of Natural History, where I am a research curator. The two authors of the study, Joe Sertich and Mark Loewen, are ex-students of mine (Sertich is now a doctoral candidate at Stony Brook University, and Loewen is now an instructor at the University of Utah).

Seitaad is (or, more precisely, was) a prosauropod dinosaur: a mid-sized, long-necked, small-headed, two-legged herbivore that was a locomotory switch-hitter—capable of walking on two or four legs. It belonged to the first major radiation of dinosaurs (formally referred to as basal sauropodomorphs) that swept across much of the supercontinent Pangaea during the Late Triassic and Early Triassic. Seitaad lived in an arid desert setting, and the only known individual apparently experienced a premature demise in a dune collapse. Although small as dinosaurs go (~10-15 feet long; 150-200 lbs), this prosauropod may well have been the largest herbivore in its habitat, with titanic relatives like Brachiosaurus and Diplodocus still millions of years away. I greatly enjoyed Mark and Joe’s excellent study of this ancient desert denizen.

I also enjoyed their choice of moniker, which is both interesting and pretty typical of the process that paleontologists (and biologists generally) go through in naming newly discovered animals. The first part of the name, Seitaad, refers to a mythological sand-desert monster from Navajo (Diné) lore, simultaneously honoring the local indigenous peoples and the name of the rock unit entombing the specimen (the Navajo Sandstone). The latter part of the name, reussi, derives from Everett Ruess, a famous young explorer, poet, artist, and historian who mysteriously disappeared in the southern Utah desert in 1934.

So here’s the deal. You can name a dinosaur, or any other newly discovered organism, after a place, a time, a person, some particular feature of the creature in question, or just about anything at all, as long as the name has not been used previously. One caveat. It’s regarded as highly uncouth (and, for all I know, against the rules) to name a new species after oneself. With that single exception, however, the honoree may be real or fictitious, human or nonhuman. Once the subject(s) of the name is (are) chosen, you must then follow a formal (though not cumbersome) set of do’s and don’ts dictated by International Code of Zoological Nomenclature.

The two-part name—for example, Seitaad ruessi, Tyrannosaurus rex, or Homo sapiens—is a biological standard set in the 18th Century by the famed Swedish biologist Carolus Linnaeus, and still used to this day. The first part of the name is called the “genus,” whereas the latter is the “species.” The genus-species duo represents a hierarchy, with the genus being the more inclusive category. So a single genus often contains multiple species (e.g., Homo sapiens, Homo erectus, Homo ergaster, etc.).

Mark and Joe are certainly not the only paleontologists with a penchant for mythology. If one looks solely among dinosaurs beginning with letter “A,” examples include: Achillobatar (named for the mythical hero Achilles), Aeolosaurus (named after the Greek god of winds), and Atlasaurus (for Atlas, a giant who, in Greek mythology, held up the heavens). In 1995, I added another to the bunch (2)—Achelousaurus, a ceratopsian (horned) dinosaur named after Achelous, a mythological river god of the ancient Greeks who was capable of shape-shifting. In order to fight Heracles (Hercules of Roman mythology) over (what else) a woman, Achelous changed himself into a bull. Heracles won the battle when he ripped off the horns of the bull. The name fits because Achelousaurus was a hornless ceratopsian dinosaur that evolved from horned ancestors. Many, many more mythological creatures can be found embodied in the names of dinosaurs.

Just as mythology is one common theme used for naming dinosaurs and other animals, famous characters are another. Indeed fame seems to be a regular attractor for scientists naming new critters, whether the honoree is real or fictitious. As noted, Seitaad’s second name refers to legendary adventurer Everett Ruess. Extending the scope beyond dinosaurs, we might cite the wasp named Mozartella beethoveni, the snake Montypythonoides, the trilobite Mildesdavis, the crustacean Godzillus, or the diminutive midge Dicrotenipes thanatogratus (“thanatos” is Greek for “dead” and “gratus” is Latin for grateful, in honor of the Grateful Dead). Another of my favorites is a fossil turtle dubbed Ninjemys, after the cartoon Teenage Mutant Ninja Turtles.

My single nomenclatural foray into the realm of celebrity is Masiakasaurus knopfleri, a little buck-toothed, dinosaurian predator found on the island of Madagascar. The genus designation up front combines the Malagasy word for vicious and the Latin word for lizard, whereas the species name honors singer, song-writer, and world renowned guitarist Mark Knopfler, ex-lead of Dire Straits. The full translation is “the vicious lizard of Knopfler.”

Why Mark Knopfler? Well, way back in the mid 1990’s, when there were still cassette tapes and Sony Walkmans (remember those?), one of the crew members brought a pair of small speakers along with her tape player. Among the bands featured on the quarry playlist that summer was Dire Straits, a particular favorite of expedition leader David Krause. As serendipity would have it, when we played Knopfler’s music, we tended to find more fossils of the new little meat-eater, whereas these bones were few and far between when the music wasn’t playing. Back in camp one night, my longtime friend and colleague Cathy Forster (George Washington University) suggested that we name this new dinosaur after our musical talisman, Mark Knopfler. For some reason, the consensus among crewmembers (perhaps influenced by beer consumption) was enthusiastic support for the idea.

When Masiakasaurus made its first public appearance on the cover of the British journal Nature (3), the media response was swift, overwhelming, and, shall we say, unanticipated in its direction. While some reports addressed the interesting scientific aspects of this theropod dinosaur, the bulk of the media coverage concentrated on the Knopfler reference. Needless to say, I was not used to receiving phone calls for interviews from Rolling Stone or Guitarist magazine. Some media outlets, in particular the British tabloids, went so far as to question our motives, suggesting that the moniker referenced Knopfler’s physical appearance, or perhaps his status as a rock dinosaur! As for Knopfler himself, I am pleased to say that he accepted the honor in the spirit intended, stating for the record, “The fact that it’s a dinosaur is certainly apt, but I’m happy to report that I’m not in the least bit vicious.”

So that’s my two bits on names. Hearty congratulations to Joe Sertich and Mark Loewen on their big announcement. Oh, and keep your eyes open for more announcements of new Utah dinosaurs in the near future . . .

References
1. Sertich, J.J.W and Loewen, M. A. 2010. A new basal sauropodomorph dinosaur from the Lower Jurassic Navajo Sandstone of southern Utah. PLoS ONE, 5 (3), DOI: 10.1371/journal.pone.0009789

2. Sampson, S. D. 1995. Two new horned dinosaurs from the Upper Cretaceous Two Medicine Formation of Montana, USA, with a phylogenetic analysis of the Centrosaurinae (Ornithischia: Ceratopsidae). Journal of Vertebrate Paleontology, 15(4): 743-760.

3. Sampson, S. D., Carrano, M. T., Forster, C. A. 2001. A bizarre predatory dinosaur from Madagascar: implications for the evolution of Gondwanan theropods. Nature, 409: 504-505.

Images (from top to bottom)
1. The partial skeleton of Seitaad reussi, which preserves the central portion of the body.
2. The skeletal reconstruction of Seitaad reussi, with the preserved elements highlighted.

3. Joe Sertich with Seitaad reussi specimen.
4. Prosauropod dinosaurs in desert setting. Painting by Eleanor Kish.

5. Mark Loewen with Seitaad reussi specimen.
6. Masiakasaurus knopfleri, the buck-toothed predator from Madagascar. Artwork by Bill Parsons.