Watching Jurassic Park again recently, I was struck by the scene at the beginning where Grant explains to a sceptical crowd how dinosaurs are related to birds. Nowadays this is common knowledge, and the scene seemed as redundant as if it were explaining that humans were related to primates. But at the time the movie was made, the scene was necessary for the audience.
So that set me wondering: When was the dinosaur/bird relationship first proposed and when did it become accepted by the scientific community? How long until this became widely known by the general public, and was Jurassic Park a big factor in spreading the idea?
(Mods: Please don’t send to Cafe Society! I care about the factual part more than the movie part.)
The concept that dinosaurs and birds were somehow linked dates back to the 1800s, though as memory serves me the expectation was that they simply had a common ancestor in the Triassic, not that birds were specializations from one form of dinosaur.
The idea that dinosaurs were homeothermic and active, that some conceivably might have been feather-covered, and generally were more in tune with the Jurassic Park dinosaurs than in the lumbering monsters of older dino movies, dates from the work of Robert Bakker and James Ostrom in the 1970s. Jim Jensen, the paleontologist on whom the Grant character is based, was an early convert to their view and has been a leading exponent of it for years.
Matchstick, I think you’re overestimating the bounds of :common knowledge" by quite a bit. I’d be surprised if you’d find a large proportion of people who weren’t kids in the 70s, 80s, or 90s who knew the dinosaur/bird connection (unless they had heard about it through a “debunking” of evolution, in which case they wouldn’t believe it anyway). It didn’t gain currency until the 70s, and I’ve noticed that unless someone’s dream is to become a paleontologist, they’re unlikely to follow dinosaur news or trivia once they’re past 12 or so.
Thomas H. Huxley first proposed that birds and dinosaurs were closely related in 1868, when he pointed out strong similarities between Compsognathus and birds, as well as the tranisitional nature of Archeopteryx
(Huxley, Thomas Henry. “On the Animals which are most nearly intermediate between Birds and the Reptiles,” in: Annals and Magazine of Natural History, series 4, vol. 2 (1868), pp. 66-75.)
This idea later went into disfavor because dinosaurs supposedly lacked clavicles (collar bones), which birds retained, and thus could presumably not be directly ancestral to them. However, it has since been determined that some dinosaurs had clavicles.
As Polycarp says, the revival of the bird-dinosaur link dates to the work of John Ostrom on Compsognathus and especially Deinonychus in the mid-1960s. As I recall from my graduate school days, the idea first became widespread among the general public by the 1970s, especially through the work of James Bakker.
Although most paleontologists accept this link nowadays, there is still a small but vociferous group that believes that birds are not descended directly from dinosaurs but only share a more distant ancestor with them.
That would be Robert Bakker, as noted by Polycarp.
In terms of acceptance in the scientific community, as of around 2001, there have been published approximately 88 papers, by at least 71 different authors since 1973 (thus not long after the “dino-bird” revival began) supporting the dinosaur-bird relationship. Conversely, there have been about 33 papers, by about 23 different authors, advocating a basal archosaur-bird relationship. Many of the dissenters tend to be ornithologists, rather than paleontologists, and argue for convergent evolution regarding the similarity between birds and many theropod dinosaurs.
Since paleontologists generally get more public attention than ornithologists, I would guess that if any lay person (who accepted evoution in the first place, of course…) did have an opinion on the matter, they would probably pick the “dinosaur descendents” side.
I am firmly in the “birds are not only dinosaur descendents, but should also be classified as dinosaurs” camp. The latter tends to be bigger bone of contention than the former, though
I’d agree that birds are a kind of dinosaur, in some sense. (There is more controversy, I think, over whether dinosaurs themselves are monophyletic - whether Ornithischian and Saurischian dinosaurs are sister groups - than whether birds are descended from one lineage of Saurischians.) From a cladistic point of view, there are so many shared derived characters between birds and velociraptor-type dinosaurs that it pretty much necessitates classifying them in the same group. But saying “birds are dinosaurs” somewhat distorts the actual relationship, since birds are a lot more closely related to some dinosaurs than to others.
The main sticking point concerning deriving birds from velociraptorids has to do with the fact that the three digits in the bird “hand,” as identified developmentally, do not seem to be the same as the three digits in the theropod/velociraptorid hand, as identified in the paleontological record. However, some researchers believe there has been a developmental shift and that the bird digits actually are the same as the theropod ones.
The two ornithologists that I am most familiar with in the BAND (Birds Are Not Dinosaurs) camp, Alan Feduccia and Storrs Olson, are avian paleontologists as much as they are ornithologists.
Actually, the monophyly of Dinosauria is about as universally accepted as such classifications can be these days.
True, but no moreso than saying “humans are mammals”, really. We are obviously a lot more closely related to some mammals than to others, yet most systematists wouldn’t think twice about our own classification deep within Mammalia.
Larry Martin also tends to figure in a lot of these debates. Of the aforementioned papers count, Martin wrote or co-wrote 6, and Feduccia 6 as well.
Feduccia also co-wrote the paper in which the issue of avian hand development was raised (noted as a general statement, not directed at Colibri, since he probably already knows this! – this paper is available here [.pdf doc], if anyone cares, and the developmental shift paper that Colibri also mentioned is available here). And, contrary to the notion that the dino-bird relationship is generally accepted, the debate between the BADD (Birds are Dinosaur Descendents) and BAND camps can get pretty heated at times.
