Leonard Finkelman writes...
In the summer of 1998 I sat down in a chair in my parents’ living room, opened to the first page of Jurassic Park, and did not stand up again until I had read the book in its entirety. This was not my first experience with the book—I had read through half of it seven years prior, then through the whole thing before the movie adaptation was released in 1993—but it was the beginning of what has since become an annual tradition. The exact reading date and location may change from year to year, but every summer I’ll make some time to go through Michael Crichton’s modern classic.
My ongoing annotations of the text (now numbering in the triple digits) record eighteen years of intellectual growth (such as it is) spread across three copies of the book. I cycle through these copies annually with the goal of returning to earlier notes and highlights with a fresh pair of eyes. Approaching the text this way also reveals discrepancies between different editions. One such discrepancy might explain one of Crichton's more controversial choices: his conflation of Deinonychus with Velociraptor. I think the discrepancy also shows how the philosophical foundations of paleontology have changed since the 1980s. Jurassic Park was, in this sense, very much a work of its time: Crichton wouldn't be able to justify his taxonomic choices today.
A missing link
Consider this passage from the original hardcover edition of Jurassic Park:
"What do you know about Velociraptor?" Grant asked Tim. He was just making conversation. "It's a small carnivore that hunted in packs, like Deinonychus," Tim said. "That's right," Grant said, "although the evidence for pack hunting is all circumstantial." (1990, 117)
What caught my attention this year was a curious omission: I recalled from last year's read-through that Grant had made a point about lumping Deinonychus with Velociraptor, but that point was missing here. Sure enough, when I checked the same passage in the paperback and e-book editions I found the following (highlighted) text:
"What do you know about Velociraptor?" Grant asked Tim. He was just making conversation. "It's a small carnivore that hunted in packs, like Deinonychus," Tim said. "That's right," Grant said, "although Deinonychus is now considered one of the velociraptors. And the evidence for pack hunting is all circumstantial." (1991, 115)
Crichton's addition to the text in the paperback release cuts to one question often asked about the book and movie alike: why did Crichton conflate Deinonychus, the North American dromaeosaurid described in Jurassic Park, with its much smaller Asian relative Velociraptor? This was, taxonomically speaking, a relatively big mistake. Species classified within the same genus bear a relatively high degree of similarity; sometimes non-experts might not even recognize differences between them. Species classified in different genera are less similar, and often clearly different to the untrained eye. Why, then, would Crichton--known for his meticulous research--confuse different dinosaur genera?
Different sources offer different explanations. John Ostrom--the influential dinosaur paleontologist who first described Deinonychus and advised Crichton--claimed that the author did so for purely aesthetic reasons: the author thought that "Velociraptor" was the better sounding name. By contrast, Brian Switek asserts that Crichton made the choice to conflate the two due to the influence of paleoartist Gregory S. Paul.
The change between hardcover and softcover editions of the text lends credence to Switek's argument. Paul, well known among paleontologists for his controversial views of dinosaur taxonomy, receives credit in Crichton's acknowledgements (1990, 401; 1991, 400). In his Predatory Dinosaurs of the World, released one year before Jurassic Park, Paul wrote:
The skulls [of Velociraptor and Deinonychus] show no more differences than those of modern jackals and wolves, which are in the same genus, and critical functional difference between the species' skulls and skeletons are lacking. They should therefore be regarded as one genus, one in which small gracile V. mongoliensis and V. langstoni are the "jackals" to the V. antirrhopus "wolf." ... That this [latter] species is sunk into Velociraptor is rather unfortunate, because the name Deinonychus...is a fine one. (1988, 364-367)
Later fossil evidence proved Paul incorrect regarding the morphology and function of Velociraptor and Deinonychus skulls (Witmer & Maxwell 1996). In his more recent Princeton Field Guide to Dinosaurs he's content to split one genus from the other even while pursuing a broader agenda of taxonomic lumping (2010, 136-137). At the time that Crichton was writing, however, Paul's argument was at least reasonable, if not widely accepted. One could charitably read Crichton's addition to later versions of the text as an explicit nod towards Paul's dinosaur taxonomy.
This is not to say that Ostrom was mistaken in believing that Crichton's choice was a matter of taste. The discrepancy between editions of Jurassic Park hints that Crichton's lumping of Deinonychus with Velociraptor was guided by both data and taste. Such an explanation would be consistent with Crichton's philosophy of science. It would also reveal some progress in philosophy of paleontology in the time since Jurassic Park's publication.
Michael Crichton was likely a scientific anti-realist: his mouthpiece characters, at least, tended to assert that scientific theories are either necessarily false or not grounded in reality. That view become more explicit in Crichton's later works, but its seeds were clearly sown by the character of Ian Malcolm in Jurassic Park. Throughout the novel's latter half, Malcolm offers postmodern critiques of "Western" science (see, e.g., 1990, 284-285 & 305-306). Crichton literally gave anti-realism the last word in his sequel to Jurassic Park, wherein an ally of Malcolm's (and an obvious Crichton mouthpiece) advocates a pessimistic meta-induction:
Thorne shrugged. "They're still just fantasies. They're not real. Have you ever seen a self-esteem? Can you bring me one on a plate? How about a photon? Can you bring me one of those? ... you never will, because those things don't exist. No matter how seriously people take them," Thorne said. "A hundred years from now, people will look back at us and laugh. They'll say, 'You know what people used to believe? They believed in photons and electrons. Can you imagine anything so silly?' They'll have a good laugh, because by then there will be newer and better fantasies." (1995, 393)
Nevertheless, Crichton was a careful researcher; it's not for nothing that Jurassic Park is often held up as an exemplary work of true science fiction. He used actual scientific data as a point of departure for his stories. This simultaneous commitment to the reality of data and the unreality of theoretical entities implied by the data marks Crichton as a constructive empiricist. It also explains why Crichton would feel the need to justify his choice of the name "Velociraptor" as something more than personal preference.
The Deinonychus-Velociraptor hullabaloo makes a bit more sense in this context. V. mongoliensis and D. antirrhopus are clearly different fossil taxa, distinguished by features of the frontal and nares bones (among others). Reality shows that specimens of the two species form distinct phylogenetic clusters, and so Crichton acknowledges that species-level distinction (1990, 116). At the time that he wrote, however, phylogenetic analysis in dinosaur paleontology allowed ambiguity between genus- and species-level differences (Turner et al 2012, 6-7). Reality showed that V. mongoliensis and D. antirrhopus are different taxa, but it didn't demand that difference was enough to warrant genus splitting. Some authorities, such as Ostrom, maintained that it was; others, such as Paul, disagreed. Both taxonomies were "empirically adequate," i.e., accounted for given empirical data. A constructive empiricist would hold that theory choice would then have to be made on non-scientific grounds, e.g. taste.
Crichton could therefore justify his lumping through a combination of aesthetic and empirical considerations. Reality wasn't enough to decide whether or not V. mongoliensis and D. antirrhopus were really different enough to be in different genera (hence the debate between Paul and other paleontologists). As long as Crichton's choice of name reflected the facts that the taxa are different and closely related, that choice shouldn't make any theoretical difference. As our own Adrian has argued, in that case one might as well make the more pleasing choice. Ostrom and Switek would both be correct by this interpretation.
What occurred to me during this year's read-through, and the reason Crichton's choice reveals the shifting philosophical foundations of paleontology, is that when Jurassic Park was published a paleontologist could have been an anti-realist about fossil species: at the time, it was easier to believe that reality couldn't show us the different degrees of similarity between fossil genera and fossil species. As Turner et al point out:
Application of cladistic methodology to dinosaurian taxa, beginning in the early 1980s, led to the resolution of large-scale patterns of dinosaur phylogeny [i.e., above the genus level] ... subsequent authors have made important strides in clarifying fine-scale relationships among constituent lower clade levels. (2012, 7)
In the 1980s, debates about genus-level lumping and splitting couldn't be settled by data alone. Disputants would have to rely on philosophical arguments about the sufficiency of difference to justify their taxonomies. Paul's argument by analogy with canids, for example, assumed that the nature of genera is revealed by similarities between (for example) wolves and jackals; no data regarding species- and genus-level differences in dinosaurs was cited, nor was there any reliable contemporaneous data to be cited.
Paleontologists have since developed analyses capable of species-level resolution. Most famously, Tschopp et al argue for splitting the genus Brontosaurus from Apatosaurus, but also advocate genus-level similarity between the species A. ajax and A. louisae (2015). Closer to my tyrannosaur-loving heart, Brusatte et al argue that joining Alioramus altai with A. remotus within the same genus is justified through analysis of character differences measured between twelve other tyrannosaurid taxa (2009). More data are now available to show clusters of individual fossil specimens within clusters of fossil taxa, and so realism about fossil species now seems more reasonable than the alternative (see also Currie 2015).
To be fair, Turner et al don't resolve the relationship between Velociraptor and Deinonychus to so fine a degree in their 2012 analysis of dromaeosaurids; nevertheless, if Jurassic Park were to be written today Crichton wouldn't be able to justify conflating the two names on any basis other than simple taste. Paleontology has matured to the point that the view that there isn't any real difference between fossil species and fossil genera may be untenable.
Of course, I may change my mind after another years' worth of study. One thing is certain: I'll be revisiting the issue--and the book that raised it--next summer.
I'm aware of the irony in posting this essay in the week following Derek's wonderful essay questioning the value of dinosaur paleontology. Let it suffice to say that upon seeing the title of his posted draft I shouted, "No!" at my computer screen.
- Brusatte, S. L., Carr, T. D., Erickson, G. M., Bever, G. S., & Norell, M. A. (2009). A long-snouted, multihorned tyrannosaurid from the Late Cretaceous of Mongolia. Proceedings of the National Academy of Sciences, 106(41), 17261-17266.
- Crichton, M. (1990). Jurassic Park. New York, NY: Alfred A. Knopf.
- Crichton, M. (1991). Jurassic Park. New York, NY: Ballantine Books.
- Crichton, M. (1995). The Lost World. New York, NY: Alfred A. Knopf.
- Currie, A. M. (2015). The Mystery of the Triceratops’s Mother: How to be a Realist About the Species Category. Erkenntnis, 1-22.
- Paul, G.S. (1988). Predatory Dinosaurs of the World. New York, NY: Simon and Schuster.
- Paul, G.S. (2010). The Princeton Field Guide to Dinosaurs. Princeton, NJ: Princeton University Press.
- Tschopp, E., Mateus, O., & Benson, R. B. (2015). A specimen-level phylogenetic analysis and taxonomic revision of Diplodocidae (Dinosauria, Sauropoda). PeerJ, 3, e857.
- Turner, A. H., Makovicky, P. J., & Norell, M. A. (2012). A review of dromaeosaurid systematics and paravian phylogeny. Bulletin of the American Museum of Natural History 371(1), 1-206.
- Witmer, L. M., & Maxwell, W. D. (1996). The skull of Deinonychus (Dinosauria: Theropoda): new insights and implications. Journal of Vertebrate Paleontology, 16(3).